vi-sinh-vat-hoc-thu-y

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LI NI U NHN DP TI BN LN TH NHT(Phin bn in t)Vi sinh vt hc l mt trong nhng khoa hc pht trin mnh m nht. V vy, nh k bin son li ti bn vi nhng kin thc mi v cp nht l vic rt cn thit. Gio trnh Vi sinh vt hc th y ny c xut bn nm 2002 bi Nh xut bn Nng nghip v trng i hc Nng Lm Hu. Nay ti bin son li trn c s chnh l v cp nht kin thc mi p ng yu cu ng ti di dng gio trnh in t nhn dp D n tng cng nng lc o to mc C ca i hc Hu nhm phc v ging dy v hc tp ca gio vin v sinh vin cc khoa, b mn th y v chn nui - th y cng nh cc trng i hc lin quan sinh hc. Trong ln ti bn ny ni dung nhiu chng c vit mi, nhiu chng khc c s thay i. Cc mc h Pasteurellaceae, thuc phn Vi khun hc v tt c cc chng thuc phn Virus hc u c chnh l li. Xut hin mt s tn h mi nh h Asfarviridae, h Papillomaviridae, h Polyomaviridae ph hp vi kin thc v phn loi hc hin i, khng cn chng "i din cc virus cha phn loi" m thay th bng chng "Prion...", mt s bnh c b sung. Cc k thut nghin cu trc y b b khi bn tho do qu dy nay c phc hi vi ng k l phi. Cc hnh nh minh ha ring l cng khng a li vo phin bn in t ny. Cch ghi cc thut ng c ngun gc nc ngoi khng phi gc Hn ln ny c s thay i so vi ln xut bn trc. Cc thut ng ch tn ha cht ch yu s dng chnh t (khng phi ng php) ting Anh, p ng yu cu ca d n mc C i hc Hu. Ti cm n ca cc ng nghip v s h tr v kin ng gp xy dng. Nhn y, ti mun by t cm n GS o Trng t ng gp nhiu kin xy dng nhn dp hiu nh bn tho cho ln xut bn th nht. Tc gi

TS. Phm Hng Sn *** Gio trnh Vi sinh vt hc th y *** Hu 2006

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LI NI U NHN DP XUT BN LN TH NHT (2002)Trong nhiu nm qua, cc trng i hc khi nng nghip nc ta c mt s gio trnh vi sinh vt hc th y. Nhng ti liu ging dy ng gp quan trng trong o to i hc ngnh th y. Tuy nhin, theo thi gian, cng vi s xut hin nhng bnh nguy him mi (nh Nipah, Manangle,...) v s pht trin ca khoa hc k thut, c bit l sinh hc phn t, nhiu kin thc thuc cc mn sinh vt hc ni chung v vi sinh vt hc th y tr nn c nhu cu c cp nht ha. Ngy nay, vi chnh sch i mi ca ng ta, giao lu vn ha, du lch v thng mi,... gia nc ta v cc nc trn th gii ngy cng m rng v pht trin, dn n s tng cng xut nhp khu hng ha trong c sn phm ng vt. Thc tin a li cho chng ta nhiu mt li, trong c vic nng cao mc sng ca nhn dn nhng cng a chng ta gn hn vi nguy c nhim cc bnh truyn nhim c hu ca cc vng a l khc, i hi Nh nc ta phi c nhng lut l lin quan n kim dch th y. Trong bi cnh hi nhp th gii, ni dung gio trnh mn hc vi sinh vt hc th y ang s dng trong trng i hc nc ta hin nay tr nn bt cp. Chng hn, sau my nm hc i hc th y, do ni dung trong chng trnh i hc chnh thng thiu ht, sinh vin tt nghip thnh bc s th y vn cn xa l vi tn cc bnh lit k trong "Danh mc bnh phi kim dch" ban hnh km theo Quyt nh s 607 NN-TY/Q ngy 9 thng 6 nm 1996 ca B trng B Nng nghip v Cng nghip thc phm (nay l B Nng nghip v Pht trin nng thn). Nu nhn cng tc kim dch quc t, nhng chuyn gia th y nh th kh c th m nhim c chc nng nhim v ca mnh. Trong khi , kt cu ni dung gio trnh vi sinh vt hc th y thng ging nh mt phin bn ct ngn ca gio trnh bnh truyn nhim gia sc, nn gia hai mn ny c nhiu kin thc thng trng lp khng cn thit. Mn Bnh truyn nhim cung cp cho sinh vin nhng hiu bit v bnh truyn nhim v cch khng ch (phng, chng) bnh truyn nhim, cn mn Vi sinh vt hc th y li c mc ch l gip ngi hc xy dng th gii quan v bnh truyn nhim v cch tip cn cc ngun gc gy bnh truyn nhim. Nhm khc phc nhng vn nu trn, gp phn lm gim nh s thiu ht trong chuyn mn ca sinh vin ta so vi th gii, B mn Th y trng i hc Nng Lm Hu t ra nhim v son li ni dung mt s hc phn i hc, trong c Vi sinh vt hc th y, trong khun kh Chng trnh khung do B Gio dc v o to v Chng trnh Gio dc ca trng i hc Nng Lm Hu. l l do ra i quyn gio trnh ny. Mc d bin son cho ngnh th y nhng gio trnh ny cng dng cho vic ging dy ngnh chn nui th y, lm ti liu tham kho cho cn b nghin cu vi sinh vt, cc nh chuyn mn th y,... y l hc phn th ba trong nhm cc hc phn lin tc Vi sinh vt hc i cng, Min dch hc, Vi sinh vt hc th y, Dch t hc v Bnh truyn nhim gia sc, v vy, nhiu vn khng th


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m t gio trnh ny th c th gp nhng gio trnh cn li, cng nh cc gio trnh thc tp lin quan. Ni dung gio trnh gm ba phn: Vi khun hc, Virus hc v Nm (chn khun hc) th y. Chng trnh gm bn n v hc trnh ny i hi sinh vin u t t nht hai ln thi lng (120 gi) t chun b ngoi ging ng, tng ng vi chng trnh o to cc nc pht trin. - Phn I: Vi khun hc th y, gii thiu cc nhm vi khun, bao gm c mycoplasma, rickettsia, chlamydia v bnh truyn nhim tiu biu do vi khun trong nhm gy ra. - Phn II: Virut hc th y, gii thiu cc nhm virut v bnh truyn nhim do cm nhim virut ng vt, theo trnh t nhm cc h virut ADN khng c o ngoi, cc h virut DNA c o ngoi, cc h virut ARN c o ngoi, cc h virut ARN khng c o ngoi v cc virut cha phn loi. Do vai tr ca cc ng vt gip xc (tm, cua,...) i vi nn kinh t Vit Nam ngy cng tng, chng ti b sung h Baculoviridae l h cc virus k sinh ng vt chn t. - Phn III: Nm (chn khun hc) th y, gii thiu mt s nm gy bnh nm v bnh trng c nm ng vt. Hai phn trn c trnh by theo nhm phn loi vi sinh vt hin i da trn c tnh sinh hc ca chnh vi sinh vt m t da theo c tnh dch t hc hay c tnh bnh l. Phn III, ngc li, c trnh by theo vai tr th y ca nm (nm gy bnh v nm sinh c t gy ng c nm) m khng theo cc nhm phn loi, do s chng loi nm l rt ln m s nm gy bnh th y th ch c s lng hn ch. Do t ra nhim v gii thiu vi sinh vt gy bnh th y hin c bit trn ton cu, nn gio trnh ch cp nhng kin thc chung nht, c bn nht v vi sinh vt hc th y lm c s cho cc mn hc tip theo trong chng trnh o to th y nh Bnh truyn nhim gia sc, V sinh gia sc, Kim nghim th sn,... Nhng k thut phn loi v chn on (thc ra l ng nh: identification) vi sinh vt b ct xn so vi bn tho u gi cho quyn sch khng qu dy th chng ti s chnh l v gii thiu trong cun "Vi sinh vt th y thc hnh" trong thi gian ti. Cn nhng mc thuc ni dung ging dy hc phn Bnh truyn nhim gia sc nh "Phng bnh v cha bnh" cng khng c a vo gio trnh ny. Vic ghi cc thut ng Vit ha khng c ngun gc t thun Vit hay t Hn - Vit, ch yu c ngun gc phng Ty v Nht Bn (t ch kana), l mt vn ln, phc tp trong ting Vit hin i, lm kh khn cho vic lp bng tra cu t kha. Hin nay, trn thc t tn ti ng thi nhiu cch ghi m khc nhau. y chng ti tm p dng cc quy tc sau: - Cc thut ng ni trn c vit lin, khng c du ni (tr t trng hp theo nguyn gc). - Cc thut ng c ghi li y nguyn phn thn t (cng vi tin t, nu c) vn c ca chng trong cc ngn ng h Romantic hay Latin (ghi erythromycin, ethanol, cadaverin, hydro-, khng ghi eritrmicin, tann, caaverin, hir- [c kin rng nn thay ch "d" trong chnh t ting Vit bng


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ch "z" [Hong Ph, Chnh t ting Vit, NXB Nng, 1999], nhng cn c vn bn quy phm php lut chnh thc ha), tr mt s ch hai m tit c dng tng t t ghp Hn - Vit v qu thng dng nh axit (khng ghi acid), baz (khng ghi base), virut (khng ghi virus), hydr (tc hydrogen), xy (tc oxygen),... cn phn ui t (v t), th thng c lc b a s thut ng tr tn vi sinh vt v cc ui "a" hay "ia" sau ph m (ghi vaccine, penicillin,... khng ghi vaccine, penicillinum,... nhng ghi salmonella, rickettsia,...), hoc ring tn cc enzym v ng vn c ui t "-ose" trong ting Anh v "- " v trong ting Nga th ghi "-aza" (saccharose, proteinaza,...), ui "-ol" ca mt s ng thng c lc b (ghi mannit, sorbit,... khng ghi mannitol, sorbitol,...). - Tn khoa hc nh danh ca vi khun v nm th vit hoa ch ci u (tn chi) v in nghing theo quy tc danh php sinh hc quc t p dng t nm 1992 theo "Bacteriological Code (1990 revision)" ca International Committee on Systematic Bacteriology (ICSB: y ban quc t Vi khun hc phn loi h thng) v cc hi sinh vt hc phn loi khc, ch sau vit lin, khng c gch ni, khng c khong trng (ghi Salmonella choleraesuis, khng ghi Salmonella cholerae-suis). Tn "tam danh" ch dng ( loi hay loi ph) c ch "subsp." (subspecies) hoc "var." (variety) vit trc ch th ba (Salmonella choleraesuis subsp. choleraesuis, H. capsulatum var. duboisii). Trng hp tn sinh vt c Vit ha th vit bnh thng (salmonella). Tn loi virus khng p dng nguyn tc "nh danh" m dng tn ting Vit c tham kho tn ting Anh theo ngh ca International Committee for Taxonomy of Viruses (ICTV: y ban quc t v phn loi virut), mc d trong mt s trng hp c b sung tn loi theo quy tc nh danh quc t. Tn mt s ha cht, thuc nhum c th c vit ( ln lp li) bng ting Anh tin tra cu ha cht thng phm. gip ngi c tra cu cc bnh truyn nhim ghi trong "Danh mc bnh phi kim dch" ca Nh nc ta, chng ti ch thm sau cc tn bnh thch hp k hiu "BKD" (bnh kim dch) tip theo l s th t ca bnh ghi trong danh mc sau tn ting Anh dng k hiu bc ly tha, trng hp bnh c nhiu s th t th lit k cc s t s b n s ln, v d: bnh vim gan virut vt (duck virus hepatitis)BKD12,66, bnh dch t vt (duck virus enteritis)BKD11,73. Bn cnh , mt s thut ng gc ch Hn phin m li Vit ch tn t chc, b phn vi sinh vt hoc tn bnh c th c vit km trong ngoc kp, thng sau t ting Anh tng ng nh l ngun thut ng tham kho. Vic bin son gio trnh ny c ch o bi ng li ca ng v Pht trin Vn ha, Gio dc - o to, Khoa hc cng ngh v Mi trng "i mi cn bn v ton din v ni dung, phng php dy v hc theo hng chun ha, hin i ha v dn ch ha... pht huy ni lc t hc v nghin cu khoa hc ca sinh vin" v phng chm do Lut Gio dc nc CHXHCN Vit nam quy nh "Gio trnh i hc phi th hin mc tiu, nguyn l gio dc, c th ha ni dung ('phi c tnh hin i v pht trin') v phng php ging dy ('phi coi trng vic bi dng nng lc t hc, t nghin cu, to iu kin cho ngi hc pht trin t duy sng to, rn luyn k nng thc hnh, tham gia nghin cu, thc nghim, ng dng') quy nh trong chng trnh o to ca trng i hc". Chng ti c gng th hin tnh hin i, tnh h thng, tnh


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c bn v tnh pht trin ca chng trnh mn hc. Tuy vy, do kh nng c hn, ngi vit kh trnh khi nhng sai st, c bit trong vic chn lc nhng kin thc thit yu gi cho gio trnh khng qu di. Chng ti rt mong nhn c s ng gp kin qu bu ca cc thy gio, c gio, cc qu v ng nghip, anh ch em sinh vin v bn c sch ny s tr nn hon thin hn trong dp ti bn. Nhn y, chng ti mun by t li cm n vi nhng thnh vin trong cc gia nh ca chng ti, cc ng nghip, bn b v tin bi trong khoa KHVN khuyn khch, ng vin chng ti bin son quyn sch ny. Bn cnh , s ra i ca quyn sch ny gn vi Chng trnh vit gio trnh v bi ging ca trng i hc Nng Lm Hu, trong mt s kinh ph, tuy khim nhng, dnh cho vic bin son. Chng ti nh gi cao s quan tm ca nh trng n vn nng cao cht lng o to. Chng ti chn thnh cm n GS. o Trng t, ngi khch l v b rt nhiu cng sc trong vic hiu nh quyn sch ny. Cui cng, chng ti co li cng tt c bn c v t thi gian sch hon thnh n khi ln khun in ko di gn mt nm nn nhiu thng tin cn cha cp nht kp thi.

