Lec13 Klebsiella Flashcards
What diseases does klebsiella pneumoniae cause?
- pneumonia
- UTI
- healthcare associated infections
How do you distinguish K oxytoca or e coli from K pneumoniae?
K oxytoca and e coli can produce indole from tryptophan [indole test]
= are indole positive
k pneumoniae is indole negative
What are the 4 most common enterobacteriacea?
- escherichia, klebisella, shigella, salmonella, yersinia
What are 5 less common but virulent enterobacteriaceae?
- enterobacter, serratia, proteus, morganella, providencia spp.
What are general micro properties of enterobacteriaceae?
- ferment glucose and other sugars
- produce catalase
- oxidase negative
What is the epidemiology of klebsiella pneumoniae?
- main reservoir is humans
- colonize lower GI tract, skin, female genital tract
- produce disease when get access to sterile sites
What are common clinical manifestations of k. pneumoniae?
- UTI, intra-abdominal infections, pneumonia
- in hospital see: bacteremia [bloodstream infections, wound infections, healthcare associated device related infections
Who has highest risk of K. pneumoniae?
- can be community acquired
- more often healthcare associated
- seen in patents and healthcare workers
- healthcare associated has higher potential for resistance
How can K. pneumoniae be plated?
- isolated readily on routine media
- use MacConkey media –> klebsiella and E coli both ferment lactose so turn pink
Is klebsiella pneumoniae motile?
no – non motile
What is significance of klebsiella pneumoniae having a capsule?
basis of serotyping [77 serotypes]
its a virulence factor
What are micro properites of klebsiella pneumoniae?
- non motile
- encapsulated
- catalase positive
- ferment glucose and other sugars [posiitve MacConkey]
- oxidase negative
- indole negative
What are the virulence factors of K. pneumoniae?
- mucoid polysaccaride capsule
- hypermucoviscous isolates –> makes more resistant to complement mediated killing
less important:
- LPS [acts as endotoxin] [O antigen]
- siderophores
- pili
What is string test?
- to look for hypermucoviscous isolates
What is function of type 1 vs type 3 pili?
type 1 pili helps mediate adherence to epithelium
type 3 is required for biofilm production
What is mech of action of siderophores?
- siderophores sequester iron
- iron essential for bacterial growth
What are 3 common clinical syndromes of klebsiella pneumoniae?
- pneumonia [community or healthcare acquired]
- intra-abdominal infection [liver abscesses, peritonitis, cholangitis]
- urinary tract infections
What is friedlander’s disease?
- pneumonia caused by klebsiella pneumoniae
- hemorrhagic necrotizing lobar pneumonia
- get currant jelly sputum, occurs mostly in upper lobes
- similar to other encapsulated organisms but often very complicated [effusion, empyemas, lung abscesses]
- assocated with immunocompromised
- high mortality
What kind of intra-abdominal infections does klebsiella pneumoniae cause?
- spontaneous bacterial peritonitis [ in patients with cirrhosis]
- appendicitis
- cholangitis or cholecytisis
- diverticulitis
- liver abscesses
- post op infections
What are two types of peritonitis?
spontaenous peritonitis
- occurs in patients with liver disease
- caused by E. coli, strep, klebsiella pneumoniae
secondary peritonitis
- inflamation abdominal organs
- secondary to surgical source or appendicial rupture
- caused by klebsiella or E coli
What are two main causes of UTIs? what are complications of UTI?
- E coli most common, then klebsiella pneumoniae
- complicated UTI can have
- – renal abscesses
- – emphysematous pyelonephritis
- – catheter associated UTIs
What are clinical manifestations of klebsiella pneumoniae other than UTI, intra abdominal infections, and pneumonia?
- central venous catheter associated infections
- skin and skin structure infections [necrotizing fasciitis, diabetic foot ulcers, post op wound infections]
What are treatments for klebsiella pneumoniae? 4 main drugs?
source control: remove catheter, drain abscesses, debridement
antibiotics: vary in susceptibility profiles
- all K pneumoniae are ampicillin resistant
What are K pneumoniae resistant to?
all are resistant to ampicillin
because have a penicillin-specific B lactamase
What are the 3 anti-pseudonomal penicillins?
