UTI Flashcards
What is a lower UTI infection?
Infection confined to the bladder (cystitis)
What is an upper UTI infection?
Infection involving the ureters +/- kidneys (pyelonephritis)
What bacteria colonise the distal urethra?
Coliforms
Enterococci
What is a complicated UTI?
UTI with
Systemic symptoms OR
Urinary structural abnormality/ stones
What is bacteriuria?
Bacteria present in urine
Only UTI if symptoms present
What is cystitis?
Inflammation of the bladder - not necessarily infection
Why do women get more UTIs than me?
Short, wide urethra
Proximity of urethra to anus
Increased risk with sexual activity, pregnancy
What are the routes of infection in an UTI?
Ascending infection: bacteria from bowel, perineal skin, lower end of urethra
Bloodstream: bacteraemia, seeding into kidneys
What coliforms commonly cause UTI?
E.COLI
Klebsiella
Enterobacter
Proteus
What bacteria, that is not a coliform, will cause UTIs?
Pseudomonas aeruginosa
What will a proteus UTI cause?
Struvite stones (triple phosphate stones) - staghorn calculus
How does proteus cause struvite stones?
Produces urease which breaks down urea to form ammonia, increasing urinary pH
What is the only oral antibiotic active against pseudomonas aeruginosa?
Ciprofloxacin
What is the mechanism of action of quinolones?
Inhibits bacterial DNA gyrase, preventing supercoiling of bacterial DNA
What enterococcus commonly causes UTI?
Enterococcus faecalis
What is the most common gram positive organism to cause UTI?
Staphylococcus saprophyticus - coag neg staph
Affects women of child bearing age
What are the symptoms and signs of a UTI?
Dysuria
Frequency of urination
Nocturia
Haematuria
What are the symptoms of pyelonephritis?
Fever
Loin pain
Rigors
What is the ideal urine sample for culture?
MSU as first passed urine is most likely to be contaminated with commensals
Should you dipstick urine in the elderly and those with catheters?
NO
What do nitrites signify on dipstick?
Presence of bacteria in the urine
Coliforms can reduce nitrates to nitrites HOWEVER, enterococcus, staphylococcus and pseudomonas do NOT so will have a negative teet
What level of bacteria in the urine is associated with infection?
> 10^5
What is abacterial cystitis?
Symptoms of UTI but no significant growth on culture
Should you treat an UTI if there are no symptoms?
NO
Should asymptomatic pregnant women be treated for an UTI?
YES; 20-30% will progress to pyelonephrtiis
What is the treatment for an uncomplicated lower UTI in females?
Trimethoprim or nitrofurantoin orally for 3 days
What is the treatment for an uncatheterised UTI in a male?
Trimethoprim or nitrofurantoin orally for 7 days
Should you get cultures in male UTIs?
YES
What is the treatment for a complicated UTI or pyelonephritis in the community?
Co-amoxiclav or co-trimoxazole for 14 days
What is the treatment for a complicated UTI or pyelonephritis in hospital?
Amoxicillin and gentamicin IV for 3 days
How long can gentamicin be given for?
3 days
What antibiotics can be used in ESBL producing UTIs?
Nitrofurantoin, pivmecillinam
Meropenem, ertapenem
What is a carbapenamase-producting enterobacteriaceae?
Gram negative (coliform) bacilli that are resistant to meropenem Resistant to ALL current antibiotics
What is second line for gram negs - after gent?
Aztreonam
What is second line for gram positives, after amox?
Vancomycin
What is the mechanism of action of trimethoprim?
Inhibits bacterial folic acid synthesis
Can trimethoprim be given in pregnancy?
Avoid in 1st trimester (first 3 months)
Can nitrofurantoin be used in pregnancy?
Avoid in late pregnancy, breast feeding and children under 3 months as can cause neonatal haemolysis