Tc gi


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PHN I VI KHUN HC TH Y

Pasteurella multocida (nhum Gram)

Campylobacter jejuni (nhum Gram)

Clostridium perfringens (nhum Gram)

Streptococcus suis (nhum Gram)

Bacillus anthracis (nhum Gram)

Fusobacterium necrophorum (nhum Gram)

Hnh 1: Mt s vi khun tiu biu gy bnh ng vt


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Chng 1 TRC KHUN GRAM M YM KH TY TIN A. H TRC KHUN NG RUT ENTEROBACTERIACEAE I. C IM CHUNG CA H ENTEROBACTERIACEAE1. Phn loi H Enterobacteriaceae (h trc khun ng rut) c s lng ln chi khc nhau. Cho n nm nay (2001) xc nhn c 105 loi thuc 30 chi, trong c 6 chi vi khun c ngha trong th y v y hc, Escherichia, Salmonella, Shigella, Edwardsiella, Yersinia v Klebsiella (bng I-1 n bng I14). Bn cnh cn c cc chi Buttiauxella (1 loi), Cedecea (3 loi), Citrobacter (3 loi), Enterobacter (8 loi), Ewingella (1 loi), Kluyvera (2 loi), Koserella (1 loi), Leclercia (1 loi), Leminorella (1 loi), Moelerella (1 loi), Morganella (1 loi), Proteus (3 loi), Providence (4 loi), Raknella (1 loi), Serratia (7 loi), Tatumella (1 loi),... 2. Hnh thi y l nhng vi khun hmh que nh (0,4 - 0,6 2 - 4 m), hai u trn, Gram m, tt c, tr Shigella v Klebsiella, do c lng roi (tim mao) v u l chu mao khun. Mt s vi khun mt kh nng hnh thnh tim mao, nh Salmonella pullorum-gallinarum (cng cn c coi l hai loi khc bit Salmonella pullorum v Salmonella gallinarum hay 2 dng huyt thanh hc serovar). Cc trc khun ng rut u khng hnh thnh nha bo. 3. Tnh trng sinh ha Nhng tnh trng chung l ym kh ty tin, ln men ng glucose, catalase dng tnh, oxidase m tnh, hon nguyn nitrate thnh nitrite, hm lng guanine+cytosine (G+C) (mol%) trong khong 39 n 59%. Trong s cc tnh trng trn th "oxidase m tnh" l tnh trng quan trng trong vic phn loi. Da vo tnh trng ny, cc trc khun Gram m c chia thnh hai nhm ln. Tt c cc loi oxidase m tnh c xp vo h Enterobacteriaceae. Cc trc khun Gram m cn li gm nhiu h khc nhau c xp chung vo nhm "cc vi khun Gram m hn hp (miscellaneous gram-negative bacteria)". Cc tnh trng ca cc loi khc nhau thuc h ny c lit k bng II-1, cc bin th trong mt loi ng nht biu hin mt s tnh trng khc bit c coi l cc dng sinh hc (biovar) hoc dng ha hc (chemovar). Phn ng catalase xy ra d dng khng cn c yu t hu c nhn xy (organic oxygen receptor) nh trong phn ng peroxidase, v rt n gin: Cho H2O2 3% ln khun lc (tp lc ca vi khun hoc chn khun) qut trn phin knh hoc giy thm, nu thy si bt trong vng 10 giy chng t phn ng dng tnh. kim tra phn ng oxidase ta ly khun lc qut (bng gc phin knh hay tm tre hay tm g, khng dng que cy kim loi v c th


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cho phn ng dng tnh gi) ln giy thm t trn mt phin knh ri lm t giy bng thuc th oxidase ch bng cch ha 10 mg diethyl(hoc tetramethyl-) p-phenylenediamin HCl vo 1 ml nc ct (trnh nh sng, c th ct c 2 - 3 ngy). C th nh tng git thuc th ny ln khun lc trong a Petri hoc tm thuc th vo giy thm, sy kh trong khng kh ch ti, y kn, khi dng th bi khun lc ln ri lm t giy. Cc trc khun ng rut c phn ng oxidase m tnh: khun lc khng chuyn sang mu tm en trong vng 10 giy. Mi trng kim nghim hon nguyn nitrate c ch bng cch ha 3 g cht chit tht b (cao tht: beef extract), 5 g Bacto peptone v 1 g KNO3 vo 1 lt nc ct, chnh n pH 7,3 - 7,4, rt khong 5 ml mi ng t mt ng Durham ln ngc v hp p sut cao 115 C trong 20 pht (ch : phi nc si khong 5 - 10 pht y ht kh ra khi ng Durham ri mi ng van tng p sut si). Sau khi cy 24 gi (thng thng) hoc 3 ngy (tiu chun) th kim tra kh trong ng Durham, ri cho vo ng 0,1 ml dung dch A (ch bng cch ha tan nh un nng nh 8 g acid sulphanilic vo acid acetic 5 N [ha 300 ml acid acetic m c vi 700 ml nc], [ct gi 4 C]) v 0,1 ml dung dch B (ch bng cch ha tan 5 g -naphthylamine [hoc dimethyl -naphthylamine] vo 1 lt acid acetic 5 N), v quan st s chuyn mu trong 1 pht, nu khng c chuyn mu th phn ng c th l m tnh hoc dng tnh nhng nitrate chuyn ht thnh N2 (hi trong ng Durham) cn xc nhn s hin din ca nitrate bng cch cho bt km vo ng phn ng. Mu vi bt km xut hin, chng t c nitrate, ch phn ng m tnh. V cu trc khng nguyn, cc loi, loi ph (hay loi: subspecies) biu hin tnh cht nht nh. Ni chung c cc khng nguyn thn (khng nguyn O) chu nhit v khng nguyn lng (lng roi, hay tim mao: flagellum) (khng nguyn H) khng chu nhit v khng nguyn nhung mao (lng nhung: fimbria hay pili) (khng nguyn F) chu nhit mc trung gian. Ph thuc vo c tnh khng nguyn m cc bin th trong cng loi hoc di loi ( loi) c gi l cc dng/type huyt thanh hc (serovar). Khng nguyn O (xut pht t ch Ohne Hauch - khng c mng hi) l cc hp cht lipopolysaccharide c trong thnh phn vch t bo, l cht gy st rt c i vi ng vt, chu nhit (100 C, hn 2 gi), khng b ethanol 50 ph hy nhng b formol 0,5% lm bin tnh. Cc khng nguyn thn u nm trn b mt nn c th tip xc vi h thng min dch ca c th ng vt tr mt s trng hp b khng nguyn b mt che lp. Khi trn khng nguyn thn vi khng th tng ng, th xut hin phn ng ngng kt gi l ngng kt O: thn t bo vi khun dnh vi nhau, hnh thnh nhng ht nh lc rt kh tan, huyn dch vi khun trong. Khng nguyn H (xut pht t ch Hauch - mng hi) l nhng phn t protein flagellin gn ging myosin trong c ca ng vt, khng chu nhit, d b ethanol 50 v enzyme proteinase ph hy, nhng bo tn trong formol 0,5%. Khi gp khng th tng ng, khng nguyn H hnh thnh ngng kt gi l phn ng ln bng do cc t bo vi khun dnh nhau gin tip qua cc lng roi nn hnh thnh cc khi nh khng bn, d v khi lc.


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Khng nguyn K (xut pht t ch Kapsule - v bc) l khng nguyn bao bc thn vi khun. Tuy gi l khng nguyn v nhng v mt hnh thi hc li c ngun gc t nhng hp cht c trn b mt t bo ch khng phi trong thnh phn ca v nhy. iu ng ch l nhng khng nguyn ny c ch phn ng ngng kt O rt mnh, v vy khi th nghim vi cc khng th O phi rt lu . Bng I-1. Cc tnh trng gim bit ca cc chi ch yu h trc khun ng rutEnterobacter Edwadrsiella Providencia Escherichia Salmonella Tatumella + + Klebsiela Kluyvera Cedecia V + + + + + + V D + Yersinia Shigella Serratia Proteus Erwinia V V V V + + + + + + Hafnia Chi Tnh trng Nhit ti thch (oC) Catalase Oxidase Hon nguyn nitrate Sinh indol Phn ng MR Phn ng VP Simon's citrate Sinh H2S Di ng Urease Gelatinase Phenylalanine deaminase Lysine decarboxylase Arginine dehydrogenase Ornithine decarboxylase DNase Lipase Mc 0.0075% KCN S dng malonate ONPG Glucose (acid) (hi) Lactose Saccharose D-mannit D-adonit D-sorbit Hm lng G+C (mol%) Morganella Citrobacter

+ + +d + +d + V -d + + + + D +d D

+d + D + V -d D + -d -d D V

+ + D D D + + + + D D D -

+ + + +d + + + + + -d D + +d -d -d + D

+ + -d + + +d + V V V D -d + + + V V + V +

35 - 37 + + + + D D + + +d + - + + -d V + D V + + + V + + + -d -d + V +d + + + V + + V D

+ + V + + + + D + + + V + -

+ + -d + + + + +d D + V V V + + -d V V + V +d

+ + D + D +d + + + + + D V + + -d + V V -

+ + + + + + +d + + + V V D D -

+ + + + + + + + + + V -

25 - 30 + + + D D D + V D + - D - + +d + +d -d + - D -d D D V + V V D + D 50

+ + + + + + V + + + + + + + + + V

35 - 37 + + + + - + - + - + - + + -

50 1 50 2 50 1 50 3 50 2 53 8 52 60 48 49 52 60 38 41 40 42 50

Ghi ch: +, 90% tr ln dng tnh; -, 90% tr ln m tnh; V, phn ng khng n nh; D, phn ng ph thuc loi; +d hay -d, mt s loi ngoi l dng tnh hay m tnh.

Khng nguyn K bit r nht l Vi Salmonella (virulence: c tnh, do khng nguyn ny ch c khi vi khun mi phn lp t c th bnh), khng


53 4 48 -

50 8 55

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nguyn M (t ch mucoid, c ch phn ng ngng kt O v ngng kt H) khng nguyn "5" ging khng nguyn thn v khng c ch phn ng ngng kt O, khng nguyn L, A v B Escherichia. Hin nay, ngi ta pht hin c rng bn cht ca nhiu khng nguyn K l cc si lng nhung (hay fimbria) nn ngi ta gi cc khng nguyn nhm ny l khng nguyn F (F antigen), v vy xut hin cc k hiu F1, F2,... 4. Tnh gy bnh Cc nhn t gy bnh vi khun h ny gm c tnh kt bm (adhesiveness) vo nim mc k ch, tnh xm ln (invasiveness), kh nng sn sinh cc c t rut, c t gy cht, tnh khng huyt thanh, nng lc sinh sn ni bo. Nhng c tnh ny hoc b chi phi bi cc gene trn nhim sc th vi khun hoc bi cc plasmid v thc khun th (bacteriophage).

II. ENTEROBACTERICEAE V BNH TRUYN NHIM1. Escherichia coli * c im Escherichia coli: Chi Escherichia c 4 loi khc nhau, nhng loi ch yu l E. coli. Vi khun ny pht trin rt tt trn mi trng thch thng, 35 - 37 C sau 12 - 18 gi hnh thnh khun lc trn, li, khng trong sut, bng lng. Trn thch mu, a s chng khng gy dung huyt, nhng cng c chng dung huyt. phn lp thng nui cy khi u trn mi trng tuyn la nh mi trng Istrati, MacConkey, Endo, desoxycholate,... Mi trng Istrati c ch nh sau: Cho vo 100 ml thch thng (c th pha bt mi trng ch sn NA [nutrient agar base] thng phm vo nc ct theo ch dn trn v l, hoc ch nc tht peptone (canh thang) [mt phn tht b nc ngm trong hai phn nc trong 2 gi 50 C hoc qua m trong t lnh, un si 30 pht ri lc v thm nc ct cho hai phn dch, ri thm peptone 10 g/l v NaCl 5 g/l, iu chnh pH v mc 7,2 - 7,4 bng NaOH 1 N], v 1% thch (agar) ri hp hi di p sut cao 15 pht 121 C) cc cht sau: lactose 1,5 g, mt b kh (ch bng cch lc mt b ti qua giy lc ra khay trng men, sy 120 C trong khong 30 pht cho gim lng thy phn v kh trng ri sy tip nhit 45 C cho kh, co ra v ng vo l nt kn, dng dn) 0,8 g, citrate natrium (sodium citrate) 0,8 g, citrate st 0,2 g, hyposulfide (thiosulfate) natri (Na2S2O3.5H2O) 0,85 g, trn u ri un si khong 15 pht, chnh pH 7,2, ri cho thm 2 - 4 ml xanh bromothymol (bromothymol blue) 1% (ch bng cch nghin 1 g bromothymol blue trong ci s, nh tng git NaOH 0,1 N cho n 25 ml ri thm nc ct va 100 ml, cho vo l, nt kn dng dn) n khi mi trng c mu a vng khong 50 C. Li un si 15 pht, ngui n 50 C ri rt hp lng (a) Petri. a trn mt phng khong 15 pht cho thch rn li ri m np hp m hong cho mt thch ro nc (khong 10 - 15 pht, trong bung v trng) ri cho v bao polyethylene trnh cho thch kh khi bo qun m bo qun khong 1 - 8 C (thng sau khi qua m nhit 37 C kim tra v trng, loi b cc a b ngoi nhim). Sau khi nui cy vo mi trng, 37 C qua 24 gi th ly ra c


11

kt qu. E. coli ln men ng lactose nn khun lc ban u c mu vng nht sau lu c mu xanh lc. Do vi khun ny khng sn sinh H2S nn khun lc khng chuyn sang mu en (nh cc Proteus). ch mi trng MacConkey, ngi ta ha 20,0 g peptone, 10,0 g lactose, 1,5 g mt kh (hoc 2,0 g desoxycholate natri), 0,03 g trung tnh (neutral red), 0,0001 g tm kt tinh [crystal violet], 5,0 g NaCl v 14 g agar vo 1 lt nc ct, un nng cho tan, iu chnh pH 7,2 - 7,4, hp tit trng (nu cn bo qun lu) 121 C trong vng 15 pht, a, hong ro mt thch, c th bo qun nhit phng hay t lnh 4 C. (C th dng 0,075 g neutral red thay th cho 0,03 g neutral red v 0,0001 g crystal violet nu trn). E. coli phn gii ng lactose nn khun lc c mu sau khong 18 - 24 gi nui cy. Cc vi khun khng ln men lactose c khun lc khng mu. Vi khun Gram dng khng pht trin trn mi trng ny. ch mi trng thch desoxycholate ta ha 10 g peptone, 10 g lactose, 5,0 g NaCl, 2,0 g K2HSO4, 1,0 g citrate st II, 1,0 g citrate natri, 1,0 g desoxycholate natri, 16 g agar v 0,033 g neutral red vo 1 lt nc ct, chnh n pH 7,3, un cho tan chy v trn u cc thnh phn, rt ra cc a lng petri m khng cn hp kh trng cao p. Khi pht trin, E. coli hnh thnh khun lc to, mu (tri vi Shigella v Salmonella c cc khun lc khng mu). Mi trng KIA (Kligler's iron agar: thch st Kligler) v TSI (triple sugar iron: mi trng ba ng - st) l nhng mi trng thng dng cy chuyn sau khi c la thun khit t cc mi trng thch nu trn. ch mi trng KIA, ha 20 g peptone, 3 g cao tht, 3 g cao men, 10 g lactose, 1 g glucose, 5 g NaCl, 0,5 g citrate st ammon, 0,5 g thiosulfate natri, 15 g agar v 0,025 g phenol (phenol red) vo 1 lt nc, un cho tan u, chnh (nu cn) pH n 7,4, rt vo cc ng nghim nh mt lng ln, hp cao p kh trng 121 C trong 15 pht, ngui t th nghing ng sao cho khi thch ha rn ta c phn nghing v phn y kh cao. Sau khi cy vi khun bng cch chc vo phn y v ria pht phn nghing v mt m c th thy mt s tnh trng nh sau: ln men lactose lm c phn nghing ln phn y chuyn sang mu vng (trng hp VP dng tnh th phn nghing c th tr li mu hng), nu vi khun ch ln men glucose th ch phn y c mu vng, nu vi khun sinh hi th lp agar thng b nt n v b y ln, nu hnh thnh H2S th phn y chuyn sang mu en. Bng I-2. Tnh trng gim bit ca cc loi ch yu thuc chi EscherichiaLoi Tnh trng Tnh gy bnh


12

Lysine decarboxylase Ornithine decarboxylase KCN (0,0075%)

S dng malonate

Glucose (acid)

Glucose (hi)

(gia sc, gia cm v ngi) Saccharose Lactose Mannit Adonit + Sorbit + Gy bnh ng rut Xm nhp ng rut Sinh c t ng rut Sinh c t t bo vero - Phn lp t bnh phm - t bnh phm, thc phm - t bnh phm, thc phm

E. coli

+

-

Di ng +

Citrate

Indol

+

V

-

-

+

+

+

V

+

E. fergusoni

+

V

+

+

+

+ +

V -

+ + +

+ + +

V V V

+ V

+ V +

+ E. hermannii + V + + V + + E. vulneris Ghi ch: V, phn ng khng n nh.

