Klebsiella Pneumoniae Flashcards
Enterobacteriaceae characteristics
Glucose fermenters, catalase positive, oxidase negative,
How to distinguish K. pneumoniae from E. coli?
K. pneumoniae is indole negative
Where are klebsiella located?
Human lower GI tract, skin, and female genitals. Produce disease when access sterile sites.
What does Klebsiella pneumoniae cause?
UTI, pneumonia, intra-abdominal infections
Klebsiella on MacConkey plate.
Lactose fermenter (like E. coli) produce pink colonies.
Klebsiella characteristics under microscope
Non-motile, encapsulated (virulence factor), gram negative bacilli.
Describe Klebsiella capsule
Mucoid polysaccharide capsule to evade phagocytosis. Has hypermucoviscous isolates, string test. Must important virulence factor.
O antigen
LPS
Siderophore
Another main virulence factor, capable of sequestering iron
Type 1 pili
Mediates adherence to epithelium
Type 3 pili
Mediates bilifilm production
Pneumonia caused by Klebsiella
Hemorrhagic, necrotizing upper lobar pneumonia, associated with somewhat immunocompromised hosts (diabetes), very deadly (50% mortality)
Spontaneous peritonitis
Common in patients with cirrhosis and other liver diseases (Klebsiella is the 3rd most common isolated organism)
Secondary peritonitis
Associated with abdominal organ inflammation (generally after surgery). Klebsiella is the 2nd most commonly isolated organism.
Is Klebsiella a common cause of UTI?
Yes (6-12%), after E coli.
Can Klebsiella be treated with ampicillin?
No, resistant.
Can Klebsiella be treated by any penicillin?
Yes, the anti-pseudomonal penicillins, eg: piperacillin. Has good gram negative coverage. Often combined with a beta lactamase inhibitor
Anti-pseudomonal penicillin and beta lactamase inhibitor
Piperacillin-tazobactam.
Which cephalosporin(s) treat K. pneumoniae?
Cefepime. Has excellent gram positive activity, stable against beta lactamases. Good against pseudomonas
Which organisms have chromosomal inducible beta lactamase (ampC)
SPICE. Serratia, pseudomonas aeruginosa, indole positive proteaceae, citrobacter, enterobacter
