UTI

Question 1

2. What is the difference between uncomplicated and complicated UTI?

Answer 1

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)

Question 2

3. In which groups of patients are UTIs considered ‘complicated’?

Answer 2

Men
Pregnant women
Children
Hospitalised patients

Question 3

5. List some other organisms that cause UTI.

Answer 3

Proteus mirabilis
Klebsiella aerogenes
Enterococcus faecalis
Staphylococcus saprophyticus
Staphylococcus epidermidis (can cause infection in the presence of prosthesis (e.g. procedures, indwelling catheters))

Question 4

6. Which virulence factor allows S. saprophyticus to stick to the urinary tract epithelium?

Answer 4

P-fimbriae

Question 5

7. List some antibacterial host defences in the urinary tract.

Answer 5

Urine (osmolality, pH, organic acids)
Urine flow and micturition
Urinary tract mucosa (bactericidal activity, cytokines)

Question 6

8. What is an ascending UTI?

Answer 6

The infection ascends from the female introitus and periurethral area

Question 7

9. List some causes of urinary tract obstruction.

Answer 7

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

Question 8

10. What is vesicoureteric reflux?

Answer 8

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

Question 9

11. Describe how UTI can become established via the haematogenous route.

Answer 9

The kidney is a frequent site for abscesses in patients with S. aureus bacteraemia or endocarditis

Question 10

12. Outline the symptoms of UTI in:

Answer 10

a.	Neonates and children < 2 years 
Failure to thrive 
Vomiting 
Fever 
b.	Children > 2 years 
Frequency 
Dysuria 
Abdominal pain

Question 11

13. List some symptoms of upper UTI.

Answer 11

Fever (and rigors)
Flank pain
Lower urinary tract symptoms

Question 12

15. List some investigations for uncomplicated UTI.

Answer 12

Urine dipstick
MSU for urine MC&S
Bloods – FBC, CRP, U&E

Question 13

16. List some further investigations that may be considered in complicated UTIs.

Answer 13

Renal ultrasound scan

IV urography

Question 14

18. What does nitrite-negative leukocyte-positive urine suggest?

Answer 14

UTI caused by non-coliform bacteria

Question 15

20. What does the presence of white cell in the urine (pyuria) suggest?

Answer 15

Infection

Question 16

21. What does the presence of squamous epithelial cells in the urine suggest?

Answer 16

Contamination

Question 17

22. What is the microbiological definition of UTI?

Answer 17

Culture of single organisms > 105 colony forming units/mL with urinary symptoms

Question 18

23. What number of white cells in the urine represents inflammation?

Answer 18

More than 104/mL

Question 19

25. List some causes of sterile pyuria.

Answer 19

STIs (e.g. chlamydia)
TB
Prior antibiotic treatment (MOST COMMON)
Calculi
Catheterisation
Bladder cancer

Question 20

26. What type of agar is used for urine culture? What do the colours suggest?

Answer 20

Chromogenic agar
• Pink = E. coli
• Blue = other coliforms
• Light blue = Gram-positives

Question 21

27. List some methods of sampling urine for investigations.

Answer 21

MSU
Catheterisation
Suprapubic aspiration (usually in young children)

Question 22

28. What type of therapy may be needed for patients with UTIs caused by ESBL producing organisms?

Answer 22

Outpatient parenteral antibiotic therapy (OPAT)

Question 23

29. 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

Answer 23

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

Question 24

31. In which patients do Candida UTIs tend to occur?

Answer 24

Patients with indwelling catheters

Question 25

How should Candida UTIs be treated?

Answer 25

Remove the catheter - no evidence of fluconazole being effective

Question 26

33. In which exceptional cases should Candida UTI be actively treated?

Answer 26

Renal transplant patients

Patients waiting to undergo elective urinary tract surgery

Question 27

34. Which part of the kidney is more susceptible to infection?

Answer 27

Renal medulla

Question 28

35. What is the main treatment option for pyelonephritis?

Answer 28

Co-amoxiclav with or without gentamicin

Question 29

36. List some complications of pyelonephritis.

Answer 29

Perinephric abscess
Chronic pyelonephritis (scarring, renal impairment)
Septic shock
Acute papillary necrosis