Nonfermentative GNB Flashcards
(29 cards)
Where are nonfermentative GNB found and what percent of all GNB are nonfermentative GNB (NFB)?
- water, soil, food, plants, few are normal flora in humans
- 20%
List general traits of NFB
oxygen requirement
sporulation
carb metabolism
oxidase
TSI
Grow on what plate(s)
- obligate aerobes
- don’t form spores
- don’t ferment carbs
- most are oxidase pos
- TSI: K/no change
- SBA and varied MAC growth
Most important NFB
Pseudomonas aeruginosa
Pseudomonas fluorescent group
- P. aeruginosa
- P. fluoresceins
- P. putida
All members of Pseudomonas fluorescent group produce ____ pigment
fluorescein aka pyoverdin
yellow fluorescent pigment
____ agar enhances fluorescein production
Cetrimide
P. aeruginosa disease association
- eye (contact lens) infections
- ear infections (swimmers ear)
- cystic fibrosis lower resp tract infection
- burn wound infections
- immunocomprosmised pt
How does P. aeruginosa fare against disinfectants?
- resistant to a lot of disinfectants
- nosocomial infections in hospitals, equipment, whirlpools, and swimming pools
P. aeruginosa biochemical traits
oxidase
motility
lactose
growth temp
grows on MAC?
colony color
- oxidase pos
- motile
- lactose neg
- 42°C
- yes, grows on MAC
- bluish green pigment
P. aeruginosa virulence factors
- Pili
- LPS endotoxin
- Exotoxin A
- extracellular alginate slime to inhibit phagocytosis
- proteolytic enzymes
- intrinsic antimicrobial resistance
P. aeruginosa colony morphology
- large irregular colonies with grape-like odor and metallic sheen on SBA
- beta hemolytic with feathery edge on SBA
- mucoid colonies if isolated from CF pt
- pyocyanin blue pigment unique
Stenotrophomonas maltophilia disease association
- pneumonia
- UTIs
- wound infections
How is S. maltophilia acquired?
hospitals
S. maltophilia identifying traits
oxidase
maltose
lysine decarboxylase
antimicrobial resistance
- oxidase neg
- one of only NFB that is oxidase neg and maltose pos
- one of 2 NFB that is lysine decarboxylase positive
- resistant to most Abx
Burkholderia cepacia disease association
- nosocomial infections
- CF pt (2nd to P. aeruginosa)
B. cepacia enhanced on ____ agar, which inhibits _____
- PC
- P. aeruginosa
B. cepacia colony morphology
colorless or yellow on nutrient agar
B. cepacia biochemical traits
oxidase
lactose
lysine decarboxylase
- oxidase pos
- lactose pos
- lysine decarboxylase pos
Burkholderia mallei disease association
glanders disease of livestock (horses, mules, donkeys)
B. mallei transmission and gov’t status
- animal contact transmits to humans
- potential bioterrorism agent
B. mallei biochemical traits
growth on MAC
oxidase
motility
nitrate reduction
glucose OF
- grows on MAC
- oxidase variable
- nonmotile
- reduces nitrate to nitrite without gas
- oxidizes glucose
Burkholderia pseudomallei disease association
- Melioidosis
- endemic to southeast Asia and northern Australia
B. pseudomallei is found where?
soil
infections acquired thru skin or inhalation tho
B. pseudomallei biochemical traits
growth on MAC
oxidase
motility
reduction of nitrate
carb OF
- grows on MAC
- oxidase pos
- motile
- reduces nitrate to nitrite with gas
- oxidizes glucose and lactose
