Pseudomonas, other Gram neg rods Flashcards
What are two microbiological characteristics that definitively indicate Pseudomonas?
Non-lactose fermenting
Oxidase positive
Where do you find Pseudomonas?
Everywhere in the environment
Almost anything in the hospital can be contaminated
What are the cell surface virulence factors associated with Pseudomonas?
Pili, flagella (adherence)
LPS (sepsis)
Polysaccharide capsule
What are the extracellular enzymes/toxins associated with Pseudomonas?
Exotoxin A
Type III secreted toxins
Degredative enzymes (Phospholipase C, elastase, cytotoxin)
What are some diseases caused by Pseudomonas infection?
Pneumonia (almost always health care associated) Bacteremia Endocarditis Skin/Soft tissue infections Bone infections UTI Otitis externa (swimmer's ear)
What is a visible clue of Pseudomonas bacteremia?
Ecthyma gangrenosum (not specific to Pseudomonas but gives a clue) - Looks like punched out lesion
How can you tell a Pseudomonas infection of a burn patient?
Blue green exudate
Grape smell
What can you contract from a hot tub?
Folliculitis due to Pseudomonas
Puritic tender pustules
When will you usually get osteomyelitis due to Pseudomonas?
Sternum (due to surgery where they cracked open sternum)
Have to remove entire bone to treat this
What drugs can be used to treat Pseudomonas?
Piperacillin/Tazobactam
Ciprofloxacin
3rd/4th gen cephalosporin (Ceftazidime, Cefepime)
Carbapenems (except Ertapenem)
Aminoglycosides (used in conjunction with B lactam)
Aztreonam
Polymyxins (important for multidrug resistant organisms)
How can you differentiate Acinetobacter from Pseudomonas?
Both are non-lactose fermenting
Aceinetobacter is oxidase negative (unlike Pseudomonas)
Why are we worried about Acinetobacter now?
Very resistant to many drugs
What environment does Acinetobacter prefer v. Pseudomonas
Acinetobacter - dry conditions
Pseudomonas - wet conditions
What treatment is used for Stenotrophomonas maltophila?
TMP/SMX
