PSEUDOMONAS

Introduction

Large group of aerobic non sporing gram negative motile by polar flagellaubiquitousoppurtunistic infectionsnewer genera-Burkholderia Stenotrophomonas

SpeciesPseuomonas aeruginosaStenotrophomonas maltophilaBurkholderia cepaciaBurkholderia malleiBurkholderia pseudomallei

Pseudomonas aeruginosaMorphologyslender,Gram negative bacillussize-1.5 microns-3*1.5micronsmotile by polar flagellanon capsulated though some mucoid strains may sometimes occursome are pilated

Cultural characteristicsObligate aerobeWide range of temperature 5c-42c optimum 37cOrdinary media large,opaque,irregular,with distinctive musty,mawkish,earthy smell

Cont..Nutrient agar-Colonies are smooth,large,translucent,low convex,2-4mm in diameter.Produce sweetish aromatic odourGreenish blue pigment diffuses

Cont..Blood agarSimilar to nutrient agar Many are haemolyticMac conkey agarColourless,non lactose fermentersCetrimide agar selective media

Pigment productionPyocyaninBluish green phenazine pigment Soluble in chloroform and waterNot produced by other speciesPyoverdin(fluorescin)It is a greenish yellow pigment Insoluble in chloroform but soluble in waterProduced by many other species

Pyocyanin Pyoverdin

Cont..PyorubinReddish brown pigment Insoluble in chloroform but soluble in waterpyomelaninBrown to black pigmentProduction is uncommon

Biochemical reactionsO/F test-oxidativeCatalase-positiveOxidase-positiveNitrate reduction-positive

Cont..Indole test-negativeMethyl red test-negativeVp test-negativeCitrate test-positiveUrease test-negative

ContSugar fermentation testsGlucose-only acid Lactose-negativeSucrose-negativeMannitol-negative

ResistanceSusceptible to heat,killed at 55c in one houracidsbeta glutarldehydeSilver saltsstrong phenolic disinfectantsSo,silver sulphonamide as a topical cream in burns is used

ContResistant to chemical agents common antiseptics disinfectants -ammonium compounds chlroxylenolhexachlorophane antibiotics -aminoglycosides cephalosporins pencillins

Antigenic structureO antigensPossesses 19 distinct,group specific O antigensHeat labileH antigens Two heat labile antigens recognised in Ps.aeruginosa

Toxins and enzymesExtracellular products Pyocyanin inhibits mitochondrial enzymes and causes disruption and cessation of ciliary beat on ciliated nasal eptheliumExtracellular enzymes and haemolysins Produces proteases,haemolysins and lipasesExotoxins Produces two exotoxns A and SEndotoxins It is a lipopolysaccharide have pyrogenic action

Typing methodsBacteriocin typingThree types of bacteriocins are produced-R,F,SPyocin produced by test strain is employed to assess the growth inhibition of 13Depending upon the growth inhibition of 13 indicators strains,105 types are recognisedMost popular method used

Phage typing Serotyping based on O and H,17 serotypes of Ps.aeruginosa are recognisedMolecular Method Restriction endonuclease typing with pulsed-field gel electrophoresis(PAGE) is most reliableCont..

PATHOGENESISImportant agent in causing nosocomial infectionsMost common infections are Urinary tract infections following catheterisationAcute purulent meningitis following lumbar puncturePost-tracheostomy pulmonary infectionSepticaemia in debilitated patients

cont..Wound and burn infectionsChronic otitis media and otitis externaEye infectionsAcute necrotising vasculitis Infantile diarrhoea

Mechanism Of PathogenesisCaused by exotoxins,proteases,elastases,haemolysins,lipases and enterotoxinsExotoxin A-lethal toxinElastases-haemorrhagic lesions Enterotoxins-diarrhoeal diseaseSlime layer acts as a capsule and enhances virulence

Thank you

HAEMOPHILUSINTRODUCTION

HAEMOPHILUS INFLUENZAEMORPHOLOGYSMALL [ 1.0 X 0.3 MICRONS]GRAM NEGATIVENON MOTILENON SPORINGEXHIBIT PLEOMORPHISM

CULTURAL CHARACTERISTICSFACTOR XHEAT STABLE

HEMIN

AEROBIC RESPIRATIONFACTOR VHEAT LABILE

BACTERIAL VITAMIN

ANEROBIC RESPIRATION

CONTAEROBICGROWS ANEROBICALLY ALSOOPTIMUM TEMPERATURE-37CSOME STRAINS REQUIRE 10% CO2BLOOD AGAR-SCANTY GROWTH

SATELLITISMStaph.aureus is streaked across a plate of blood agar on which a specimen containing H.influenzae has inoculatedAfter overnight incubation-Colonies large -along the streak of Staph.aureus small farther away

satellitism

CONTLEVINTHAL`S MEDIUMBoiling and filtering a mixture of blood and nutrient brothCapsulated strains produce translucent coloniesFILDES AGARBy adding a peptic digest of blood to nutrient agarBest for primary isolationCopious growth