Tnh trng ca E. coli l indol dng tnh, methyl red (MR) dng tnh, Voges-Proskauer (VP) m tnh, phn ng s dng citrate m tnh, phn ng sinh H2S m tnh, di ng dng tnh, lysine decarboxylase dng tnh, ln men lactose v mannit. Hm lng G+C (mol%) l 50 - 51%. Hin ti, khng nguyn ca chi Escherichia c bit gm trn 167 loi khng nguyn O, 72 loi khng nguyn K, 54 loi khng nguyn H v 12 loi khng nguyn F. Indol hnh thnh trong mi trng nh phn gii tryptophan (do thm vo mi trng di dng tinh ch hoc do phn gii peptone) c pht hin bng thuc th Ehrlich (p-dimethyl aminobenzaldehyde) nhng trong phng php tiu chun phi dng thuc th Cova. c mi trng th indol ta ha 10 g peptone v 5 g NaCl vo 1.000 ml nc ct, chnh n pH 7,2 - 7,4 rt vo ng hp ri kh trng 121 C trong 20 pht. th s hin din ca indol, ta cho 0,2 ml thuc th Cova (ch bng cch ha tan, nh h nng nh, 5 g p-dimethyl aminobenzaldehyde vo 75 ml isoamyl alcohol, sau cho thm mt lng acid HCl m c bng 1/3 th tch dung dch . Dung dch ny c th bo qun trnh nh sng c 2 thng) ri lc u vi canh khun. E. coli pht trin hnh thnh indol lm cho lp thuc th c mu m (ngc vi mu vng nht trong phn ng m tnh). Mi trng th MR-VP c ch bng cch pha 7 g peptone, 5 g glucose v 5 g K2HPO4 vo 1 lt nc, chnh pH 7,5, rt vo ng hp 2 - 3 ml ri hp kh trng di p sut cao 115 C trong vng 20 pht. Thuc th MR c ch bng cch ha tan 0,25 g methyl (methyl red) vo 100 ml ethanol. Sau khi nui cy vi khun 2 ngy (thng dng) hoc 4 ngy (tiu chun) 37 C, ly ra nh 1 git thuc th MR. E. coli c phn ng MR dng tnh lm ng c mu (pH duy tr di 4,5) sau v tip tc gi mu sau mt thi gian nui cy na (tri vi cc vi khun MR m tnh ng nghim c mu vng, hoc nu th cng chuyn vng sau khi nui cy


13

tip, v d Serratia marcescens). Phn ng VP c thc hin sau khi nui cy vi khun trong mi trng MR-VP 2 (thng dng) hoc 4 (tiu chun) ngy, bng cch nh 0,6 ml dung dch -naphthol trong cn tuyt i (5 g -naphthol, 100 ml ethanol tuyt i [ch bng cch cho sulfate ng khan nh nung qua m 160 C cho n khi c mu trng vo mt l c nt kn ri rt ethanol 95 hoc 99 vo, ch tnh sao cho lng Cu(OH)2 d ht ht nc trong cn v chuyn thnh Cu(OH)2.5H2O c mu xanh], dung dch c mu rm m) v 0,2 ml dung dch KOH (KOH 40 g, nc ct 100 ml). t nghing ng ri c kt qu sau 15 v 60 pht. E. coli c phn ng VP m tnh: khng c phn ng mu, i khi c mu ng hay hng nht (tri vi VP dng tnh, mu ng chuyn sang m, v d Enterobacter cloacae). Mi trng citrate c hai loi nhng thng dng mi trng ammonium citrate ca Simmon (Simmon's citrate). Mi trng ny c ch bng cch ha 5 g NaCl, 1 g NH4H2PO4, 1 g K2HPO4, 0,2 g MgSO4.7H2O, 2 g sodium citrate v 9 g agar vo 1 lt nc, thm 40 ml dung dch 0,2% bromothymol blue (xanh bromothymol, ch bng cch ha 2 g bromothymol blue vo 50 ml NaOH 0,1 N v 950 ml nc ct), chnh pH 6,8, rt ra ng ri kh trng 115 C trong 20 pht, t nghing ch ngui c mi trng c vi phn y ngn v phn nghing di. Cy lng nh vi khun v n 4 ngy. E. coli khng mc v khng lm thay i mu xanh lc ca mi trng (ngc vi Citrobacter freundii, chng hn, mc v chuyn mi trng sang mu xanh dng). * Bnh cm nhim Escherichia coli: Vi khun E. coli gy vim rut, tiu chy ngi v cc loi ng vt khc nhau c gi l E. coli sinh tiu chy (diarrhogenic E. coli), ngi c chia thnh 4 nhm ln: Bng I-3. Cc dng huyt thanh, tnh sinh c t v tnh khng nguyn ca E. coliK ch Dng huyt thanh hc O8:K85:H-:F5 O9:F5 O20:K+:H-:F5 O101:K28:H-:F5 O115:F5 O26 O111 O119 O141:H4 O157:H7 O8:K87:H-:F4 O149:H10:F4 O149:F5 O157:F4 O78:F4 O101:F4 O149:H10:F4 O9K103:H-:F5 O9:K103:H-:F6 LT + + + + + + + c t ST VT + + + + + + + + + + + + + + + + Bnh trng

B

Bnh do E. coli b ngh s simh (tiu chy, vim d dy - rut, bnh trng c huyt ng rut (enterotoxemia), vim v

Ln

Bnh E. coli ln con s sinh (tiu chy phn trng) Bnh E. coli ln sau cai sa (vim d dy rut, tiu chy)


14

O20:K101:H-:F6 + O101:F41 + O157:F4 + O138:H14 + Bnh ph u, vim huyt qun no ty O139:K82:H1 + O141:H4:F4 + + O2 O8 Nhim khun mu, bi huyt (vi khun pht O78 trin trong mu) O114 O137 O1 O2 Bi huyt cp tnh, vim tng mc cp Gia tnh, u tht mn tnh (i khi, vim rut xut O9 cm huyt) O26 O78 Chut O115a,c:K(B) Bnh ph i rut (megaenteron) Ghi ch: Tnh sinh c t LT: heat-labile enterotoxin (c t ng rut khng chu nhit), ST: heat-stable enterotoxin (c t ng rut chu nhit), VT: verocytotoxin (c t [gy c] t bo vero).

E. coli bnh nguyn ng rut (enteropathogenic E. coli - EPEC) thuc vo mt nhm huyt thanh hc ring bit, c tnh kt bm (bm dnh). E. coli xm ln ng rut (enteroinvasive E. coli - EIEC) c kh nng xm nhp ng rut, do plasmid chi phi. E. coli c t nguyn ng rut (enterotoxigenic E. coli - ETEC) c nng lc hnh thnh cc khng nguyn lng F2 (tn c CFA/I), F3 (CFA/II), F4 (K88), F5 (K99), F6 (987P) v cc c t rut (enterotoxin) do plasmid chi phi. E. coli sinh c t t bo vero (verocytotoxin-producing E. coli - VTEC) hay E. coli xut huyt rut (enterohemorrhagic E. coli - EHEC) c nng lc sn sinh c t vero gy c t bo do bacteriophage chi phi. Tt c cc vi khun trn u gy bnh cc b. Ngoi ra, i khi E. coli xm nhp kt bm v pht bnh cc c quan khc nhau ngoi ng rut. a. Tiu chy phn trng do E. coli b ngh (enteric colibacillosis in calves) Bnh ny do ETEC gy ra b ngh mt tun sau sinh, nh c khng nguyn lng (ch yu l khng nguyn F5 - tc K99) m vi khun kt bm v sn sinh enterotoxin. b. Vim v do E. coli (coliform mastitis) Trong thi k b cho sa E. coli trong mi trng c th xm nhp vo bn trong bu v, pht trin v pht bnh. Tuy tn sut xut hin nh nhng cng c nhiu trng hp vim v hoi t cp tnh v cp tnh. L chng bnh do ni c t vi khun Gram m (>107 pg/ml sa), vim v hoi t c th gy ra bi cc vi khun khc, bn cnh E. coli, nh Pseudomonas


15

aeruginosa, Klebsiella pneumoniae. c. Bnh E. coli ln (colibacillosis in pigs) Trong nhm ny gm bnh tiu chy phn trng (bch l) ln con, tiu chy (vim d dy - rut) hay ph mt ln sau cai sa, bi huyt (vi sinh vt sinh sn pht trin trong mu), vim huyt qun no ty. Bnh nguyn gy tiu chy l nhng ETEC khc nhau mang yu t kt bm l cc khng nguyn lng (khng nguyn F4 - tc K88, F5 - K99, F6 - 987P, F41) cng vi cc E. coli sn sinh cc enterotoxin ST-I v ST-II chu nhit, LT-I v LT-II khng chu nhit. d. Bnh E. coli g (colibacillosis in chicken) Bn cnh nhiu bnh trc khun i trng g khng phi l bnh ng rut nh bi huyt cp tnh, vim tng mc cp tnh, u tht mn tnh,... i khi c bnh vim rut xut huyt. Bnh ng rut do E. coli g thng c trng bi phn nho, mu xanh thm, rt hi thi ("ct g sp"). e. Bnh to rut chut (megaenteron of mice) Bnh ny do cc E. coli thuc dng huyt thanh hc O115a, c:K(B) gy ra chut con cai sa 2 - 3 tun tui, c trng bi s hnh thnh qu mc ca t bo thng b nim mc rut, tiu chy dng nc vi t l t vong cao. 2. Escherichia coli v trng c thc phm Trng c (thc ra l chng tiu chy) do E. coli kh ph bin v thng xut hin tp on ngi cng s dng mt loi thc phm nhim khun. Trong a s trng hp, sau khi n thc n nhim E. coli gy tiu chy 10 - 15 gi th pht bnh, c trng bi nn ma, au bng, tiu chy, pht st, hi phc sau 2 - 3 ngy. C khi ty thuc vo s gia tng s lng vi khun pht trin ng rut v lng c t khuych tn trong ng rut m trng c c thi k tim n khong 6 - 72 gi, dng ny c th phn bit l trng c dng cm nhim. Cn cc trng hp khc sau khi n thc n nhim khun trong c th bt u hnh thnh c t dn n hin tng trng c th gi l trng c c t ni sinh. Cc E. coli sinh bnh ng rut (EPEC) do c kh nng kt bm vo t bo HeLa, cho nn c th kim nh E. coli kt bm ng rut (enteroadherent E. coli - EAEC) hay E. coli lin quan n tnh gy bnh ng rut. Cc E. coli c tnh xm nhp t chc ng rut gy nn cc triu chng ging bnh l (tc kit l, hay hng l) trc trng thng khng sn sinh lysine decarboxylase. Cc E. coli sinh c t (ETEC) c cc khng nguyn lng (khng nguyn F2 - CFA/I hoc F3 - CFA/II) v sn sinh enterotoxin nhng c ba loi l ETEC sn sinh ch LT, ch ST hoc c hai loi LT v ST. Triu chng lun lun l tiu chy nh bnh dch t (cholera) do Vibrio cholerae gy ra. Cc triu chng trng c do VTEC thng l tiu chy ra mu dng kit l v au bng d di.


16

3. Salmonella v bnh truyn nhim * c im: Salmonella l mt chi vi khun ln thuc h trc khun ng rut. Vic phn loi chi ny khng thng nht gia cc nh vi sinh vt hc cc khu vc khc nhau. nhiu nc, cc i din Salmonella c c tnh khc nhau thng c coi l cc loi khc nhau, v tn vi khun ny c vit theo quy tc "nh danh" (binomial name) in nghing gm tn chi (c ch ci u vit hoa) v tn xc nh loi (vit thng). Chng hn, Salmonella abortusequi. Nhng vi Hi sinh vt hc mt s nc khc th chi ny li c coi ch gm hai loi l S. choleraesuis v S. bongori (bng I-3), trong loi u gm 6 loi ph (subspecies) khc nhau tng ng vi cc dng huyt thanh hc khc nhau. Vic t tn, do vy, cng khng thng nht vi danh php ni trn. Tn loi ph in nghing gm tn loi cng thm phn ph sau ch subsp. (vit tt ca ch "subspecies") khng in nghing, chng hn, S. choleraesuis subsp. choleraesuis, cn tn gi theo dng huyt thanh hc li vit hoa ch ci u v khng in nghing t sau ch Salmonella trc tip hoc thm ch serovar khng in nghing, v d Salmonella serovar Typhi hoc Salmonella Typhi. Ngoi S. choleraesuis subsp. choleraesuis ra, cn c cc loi ph khc nh S. choleraesuis subsp. arizonae, S. choleraesuis subsp. diarizonae, S. choleraesuis subsp. salamae, S. choleraesuis subsp. houtenae v S. choleraesuis subsp. indica. S. choleraesuis subsp. choleraesuis (S. enterica),... Chng pht trin tt trn mi trng thch thng, 35 - 37 C, sau 20 - 24 gi hnh thnh khun lc trn t trong sut khng mu n hi c, hi li hoc c dng git sng, bng lng. nui cy phn lp thng dng mi trng tuyn la nh thch MacConkey, SS, EMB,... hoc l sau khi nui cy bi dng trong mi trng 50% dch mt (b, ln,...) ri dng mi trng tuyn la nui cy khi u phn lp. Salmonella c phn ng indol m tnh, MR m tnh, VP m tnh, s dng citrate dng tnh, hon nguyn nitrate dng tnh, di ng, lysine decarboxylase dng tnh, adonit m tnh, ln men mannit, thng khng ln men lactose, saccharose tr mt s ngoi l dng huyt thanh hc, dng sinh hc nht nh. Hm lng C+G (mol%) l 50 - 53. Mi trng SS c ch bng cch ha 5 g cao tht, 5 g peptone, 10 g lactose, 8,5 g desoxycholate natri, 8,5 g citrate natri, 1 g citrate st, 2,5 ml neutral red 1%, 0,33 ml lc sng (brilliant green) 0,1%, v 13, 5 g agar vo 1 lt nc ri un si cho tan, khng cn kh trng bng cao p, a Petri. Salmonella v Shigella pht trin to khun lc khng mu, cn cc vi khun ln men lactose thng b c ch, nu c pht trin th c mu mn chn hoc mu . Vi khun sn sinh H2S c th hnh thnh khun lc mu en. Cc vi khun Gram dng th pht trin c trn mi trng ny. Mi trng thch EMB (eosine-methylene blue agar) c ch bng cch ha 10 g peptone, 10 g lactose, 2 g K2HPO4, 0,2 g eosine Y, 0,5 g xanh methylene (methylene blue) v 15 g agar vo 1 lt nc, chnh pH 6,8, hp cch thy kh trng 15 pht 121 C, rt a Petri ngui cho thch ha rn. Mi trng c mu hng. Trn mi trng ny E. coli c khun lc hi nh, mu lng chut hoc en tm c nh kim. Cc vi khun ln men lactose nh Klebsiella c khun lc ln, mu xanh lam khng c


