Lecture 8 - Urinary tract infections Flashcards
Describe the infection rate of UTIs
High infection rate, very common disease with 175 million cases per year worldwide
How many women and men will experience a UTI in their lifetimes?
40-50% of women
10-12% of men
what statistics show that UTIs are a recurrent disease?
25% of women experience a second UTI, and 3% of women will experience a third UTI within 6 months of the initial UTI
what is the more serious illness that can stem from UTIs?
pyelonephritis, infection spreads to kidneys
What is the main treatment for UTIs?
Antibiotics
what are the cons of treating UTIs with antibiotics?
- they can be costly
- can disrupt normal flora (surfacing of other infections)
- promotes drug resistance
what marks the treatment endpoint of UTIs?
when there is a sterilisation of urine and a loss of symptoms,
- not an eradication of the pathogen, which leads to relapse
what are the signs and symptoms of a moderate UTI?
- frequency of urination increases
- dysuria (pain while urinating)
- hesitancy
- urgency
what are the signs and symptoms of a more severe UTI?
- hematouria
- pyelonephritis (kidney infection with flank pain)
- systemic effects such as vomiting and fever
who is most commonly infected with community acquired UTIs and what is the pathogen that causes it?
mainly young women
mainly UPEC (Uropathogenic Escherichia coli)
who is most commonly infected with hospital acquired UTIs and what is the pathogen that causes it?
device related so could be anyone
UPEC but also other organisms
- higher drug resistance
what does the urine look like of someone with a UTI?
cloudy due to bacteria
smelly
sometimes with blood if more severe
what is cystitis?
inflammation of the bladder that happens during a UTI
what is urinalysis
- the process of collecting an analysing urine to detect for bacteria
describe the process of urinalysis
Midstream urine specimen collection and analysis
- clean perineal area and don’t use first bit of urine
- analyse immediately or store at 4ºC to reduce contamination of the sample
how can the UTI urine sample be contaminated with bacteria we aren’t looking for?
by passing through the lower urinary tract and skin, the urine picks up other bacteria and fungi
what is the dipstick test?
dipstick into a urine sample of someone suspected to have a UTI
what is a positive reading of a dipstick test?
- testing positive for nitrites (bacteria change NO3- to NO2-)
- positive for leukocyte esterase (indicates presence of WBC)
what would urine sediment microscopy show?
- WBCs such as neutrophils
- bacteria everywhere coz its literal pee
- transitional epithelial cells from bladder
what would a gram stain of a urine sample of someone with a UTI show?
gram negative bacilli and the presence of neutrophils.
- this can conclude UTI is due to a gram negative rod since we can see the neutrophil phagocytosing the rod
what is the main bacteria that causes community acquired UTIs?
- escherichia coli
responsible for up to 95% of UTI cases in community
what are the five less common bacteria that can cause a community acquired UTI?
- Proteus mirabilis (-ve rod)
- Klebsiella pneumoniae (-ve rod)
- Staphylococci saprophyticus (+ve cocci)
- enterobacter (HA)
- pseudomonas (HA)
what are the main bacterias that cause hospital acquired UTIs?
- E. coli (31%)
- other enteric bacteria such as
Klebsiella and enterobacter - proteus, pseudomonas enterococci and staph
how can we diagnose E.coli or Klebsiella and enterobacter using culture?
CLED agar
- Cysteine (requirement of some UPEC)
- Lactose (UPEC are lactose fermenters, and agar will turn yellow)
- Electrolyte Deficient (prevents swarming of proteus so we can actually see how many colonies we have)
