MICRO UTIs - Week 8 Flashcards
Pyelonephritis
UTI @ kidneys.
Cystitis
UTI @ bladder.
Urethritis
UTI @ urethra.
Pyuria.
Pus cells present in the urine.
2 x pathways of pyelonephritis contraction.
Ascending & haematogenous.
Most common organisms causing UTIs
E. Coli, proteus.
Virulence factors of E. Coli.
- Fimbriae – allow for bladder wall adherence.
- Capsule – inhibits phagocytosis -> pyelonephritis
- Haemolysin – toxin produced by bacteria -> renal injury -> cell membrane damage.
Virulence factors of proteus.
- Urease production – increases alkalinity of urine (optimal pH for proteus) -> kidney stone formation.
Predisposing factors of UTIs.
- Female – due to shorter length of urethra & closer proximity to anus (potential bacterial source).
- Obstructions (e.g., renal calculi, strictures, tumours, prostatic hypertrophy, pregnancy).
- Catheterisation.
- Neurological voiding issues.
- Diabetes mellitus – when uncontrolled, high glucose can increase bacterial growth and/or for controlled/uncontrolled, neuropathy can also increase risk.
- Vesicoureteral reflux – involving backflow of urine into ureters.
- Primary VUR – usually due to congenital abnormalities.
- Secondary VUR – usually due to blockage/narrowing of bladder neck/urethra.
Lower UTI symptoms & upper UTI symptoms.
Lower UTI symptoms:
* Dysuria
* Urgency
* Frequency
* Suprapubic pain
* Fever – generally absent/low grade
* Cloudy/smelly urine.
Upper UTI symptoms:
* Fever
* Chills
* Back pain/flank pain
* Nausea
* Vomiting
* Dysuria
* Frequency.
‘Symptoms’ of asymptomatic UTIs in elderly patients or infants.
Elderly pts - restlessness, hallucinations, social withdrawal, agitation, confusion, nausea.
Infants - fever, crying during urination, cloudy/foul-smelling, bloody urine, irritability, vomiting, refusing to eat.
Diagnosis of UTI
- Mid-stream urine sample (MSU).
- Microscopy.
- Urine dipstick – particularly nitrites , leukocytes, blood.
- Blood tests WBCs, CRP – particularly if pts present w fever.
- Renal and/or bladder USS
- Voiding cystourethrogram (VCUG).
How many cfu/ml must be counted for a properly collected MSU for an UTI diagnosis? What is the number for urine specimens collected from suprapubic aspiration/nephrostomy tube?
> 10^5. ? - does not apply.
Management of UTIs
Oral or IV antibiotics w follow-up culture encouraged post treatment.
Prevention measures for UTIs
- Drink water
- Cranberry juice
- Wipe from front to back
- Empty bladder soon after intercourse
- Change birth control method – avoid diaphragms and spermicide-treated condoms.