17

nh kim. Vi khun khng ln men lactose, nh Salmonella, khng lm thay i mu ca mi trng, khun lc c mu hng ca mi trng. Mi trng Endo c ch bng cch un chy 100 ml thch Martin (ly d dy ln hoc d c b ti mi, ra sch, ct b m, gn, xay nh, thm 4 ln th tch nc, ri thm 1% th tch HCl, ngm qua m nhit 50 C, trung ha bng dung dch NaOH 20% n khi c phn ng kim, hp cao p kh trng 120 C trong 15 pht, ha vi lng tng ng nc tht c bn, un si 10 pht, kim ha bng NaOH 20% n pH 7,9, un si 30 pht, lc, thm 2% agar ri hp cao p 110 trong 30 pht) ngui 70 C th ha vo 1 g lactose, ri 0,5 ml fuchsine kim bo ha trong cn ethanol 95, v 2,5 ml dung dch thiosulfate natri (sodium thiosulfate) 10%, lc u. ra a Petri, ngui cho thch ha rn. Lc u mi trng c mu hng nhng khi ngui s nht mu. Salmonella pht trin hnh thnh khun lc mu vng, E. coli c khun lc mu . Cc phn ng arginine, lysine, ornithine decarboxylase chuyn mi trng v pha kim tnh lm trung ha acid sinh ra trong qu trnh ln men nn nht thit phi c ng i chng bn cnh cc ng c mt trong ba loi amino acid nu trn. Mi trng amino acid-decarboxylase (Mller) c ch bng cch ha 5 g peptone, 5 g beef extract, 0,005 g pyridoxal, 0,5 g glucose, 2,5 ml dung dch cresol (cresol red) 0,2% v 5 ml ta bromocresol (bromocresol purple) 0,2% vo 1 lt nc ct, pH 6,0, thm amino acid (loi ny hay loi khc) cho 1% ri hp cao p 10 pht 115 C. (Dung dch bromocresol purple v cresol red pha bng cch nghin 2 g cht mu trong 50 ml NaOH 0,1 N ri thm 950 ml nc ct, ng chai, nt kn dng dn). Trc khi lm th nghim th rt lng nh (1 - 2 ml) mi trng vo cc ng nghim nh v trng, thm mt lp dy (5 mm) parafin lng v trng, cy vi khun bng cch m que cy xuyn qua lp parafin lng. Ngoi mi trng ny cn c th dng mi trng Falkow (5 g peptone, 3 g cao men, 1 g glucose, 0,02 g bromocresol purple, 1 lt nc) thay th. Phn ng kim tnh lm cho mi trng chuyn sang mu tm cn phn ng acid lm mi trng chuyn sang mu vng. kim tra cc phn ng ln men ng ca vi khun, ngi ta thng dng cc dy ng nc peptone pH 7,1 - 7,3 c hm lng peptone thp lng NH4 sinh ra do phn gii amino acid khng trung ha lng acid sn sinh ra (2 g bacto peptone, 5 g NaCl, 0,3 g K2HPO4 ha vo 1 lt nc), thm ng (loi ny hay loi khc) 0,5%. Nc peptone ng (mi trng Barsiekow) c th ch bng cch ha 0,5 g ng v 1,2 ml bromothymol blue 0,2% vo 100 ml nc peptone, phn ra ng ri hp ba ln mi ln 1 gi nhit 100 C dit khun, hoc tt hn l hp cao p kh trng ring nc peptone pha bromothymol blue (1,2 ml/l) hoc thuc th Andrade 10 ml/l (Andrade's indicator: ha 5 g acid fuchsine vo 1 lt nc ct v 150 ml NaOH 1 N, nhit phng, c lc thng xuyn, ri thm NaOH 1 N thuc th mt mu t sang vng rm) trong ng nghim c t sn ng Durham ln ngc, cn ng tinh khit cc loi c pha thnh dung dch 10% (hoc 5% i vi ng tan km, d kt ta khi bo qun t lnh), lc qua mng lc vi khun, ct 4 C, trc khi lm th nghim th pha vo nc


18

peptone trong ng nghim v trng c hm lng ng 0,5%. Vi khun ln men ng lm mi trng chuyn t mu lc sang mu vng ri mu xanh (i vi bromothymol blue) hoc chuyn t mu sang mu vng (i vi ch th mu Andrade). Mi trng TSI: ha 3 g cao tht, 3 g cao men, 15 g peptone, 5 g peptone proteose, 5 g NaCl, 10 g lactose, 10 g saccharose, 1 g glucose, 1 g FeSO4.7H2O (sulfate st II), 0,2 g Na2S2O3.5H2O (thiosulfate natri), 12 g agar v 0,024 g phenol red vo 1 lt nc ct, un cho tan u, chnh pH 7,4, rt ng khong 5 - 6 ml khi nng, kh trng 100 C trong 15 pht, t ng nm nghing c phn nghing v phn y khi mi trng tr nn rn. Mi trng c mu . Cy bng cch chc su vo tm phn y v pht b mt phn nghing. Sau khi m, kt qu sinh ha tng t nh mi trng KIA. Mi trng Drigalsky c ch bng cch thm vo 1 lt mi trng thch thng 10 g lactose v 40 ml bromothymol blue 0,2%, chnh pH n 7,2 - 7,4. Tit trng cao p 15 pht 121 C, a Petri. Vi khun phn gii lactose to khun lc mu vng, Salmonella khng phn gii lactose nn to khun lc khng mu (mu mi trng). Hin ti, chi Salmonella c 67 loi (c ti liu cng b ti 80 loi) khng nguyn O, 94 loi khng nguyn H lp 1, hn 11 khng nguyn H lp 2, khng nguyn K l khng nguyn Vi (thng ch pht hin c khi vi khun mi c phn lp t bnh phm ng vt), nhng mt b phn khng nguyn do thc khun th chi phi (bng I-6). Trong loi ph S. choleraesuis subsp. choleraesuis c nhiu dng huyt thanh hc (serovar) khc nhau, phn bit da vo phi hp khng nguyn O v khng nguyn H. Trong cm nhim Salmonella, c cc loi k ch ng vt khc nhau ph thuc vo dng huyt thanh hc ca vi khun gy bnh. Da vo ngi ta chia vi khun ny thnh 4 nhm sinh hc khc nhau. Nhm 1 gm cc chng Salmonella gy mt s ng vt nht nh bnh thng hn (typhus) hay bi huyt (vi khun xm nhp v pht trin trong mu), trong nhiu trng hp vi khun c tnh kt bm t bo (nh nhung mao pili, fimbria), tnh xm ln (nh gene invA-E) v tnh sinh sn ni bo, hoc mt s khc gy bnh ph thng hn nh tnh khng huyt thanh, tnh sinh sn ni t bo h li ni b, tnh sinh c t gy cht. Nhm ny gm c Salmonella Typhi, S. Paratyphi A (gy bnh thng hn hoc ph thng hn ngi), S. Gallinarum-Pullorum (tiu chy - bch l g con, thng hn g trng thnh), S. Abortusequi (ph thng hn, bi huyt hoc sy thai (lu sn) truyn nhim nga), S. Abortusovis (ph thng hn cu non, bi huyt hoc sy thai truyn nhim cu),... Nhm 2 gm cc chng Salmonella bn cnh gy bnh thng hn mt s ng vt nht nh cn gy bnh vim d dy - rut cp tnh hoc bi huyt ng vt. Salmonella Paratyphi B (thng hn ngi), S. Typhimurium (thng hn chut), (ph thng hn b v chut), S. Choleraesuis (tiu chy ln), S. Typhisuis (thng hn ln), S. Dublin (salmonellosis b). Trong c hai nhm 1 v 2 u c vi khun cha plasmid


19

quyt nh tnh gy bnh c trng type huyt thanh hc (bng I-6). Nhm 3 gm cc Salmonella khng thuc dng huyt thanh hc nu trn, khng c tnh c hiu k ch, nhng gy bnh vim d dy - rut cp tnh ngi v ch. Nhm 4 gm cc Salmonella tr S. choleraesuis subsp. choleraesuis, trung tm l S. choleraesuis subsp. arizonae, S. choleraesuis subsp. salamae gy bnh ng vt mu lnh. Thng thng phn lp Salmonela, do lng vi khun trong bnh phm thng t v thng b cc loi vi khun khc p o, ngi ta thng phi nui cy trong cc mi trng chn lc tng sinh Salmonella trc khi nui cy vo mi trng khi u. Mi trng Muller Kauffman v mi trng selenite thng c s dng v mc ch ny. Mi trng Muller Kauffman c ch bng cch pha 5 ml mt b, 1 ml dung dch malachite green (hoc lc sng - brilliant green) 0,1%, 2 ml dung dch iodine (it) (20 g I, 25 KI g, 100 ml nc) v 10 ml dung dch thiosulfate natri 50%, ri lc qua mng lc hay nn lc vi khun c dch lc v trng. Mt khc, ha 5 g CaCO3 vo 90 ml nc tht thng pH 7,5, hp cao p kh trng, ngui, trc khi dng th pha dch lc nu trn, rt ng 3 - 5 ml. Sau khi vi khun mc trong mi trng ny th cy chuyn sang cc mi trng nui cy khi u nh SS, MacConkey, Istrati, Endo, EMB, Drigalsky, Kristensen hay Wilson Blaire,... Mi trng selenite: ha 5 g peptone, 4 g lactose, 10 g Na2HPO4 v 4 g natri bi-selenite (NaHSeO) vo 1 lt nc, chnh pH n 7,2, rt ng 10 - 15 ml, un tit trng 100 C trong vng 15 pht. Khi nui cy th cho vo mt lng bnh phm khong 1/10 n 1/5 mi trng. Mi trng ny tuyn chn bi dng Salmonella. Mi trng Wilson Blaire c ch bng cch trn 0,05 g cao tht (beef extract), 1 g peptone vo 100 ml nc ct, sa pH n 7,4, un si, thm 2 g agar, un tip cho thch tan u ri hp cao p 120 oC tit trng. a ra duy tr nhit 80 C, cho 2 g natri sulfide, 0,5 g glucose, 2,5 ml dung dch ch th bismuth (ch bng cch ha 12 g bismuth citrate vo 96 ml nc ct ri thm 4 ml nc ammoniac 28%, gi trong l nt kn), un cch thy 2 - 3 pht. Thm vo 5 ml dung dch Na2HPO4 10%, 0,05 g sulfate st v 0,25 ml dung dch brilliant green 1%. Trn u, ra cc a Petri. Lc sng ngn tr s pht trin ca cc vi khun Gram dng. E. coli b ngn tr pht trin bi bismuth citrate v natri sulfide, khun lc li, t, lc u trong sut sau chuyn sang mu nu. Proteus c khun lc mu lc sm. Salmonella sinh H2S nn khun lc c mu en do phn ng vi mi trng to FeS. Sau 48 gi nui 37 C th vi khun ny mi mc tt. Bismuth kim loi hnh thnh c mu ng nh. * Bnh cm nhim Salmonella: xy ra nhiu loi ng vt khc nhau, t ngi n cc ng vt mu lnh. a. Bnh ph thng hn b ngh (paratyphus) Bnh ny cn gi l bnh do salmonella b ngh (salmonellosis in


20

calves), gy ra b ngh trong vng 6 thng tui dng vim d dy - rut. Tc nhn gy bnh ch yu l Salmonella thuc cc dng huyt thanh Dublin, Typhimurium; ngoi ra c th gp dng Enteritidis (th vim rut), Newport, Heidenberg,... tru, b trng thnh, cm nhim Salmonella Typhimurium v Dublin thng dn n s mang trng trong thi gian ngn, nhng tru, b c cha thng gy sy thai v s mang trng n tnh. b. Bnh ph thng hn nga (equine paratyphoid)BKD52 Do Salmonella Abortusequi gy ra, nga trng thnh thng l nhim khun ng rut cc b, nga ci c cha bnh thng gy ra sy thai, nga c thng gy vim tinh hon, nga non thng l vim khp xng, ha m v tiu chy mn tnh. c. Bnh ph thng hn ln (paratyphus in swine)BKD60 Bnh ny cn gi l bnh salmonella ln (salmonellosis in swine), do Salmonella Choleraesuis, Typhisuis, Typhimurium,... gy ra. Cc vi khun ny ch yu pht sinh bnh ln con 2 - 3 thng tui. Cm nhim S. Choleraesuis v S. Typhisuis thng gy dng bnh bi huyt cp tnh, cn Salmonella cc dng huyt thanh hc khc, c bit l tiu chy cp tnh hoc mn tnh, sau tr thnh ln mang trng. d. Bnh bch l g con (pullorum disease)BKD69,70 Bnh ny gy ra bi Salmonella Gallinarum-Pullorum. Thng thng, triu chng ch yu l tiu chy phn mu trng g con, dn n cht do bi huyt cp tnh. g con my tun tui v g trng thnh c sc khng tng, cm nhim vi khun ny thng tri qua m khng c triu chng nhng nhiu trng hp g tr nn mang trng. kim tra g mang trng, ngi ta phi kim tra khng th c trong huyt thanh. Mt khc, cm nhim Salmonella biovar Gallinarum thuc serovar Gallinarum-Pullorum g gi l bnh thng hn g (fowl typhoid), g con xut hin triu chng bch l (tiu chy phn mu trng), cn g trng thnh trong nhiu trng hp gy nn bnh dng bi huyt. e. Bnh ph thng hn g (fowl paratyphoid)BKD69,70 Cm nhim cc Salmonella ngoi S. Gallinarum-Pullorum g gi l ph thng hn gia cm, cc loi chim khc ngoi g cng mc bnh. Thng thng g trong vng 1 thng tui xy ra tiu chy. Nu nhim cc vi khun bnh nguyn ny, tht g gy trng c thc n. Thng thng, chn on bnh ph thng hn g ngoi vic phn lp v ng nh vi khun bnh nguyn, ngi ta cn thng dng cc phn ng ngng kt pht hin g mc bnh hoc mang trng lm ngun bnh ly lan. Trong , phn ng ngng kt nhanh trn phin knh vi git mu nguyn l phng php ph bin, tin li, n gin c th thc hin ngay ti c s sn xut, v kh chnh xc. Khng nguyn chun c s dng l cc chng Salmonella Gallinarum-Pullorum c cu to khng nguyn y (Salmonella I, IX, XII2, XII3:-.-) v c nhum bng crystal violet (hoc Gentian violet). Dng ng ht nh 2 - 3 git khng nguyn ln b mt vng ( nh du) nh trc trn mt tm knh sch


