UTI

Question 1

what causes symptomatic infection?

Answer 1

when micro org invade tissues of urinary tract and adjacent structures, leading to inflammatory response

Question 2

Enterobacteriaceae family includes

Answer 2

Escherichia coli, Klebsiella, Proteus
- gut gram negative bacilli
(ascending route of infection, colonic/fecal flora)

Question 3

Eg. of organisms arising from descending (hematogenous) route of infection?

Answer 3

Staphylococcus aureus, Mycobacterium tuberculosis

Question 4

factors determining development of UTI

Answer 4

1. competency of natural host defense
2. size of inoculum
3. virulence/pathogenicity of the microorg

Question 5

1. natural host defense

Answer 5

• bacteria in bladder stimulates micturition, increasing diuresis, emptying of bladder
• antibacterial properties of urine and prostate secretions
• anti-adherence mechanisms of bladder mucosa, prevent bacterial attachment, unable to invade tissues to cause infection
• inflammatory response with polymorphonuclear leukocytes, phagocytosis, prevent/control spread

Question 6

2. size of innoculum

Answer 6

incr with obstruction/urinary retention

Question 7

3. virulence/pathogenicity of microorg

Answer 7

eg. bacteria with pili such as E.coli, resistant to washout or removal by anti-adherence mechanisms of the bladder

Question 8

risk factors for UTI (11)

Answer 8

1. f>m
2. sexual intercourse
3. abnormalities of urinary tract
4. neurological disturbances
5. anti-cholinergic drugs
6. catheterization and other mechanical instrumentation
7. diabetes
8. pregnancy
9. use of diaphgrams and spermicides
10. genetic assoc (pos family history)
11. previous UTI

Question 9

what are some atypical and subtle smx of complicated UTI?

Answer 9

oweing to catheterisation, impaired sensation, altered mental status

Question 10

does antimicrobial resistance warrant the designation of complicated UTI?

Answer 10

No, though multidrug resistance common in complicated UTI
- uncomplicated: healthy, ambulatory women with no history suggestive of anatomical or functional abnormality of the urinary tract

Question 11

What kind of subjective smx does elderly present with?

Answer 11

Frequently unspecific smx ie. altered mental status (drowsy, less alert, change in eating habits, GI)

Question 12

Urinalysis

Answer 12

UFEME, chemical analysis

Question 13

WBC threshold for pyuria

Answer 13

> 10WBCs/mm3

• signifies presence of inflammation, may or may not be due to infection
• unlikely pyruia = unlikely UTI

Question 14

What does presence of WBC cast indicate?

Answer 14

masses of cells and proteins that form in renal tubules (in kidney), indicate upper tract infection/disease

Question 15

What does presence of squamous epithelial cells in UFEME indicate?

Answer 15

High level of contamination, urine sample not well collected

Question 16

Empiric first line abx for uncomplicated cystitis in women (CA)

Answer 16

PO co-trimoxazole 800/160mg bid x3d
PO nitrofurantoin 50mg qid x5d
PO fosfomycin 3g single dose

Question 17

Alternative abx for uncomplicated cystitis in women (CA)

Answer 17

PO beta-lactams x3-7d

• cefuroxime 250mg bid
• cephalexin 500mg bid
• amoxi/clav 625mg bid

PO fluoroquinolones x3d

• ciprofloxacin 250mg bid - good resolution rate, but concern of collateral damage (last line)
• levofloxacin 250mg daily

Question 18

HA/complicated UTI org

Answer 18

E.coli, Enterococci

Klebsiella spp, Proteus spp, Pseudomonas aeruginosa, Enterobacter spp

Question 19

HA/complicated UTI org

Answer 19

50% E.coli
Enterococci (gram pos)
Klebsiella spp, Proteus spp, Pseudomonas aeruginosa, Enterobacter spp (gram neg)

Question 20

Staphylococcus aureus

Answer 20

commonly due to bacteremia, consider other primary sites of infection

Question 21

Yeast or Candida

Answer 21

commonly present in colonal bowel, possible contaminants, or consider other sites of infection

Question 22

Treatment for complicated cystitis in women

Answer 22

Treat for longer duration eg 7-14 days

fosfomycin dos: PO 3g EOD x3 doses

Question 23

Empiric abx for CA pyelonephritis in women

Answer 23

PO fluoroquinolones (first line) - shorter duration hence benefits>risks:

• ciprofloxacin 500mg bid x7d
• levofloxacin 750mg daily x5d

PO cotrimoxazole 960mg bid x14d

PO beta-lactams x10-14d:

• cephalexin 500mg bid
• amoxi/clav 625mg tds

Question 24

For severely ill patients who require hospitalisations or who are unable to take oral drug (pyelonephritis)

Answer 24

consider IV therapy:
IV ciprofloxacin 400mg bid or IV cefazolin 1g q8h or IV amoxi/clav 1.2g q8h
and/or
IV/IM gentamicin 5mg/kg, cover for ESBL-producing Klebsiella and E.coli
then switch to oral when pt improve or able to take orally

Question 25

Empiric abx for nosocomial/healthcare-assoc pyelonephritis

Answer 25

possibility of Pseudomonas aeruginosa and other resistant bacteria eg ESBL producing E.coli and Klebsiella IV cefepime 2g q12h +/- IV amikacin 15mg/kg/d IV imipenem 500mg q6h or IV meropenem 1g q8h PO ciprofloxacin 500mg bid PO levofloxacin 750mg - consider oral options for less sick patients 7-14d

Question 26

Empiric abx for CA-UTI in men

Answer 26

for cystitis, if no concern for prostatitis, treat as per complicated cystitis (7-14d) in women cystitis with concern for prostatitis or pyelonephritis: PO co-trimoxazole 960mg bid, 10-14d PO ciprofloxacin 500mg bid x10-14d Will need longer duration if prostatitis is confirmed (6 weeks)

Question 27

Most common cause of nosocomial UTI

Answer 27

catheter-assoc UTI

Question 28

Causative organisms of catheter-assoc UTI

Answer 28

``` short term (<7d) - 85% single org, reflecting that prevailing in envi long term (>28d) - 95% polymicrobial ie 2-3 org ```

Question 29

When is treatment of asymptomatic bacteriuria for catheter-assoc UTI recco?

Answer 29

Prior to traumatic urological procedures

Question 30

Catheter-assoc UTI smx

Answer 30

fever, rigors, altered mental status, malaise, lethargy with no other identified cause, flank pain, costovertebral angle tenderness, acute hematuria, pelvic discomfort

Question 31

Empiric abx for catheter-assoc UTI

Answer 31

IV imipenem 500mg q6h or IV meropenem 1g q8h IV cefepime 2g q12h +/- IV amikacin 15mg/kg (1dose) PO/IV levofloxacin 750mg x5d (for mild cases) PO co-trimoxazole 96-mg bid x3d (for women =< 65yo with catheter-uti wo upper urinary tract smx after an indwelling catheter has been removed) usually 7days with prompt resolution fo smx (deferverse in 72hrs) and 10-14d for those with delayed treatment