BIOCHEMICAL REACTIONSCatalase-positive

Oxidase-positive

Glucose,Xylose-fermented with acid production

Lactose,Sucrose,Mannitol-not fermented

RESISTANCEDestroyed by heating refrigeration drying disinfectantsCultures may be preserved for about a month on choclate agar slopes in screw capped bottlesLong term preservation culture may be lyophilised

ANTIGENIC PROPERTIES3 Major surface antigens Capsular polysaccharide Outer membrane protien Lipo oligosaccharideMajor antigenic determinant of capsulated strains Capsular polysaccharidePittman classified into 6 capsular strains i.e type a to f

Meningitis belong to type b strainType b strain contains pentose sugars ribose &ribitol instead of hexoses & hexosamines in other 5 serotypesCapsular polyribosyl ribitol phosphate antigen of Hib induces IgG IgM IgA antibodies which are bactericidal and protective

CONT.Strains lacking a capsule cannot be typed and are called NON TYPABLE STRAINSOuter membrane protein antigens of H influenzae type b have been classified into 13 sub typesLipo oligosaccharides are antigenically complex

PATHOGENECITYExclusively human pathogen Not pathogenic for animals but intra peritoneal inoculation of large doses is fatal in mice,guinea pigs &rabbitsDiseases due to H influnzae considered under 2 groups invasive and non invasive

INVASIVESpread through Blood

Meningitis,arthritis, endocardits,conjuctivitis,pancarditis

Seen in children

Caused by capsulated strains NON INVASIVE Spread through local invasion

Otitis media,sinusitis

Seen in adults

Caused by non capsulated strains

CLINICAL MANIFESTATIONSMENINGITISBacilli reach meninges from nasopharynx through blood streamCommon in children

LARYNGO EPIGLOTTISAcute inflammaton of epiglottis with obstructive laryngitisChildren above 2 years

CONT.PNEUMONIAInfants accompanied by empyemaOlder children & adults by lobar pneumonia These are primary infections due to capsulated strainsBroncho pneumonia may occur as secondary infection due to non capsulated strains

CONTSUPPURATIVE LESIONSArthritis,endocarditis& pericarditis may result from hematogenous disseminationOtitis media occurs by direct spread from nasopharynxBRONCHITISAssociated with pneumococci in acute exacerbationof chronic bronchitis &bronchiectasis

LAB DIAGNOSIS1.SPECIMENSCSFBlood Throat swabSputumPus Aspirates from joints ,middle ears

2.COLLECTION &TRANSPORTCollected in sterile containers & under aseptic conditionsVery sensitive to low temp so should not be refrigeratedTransported to laboratory with out delayInoculated on culture media immediately

CONT.....3.DIRECT MICROSCOPYGram stainingImmunoflouroscence and quellung reactionAntigen detectionLatex agglutinationCo-agglutinationCounter immuno electrophoresis

CONT 4.CULTURECSF cultureBlood cultureSputum culture5.COLONY MORPHOLOGY AND STAINING6.SEROTYPING

TREATMENTCefotaxime & Ceftazidime is the drug of choice for meningitisAmpicillin &Cotrimoxazole respiratory infectionsAmoxycillin - clavulanate or clarithromycin is more effective

EPIDEMIOLOGY & PREVENTIONInfection transmitted by respiratory routeImmunity is type specific Active immunization with Hib PRP vaccine is indicatedConjugate Hib PRP is used for younger childrenRifampicin -4 days prevents secondary infection in contacts & also eradicates carrier state

Haemophilus aegyptiusKOCH WEEKS BACILLUSNon capsulatedCauses highly contagious form of conjuctivitis [ pink eye ]Causative agent of Brazilian purpuric fever [BPF] Responds to local sulphanamides & gentamicin

Haemophilus ducreyiDucrey demonstrated in chancroid lesionsShort ,ovoid bacillus Gram nagative often may appear gram positive & frequently show bipolar stainingMay be arranged in small groups or whorls or in parallel chains giving a SCHOOL OF FISH or RAIL ROAD TRACK appearance

CONTCan be grown on fresh clotted rabbit bloodMay also grown on chorio allontioc membrane of chick embryoOn choclate agar enriched with isovitalex and fetal calf serum & containing vancomycin as a selective agentForms small ,grey ,translucent colonies after incubation at 35 c under 10 % co2 & high humidity in 2 8 days

CONTAntigenically homogenous Cultures may be identified by agglutinatoin with anti serumSusceptible to sulphonamides & many antibioticsErythromycin ,Cotrimoxazole ,Ciprofloxacin may be used for treatment

Choclate agar

Haemophilus parainfluenzaeRequires factor V & not the factor XCommensel in the upper respiratory tract Causes bacterial endocarditis ,urethritis ,acute pharyngitis

Haemophilus haemolyticusRequires both factor X & VCommensal of upper respiratory tractStrains that donot require factor X have been designated as H parahaemolyticus

Haemophilus aphrophilusRequires factor X but not factor V Cause bacterial endocarditis ,brain abscess ,sinuisitis pneumoniaStrains requiring factor V but not factor X have been termed as H paraaphrophilus

HACEK group bacteriaFastidious slow growing bacteria H - Haemophilus species A - Actinobacillus C - Cardiobacterium hominis E - Eikenella corrodens K - Kingella kingae

Thank you

*