21

(hoc tm gch men sch), dng que cy (c khuyn cy ng knh 2 - 3 mm) ly mt khuyn mu nguyn ha u vo khng nguyn, c kt qu sau khong 45 giy. Phn ng dng tnh cho hin tng ngng kt tc cc t bo vi khun kt cm li tng phn vi nn trong sut mu hng nht, thy c bng mt thng. Trong trng hp m tnh, hn dch khng nguyn - mu nguyn khng i tc c mu ng nht. Ch rng nh gi kt qu phn ng ch trong vng 2 pht, v mi ln ch nn lm 4 mu trnh hin vng vin trng nh ngng kt do git khng nguyn b kh. Bng I-4. Tnh trng ch yu ca cc loi, loi ph v dng sinh hc ch yu ca SalmonellaLoi (loi ph, dng huyt thanh hc) Salmonella cholaeraesius subs. cholaeraesius subsp. diarizonae subsp. arizonae subsp. salamae Tnh trng Typhimurium Abortusequi Abortusovis Paratyphi A subsp. houtenae

Choleraesuis

subsp. indica + + v + + v + + + + + + + + + v + + + +

Gallinarum

Glucose (acid) Glucose (hi) Lactose Sorbit Tartrate Citrate H2S -galactosidase Gelatinase Xylose Rhamnose Mannit Trehalose Melibiose S dng malonate Acid galacturonic KCN (0,0075%) -Glutamyla Lysine decarbob Arginine dehydroc Ornithine decarbob Acid muric Di ngPhage Salmonella O1

+ + + + + + + + + + + v + v + + + +

+ + + + + + + + + + + + v + + + +

+ + + + + + + + + + +

+ + + v + v + + + + v + + +

+ + + + v + + + v + + +

+ + + + v + + + v + + v + + +

+ + + v v + + v + + +

+ + + + v + + + + + + + +

+ + (+)

v + v + v v + + +

+ + + v v + + v +

+ + + + + + + + + + v + +

+ + v + + + + + + + + + + + + + + + + -

+ + v + + + + + + + + + + + + + + + + v + v

+ + + + + + + + + + + + + + + + + + + +

+ + + + + + + + + + + + + + + v + + -


S. bongori + + + + + + + + + + + + + + + + + + + v

Typhisuis

Pullorum

Sendai

Dublin

Typhi

22

Ghi ch: a, -Glutamyl transferase; b, Lysine decarboxylase; c, Arginine dehydrogenase; d, Ornithine decarboxylase.

f. Bnh cm nhim salmonella gm nhm (salmonellosis in rodents) Cm nhim Salmonella chut nht, chut cng, chut lang,... gy nn nhim khun mu cp tnh, cm nhim ng rut mn tnh v thng hn thng tri qua cm nhim n tnh. Tc nhn gy bnh nht thng l Salmonella serovar Typhimurium v S. Enteritidis. Bn cnh , chut nht v chut cng mn cm cao vi cc Salmonella thuc dng huyt thanh hc khc. g. Cc bnh salmonellosis khc Cc loi ng vt c v v chim khc nhau cng cm nhim Salmonella nh gia sc, gia cm. Cc loi c v cn trng (rui, ong,...) cng c th nhim vi khun ny do ngun nc nhim v tr thnh cc ng vt ngun gc nhim thc phm. Bng I-5. Cc dng huyt thanh ch yu v tnh gy bnh ca SalmonellaNhm KN O O2 Dng huyt thanh hc (loi ph) Paratyphi A Abortusequi Paratyphi B Abony Abortusovis Saintpaul Derby Agona Typhimurium Bredeney Heidelberg Paratyphi C Choleraesuis Typhisuis Livingstone Montevideo Oranienburg Thompson Postdam Infantis Bareilly Newport Blockley Sendai Typhi Enteritidis Dublin Gallinarum Pullorum Muenster Khng nguyn O 1, 2, 12 4, 12 1, 4, (5), 12 1, 4, (5), 12, 27 4, 12 1, 4, (5), 12 1, 4, (5), 12 1, 4, (5), 12 1, 4, (5), 12 1, 4, 12, 27 1, 4, (5), 12 6, 7, [Vi] 6, 7 6, 7 6, 7 6, 7, 14 6, 7, 14 6, 7, 14 6, 7, 14 6, 7, 14 6, 7, 14 6, 8, 20 6, 8 1, 9, 12 9, 12, [Vi] 1, 9, 12 1, 9, 12, [Vi] 1, 9, 12 1, 9, 12 3, 10, [15, 34] Khng nguyn H Lp 1 Lp 2 a [1, 5] e, n, x b 1, 2 b e, n, x c 1, 6 e, h 1, 2 f, g [1, 2] f, g, s Tnh gy bnh

O4

O7

O8

O9

O3,

Ph thng hn (ngi) Ph thng hn nga Salmonellosis (ngi) Ph thng hn tru b Ph thng hn cu Trng c thc phm Trng c thc phm nhim tht, trng Salmonellosis b, vim d dy-ru i 1, 2 ngi l, v 1, 7 Trng c thc phm r 1, 2 Nhim tht, trng c 1, 5 Salmonellosis (ngi) c 1, 5 Ph thng hn ln con c 1, 5 Ph thng hn ln con d L, w Nhim tht, trng g, m, [p], s [1, 2, 5] Trng c thc phm m, t [Z57] Trng c thc phm k 1, 5 Cm nhim tht, trng l, v E, n, z15 Nhim tht, trng, ch r 1, 5 Cm nhim tht, trng y 1, 5 Nhim tht, trng e, h 1, 2 Nhim tht, trng, ngi e, h 1,5 Cm nhim tht, trng a 1, 5 Salmonellosis (ngi) d Thng hn rut (ngi) Salmonellosis b, vim d dy ru [f], g, m, [p] [1, 7] ngi g, p Salmonellosis b Thng hn g Tiu chy (bch l) g con e, h 1, 5 Vim d dy vt, nhim thc phm


23

10

O1, 3, 19 O18, O21

Anatum Meleagridis London Give Liverpool Senftenberg Cerro Minnesota

3, 10, 15, 34 3, 10, [15, 34] 3, 10, [15] 3, 10, [15, 34] 1, 3, 19 1, 3, 19 6, 14, 18 21 a dng a dng

e, h e, h l, v [d], l, v d g, [s], t z4, z23 b a dng a dng

1, 6 1, w 1, 6 1, 7 e, n, z15 [1, 5] e, n, x -

S. subsp. arizonae S. subsp. diarizonae

Cm nhim tht, trng, cm nhim ch Cm nhim tht, trng Cm nhim tht, trng Cm nhim tht, trng nhim thc phm Bi huyt chim, nhim b st, lng th

a Cm nhim b st, lng th dng Ghi ch: [ ]: khng nguyn him; ch s gch chn: khng nguyn chi phi bi bacteriophage.

Cc dng huyt thanh hc Salmonella choleraesuis subsp. salamae, arizonae gy bnh truyn nhim ng vt b st (c bit, ra, thn ln, rn) v lng th (ch nhi). Salmonella choleraesuis subsp. arizonae i khi gy cm nhim gia cm, ngi v gia sc. Mt khc, cc ng vt lng th, b st c th cm nhim Salmonella choleraesuis subsp. choleraesuis v tr thnh ngun gc nhim v dch. 4. Salmonella v trng c thc phm Ngoi ba dng huyt thanh hc vi khun Salmonella l Typhi (trc khun thng hn ln), Paratyphi A (trc khun ph thng hn) v Paratyphi B, cc dng huyt thanh hc khc c th l nguyn nhn vim d dy - rut cp tnh, au bng, nn ma, tiu chy, st l nhng triu chng chnh; thi k tim n khong 18 - 36 gi. Ngoi ra, cn c trng hp nhim khun huyt, bi huyt, vim mng ty, vim mng xng,... Bng I-6. Plasmid c tnh c hiu dng huyt thanh hc SalmonellaDng huyt thanh hc Typhimurium Dublin Naestved Enteritidis Choleraesuis Gallinarum-Pullorum ln (kb) 90 75 75 54 50 85 Biu hin tnh gy bnh ch yu c tnh gy cht, gim thiu tnh thm thu ca cc cht k thy c tnh gy cht, tnh khng huyt thanh, nng lc tng trng trong t bo h li ni b Ging nh plasmid serovar Dublin c tnh gy cht c tnh gy cht, gy chng nhim khun mu chut c tnh gy cht

Cc vi khun Salmonella gy trng c ch yu l Salmonella serovar Typhimurium, Enteritidis, Thompson,... thng gy nhim t nhiu loi gia sc gia cm khc nhau, cc ng vt cnh, cc ng vt hoang d, chim, b st, lng th,... n nc sng sui, nc thi, c bit l vn nhim thc n gia sc, tht trng, dng c ch bin sa,... Plasmid thng c phn ly bng nhiu phng php nhng ph bin nht l phng php kim Birmboim v Doly (1979). Nguyn tc ca phng php ny l gy dung gii t bo bng dung dch kim (c hoc khng c x l protease hoc lysozyme), sau a nhanh pH ca dch v


24

trung tnh. Do c phn t lng ln, DNA nhim sc th v RNA b ri vi cc protein b bin tnh, cn DNA plasmid th do c cu trc siu xon nn vn gi c tnh tan trong nc v c phn tch khi ta nh ly tm. DNA tan ca plasmid c tinh khit ha b sung bng cch cho thm vo dch lng nh RNase phn gii RNA cn st li, sau c in di trong gel agarose thun khit v xc nh phn t lng nh i chiu vi nng lc di ng trong in trng ca cc on DNA "du phn t lng" (DNA molecular weight marker) c phn t lng bit trc cng c in di song song. S hin din ca cc phn t DNA trong gel (c DNA mu ln DNA du c xc nhn nh nhum bng thuc nhum pht hunh quang ethidium bromide v quan st di bc x t ngoi. Phn gel cha DNA c th c ct ra khi tm gel tinh ch DNA bng nhiu phng php khc nhau. 5. Trc khun l Shigella v bnh truyn nhim * c im Shigella: thuc chi ny c 4 loi vi khun, S. dysenteriae, (trc khun l Shiga - l nhm A), S. flexneri (trc khun l Flexneri - l nhm B), S. boydii (trc khun l Boyd - l nhm C) v S. sonnei (trc khun l Sonne - l nhm D) (bng I-7). * Bnh cm nhim Shigella: Hu nh ch xy ra cc loi linh trng, k c ngi. Tuy vy, cc loi ng vt khc nhau c th l cha ca vi khun ny. a. Bnh (hng) l kh (disentery in monkeys) Bnh nhim khun Shigella kh gi l bnh l hay hng l. S. dysenteriae hoc S. flexneri nhim qua ng n ung, sau khong 2 - 6 ngy nung bnh, dn n tiu chy phn nhy nh dch mi thng c mu, km pht st. Cm nhim S. boydii v S. sonnei thng i qua vi cc triu chng nh, kh b bnh thng tr thnh vt mang trng v l ngun gc bnh dch. b. Bnh (kit, hng) l ngi (disentery in human) Cc Shigella gy bnh l trc khun ngi, c th tr thnh dch. Thi gian nung bnh ngn (24 gi), bnh khi pht t ngt vi nhng triu chng thng gp l tiu chy, au bng, i phn nhy mi ln thng t nhng phi i nhiu ln trong ngy, nhiu khi ln mu. Cc th lm sng c th t cp tnh n th n vi nhng du hiu vim d dy - rut, thng nng tr em, c th tr thnh dch tiu chy. Th bnh nng nht l do trc khun l Shiga do c c t thn kinh. Bng I-7. Cc tnh trng gim bit ca ShigellaLoi Tnh trng Tnh gy bnh


25

Raffinose (Melitose)

Glucose (sinh acid)

S. dysenteriae S. flexneri S. boydii S. sonnei

V V V -

+

V V +

+ + + +

-

V -

+

+

V +

+ + +

-

A B C D

L 1 - 12 +++ 1 - 6, x, y ++ (Hng l 1 - 18 ++ hay kit l) ++

6. Edwardsiella v bnh truyn nhim * c im Edwardsiella: Chi ny gm 3 loi (bng I-8), trong bnh nguyn ch yu cho ng vt l Edwardsiella tarda. Vi khun ny c nhit pht trin ti thch vo khong 25 - 31 C, pht trin tt trn mi trng thch thng. 25 C, sau 24 gi nui cy vi khun pht trin thnh khun lc trn nh, mu trng tro, bng lng. phn ly vi khun ngi ta thng dng mi trng tuyn chn nh thch SS, thch DHL, XLD,... Do hnh thnh H2S, cc khun lc vi khun ny c mu en r tm. Edwardsiella c cc tnh trng sau: indol dng tnh, phn ng MR dng tnh, phn ng VP m tnh, citrate dng tnh, phn ng hon nguyn nitrate c th dng tnh hoc m tnh ty chng, phn ng di ng dng tnh, phn ng lysine decarboxylase dng tnh, khng phn gii cc ng saccharose, lactose, mannit, adonit. Hm lng G+C (mol%) l 50 - 51. Bng I-8. Cc tnh trng ch yu v c im gy bnh ca EdwardsiellaTnh trng Glucose (sinh acid) Loi (dng sinh hc biovar) Pht trin 37C Glucose (sinh hi) Pht trin 25C

Sinh indol

Sinh H2S

Saccharose

Arabinose

Trehalose

Tnh gy bnh ( c, ng vt c v, ngi) Maltose Mannit

E. tarda 1 E. tarda 2

+ V

+ + + -

+ + -

MR

+ + + -

+ -

+ + + +

+ V

+ -

+ -

+ + -

+ + + -

+ + -

E. hoshinae + + E. ictaluri

Bnh do edwardsiella c Tiu chy, cm nhim vt thng Bnh do edwardsiella ln Bnh do edwardsiella c tr

V cu trc khng nguyn, vi khun ny c 17 loi khng nguyn O, 11 loi khng nguyn H, cc chng vi khun c phn loi thnh t nht 54 dng huyt thanh hc khc nhau. Yu t gy bnh ca vi khun ny cha c r.


