Class: UTIs - E.coli and others Flashcards
MacConkey Agar grows what two types of organisms and shows what color
gram (-)
lactose fermenters = pink (lactase+)
MC encountered enterobacteriaceae
e. coli
E.coli activity on Blood agar
B-hemolytic
4 virulence factors fro e. coli
LPS = endotoxin
Capsule (contains K-antigen )
Pili (fimbriae)
Hemolysin
Type -1 fimbriae of E.coli bare specific for what
mannose on epithelial surface
P-fimbriae of e.coli are specific for what
bind to Gal-Gal on P blood-group antigen
what is most important virulence factor
K-antigen
what serotype of the K-antigen is most invasive
K1 serotype
most UTIs are caused by
e. coli
2 complications of e.coli infx
neonatla meningitis
bactermia/sepsis
how does e.coli bind uroepithelial cells
type-1 fimbriae
where do e.coli bacteria live exaclty
invade and replicate in epithelial cells = intracellular!!!!
2 complications of e. coli UTIs
cystitis
pyelonephritis
what type of e.coli infx is the 2nd MC cuase of community acquired sepsis?
UTI
E. coli is the MC cause of what nosocomial inx?
PNA!!!!!!!!!!!!!!! - it is #1!!!
urine dipstick tests fro what 2 chemical
leukocytes esterase
nitrites
2 other invasive infx of E.coli (other than nosocomial PNA)
neonatal meningitis
bacteremia/septic shock/dissemination–> PNA
Enterobacter family is resistant to what family of ABX
3rd gen cephalosporins
Enterobacter family is usually susceptible to what 2 groups of drugs
β-lactamase inhibitors and carbapenems
what bacteria is a carbapenemase that merged in 2000s
Klebsiella
New Delhi metallo-β-lactamase is resistant to what classes? (2)
all β-lactam antibiotics,
including carbapenems
What is tx for UTI
Start empirically: TMP-SMX
CRE/KPC strains are usually still susceptible to what
Dual therapy (ALWAYS USE 2) tigecycline and colistin (polymyxin B)
What is Klebsiella’s major virulence factor for invasive disease
– large mucoid capsule
