Urinary Tract Infections

Question 1

What are the 5 main types of UTI?

Answer 1

• Asymptomatic bacteriuria
• Acute urethral syndrome
• Cystitis
• pyelonephritis
• Urosepsis (positive blood culture)

Question 2

Which organisms most commonly cause community-aquired UTIs?

Answer 2

E.Coli
Staphylococcus saprophyticus
Klebsiella, enterococcus, pseudomonas

Question 3

Which organisms mostly cause hospital acquired UTIs?

Answer 3

Enterococcus, Klebsiella, pseudomonas.

Candida.

Question 4

What are the indications for a urinalysis?

Answer 4

• symptomatic e.g. Dysuria, frequency
• complicated infection, flank pain
• failure to respond to initial therapy
• recurrent symptoms <1 month after treatment for UTI not previously cultured.
• UTI following international travel
• UTI following hospitalisation

Question 5

What are the different specimen types?

Answer 5

STERILE (ideal)
Nephrostomy
In and out catheter
Suprapubic aspirate
Cystoscopy
LOW LEVEL CONTAMINATION
Mid-stream catch
HIGH LEVEL CONTAMINATION:
Long term catheter 
Urine bag
Fistula

Question 6

How should urine samples be transported?

Answer 6

Labelled: method of collection, symptoms, current antibiotics, time of collection.
Transport: transport within 2 hours and process immediately as colony count is important. Or refrigerate at 4 degrees and do not freeze.

Question 7

False positive results for a UTI?

Answer 7

Contaminating bacteria
Eosinophils
Trichomas
Formalin

Question 8

False negatives

Answer 8

Boric acid
Ascot box acid
Oxalic acid

Question 9

What can you find on a urine microscopy and what do the findings mean?

Answer 9

Squamous cells: contaminated specimen, not a midstream catch
WBC: infection
RBCs: infection, kidney stone, bladder neoplasm.
Cylinders: pyelonephritis

Question 10

How do you interpret a urine culture?

Answer 10

Is there a uropathogen?
Is the culture mixed?
Are they equal in numbers? Is one predominant?
Quantification:

Question 11

What factors affect the colony count of bacteria in urine?

Answer 11

• inoculum size
• intrinsic urine antibacterial action
• urine pH
• urine constituents
• Irvine flow rate
• frequency of voiding
• residual urine volume
• urinary antiseptics (extrinsic chemical used by doctors to kill pathogens)

Question 12

What situations would an Asymptomatic UTI be important?

Answer 12

• pregnancy
• invasive urinary Tracy surgery
• child with vesico-ureteral reflux

Question 13

What is the treatment approach for a UTI?

Answer 13

• symptomatic relief: urinary alkalising agents +high fluid intake
• antibiotics: trimethoprim