Khng nguyn c hiu dng

Khng nguyn loi

Glucose (sinh hi)

( vn v ngi)

Ornithine d b l -galactozidase

Saccharose

Sinh indol

Lactose

Mannit

Xylose

Dulcit

26

* Bnh cm nhim Edwardsiella: Bnh do Edwardsiella ( c) - edwardsiella disease, edwardsiella septicemia (in fish) E. tarda gy bnh truyn nhim cc loi c, k c ln. Vi khun ny tuy tn ti trong ng rut ca cc loi b st v lng th, nhng thng ch gy bnh c: c chnh, c chp, c hanh, c nc,... hnh thnh nhng p xe thn v gan. min nam nc M bnh thng do E. ictaluri (l vi khun khng di ng) gy ra c tr (channel catfish) . Bnh cm nhim vi khun ny thng pht sinh v ma m p trong nm (nhit nc 20 - 30 C), vy v bng xut hin chm , hu mn trng cng v . Vi khun ny thng c phn lp ngi v ng vt, mc d du hiu gy bnh vn cha c xc nh nhng ngi ta nghi ng y l bnh nguyn bnh ly chung ngi v ng vt (zoonosis). 7. Yersinia v bnh truyn nhim * c im ca cc loi thuc chi Yersinia c k bng I-9. Trong s 11 loi thuc chi ny c 4 loi ch yu gy bnh cho ngi v ng vt: Y. pseudotuberculosis, Y. pestis, Y. enterocolica v Y. ruckeri. Vi khun ny pht dc tt 25 - 30 C, nhng 4 C cng nh 37 C u c kh nng sinh trng. C 4 loi gy bnh k trn u pht trin tt trn mi trng thch thng, thch mu, sau 24 - 48 gi nui cy 25 - 30 C hnh thnh khun lc dng S trn, li, trong nh git sng n hi c, n mu xm tro, t, bng lng. Nui cy 37 C hnh thnh khun lc R, b mt th nhm, phng, kh. phn lp, thng dng mi trng thch desoxychocolate, thch SS,... V tnh trng sinh l sinh ha, Yersinia c phn ng indol, VP khc nhau cc loi khc nhau. Phn ng MR dng tnh, citrate m tnh, nhng Y. ruckeri li c phn ng ny dng tnh, hon nguyn nitrate m tnh. V tnh di ng, ch c Y. pestis l m tnh chc chn, cn cc loi Yersinia khc di ng khi nui cy 30 C, nhng khng di ng khi nui cy 35 - 37 C. Cc phn ng urease, -xylosidase, rhamnose, cellobiose th khc nhau ty loi. Ln men mannit, cn adonit m tnh. Hm lng G+C (mol%) l 50. Bng I-9. Cc tnh trng gim bit ch yu v tnh gy bnh ca YersiniaTnh trng Hon nguyn nitrate Lysine decarboxylase Tnh gy bnh (3)

Phn ng VP

Saccharose

-Glutamine

-Xylodase

Rhamnose

Gelatinase

Cellobiose -

Urease

DNase

Ornithine

Xylose

Melobiose v +

Arabinose

Trehalose

Sinh indol

Loi (dng sinh hc)

Di ng

Citrate

Lypase

Y. pestis Y. pseudotub* Y. enterocolica

-

-

v +

+

+

+ v

+ +

v

-

-

-

-

+ +

+ +

+

+ +

-


Sorbit

- (1) - (2)

27

biovar 1 + + - + + + - - + - + - + + + - + + + - + biovar 2 + + - + + + - - + - - - + + + - + + + - + biovar 3 - + - + + + - - + - - - + + + - + + + - + biovar 4 - + - + + + + - + - - - + - + - + + + - + biovar 5 - + - - + + + - + - - - + - + - - v + - + + + + + + + - - + - v - + + + + + + + + + Y. intermedia + + v + + + - v + - v - + + + + + + + - + Y. fredriksenii v - - + + + - - + - v - + + + - + - + - + Y. kristensenii - v + + v - - - + + v + + - - - + - - - - (4) Y. ruckeri Ghi ch: Tnh gy bnh (1), bnh dch hch [ngi]; (2), bnh gi lao [ cc loi gm nhm]; (3), vim d dy - rut, trng c thc phm, vim khp [ ln, gm nhm, ch, ngi]; (4), bnh ming [ c hi]; Y. pseudotub* = Y. pseudotuberculosis.

kim tra tnh di ng ca vi khun ngi ta c th hin vi tiu bn soi ti (git treo, git p) hoc cy vi khun theo ng chch su vo mi trng thch bn c th (na lng, cha 0,5% agar). Khi nui cy trong mi trng ny, nhng loi vi khun khng di ng ch mc theo ng cy cn vi khun di ng mc lan rng lm c dn c mi trng. Vi khun c phn loi trn c s huyt thanh hc thnh cc nhm huyt thanh hc (serogroup) nh c cc khng nguyn O chu nhit, cc khng nguyn K, H, khng nguyn "envelope" khng chu nhit. Y. pseudotuberculosis c 8 nhm huyt thanh hc. Y. enterocolica c chia thnh 57 dng huyt thanh hc (serotype) v 5 dng sinh hc (biovar). cc vi khun ny c cc yu t gy bnh chung l kh nng tng hp purine, adhesin, cng nh khng nguyn V - W do plasmid chi phi, protein Yersinia ngoi mc (YOP: Yersinia outer membrane protein), tnh khng huyt thanh,... nh vy chng biu hin nng lc pht trin bn trong cc t bo thc bo k ch hay tnh k sinh ni bo. * Bnh cm nhim Yersinia: kh ph bin. a. Cm nhim Yersinia ln (yersinia infection in swine) L bnh truyn nhim do Y. enterocolica hoc Y. pseudotuberculosis gy ra. Bnh ny ln v bo trong thi k u biu hin tiu chy nh, st, i khi gy vim khp xng, bi huyt. Cc dng huyt thanh hc gy bnh ch yu l Y. enterocolica biovar 3, 4 (serovar O3), biovar 2 (serovar O5, O27, O9), biovar 1 (serovar O4, 32; O8; O13; O18; O20; O21). Sau thi k s nhim ln hnh thnh min dch phng v cm nhim, c kh nng ngn cn s cm nhim cc dng huyt thanh hc khc. Ln mc bnh bi xut lng ln vi khun trong phn, tr thnh nhim trng. b. Bnh gi lao (pseudotuberculosis) L bnh truyn nhim gy ra bi vi khun Y. pseudotuberculosis (bnh ny cn do Corynebacterium pseudotuberculosis - xem phn "Cc trc khun lin quan x khun"). Yu t gy bnh ca vi khun ny l plasmid ph thuc nhit (37 C), cc khng nguyn V - W do gene nhim sc th chi phi (ph


28

thuc Ca: biu hin khi khng c Ca trong mi trng), tnh khng huyt thanh, khng nguyn YOP, tnh hp ph cng-g (congo red), tnh xm ln t chc,... Bnh gi lao do Y. pseudotuberculosis ch yu gy ra th v cc loi gm nhm nh chut lang,... Ngoi ra, ln, d, tru b, hu, ch, mo, ngi v chim hoang,... cng cm nhim, gy st, pht ban, chm khp, sng cc hch lympho (lm ba) mng rut, p xe gan v lch dng casein, vim cc khp, bi huyt,... d ci c cha thng gy sy thai. c. Bnh ming hay "bnh ming - rut" (enteric red-mouth disease ERM) Gy ra bi vi khun Y. ruckeri cc loi c thuc h Hi. Vi khun ny c c tnh pht trin 37 C nn vo thi k m p trong nm cm nhim nh, hnh thnh cc hoi t lch v thn, xut hin cc chm sung huyt, xut huyt vng quanh ming v mang. d. Bnh dch hch (pest, plague) L bnh truyn nhim cp tnh do Y. pestis gy ra cc loi gm nhm v ngi. Vi khun ny, ngoi cc yu t gy bnh chung ca chi ra, cn c nng lc hnh thnh khng nguyn "envelope" gip m (phn on 1 - fraction 1), nng lc chim st, cc c t chi phi bi plasmid, sn sinh coagulase, fibrinolysin, tnh khng thc bo v pht trin ni bo. Vi khun ny pht trin phn trc d dy ca rn. Rn va ht mu ng vt gm nhm mang trng truyn tc nhn gy bnh cho ngi. T vt t ca rn mang trng hoc t nim mc, vi khun xm nhp gy chng vim xut huyt cc hch lympho, gy sng, mng m, lot hch lympho v pht st th gi l dch hch th hch (hay th tuyn), cn nu hnh thnh cc im xut huyt n tnh, ph thng, hoi t do chng bi huyt, vim kh qun - ph qun th sinh th gi l dch hch th phi. S pht bnh thng lin quan n c t dch hch. 8. Yersinia v trng c thc phm Y. enterocolica gy ra trng c thc phm ngi thng qua thc n, nc ung. Thi k tim n ca trng c dng cm nhim do Yersinia 5 - 7 ngy, bnh thng a dng. tr b sa a s trng hp l vim d dy rut cp tnh vi triu chng ch yu l tiu chy, pht st, ngi ln thng vim hi trng vi triu chng ch yu l au d di vng bng di bn phi, vim hch lympho mng rut dng t ngt nh vim rut tha. Ngoi ra, bnh c th tin trin dn n hnh thnh ban m dng nt hch, vim khp, chng bi huyt. 9. Klebsiella v bnh truyn nhim * c im Klebsiella (bng I-10): Trong chi ny c 5 loi vi 3 loi ph. Bnh nguyn ch yu l K. pneumoniae subsp. pneumoniae. Cc vi khun chi ny pht trin tt trn mi trng thch thng, sau khi nui cy trn mi trng ny 15 - 20 gi 35 - 37 C hnh thnh khun lc mu trng tro, rt nhy, bng lng. V tnh trng sinh vt ha hc, vi khun ny khng pht trin nhit 10 C, hnh thnh gip m, phn ng indol m tnh, phn ng MR m tnh, phn


29

ng VP m tnh, citrate dng tnh, khng sn sinh H2S, khng di ng, ln men lactose, ln men mannit. Hm lng G+C (mol%) trong khong 53 - 58. Bng I-10. Cc tnh trng gim bit v tnh gy bnh ca cc loi Klebsiella ch yuTnh trng Arginine dehydrogenase

Lysine decarboxylase

Glucose (sinh acid)

Lactose (sinh acid)

Mc 10C

Sn sinh indol

Loi (loi ph)

S dng malonate

Glucose (sinh hi)

Lactose (sinh hi)

Gelatinase

Tnh gy bnh (ng vt, ngi) Pectin + (A) Vim mi Vim mi (B)

Urease

Citrate

K. pneumoniae subsp. pneumoniae ozaenae rhinoscleromatis K. oxytoca K. terrigena K. planticola

+ + +

+ V

+ + V + +

+ + + +

+ V + + +

+ + +

+ + + +

+ + + +

-

+ + + + + +

+ + +

+ V + + + +

+ V . . .

Dulcit V V V

MR

VP

+ + + + V +

Ghi ch: (A): Vim v hoi th b sa, ha m, vim phi nga non, vim t cung nga ci, nhim niu o, phi ch; (B): Cm nhim c hi.

Cc vi khun chi Klebsiella c 8 loi khng nguyn O, tn ti t nht 77 loi khng nguyn K, thng khc nhau v dng khng nguyn. Vic hnh thnh gip m c s chi phi ca c nhim sc th ln plasmid v lin quan n tnh khng s thc bo. Gip m ca vi khun c th quan st c di knh hin vi trong tiu bn nhum mc tu (nhum m bn, nhum sng) bng cch nh mt git nh mc tu ln phin knh ri ha vo mt git nh huyn dch vi khun, y bng l knh (lamen) ri quan st di knh hin vi. Gip m thy di dng vng trong sut gia khong en ca mc tu v t bo c tnh chit quang cao hn. Gip m c thy r hn nu c nhum dng bn. Phng php Hiss nhum gip m nh sau: nhum tiu bn ln mng ( kh v c nh) bng dung dch Gentian violet (5 phn dung dch Gentian gc [5 g Gentian violet trong 100 ml ethanol] v 95 phn nc), gia nhit cho n khi thuc nhum bc hi chng 30 giy. Sau ra li bng dung dch sulfate ng 20%, khng ra nc, ch thm cho bt dung dch trn phin knh ri hin vi. * Bnh cm nhim Klebsiella (bng I-10): a. Bnh vim v do Klebsiella b (klebsiella mastitis in cattle) Cm nhim Klebsiella pneumoniae b ci trong thi k vt sa gy ra vim v hoi t cp tnh hoc qu cp tnh, nhiu b v vy phi loi thi. Bnh ny lin quan n ni c t ca vi khun.


30

b. Cm nhim klebsiella nga (klebsiella infection in horse) Klebsiella pneumoniae cm nhim nga con gy mng m, vim phi, thng ko theo chng bi huyt. Nga ci thng b vim t cung hoc vim c t cung, cn nga c cha cm nhim vi khun ny dn n sy thai. Bng I-11. Cc tnh trng gim bit ca cc loi ch yu thuc chi CitrobacterArginine dehydrogenase Tnh trng Ornitine decarboxylase KCN (0,0075%) (mc) S dng malonate

Loi Sinh indol Sinh H2S

Tnh gy bnh Adonit + + Cm nhim c hi (nhim ng tit niu, kh qun, vt thng, vim v b ci,...)

C. freundii C. diversus C. amalonaticus

+ +

+ -

V + +

V + +

+ +

+ -

10. Cc vi khun khc thuc h Enterobacteriaceae a. Chi Citrobacter Bng I-12. Tnh trng gim bit v tnh gy bnh ca cc loi Enterobacter ch yuArginine dehydrogenase Ornithine decarboxylase Tnh trng KCN (0,0075%) (mc) Lysine decarboxylase

Acid mucic

Gelatinase

Loi Urease

Tnh gy bnh Adonit Arabit V + + Cm nhim c hi (phn b ng rut ng vt , mi trng) Sorbit V + -

E. cloacae E. aerogenes E. gergoviae E. sakazakii

V + -

(+) -

+ -

+ + +

+ + + +

+ + +

V + -

V + -

Chi Citrobacter gm 3 loi (bng I-11), trong C. freundii l vi khun gy cm nhim c hi (opportunistic infection) c th phn lp, ngoi ng rut ra, t cc chng vim v b ci, cc hi chng mt sa sau sinh ln,.... Ngoi ra, vi khun ny cn gy nhim trng th cp nhiu loi ng vt thy sn. b. Chi Enterobacter Chi Enterobacter gm 12 loi (bng I-12), phn lp c ng rut, trong E. cloacae v E. aerogenes l nhng vi khun gy cm nhim c hi, i khi gy vim c quan sinh dc, sy thai nga, gy vim v, sy thai b, hi chng mt sa sau sinh ln ni.


