Intro to UTIs

Question 1

Describe the pathophysiology of UTIs?

Answer 1

The female urethra is usually colonized by bacteria from fecal flora due to close proximity to the perianal area. Bacteria can ascend easily through the urethra to the bladder and cause an infection. Once bacteria have reached the bladder, they can multiply quickly and ascend the ureters to the kidneys.

Question 2

What is the concern if S. Aureus is identified in urine culture?

Answer 2

If Staphylococcus aureus is identified in urine culture, STAT blood cultures are recommended to rule out hematogenous spread as staphylococcal bacteremia will require aggressive treatment.

Question 3

Describe the classification of UTIs?

Answer 3

Question 4

What are 3 iatrogenic risk factors for UTIs?

Answer 4

• Indwelling catheter
• Antibiotic use
• Spermicides

Question 5

What are two behavioral risk factors for UTIs?

Answer 5

1. Voiding dysfunction
2. Frequent or recent sexual intercourse

Question 6

What are antatomic/physiologic risk foactors for UTI?

Answer 6

• Vesicoureteral reflux - retrograde flow
• Female sex - short urethra
• Pregnancy - progesterone mediated smooth muscle relaxation to the bladder and ureters and compression of ureters by uterus.

Question 7

What are genetic risk factors for UTIs?

Answer 7

• Familial tendency
• susceptible uroepithelial cells (less IgA secreted)
• Vaginal mucus properties (can allow E.Coli to bind more readily)

Question 8

What is the diagnostic approaches for UTIS?

Answer 8

1. Uncomplicated UTIs (females) can be suspected based on symptoms of dysuria, urinary frequency, or urgency, and pain (>90% accuracy) in the absence of vag symptoms. Chills, fever, and back pain is likely systemic and indicative of upper UTI
2. Urinalysis - color, appearance, specific gravity, pH, protein, glucose, ketones, bilirubin, blood, leukocyte sterase, nitrite, RBC, WBC casts and bacteria - false positives, and false negatives results are not unusual. RESERVED for cases where clinical presentaiton is not typical
3. Culture and susceptibility - Mainstay for diagnosis

Question 9

When is a urine culture and Sensitivity warrented?

Answer 9

• complicated UTI is suspected
• Symptoms do not resolve with treatment or recur within 4 weeks of antibiotic treatment
• Pts with atypical symptoms
• Previous UTI with specific resistant organisms
• Pregnant women
• recent travel outside of Canada/USA,
• recent quinolone or cephalosporin use and recent hospitalizaiton are also included as clinical situations where urine culture and susceptibililty tests are reocmmended.

Question 10

Whatare the commone Gram negative bacteria implicated in UTI?
Gram positive?

Answer 10

Gram -VE
ECOLI - 75-95%)
Klebsiella
Proteus miabilis

Gram +Ve
Staphlococcus. Saprophyticus (5-15%)
Enterococcus faecalis
Entercoccus feacium

In complicated UTIs or catheter associated UTIs, you may see more resistant organisms, such as Enterobacter, Serratia, Citrobacter, and Pseudomonas species.