Pseudomonas and Nonfermenting Misc. Flashcards
Pseudomonas and Nonfermenting and Misc. Gram-negative bacilli
- may or may not grow on MacConkey
- don’t ferment sugars
- some oxidize saccharolytic sugars
- oxidase positive
- TSI slants K/K (nonfermenters)
- use O/F media
Nonfermenting means it doesn’t ferment _______
glucose
Pseudomonas and Nonfermenting (source)
- found in environment (soil, water, plants)
- lots of nosocomial infections
- prefer moist environments (nebulizers, catheters, etc.)
- rarely part of normal flora
Pseudomonas and Nonfermenting (treatments)
- can withstand chlorohexidine and ammonium cleaning products
- resistant to multiple antibiotics
Pseudomonas and Nonfermenting (clinical infections)
**usually in hospitalized patients** septicemia meningitis osteomyelitis wound infections
Three clinically important bacteria of group
Pseudomonas aeruginosa
Acinetobacter species
Stenotrophomonas maltophilia
- fluorescent group
- grape-like odor, blue-green hue, beta-hemolytic
- oxidase + and catalase +
- oxidizes carbohydrates
Pseudomonas aeruginosa
Pseudomonas aeruginosa (virulence factors)
- Endotoxin in LPS, exotoxins (Exotoxin A)
- motile, pili, capsule
- proteases, hemolysin, lecithinase, elastase, DNase, alginate
Exotoxin A
similar to diphtheria toxin - blocks proteins synthesis
Pseudomonas aeruginosa (clinical infections)
- wound infections and burns
- pulmonary infections, pneumonia (CF patients)
- nosocomial UTI’s and bacteremia
- endocarditis, Keratitis
- Hot tub syndrome
Pseudomonas aeruginosa (general characteristics)
- beta-hemolytic on SBA
- produces pyoverdin (fluorescence) and pyocyanin (green hue)
- Arginine dihydrolase (ADH) +, citrate +
- grows at 42C
- acetamide utilization
- very drug resistant
Drugs to use on Pseudomonas aeruginosa
aminoglycosides work best; drug combo for severe infections
P. fluorescens and P. putida
part of fluorescent group (pyoverdin); low virulence (UTI’s, wounds); doesn’t grow at 42C
P. stutzeri, P. mendocina, P. pseudoalcaligenes, P. alcaligenes, P. luteola, P. oryzihabitans
Nonfluorescent group (Pseudomonas)
P. stutzeri
wrinkled colonies, light yellow or brown arginine dihydrolase (ADH) -, starch hydrolysis +
Acinetobacter (source)
sometimes normal flora
environment (soil, water)
hospitals (ventilators, humidifiers)
strict aerobe, glucose oxidizer gram-negative coccobacilli oxidase - and catalase - non-motile, smooth, non-hemolytic, NLF, purple (on Mac) resistant to antibiotics
Acinetobacter baumanii
Acinetobacter baumanii (clinical infections)
UTI’s, pneumonia, endocarditis, septicemia, meningitis, wounds, burns, eye infections
A. lwoffii
less virulent
glucose negative
non-hemolytic
more susceptible to antibiotics
Stenotrophomonas maltophilia (sources)
environment (soil, water)
hospitals (blood drawing equipment, disinfectants, etc.)
Stenotrophomonas maltophilia (clinical infections/treatment)
pneumonia, endocarditis, bacteremia
SXT (sulfa drugs) is drug of choice
- rough colonies, lavender-green, ammonia odor (SBA)
- NLF on Mac
- catalase + and oxidase -
- DNase +, Esculin +, Lysine decarboxylase (LDC) +, Gelatin hydrolysis
Stenotrophomonas maltophilia
- nosocomial pathogen (pneumonia in CF patients)
- wound infections from contaminated water
Burkholderia cepacia
- oxidase variable (weak, slow positive)
- motile, ONPG positive, LDC +, ODC -, ADH -
- utilizes lactose, maltose, glucose and mannitol
- yellow or green on SBA, non-wrinkled
- selective agars: OFPBL, BCSA
- multi-drug resistant
B. cepacia