31

c. Chi Proteus, chi Providencia v chi Morganella C cc c tnh ch yu nh bng I-13. Chi Proteus gm 4 loi. P. mirabilis v P. vulgaris l nhng vi khun gy bnh cm nhim c hi, gy vim bng quang (bng i), c phn lp vi tn sut cao t cc chng bnh tit niu, b gy vim ni mc t cung, sy thai, vim d dy - rut b ngh, vim khp, chng bi huyt, ln gy hi chng mt sa sau sinh, cm nhim ng tit niu, tiu chy, ch v mo, gy vim bng quang, cm nhim ng tit niu, lin quan n vim tai ngoi. i khi Proteus c phn lp nh l nguyn nhn gy trng c thc phm. nhiu loi c, P. rettgeri gy bnh xut huyt. Bng I-13. Cc c tnh gim bit v tnh gy bnh ca cc loi ch yu chi Proteus, chi Providencia v chi MorganellaTnh trng Trn (swamming)

Phn ng VP

Loi

Gelatinase

Sinh indol

Trehalose

Mannose

Tnh gy bnh Mannit Adonit Inosit

+ + - + v - + v v + - + v P. vulgaris (A) + - v + v + + + + + - + P. mirabilis (+) - + v - + v v + - + v P. penneri - + - + - + - + P. alcalifaciens (B) - + - + - v - + - + + P. stuartii - + - + - + - + - + + + P. rettgeri - + - + + - + (C) M. morganii Ghi ch: (A), cm nhim c hi (vim bng quang, ng tit niu, vim tai, trng c); (B), (C), cm nhim c hi.

Chi Providencia c 5 loi, chi Morganella ch c 1 loi. P. rettgeri v M. morganii l nhng vi khun gy bnh c hi, ngoi ng rut ra, cc vi khun ny i khi phn lp t t chc bnh phm. d. Chi Serratia Bao gm 10 loi khc nhau (bng I-14) nhng ch c S. marcescens v S. liquifaciens thng phn lp c t bnh phm vim kt mc nga, vim phi, chng bi huyt nga con, vim v v sy thai b nh nhng vi khun gy bnh c hi. Ngoi ra, c th phn lp c S. liquifaciens t c mc bnh xut huyt, cn S. plymuthica c th gy chng nhim trng th cp nhiu loi c. e. Chi Hafnia, chi Kluyvera, chi Tatumella, chi Cedecea, chi Erwinia Hafnia alvei l vi khun gy cm nhim c hi, phn lp c, ngoi ng rut ra, t bnh phm t chc nh sy thai nga, vim v b, vim kt mc nga. Kluyvera ascorbata, Tatumella ptyseos l vi khun gy cm nhim c hi lin quan n cc chng cm nhim ng h hp, vim ng


H2S

Maltose

Ornitine

Urease

Lipase

Citrate

Xylol

32

tit niu ca ng vt v ngi. Cedecea davisae phn lp c t bnh phm, thc phm. Trong chi Erwinia c 17 loi, l nhng tc nhn gy bnh thc vt, cn ng vt th khng biu hin tnh gy bnh. Bng I-14. Cc c tnh gim bit v tnh gy bnh ca cc loi ch yu chi SerratiaTnh trng Lysine decarboxylase Mc Glucose (sinh hi) Tnh gy bnh (trng c thc phm, cm nhim c hi) + +

Loi Sinh indol 37 C 42 C

Rhamnose

l

Arabinose

Ornitine d b DNase

Xylose

Lipase

S. marcescens S. liquifaciens S. plymuthica S. adorifera

+ + +

+ + v -

+ -

+

+ + +

+ + v

+ + + +

+ + v v

+ v -

+ + +

+ + +

v +

+ + v +

B. PHY KHUN (H VIBRIONACEAE) I. C IM CHUNG CA PHY KHUN1. Phn loi Phn loi cc phy khun c k bng I-15. H phy khun Vibrionaceae c 6 chi, phn nhiu phn b trong nc ngt v nc bin, phn lp c t cc loi c. 2. Hnh thi Cc phy khun l trc khun ngn Gram m, trong c dng un khc hnh du phy, nhiu khi mt s t bo xp st nhau nn c dng ch S. Chng khng hnh thnh nha bo v gip m. y l nhng vi khun cc n mao (Vibrio, Aeromonas) hoc n tng mao khun (Plesiomonas). Aeromonas salmonicida khng c kh nng vn ng.

nhum lng (lng roi) vi khun c th s dng mt s phng php nhum. Trong tt c cc phng php (Leifson, Toda, Ryu) u dng bin php khuych i kch thc ca lng bng acid tannic v phin knh tiu bn phi tht sch. y ch gii thiu phng php Leifson (Leifson's flagella stain): Trc ht lm cht vi khun trong canh khun bng cch cho thm 0,25 ml formalin (dung dch thng phm formaldehyde khong 37%) vo 4 ml canh khun, lc nh ri yn khong 15 pht, ly tm 2.000 vng/pht trong 5 pht, phn nc trong trn, thm 8 ml nc ct, ly tm ri li nc trn, thm nc ct v lc huyn dch ha cho n khi c dch c nh. H nng nh phin knh trn ngn la. Nh mt git huyn dch vi khun gn u phin knh ri


Arabit -

Sorbit

4 C

33

nghing phin knh khong 80 cho dch chy dc b mt knh. Loi b dch tha bng giy thm. Khng cn c nh bng nhit, tiu bn s c c nh bng chnh thuc nhum. Ph tiu bn bng dch thuc nhum Leifson (ch bng cch pha 100 ml basic fuchsine trong cn ethylic [0,8 g basic fuchsine, 100 ml ethanol 95%] vo 200 ml dung dch acid tannic - mui n trong nc [3 g acid tannic, 1,4 g NaCl, nc ct 200 ml]) trong vng 5 - 15 pht ph thuc vo nhit phng cho n khi thuc nhum kt ta sng trong dung dch. Khng b thuc nhum, ra nh bng nc, vy bt nc ri kh trong khng kh. 3. Tnh trng sinh ha Cc phy khun l nhng vi khun ym kh ty tin, i a s cc chng c phn ng oxidase dng tnh, nhiu loi vi khun thuc chi Vibrio yu cu 0,5 - 3.0% NaCl pht trin. 4. Tnh gy bnh Trong s cc phy khun c nhiu loi c tnh gy bnh ngi, gy vim d dy - rut, tiu chy, bi huyt, nhim trng vt thng. Phy khun t (Vibrio cholerae) v cc phy khun gy vim rut thng gy trng c thc phm. i vi gia sc, khng c i din no trong h ny gy bnh nhng nhiu loi nht nh thuc chi Vibrio, Listonella v Aeromonas biu hin tnh gy bnh c, c ng vt gip xc k sinh v ng vt thn mm hai mnh (trai, hn,...).

II. VIBRIO V TRNG C THC PHMChng ng thc n do phy khun gy vim rut Vibrio parahaemolyticus xy ra vi tn s cao cc nc hay n gi c. Ngoi ra, V. mimicus, V. fluvialis, Aeromonas sorbia, A. hydrophila, Plesiomonas shigelloides c ch nh l nhng vi khun gy ng c thc phm. Trng c thc phm l do n nhng thc phm l c nhim cc vi khun ny. Tiu chy, au bng, nn ma, st l nhng triu chng ca nhim c th cm nhim.

III. BNH CM NHIM VIBRIO1. Bnh cm nhim vibrio (vibriosis) Cm nhim Listonella anguillarum v V. ordalii cc loi c thuc h hi, c mng, l bnh truyn nhim th bi huyt cp tnh. Ton thn xut huyt, vi nhng triu chng in hnh nh c v ton b mt thn th hnh thnh nhng vt lot c m. L. anguillarum trc y c xp vo chi Vibrio nn cc ti liu thng vn gi bnh ny l vibriosis (bnh do Vibrio). 2. Bnh nht c (furunculosis, non-motile aeromonas infection, boil-like ulcer, carp erythrodermatitis ( c chp chu u), ulcer disease ( c hi chu M) L bnh truyn nhim cp tinh, cp tnh do cm nhim A. salmonicida. cc c h Hi thng hnh thnh nhng vt lot c m dng t khp. Thc ra bnh tch hnh thnh trong c v trong cc c quan ni tng. cc loi c


34

thuc h Chp, hnh thnh nhng vt vim da chm , da hoi t lm trc vy m hnh thnh nhng l. ln thng hnh thnh vt lot u. Bng I-15. Phn loi h VibrionaceaeChi Vibrio G+C (mol%) Loi 38 - 51 V. alginolyticus V. ordalii V. vulnipicus V. harveyi V. parahaemolyticus Tnh gy bnh Bnh dc thn u trng tm, bnh dc thn v n mn v chitin tm, bnh xut huyt c Bnh pht sng, thn v n mn v chitin gip xc Bnh pht sng, thn v n mn v chitin gip xc, trng c thc phm ngi Bnh dch t, trng c thc phm ngi,

Aeromonas

57 - 63

Plesiomonas Photobacterium Listonella Shewanella

51 40 - 44 44 - 47

V. cholerae Ngoi ra, c 25 loi khc Mng m, hnh thnh lot c (bnh nht A. salmonicida c) Bnh vim xut huyt m c, bnh A. hydrophila m nu tm cng xanh A. sobria, A. caviae P. shigelloides P. phosphoreum Ngoi ra, c 3 loi khc Bi huyt xut huyt c, bnh thn v L. anguillarum n mn v chitin tm Ngoi ra, c 2 loi khc S. putrefaciens Ngoi ra, c 2 loi khc

3. Bi huyt do aeromonas di ng (motile aeromonas septisemia) A. hydrophila di ng gy bnh truyn nhim cc loi c nc ngt khc nhau, ln gy chng vy, c mng v cc loi thuc h Chp thng gy chng m . cc c b bnh, cc c, ni tng v rut xut huyt. Vi khun ny cn gy bnh m nu tm cng xanh. 4. Nhng bnh do Vibrio khc Ngi ta cho rng V. parahaemolyticus v L. anguillarum gy bnh truyn nhim cc loi tm (bnh thn v n mn chitin v tm), bnh xut huyt c, cua, cn L. anguillarum, V. ordalii, V. vulnipicus v V. alginolyticus gy bnh dc thn u trng tm, bnh thn v n mn chitin v tm, bnh xut huyt c bin, bnh cc loi thn bng hai mnh (trai, hn,...), V. harveyi gy bnh pht sng, thn v n mn v chitin gip xc.

C. H PASTEURELLACEAE I. C IM CHUNG CA H PASTEURELLACEAE1. Phn loi Gn y h mi Pasteurellaceae c thit lp gm ba chi Pasteurella, Actinobacillus, Haemophilus thng gi chung l nhm HAP, chi mi Histophilus (G+C 37 - 39 mol%) v mt s chi mi khc (bng I-16).


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2. c im chung ca h Pasteurellaceae H Pasteurellaceae bao gm cc vi khun nh, Gram m, thng hnh trng bt mu m hai u (bt mu lng cc) khi nhum bng cc loi thuc nhum khc nhau, nhng nhiu khi, c bit khi nui cy ko di trn mi trng nhn to, c th c dng si, cu c vch t bo khng chc chn. Bng I-16: Phn loi hc PasteurrellaceaeChi, loi Chi I. Pasteurella (type genus) Pasteurella multocida (type species) Pasteurella multocida subsp. multocida Pasteurella multocida subsp. gallicida Pasteurella multocida subsp. septica Pasteurella pneumotropica Pasteurella testudinis Pasteurella aerogenes Pasteurella canis Pasteurella dagmatis Pasteurella langaaensis Pasteurella stomatis Pasteurella bettyae Pasteurella caballi Pasteurella mairii Pasteurella trehalosi Pasteurella skyensis Chi II. Actinobacillus Actinobacillus lignieresii (type species) Actinobacillus actinomycetemcomitans Actinobacillus equuli subsp. equuli Actinobacillus equuli subsp. haemolyticus Actinobacillus capsulatus Actinobacillus suis Actinobacillus pleuropneumoniae Actinobacillus hominis Actinobacillus ureae Actinobacillus muris Chng lu tr Type strain: NCTC 10322T (=ATCC 43137T =CCUG 17976T) Type strain: NCTC 10204T (=CCUG 17978T) Type strain: NCTC 11995T (=CIP A125T =ATCC 51687T =CCUG 17977T) Type strain: NCTC 8141T (=ATCC 35149T =CIP 6616T =CCUG 12398T) Type strain: CCUG 19802T (=ATCC 33688T =NCTC 12150T) Type strain: ATCC 27883T (=CCUG 9995T =CIP 80.14T =DSM 10153T) Type strain: ATCC 43326T (=NCTC 11621T =CCUG 12400T) Type strain: ATCC 43325T (=NCTC 11617T =CCUG 12397T) Type strain: ATCC 43328T (=NCTC 11411T =CCUG 15566T) Type strain: ATCC 43327T (=NCTC 11623T =CCUG 17979T) Type strain: CCUG 2042T (=NCTC 10535T =ATCC 23273T) Type strain: ATCC 49197T =CIP 103915T =CCUG 28833T) Type strain: ATCC 33393T (=CCUG 27189T =NCTC 10699T) Type strain: NCTC 10370T (=ATCC 29703T =CCUG 27190T) Type strain: ATCC 13204T (=NCIMB 13593T) Type strain: NCTC 4189T (=ATCC 49236T =CCUG 41384T) Type strain: ATCC 33384T (=CIP 52106T =CCUG 13227T =NCTC 9710T) Type strain: NCTC 8529T (=ATCC 19392T =CCUG 2041T) Type strain: CCUG 19799T (=NCTC 13195T =CIP 107709T) Type strain: NCTC 11408T (=CIP 103283T =CCUG 12396T =ATCC 51571T) Type strain: ATCC 33415T (=CIP 103354T) Type strain: ATCC 27088T (=CCUG 41656T) Basonym: Haemophilus pleuropneumoniae Type strain: CCUG 19800T (=NCTC 11529T) Type strain: NCTC 10219T (=DSM 5568T =ATCC 25976T =CCUG 2139T). Basonym: Pasteurella ureae Type strain: CCUG 16938T (=NCTC 12432T =CCUG


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Actinobacillus seminis Actinobacillus indolicus Actinobacillus minor Actinobacillus porcinus Actinobacillus rossii Actinobacillus delphinicola Actinobacillus scotia Actinobacillus succinogenes Actinobacillus arthritidis Chi III. Haemophilus Haemophilus influenzae (type species) Haemophilus haemolyticus Haemophilus aegyptius Haemophilus parainfluenzae Haemophilus ducreyi Haemophilus haemoglobinophilus Haemophilus aphrophilus Haemophilus parahaemolyticus Haemophilus paraphrophilus Haemophilus parasuis Haemophilus paraphrohaemolyticus Haemophilus segnis Haemophilus paracuniculus Haemophilus felis Haemophilus pittmaniae Chi IV. Lonepinella Lonepinella koalarum (type species) Chi V. Mannheimia Mannheimia haemolytica (type species) Mannheimia glucosida Mannheimia granulomatis Mannheimia ruminalis Mannheimia varigena Chi VI. Phocoenobacter Phocoenobacter uteri (type species) Chi VII. Gallibacterium Gallibacterium anatis (type species) Genus VIII. Histophilus Histophilus somni (type species)

