UTI

Question 1

Is the urethra sterile?

Answer 1

– the urethra is NOT sterile (whilst urine in the bladder is sterile, the urine coming out the urethra is not sterile)

Question 2

What happens if you fins squamous cells in an MSU

Answer 2

o Squamous epithelial cells are found at the end of the urethra
o If squamous epithelial cells are found in an MSU sample, the sample has not been taken properly

Question 3

Is bacteruria bad?

Answer 3

o Asymptomatic bacteriuria is NOT usually relevant

o However, asymptomatic bacteriuria with coliform is significant in PREGNANCY

Question 4

Difference between an uncomplicated and complicated UTI?

Answer 4

o Uncomplicated: infection is a structurally and neurologically normal urinary tract
o Complicated: infection with functional or structural abnormalities (including indwelling catheters and calculi)

Question 5

Groups of patients where it is regarded as complicated?

Answer 5

 Men Pregnant women

 Children (not young girls) Patients in a healthcare- or HC-associated settings

Question 6

Most common causes of UTIs?

Answer 6

• Most Common = Escherichia coli
o Staphylococcus saprophyticus (coagulase -ve staphylococcus)
 2nd most common cause of UTI in younger women
Recurrent causes- non E coli

Question 7

Causes of obstruction leading to UTIs?

Answer 7

Mechanical
Extrarenal- valves, calculi, stenosis
Intrarenal- nephrocalcinosis, PKD
Neurogenci- DM, poliomyelitis

Question 8

How Vesicoureteric Reflux (VUR) causes infection

Answer 8

 Perpetuate infection by maintaining a residual pool of infected urine in the bladder after voiding
 The reflux can result in scarring of the kidneys

Question 9

Haematogenous route of infection the kidney

Answer 9

o Kidney is a frequent site of abscesses in patients with S. aureus bacteraemia or endocarditis

o Infection of the kidney with Gram-negative bacilli rarely occurs by the haematogenous route

Question 10

Symptoms of UTI in children

Answer 10

o Failure to thrive
o Vomiting
o Fever

Question 11

Symptoms of UTI in adults

Answer 11

o Frequency
o Dysuria
o Abdominal or flank pain

Question 12

Upper vs lower UTI symptoms

Answer 12

Lower: irritation of urethral & vesical mucosa  frequent/painful urination of small amounts of turbid urine
o Suprapubic heaviness or pain
o Gross haematuria
o Fever absent

Upper: Lower symptoms May precede UUTS by 1-2 days plus
o Fever (sometimes with rigors)
o Flank pain

Question 13

Older patients symptoms?

Answer 13

Atypical

Abdo pain, mental state change

Question 14

Investigations of UTIs

Answer 14

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

Question 15

Interpreting Urine Culture Results:

Answer 15

o Culture of single organisms >105 CFUs/mL + urinary symptoms  diagnostic of UTI

o Culture of E. coli or S. saprophyticus organisms >103 CFUs/mL + urinary symptoms  diagnostic of UTI

 White cells >104/mL (or 107/L) = inflammation
 Pyuria is usually ABSENT in children

 Mixed growth reduces the significance of culture (suggests contamination)
 Epithelial cells present in high numbers suggest a failed MSU technique

Question 16

What does sterile pyuria suggest

Answer 16

o If sterile pyuria (raised WCC but no growth on culture), consider:
 Prior treatment with antibiotics (MOST COMMON)
Calculi
 Catheterisation Bladder neoplasm
 TB STI (Chlamydia trachomatis)

Question 17

What colour represents what species in a culuture?

Answer 17

 Pink  E. coli
 Blue  other coliforms
 Light blue  gram +ve

Question 18

Usual ABx used for treatment

Answer 18

normally Trimethoprim/Nitrofurantoin/Cephalexin in for uncomplicated UTIs for 3 days
o No nitrofurantoin in pregnancy as associated with haemolysis

7 days of treatment
 History of previous urinary tract infection caused by antibiotic-resistant organisms
 >7 days of symptoms

Question 19

Fungal infections causes in the UT and the treatment

Answer 19

o Most Candida UTIs occur in patients with indwelling catheters

o Management  removal of the catheter (antifungals no more effective than no therapy)

Question 20

Management of pyelonephritis

Answer 20

o Prior to culture results  amoxicillin (or ciprofloxacin)

o Culture results  co-amoxiclav ± gentamicin (broad spectrums)

Question 21

Complications of pyelo

Answer 21

o Perinephric abscess
o Chronic pyelonephritis  scarring, chronic renal impairment
o Septic shock
o Acute papillary necrosis