Microbiology

Question 1

what is the lower end of the urethra colonised by?

Answer 1

coliforms

enterococci from large bowel

Question 2

is the urinary tract sterile?

Answer 2

yes, except for lower end of urethra

Question 3

risk factors for UTI

Answer 3

female
pregnancy
catheterised patients
abnormalities of urinary tract

Question 4

what makes females more at risk of UTIs?

Answer 4

short, wide urethra
proximity of urethra to anus
sexual activity

Question 5

gram negative causative organisms for UTI

Answer 5

coliforms (E. coli, klebsiella, enterobacter)
proteus
pseudomonas

Question 6

presentation of proteus

Answer 6

foul smelling urine

renal calculi

Question 7

associations with pseudomonas as causation of UTI

Answer 7

catheters

instrumentation

Question 8

management of pseudomonas

Answer 8

ciprofloxacin

Question 9

gram positive causative organisms for UTI

Answer 9

enterococcus (faecalis and faecium)
staph saphrophyticus
staph aureus

Question 10

associations with enterococcus (faecalis and faecium) causing UTI

Answer 10

hospital acquired infections

Question 11

who gets staph saphrophyticus?

Answer 11

coagulase negative staph affects women of child-bearing age

Question 12

when does staph aureus cause a UTI?

Answer 12

usually only in bacteraemia

Question 13

presentation of UTI

Answer 13

dysuria
frequency
nocturia
haematuria
if upper= fever, loin pain, rigors

Question 14

diagnosis of UTI

Answer 14

• mid-stream sample (MSU)
• other urine samples e.g. clean catch urine, bag urine, catheter specimen (CSU) or suprapubic aspiration
• dipstick
• microscopy

Question 15

how should a mid-stream sample MSU be transported to the lab?

Answer 15

boricon container

sterile universal container

Question 16

when is dipstick not used in diagnosis of UTI?

Answer 16

elderly

catheter

Question 17

what does a dipstick show?

Answer 17

leukocyte esterase (WBC)
nitrates (bacteria reduces nitrates)
protein
blood

Question 18

when is microscopy used in UTI?

Answer 18

urgent cases to look for pus cells, bacteria +/- red cells

Question 19

what criteria is used for culture of urine?

Answer 19

Kass’s criteria

Question 20

Kass’s criteria

Answer 20

> 10^5 organisms/ml= probable UTI
10^4 organisms/ml = repeat specimen
<10^3 organisms/ml= not significant

mixed growth not significant

Question 21

who does Kass’s criteria apply to?

Answer 21

women of childbearing age

Question 22

antibiotic of choice for pseudomonas?

Answer 22

ciprofloxacin (c.diff)

Question 23

antibiotic of choice for coliforms

Answer 23

gentamicin IV (hospital, narrow therapeutic range)

Question 24

antibiotic of choice for enterococci faecalis

Answer 24

amoxicillin

if allergic then co-trimoxazole- SJS

Question 25

what is ESBL resistant to?

Answer 25

cephalosporins

penicillin

Question 26

antibiotic of choice for ESBL

Answer 26

nitrofurantoin

Question 27

what is CPE resistant to?

Answer 27

all

Question 28

associations with CPE

Answer 28

UTI and travel to india

Question 29

what kind of organism is CPE

Answer 29

klebsiella

Question 30

antibiotics safe to use in pregnancy for UTI?

Answer 30

amoxicillin
cefalexin
co-amoxiclav

Question 31

antibiotics if complicated UTI/ urosepsis

Answer 31

gentamicin unless poor renal function, then temocillin

Question 32

what is abacterial cystitis/urethral syndrome?

Answer 32

symptoms of UTI with pus cells but no growth on culture

Question 33

causes of abacterial cystitis/urethral syndrome?

Answer 33

early phase UTI
urethral trauma (honeymoon cystitis)
chlamydia/gonorrhoea

Question 34

management of abacterial cystitis/urethral syndrome?

Answer 34

alkalinise urine for symptomatic relief

Question 35

what is asymptomatic bacteriuria?

Answer 35

significant bacteriuria but patient is asymptomatic

antibiotics not required unless pregnant