UTI Flashcards
- What is the difference between uncomplicated and complicated UTI?
Uncomplicated – infection in a structurally and neurologically normal urinary tract
Complicated – infection in a urinary tract with functional or structural abnormalities (includes indwelling catheters and calculi)
- In which groups of patients are UTIs considered ‘complicated’?
Men
Pregnant women
Children
Hospitalised patients
- List some other organisms that cause UTI.
Proteus mirabilis Klebsiella aerogenes Enterococcus faecalis Staphylococcus saprophyticus Staphylococcus epidermidis (can cause infection in the presence of prosthesis (e.g. procedures, indwelling catheters))
- Which virulence factor allows S. saprophyticus to stick to the urinary tract epithelium?
P-fimbriae
- List some antibacterial host defences in the urinary tract.
Urine (osmolality, pH, organic acids)
Urine flow and micturition
Urinary tract mucosa (bactericidal activity, cytokines)
- What is an ascending UTI?
The infection ascends from the female introitus and periurethral area
- List some causes of urinary tract obstruction.
Extrarenal • Valves, stenosis or bands • Calculi • BPH Intrarenal • Nephrocalcinosis • Nephropathy (uric acid, analgesic, hypokalaemic) • Polycystic kidney disease Neurogenic malfunction • Poliomyelitis • Tabes dorsalis (demyelinating condition caused by advanced syphilis) • Diabetic neuropathy • Spinal cord injuries
- What is vesicoureteric reflux?
A condition in which urine can reflux into the ureters
It results in a residual pool of infected urine in the bladder after voiding
It can result in scarring of the kidneys
- Describe how UTI can become established via the haematogenous route.
The kidney is a frequent site for abscesses in patients with S. aureus bacteraemia or endocarditis
- Outline the symptoms of UTI in:
a. Neonates and children < 2 years Failure to thrive Vomiting Fever b. Children > 2 years Frequency Dysuria Abdominal pain
- List some symptoms of upper UTI.
Fever (and rigors)
Flank pain
Lower urinary tract symptoms
- List some investigations for uncomplicated UTI.
Urine dipstick
MSU for urine MC&S
Bloods – FBC, CRP, U&E
- List some further investigations that may be considered in complicated UTIs.
Renal ultrasound scan
IV urography
- What does nitrite-negative leukocyte-positive urine suggest?
UTI caused by non-coliform bacteria
- What does the presence of white cell in the urine (pyuria) suggest?
Infection
- What does the presence of squamous epithelial cells in the urine suggest?
Contamination
- What is the microbiological definition of UTI?
Culture of single organisms > 105 colony forming units/mL with urinary symptoms
- What number of white cells in the urine represents inflammation?
More than 104/mL
- List some causes of sterile pyuria.
STIs (e.g. chlamydia) TB Prior antibiotic treatment (MOST COMMON) Calculi Catheterisation Bladder cancer
- What type of agar is used for urine culture? What do the colours suggest?
Chromogenic agar
• Pink = E. coli
• Blue = other coliforms
• Light blue = Gram-positives
- List some methods of sampling urine for investigations.
MSU
Catheterisation
Suprapubic aspiration (usually in young children)
- What type of therapy may be needed for patients with UTIs caused by ESBL producing organisms?
Outpatient parenteral antibiotic therapy (OPAT)
- Outline the treatment options for:
a. Uncomplicated UTI in women
b. UTI in pregnant or breastfeeding women
c. UTI in men
d. Pyelonephritis or systemically unwell with a UTI
e. Catheter-associated UTI
a. Uncomplicated UTI in women
Cefalexin 500 mg BD PO for 3 days
OR
Nitrofurantoin 50 mg POQ QDS for 7 days (check renal function)
b. UTI in pregnant or breastfeeding women
Cefalexin 500 mg BD PO for 7 days
2nd line: co-amoxiclav 625 mg TDS PO for 7 days
c. UTI in men
Cefalexin 500 mg BD PO for 7 days
OR
Ciprofloxacin 500 mg BD PO for 14 days if suspicion of prostatitis
Chronic prostatitis: ciprofloxacin 500 mg BD PO for 4-6 weeks
d. Pyelonephritis or systemically unwell with a UTI
Co-amoxiclav 1.2 g IV TDS
Consider adding IV amikacin or gentamicin
Penicillin allergy: ciprofloxacin 400 mg IV BD
e. Catheter-associated UTI
Remove catheter (but give stat doses before removal of infected catheter)
Gentamicin 80 mg STAT IV/IM 30-60 mins before procedure
OR
Amikacin 140 mg STAT IV/IM 30-60 mins before procedure
- In which patients do Candida UTIs tend to occur?
Patients with indwelling catheters
How should Candida UTIs be treated?
Remove the catheter - no evidence of fluconazole being effective
- In which exceptional cases should Candida UTI be actively treated?
Renal transplant patients
Patients waiting to undergo elective urinary tract surgery
- Which part of the kidney is more susceptible to infection?
Renal medulla
- What is the main treatment option for pyelonephritis?
Co-amoxiclav with or without gentamicin
- List some complications of pyelonephritis.
Perinephric abscess
Chronic pyelonephritis (scarring, renal impairment)
Septic shock
Acute papillary necrosis
