Acinetobacter, Stenotrophomonas,and Similar OrganismsChapter 21 General characteristics Epidemiology Pathogenesis Laboratory diagnosis Acinetobacter Stenotrophomonas maltophilia Pseudomonas luteola andPseudomonas oryzihabitans Burkholderia gladioliGeneral Characteristics Grow on MAC e!cept C"C gro#p $O%1& 'hey pre(er and grow m#ch better in an aerobic en)ironment Some gro#p members o!idi*e carbohydrates to deri)e energy (or their metabolism + O!idi*ers Others do not brea, down carbohydrates at all and are inert or biochemically inacti)e + nonoxidizers or asaccharolytic $on(ermenters Either o!idi*e gl#cose or do not #tili*e gl#cose asaccharolytic&O- Medi#m'est the ability o( the organism to #se carbohydrates s#bstrates gl#cose& to prod#ce acid by prod#ctsFermentative: Change in color in both t#bes. Enterobacteriaceae, Vibrio, Aeromonas, Plesiomonas and ChromobacteriumOxidative: Change in color in t#bes w/o#t mineral oil Open t#be&

Acinetobacter, Stenotrophomonas, Pseudomonas, BurkholderiaNonsaccharolytic : $o change in color in both t#bes. Alcaligenes , OligellaEpidemiology 0nhabit en)ironmental niches $at#ral 1 hospital en)ironment Opport#nistic pathogens 2#man s,in coloni*er 'ap water and saladsPathogenesis Opport#nistic $o )ir#lence (actors ,nown Common coloni*ers o( hospitali*ed patients 3is, (actors45 0mm#nos#ppression5 'ra#ma5 -oreign body implantation5 0n(#sed li6#ids $osocomial Laboratory diagnosis Specimen collection transport 1 processing4 no special considerations "irect detection4 Gram Stain C#lt#re45 MAC, 78 Sheep 9lood 1 C2OC5 9lood c#lt#re systems, thioglycollate 1 920 0nc#bation4 9AP + :7oCAcinetobacter 2nd most commonly isolated $- bacilli -amily Mora!ellaceae 2a)e the tendency to resist alcohol denat#ration Microscopy45 Pl#mp Gram %& coccobacilli, appear in pairs5 Can appear as gram positi)e cocci in smears made (rom blood c#lt#re bottles C#lt#re45 MAC;p#rplish colonies;$L-, might be mista,en (rom lactose (ermenters5 9AP;9#bble g#m colonies smooth, opa6#e, raised, creamy 1 smaller than enterobacteriaceae&;some are beta%hemolytic 9iochemical45 Strict aerobic 1 nonmotile5 Catalase positi)e, o!idase negati)e5 Optim#m growth < :=%:7oC> p2 7.7%?.= 3elated in(ections4 @'0, pne#monia, endocarditis, meningitis 1 cell#litis Species45 A. baumanii; gl#cose%o!idi*ing> nonhemolytic5 A. lwo; nongl#cose%o!idi*ing> nonhemolytic5 A. hemolyticus; gl#coseo!idi*ing> hemolyticStenotrophomonas maltophilia :rd most commonly isolated $L- 0solated (rom plant materials, water, mil,, (ro*en (ood 1 sewage Strictly aerobic motile with growth < A2oC Can contaminate blood drawing equipments 1 disin(ectants BmaltophiliaC;maltose%lo)ing> prod#ce acid with maltose 1 not gl#cose Microscopy45 Short to medi#m si*e Gram negati)e straight rods C#lt#re45 9AP;la)ender%green to light p#rple pigment with Cammonia smellC5 920Dtyrosine;brown pigment 9iochemical test45 O!idase%&$L-5 Positi)e4catalase, "$Ase, esc#lin and gelatin hydrolysis 1 Lysine"ecarbo!ylase Assoc. with Cpse#doin(ectionsC;as a res#lt o( contaminated blood collection t#bes S#sceptible to SE' dr#g o( choice (or most in(& Antimicrobial tests45 9roth microdil#tion5 Etest9roth microdil#tionEtestPseudomonas luteola andPseudomonas oryzihabitans Pseudomonas luteola (ormerly Chryseomonas luteola! Pseudomonas oryzihabitans (ormerly "la#imonas oryzihabitans!5 (o#nd in Fapanese rice paddies and has been isolated (rom hospital drains and respiratory therapy e6#ipment5 isolated in eye c#lt#res and was described as the ca#se o( Bstic,y eyeC gram%negati)e, non(ermentati)e, Catalase positi)e and motile, o!idi*e gl#cose and other s#gars, MAC agar4 intracell#lar nondiG#sible yellow pigmentBurkholderia gladioli Primarily a plant pathogen (o#nd in patients with C- and chronic gran#lomato#s disease motile by means o( one or two polar Hagella catalase and #rease positi)e o!idi*es gl#cose, is mannitol positi)e and decarbo!ylase negati)e