UTIs - organisms, symptoms, diagnosis

Question 1

what is a lower UTI

Answer 1

infection confined to bladde (cystitis)

Question 2

what is an upper UTI

Answer 2

infection involving ureters +/- kidneys (pyelonephritis)

Question 3

what is a complicated UTI

Answer 3

systemic symptoms or urinary structural abnormalities eg stones

Question 4

why are UTIs more common in women > men

Answer 4

women have shorter urethras, urethra closer to anus, sexual activity and pregnancy increase risk

Question 5

which is the only part of the urinary tract that has commensal bacteria

Answer 5

lower end of urethra - kidneys, ureter and bladder sterile

Question 6

what types of organisms are commonly found in the lower end of the urethra

Answer 6

coliforms and enterococci from bowel

Question 7

what is the most common route of infection for UTI’s

Answer 7

ascending route where bacteria (gram -ive)from bowel comes into contact with urethra and ascends to the kidneys

Question 8

what other way can UTI’s be caused (not ascending route)

Answer 8

blood stream –> kidneys –> multiple small abscesses (uncommon)

Question 9

what is the most common causative organism of UTIs

Answer 9

E. coli

Question 10

what other causative organisms are there

Answer 10

klebsiella, enterobacter, pseudomonas A, proteus

Question 11

what gram stain is E. coli and what toxin can it release

Answer 11

gram -ive, endotoxin LPS

Question 12

what can a proteus infection cause urine to smell like

Answer 12

foul smelling - burnt chocolate

Question 13

how does proteus change the pH to cause stones

Answer 13

produces urease which breaks down urea –> ammonia –> increased pH (alkali) –> struvite (kidney) stones/ salts

Question 14

what is seen on a proteus culture

Answer 14

gram -ive and ‘swarming’ - looks like a bulls eye and can cover whole agar plate

Question 15

what type of bacteria is pseudomonas A

Answer 15

gram-ive bacillus (not a coliform)

Question 16

which patients commonly get pseudomonas A UTIs

Answer 16

those with catheters

Question 17

pseudomonas A is resistant to most antibiotics so which one is recommended for it and what class of AB is it

Answer 17

ciprofloxacin - quinolone

Question 18

when is ciprofloxacin contraindicated

Answer 18

young children and pregnant women and causes C diff

Question 19

what type of enterococcus can commonly cause UTI’s and what gram stain is it

Answer 19

enterococcus faecalis gram +ive

Question 20

what type of staph can commonly cause UTI’s in women and what coagulase is it

Answer 20

staph saprophyticus, coagulase -ive

Question 21

if staph A was found to be causing a UTI what would this indicate

Answer 21

bacteraemia and a spread from infection somewhere else in the body (is uncommon)

Question 22

what are symptoms of a lower UTI

Answer 22

dysuria, increased frequency, increased urgency, suprapubic pain (no systemic signs)

Question 23

what does sterile pyruia (pus in urine) indicate in a patient with lower UTI symptoms

Answer 23

chlamydia or gonorrhoea infection

Question 24

what are symptoms of an upper UTI

Answer 24

fever, flank pain, N+V + lower UTI symptoms

Question 25

who is more at risk of developing an upper UTI

Answer 25

females, young people, diabetics, pregnancy, catheterised patients

Question 26

how do you correctly collect a urine specimen

Answer 26

wash perineum with sterile saline (often skipped), collect midstream urine (first pass urine contaminated with normal flora)

Question 27

what is a suprapubic aspiration

Answer 27

aspiration directly from bladder, very invasive

Question 28

what is a clean catch specimen and who would require it

Answer 28

urine sample assisted by physician eg for children or special needs

Question 29

what is bag urine sample, when is it used and what would the results indicate

Answer 29

used on babies and is normally contaminated with bowel flora, negative culture rules our UTI, positive needs further investigations

Question 30

what is the best transport and why medium for urine samples

Answer 30

boricon container - presevres bacteria from multiplying

Question 31

if a sterile universal container is used what timeframe must it reach the lab by

Answer 31

within 2 hours

Question 32

what might be seen on a dipstick that would indicate a UTI

Answer 32

leukocyte erserase (WBCs), nitrites, (RBC - does not always indicate infection diagnosis alone)

Question 33

in which patients would a positive dipstick not always indicate a patient

Answer 33

catheter patients or elderly women as bacteriuria common - would need clinical diagnosis also

Question 34

how is a diagnosis made in the lab

Answer 34

microscopy (not routine) , culture