Microbiology of UTI Flashcards
the lower end of the urethra is colonised by what 2 main types of bacteria?
coliforms
enterococci
complicated UTI is a UTI complicated by..
systemic symptoms
structural abnormality
stones
most common route of infection?
ascending from bowel -> urethra up to kidneys potentially
what bacteria can travel in the bloodstream to cause a UTI?
staph aureus
most common UTI bug?
e coli
how does e coli stay in the urinary tract?
fimbriae which help it cling to surfaces
urinalysis is mainly only used for ruling out infection in UTI T or F
T, you want a culture to confirm infection
what are you expecting to see on microscope in a common UTI?
gram negative bacilli (E coli)
lipopolysaccarides live in gram _ve cell walls
negative
which coliform bacteria causes stones?
proteus
“swarming cultures” are a sign that ___ has grown
proteus
what does proteus smell of?
burnt chocolate
how does proteus cause stones?
produces urease which increases pH
which non-coliform can cause UTIs?
pseudomonas aeruginosa
pseudomonas is resistant to most oral antibiotics except ___
ciprofloxacin
what does ciprofloxacin inhibit?
DNA gyrase
most common gram +ve cause of UTI?
enterococcus faecalis
what 2 types of bacteria cause an upper UTI?
coliforms
gram +ves (e. faecalis mainly)
staph saphrophyticus can be found in who?
women of child bearing age
symptoms of UTI?
dysuria
frequency
nocturia
haematuria
what symptoms make you think upper UTI?
fever
loin pain
rigors
how should urine be collected in UTI?
get a mid stream sample: wash urethra with saline pee into toilet pee into bowl mid pee finish pee in toilet
what colour container is used to collect urine in the community
red top
urine can only be collected in a white container if it reaches the lab within _ hrs
2
nitrites confirm the presence of what bacteria?
coliforms
who shouldnt get urinalysis?
elderly
people with catheters
main Ix for UTI?
urine culture
UTI is caused by a single organism T or F
T
Tx for female uncomplicated UTI?
trimethoprim 3 days
Tx for male uncomplicated UTI?
trimethoprim or nitrofurantoin 7 days
Tx for complicated UTI in primary care?
co-trimoxazole or co-amoxiclav 7 days
Tx for complicated UTI in hosp?
amoxicillin + gentamicin IV 7 days
Tx for complicated UTI in hosp (pen allergic)
co-trimoxazole PO + gentamicin IV 3 days
gentamicin has a __ therapeutic index making it likely to become toxin
narrow
what drug should be used for ESBL bacteria?
meropenem
what should be used 2nd line if the patient has renal problems and cant have gentamicin?
aztreonam
why cant pregnant women use trimethoprim in the 1st trimester?
inhibits folic acid synthesis