23134T) Type strain: ATCC 15768T (=NCTC 10851T =CCUG 27187T =CIP 105315T) Type strain: CIP 105316T Type strain: CCUG 38923T (=CIP 105314T) Type strain: CCUG 38924T Type strain: ATCC 27072T (=CCUG 12395T =CIP 102634T =NCTC 10801T) Type strain: NCTC 12870T (=CCUG 41362T) Type strain: ATCC 27072T (=NCTC 12922T =CIP 105697T) Type strain: ATCC 55618T (=CCUG 43843T =CIP 106512T) Type strain: CCUG 24862T (=ATCC 13376T) Type strain: ATCC 33391T (=NCTC 8143T =DSM 4690T) Type strain: NCTC 10659T (=ATCC 33390T =CCUG 12834T) Type strain: NCTC 8502T (=CCUG 25716T =ATCC 11116T) Type strain: ATCC 33392T (=CCUG 12836T =NCTC 7857T =DSM 8978T) Type strain: CIP 54.2T (=NCTC 10945T =CCUG 4438T =ATCC 33940T) Type strain: NCTC 1659T (=ATCC 19416T) Type strain: ATCC 33389T (=CCUG 3715T =NCTC 5906T) Type strain: NCTC 8479T (=ATCC 10014T) Type strain: ATCC 29241T (=CIP 70.22T =NCTC 10557T) Type strain: NCTC 4557T (=CCUG 3712T =ATCC 19417T) Type strain: NCTC 10670T (=ATCC 29237T) Type strain: ATCC 33393T (=CCUG 12838T =NCTC 10977T) Type strain: ATCC 29986T (=CIP 107045T =CCUG 43573T) Type strain: ATCC 49733T (=CIP 103890T) Type strain: CCUG 48703T (=NCTC 13334T) Type strain: ATCC 700131T (=DSM 10053T) Type strain: NCTC 9380T (=ATCC 33396T =CCUG 12392T =DSM 10531T). Basonym: Pasteurella haemolytica Type strain: CCUG 38457T (=CIP 106063T) Type strain: ATCC 49244T (=CIP 103433T) Basonym: Pasteurella granulomatis Type strain: CCUG 38470T (=CIP 106062T) Type strain: CCUG 38462T (=CIP 106064T) Type strain: NCTC 12872T (=CIP 106491T =ATCC 700972T =CCUG 47322T) Type strain: ATCC 43329T (=NCTC 11413T =CCUG 26456T =CCUG 15563T) Basonym: Pasteurella anatis Type strain: CCUG 36157T (=ATCC 43625T)


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Chi IX. Volucribacter Volucribacter psittacicida (type species) Volucribacter amazonae Avibacterium gallinarum (type species) Avibacterium avium Avibacterium paragallinarum Avibacterium volantium Chi XI. Nicoletella Nicoletella semolina (type species) Cc nhm phn loi khc c cc chng trong cc b su tp vi khun Pasteurella sp. A Pasteurella sp. B Actinobacillus genomosp. 2 'Actinobacillus porcitonsillarum' Gallibacterium genomosp. 1 Taxon 2 Taxon 3 Taxon 5 Taxon 6 Taxon 7 Taxon 8 Taxon 10 Taxon 14 Taxon 16 Taxon 17 Taxon 26 (Avian haemolytic Actinobacillus-like)

Type strain: CCUG 47536T (=DSM 15534T) Type strain: CCUG 47537T (=DSM 15535T) Type strain: NCTC 11188T (=ATCC 13361T =CCUG 12391T) Basonym: Pasteurella gallinarum Type strain: NCTC 11297T (=ATCC 29546T =CCUG 12833T) Basonym: Haemophilus avium Type strain: NCTC 11296T (=ATCC 29545T =CCUG 12835T) Basonym: Haemophilus paragallinarum Type strain: NCTC 3438T (=ATCC 14385T =CCUG 3713T) Basonym: Pasteurella volantium Type strain: CCUG 43639T (=DSM 16380T)

CCUG 18782 CCUG 19794 CCUG 15571 CCUG 46996 CCUG 23139 CCUG 15564 (=CCUG 36325 =NCTC 11414) NCTC 11412 (=CCUG 15565) CCUG 16493 CCUG 15568 CCUG 24852 CCUG 16494 CCUG 15572 CCUG 16499 CCUG 17204 CCUG 17206 CCUG 28015

Cc vi khun thuc h ny pht trin chm trn cc mi trng dinh dng, nhiu loi v chng yu cu yu t sinh trng. Khun lc thng nh, trn, biu hin mu sc v hnh dng b mt khc khc nhau.

II. H PASTEURELLACEAE V BNH TRUYN NHIM1. c im vi sinh vt hc ca cc Pasteurella Thuc chi ny c t nht 11 loi khc nhau bn cnh mt s chng cha xc nh chi (bng I-16). Bn cnh , loi trc y tng c gi l "Pasteurella anatipestifer" nay c sp xp li v thuc chi mi thit lp Riemerella, tc l loi ny c tn mi l R. anatipestifer, thuc nhm vi khun thng gi l "t hp Flavobacterium-Cytophaga" (Flavobacterium-Cytophaga complex) khng phi l i tng ca phn ny (xem phn "Trc khun Gram m ym kh ty tin khc").


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a. Hnh thi Pasteurella l nhng vi khun nh bt thng (0,3 - 1 1 - 2 m), hnh cu, hnh trng hoc hnh que, Gram m, khng di ng, khng hnh thnh nha bo, phn b ring l hoc chui ngn, i khi a hnh thi, thng biu hin tnh bt mu lng cc (hai mu nhum mu r hn). i a s cc vi khun mi phn lp c gip m. Trn mi trng thch thng, khun lc c ng knh 1 - 4 mm, hnh trn, hi c, mu trng xm, i khi xut hin cc khun lc ly gii. Nhng vi khun hnh thnh gip m thng rt nhy, nu chiu xin gc khun lc v quan st qua knh hin vi c phng i nh th thng thy s pht mu hunh quang (hin tng dung quang). b. Tnh trng sinh ha Cc Pasteurella pht trin tt iu kin ym kh ty tin trn cc mi trng c thm mu hoc cc sn phm protein phn gii. Chng phn gii cc ng nh ln men, hnh thnh acid nhng khng sinh hi. Phn ng hon nguyn nitrate dng tnh, oxidase v catalase dng tnh, ty loi c th sinh indol v phn gii urea. Gelatinase m tnh. Hm lng G+C (mol%) l 37 - 45. Pasteurella multocida c 5 loi khng nguyn gip m k hiu A, B, D, E v F (theo phn loi ca Carter, 1957) v 16 loi khng nguyn thn, k hiu t 1 n 16 (theo phn loi ca Heddleston et. al, 1972), kt hp cc loi khng nguyn ny c th phn cc vi khun ny thnh cc dng huyt thanh hc khc nhau. P. hemolytica do cc i din c tnh trng sinh ha v sinh vt hc xa nhau nn c phn thnh hai nhm (A v T), c n 16 loi khng nguyn gip m, 4 loi khng nguyn thn (A, B, C, D) tn ti, c th phn thnh cc nhm huyt thanh hc khc nhau tng t nh trn. Gn y, dng sinh hc (biovar) T ca P. hemolytica c phn loi li thnh loi mi c lp ca chi ny: loi P. trehalosi. Bng I-17. Cc loi Pasteurella k sinh v k ch ch yuLoi P. multocida P. dagmatis P. gallinarum P. volantium P. species A P. species B P. canis P. stomatis P. avium P. langa P. anatis P. pneumotropica P. haemolytica P. trehalosi P. piscicida" Loi ph multocida septica gallicida ng vt k ch ch yu ng vt c v, ngi, chim ng vt c v, ngi, chim Chim Ngi, ch, mo G G, ngi Gia cm Ch, mo,ngi Ch, ngi, b, ngh Ch, mo, ngi G G Vt Chut nht, chut cng B, tru, cu, d Cu, tru, b C


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c. Tnh gy bnh Cc Pasteurella gy bnh cm nhim cc loi ng vt, chim v c khc nhau vi nhng th bnh khc nhau. P. multocida v P. trehalosi l nhng vi khun gy bnh nguyn pht, gy cc chng bi huyt xut huyt (bnh t huyt trng) cc loi ng vt khc nhau, gy bnh teo mi truyn nhim (atrophic rhinitis - AR) ln, vim phi, cc bnh ng h hp v bi huyt nh l nhng yu t gy bnh nguyn pht hoc th pht. Cc loi Pasteurella khc thng phn lp c nh nhng yu t gy bnh th pht. Tnh gy bnh ca cc Pasteurella lin quan n dng huyt thanh hc cng nh dng sinh hc. Cc chng c gip m c c tnh cao hn cc chng khng c gip m, do kh nng khng b th khc nhau. Ni c t do vi khun sn sinh lin quan n t l cht do chng bi huyt. c t (gy) hoi t da (dermonecrotic toxin - DNT) do P. multocida sn sinh ra l c t khng chu nhit gy ra chng teo mi ln. Cn P. hemolytica li c bit l sinh ra cytotoxin (c t c t bo) v ngoi c t ny cng lin quan n tnh gy bnh. 2. Bnh cm nhim Pasteurella a. Bnh t huyt trng (pasteurellosis, hemorrhagic septisemia - bi huyt xut huyt)BKD26 Do cc vi khun P. multocida c khng nguyn gip m B v E cm nhim tru b cc nc nhit i l bnh truyn nhim bi huyt cp tnh, hm di sng to do ph thng, tuyn lympho sng to, xut huyt, di da, ni tng b mt cc tng mc ton thn thng xut huyt im. Bng I-18. Cc bnh ng vt tiu biu do cm nhim PasteurellaTn bnh T huyt trng tru b Vim phi tru b (st chuyn ch) Bnh do pasteurella d cu Bnh t huyt trng ln Bnh t huyt trng gia cm Bnh ngt mi th Bnh do pasteurella ng vt th nghim Bnh gi lao c Bnh nguyn P. multocida P. multocida P. haemolytica P. haemolytica P. trehalosi P. multocida P. multocida P. multocida P. multocida P. pneumotropica "P. piscida"* ng vt cm nhim B, tru B, tru B, tru D, cu Cu non Ln Chim Th Chut lang Chut nht, chut cng C nc, c bin khc Bnh trng Sng hu, bi huyt xut huyt Vim phi Vim phi Vim phi, bi huyt Bi huyt Vim phi, vim mi teo dn Tiu chy, bi huyt xut huyt hoc khng xut huyt Vim mi, vim phi Vim phi nung m im trng nh ni tng

b. Vim phi tru b (pneumonia in bovine)BKD26 P. hemolytica c lp hoc phi hp cc vi khun khc gy ra. Thng thng, y l bnh cm nhim hn hp gy ra bi Pasteurella, virus v Mycoplasma, thng c gi l "st chuyn ch (shipping fever)" ph bin b hn tru.


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c. Bnh do Pasteurella d cu (pasteurellosis in sheep and goat)BKD26 Cng cn gi l bnh t huyt trng d cu, thng l chng vim phi do P. hemolytica v chng bi huyt do P. trehalosi d cu non. d. Bnh do Pasteurella ln (pasteurellosis in swine)BKD26,40 Vim phi v teo mi hoi t truyn nhim ln do l nhng bnh trng yu, cn gi l (cc th) bnh t huyt trng ln. Chng vim phi thng do P. multocida n c hoc phi hp cc loi vi khun. Chng teo mi hoi t truyn nhim (atrophic rhinitis of swine) ch yu l do cc vi khun P. multocida dng D huyt thanh hc (serotype D) sn sinh c t hoi t da gy ra mt cch n c hoc phi hp vi vi khun Bordetella bronchiseptica l bnh tin trin mn tnh lm teo dn xng xoang mi ca ln b cm nhim. e. Bnh t huyt trng gia cm (fowl cholera)BKD26 L bnh truyn nhim do P. multocida gy ra hu ht tt c cc loi chim khc nhau. Trong trng hp cp tnh, gia cm thng cht do chng bi huyt xut huyt. Mc d y l mt trong nhng i tng ch vaccine phng bnh u tin nhng cho n nay vic ch vaccine hiu qu phng bnh ny vn cn l mt trong nhng vn nan gii nht ca min dch hc hin i. f. Bnh do Pasteurella ng vt th nghim (pasteurellosis in experimental animals)BKD26 Gy ra bi P. multocida th bnh ngt mi (snuffles) v P. pneumotropica chut nht, chut cng chng nung m. Bnh ngt mi th thng km theo vim tai, vim kt mc, vim phi, i khi cht do chng bi huyt. g. Bnh gi lao c nc (pseudotuberculosis in yellowtail, pasteurellosis in yellowtail) L bnh c trng bi nhng m trng nh (hch lao gi) xut hin nhiu lch v thn. Yu t gy bnh l "Pasteurella piscicida" hin nay khng cn xp vo chi Pasteurella na. (Du ngoc kp ca tn khoa hc trong ch rng tn cha c cng nhn chnh thc, tc l cha ng k tp ch "International Journal of Systematic Bacteriology", trc 1/2000, nay i thnh "International Journal of Systematic and Evolutionary Microbiology", t 1/2000 ca Hi Vi sinh vt hc Quc t).

III. HAEMOPHILUS V BNH TRUYN NHIM1. c im chung ca Haemophilus a. Phn loi Haemophilus l nhng trc khun Gram m, i hi yu t V (hemin hoc mt porphyrin khc) hoc yu t X (NAD: nicotinamide adenosine dinucleotide) hoc c hai yu t pht trin. Nh cc th nghim tnh tng ng DNA m loi ny c tch ra ring bit. "Haemophilus somnus" l loi khng cn hai yu t pht trin k trn, ng thi cng nh cc th nghim v tnh tng ng DNA m vi khun c tch khi chi Haemophilus. Mc d vy, thun tin


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ngi ta cn s dng tn c ny. b. Hnh thi Gram m, hnh cu nh hay hnh que ngn (0,2 - 0,5 0,5 - 1,5 m), thng thng c tnh a hnh thi v tnh lng cc, i khi biu hin dng si. a s loi c gip m, khng hnh thnh nha bo, khng c tim mao. Kh nng ngng kt hng cu ca cc chng H. influenzae l nh c cc lng nhung (fimbria hay pili). Trn mi trng thch (c cha yu t sinh trng cn thit) hnh thnh khun lc sau 48 gi nui cy, c ng knh 0,5 - 2,0 mm, hi dt hoc trn li. S pht trin cng c thc tin di iu kin kh quyn c 5 - 10% CO2. Nh sn sinh yu t V, khun lc t cu vng Staphylococcus aureus thng thc y s pht trin ca khun lc Haemophilus vng cn k (hin tng v tinh). c. Tnh trng sinh ha Cc Haemophilus l nhng trc khun nh khng di ng, khng khng acid, hiu kh hoc ym kh ty tin, a s loi i hi mt hoc c hai yu t sinh trng V v X. Cc Haemophilus phn gii cc ng nh ln men. Cc phn ng oxidase v catalase khc nhau ty thuc loi v chng. Phn ng hon nguyn nitrate dng tnh. Chng c tnh k sinh ng vt,

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