- piperacillin, ticarcillin, carbenicillin [piperacillin most potent]
- often combined with B lactamase inhibitor
ex. piperacillin-tazobactam
What do anti-pseudonomal penicillins cover?
- gram negative rods including pseudomonas
- often compined with B lactamase inhibitor
- — piperacillin- tazobactam
What is ampicillin-sulbatcam used to treat?
- ampicillin susceptible enteroccocus
- anaerobes
- sinusitis, dog and cat and human bites, community acquired lung abscesses, intra-abdominal infections
What is piperacillin-taxobactam [or ticarcillin-clavulanate] used to treat?
- pseudomonas
- ampicillin-susceptibl enterococcus
- anaerobes
- healthcare associated infections
covers everything of ampicillin sulbactam + better gram negative coverage
What is cefazolin used to treat?
- gram positive cocci [MSSA, GBS]
- e coli, k pneumoniae, p mirabilis
What is cefepime used to treat? does it cross blood brain barrier? is it susceptible to b lactamases?
- excellent gram + and - coverage
- including pseudomonas, MSSA
- stable against many B lactamases
- crosses BBB
- not reliable against anaerobes
used to treat healthcare associated infections
What oganisms have chromosomal inducible B-lactamase?
organisms have them inherently and they get turned on in presence of antibiotics
SPICE organisms S: serratia spp P: pseudomonas aeruginosa I: indole-positive proteceae [proteus vulgaris, providencia spp, morganella morganii] C: citrobacter spp E: enterobacter spp
What are two plasmid mediated B lactamases?
ESBL
KPC
What is ESBL? What drug do you use with organisms that have ESBL?
- extended spectrum B lactamase
- in E coli and k pneumoniae
- associated with use of broad spectrum antibiotics
- — when you use ceftriaxone, piperacillin-tazobactam you get induction of ESBL enzyme production
- resistant to penicillins, cephalosporins, aztreonam
- treat with carbapenems
What is clinical use of carbapenems?
- broad spectrum activity against aerobic and anaerobic g+ and g-
- reserved for treatment of serious healthcare associated infections
- broadest spectrum, can treat bacteria with ESBL
What are the four carbapenems?
imipenem-cilastatin
meropenem
ertapenem
doripenem
What is clinical use of imipenem-cilastatin?
- treat ESBL-producing gram negatives
- acinetobacter and pseudomonas
What is clinical use of meropenem?
- carbapenem of choice for meningitis
- activity against burkholderia cepacia
What is clinical use of doripenem?
- similar to meropenem
- use for meningitis, burkholderia cepacia
What is clinical use of ertapenem?
- no activity against pseudomonas or acinetobacter
- minimal activity against enterococcus
What do you have imipenem and cilastatin together?
- imipenem degraded by dihydropeptidase in proximal renal tubule, can accumulate nephrotoxic but inactive metabolite
- cilastatin is dihydropeptidase inhibitor, administered with imipenem to avoid this side effect
What are adverse rxns of imipenem-cilastatin?
- seizures
- hypersensitivity
What is struct of aztreonam? what kind of activity? can it be used to treat bacteria with ESBLs?
- monobactam that lacks thizolidine ring
- only active against gram neg + pseudomonal [not g+ or anaerobes]
- hydrolyzed by ESBLs
- used for patients with severe penicillin/B-lactam allergy
What is mech by which you get carbapenem resistant K. pneumoniae?
- KPC [K pneumoniae carbapenamase] = plasmid mediated B lactamase that hydrolyzes all B lactams including carbapenems
less common in US - metallo-B-Lactamases [NDM1, IMP, VIM]
- oxacillinases [OXA-48]
What are treatment options for resistance to carbapenems?
- polymyxin
- gentamicin
- tygacil
What are polymyxins? what do they treat?
- cation that binds to outer membrane and disrupts integrity
- treats only gram negative [E coli, klebsiella spp, enterobacter spp, pseudomonas aeruginosa, acinetobacter spp]
What are shortcomings and adverse effects of polymyxins?
- can’t penetrate specific sites [lungs, CSF]
- nephrotoxicity
- neurotoxicity
What can tigecyclin treat?
- skin infections, pneumonia, abdominal infections
- gram negative bacilli [including ESBL producing enterobacteriaceae]
- no activity against proteus, pseudomonas, providencia
- not recommended for bloodstream infections
