Week 5: Urinary Tract Infections

Question 1

Cystitis symptoms.

Answer 1

Irritation of the lower urinary tract mucosa

• dysuria
• urgency
• increased frequency of urination
• suprapubic tenderness, pelvic discomfort
• small volume voiding
• increased # WBCs in the urine (pyuria)

Question 2

Pyelonephritis symptoms

Answer 2

Ascension of the bacterial to the kidney from lower urinary tract but can also be from hematogenous spread

• fever
• flank pain and tenderness
• CVA tenderness
• nausea and vomiting

Question 3

Who get’s UTIs?

Answer 3

• males in neonatal period
• majority are adult females
• postmenopausal women due to loss of estrogen that causes change in vaginal flora
• males >50s yo due to BPH
• other risk factors: kidney stones, catheters, DM, immunosuppressed, neurogenic bladder, pregnant women

Question 4

Microbiology of UTIs

Answer 4

• E coli (75-95%). Enterobacteriaceae (Porteus and Klebsiella pneumonia)
• Staph saprophyticus

Question 5

Virulence mechanisms of UTIs

Answer 5

• bacterial adhesion onto urothelial cells
• virulene usually with serotype O e.coli
• 2 adhesins (pap and sfa) at tip of fimbriae (pili) and also nonfimbriae adhesions promote adherence onto urothelial cells and biofilm growth
• enterobacteriaciae are too small to overcome negative charge of epithelial cells so need fimbriae or other adhesion system
• epithelial cells internalize E coli cells, LPS produced from E coli induces production of cytokines in kidney that causes increased complement to gain entry into bladder

Question 6

Urinanlysis findings in UTI

Answer 6

• leukocyte esterase: dipsticks in use can detect >10 leukocytes per high power field (abnormal is more than 10)
• nitrite (enterobacteriacea): the bacteria metabolizes nitrate to nitrite.

Question 7

Indications for urine culture when UTI suspected

Answer 7

• is symptoms persist within 3 months
• women with negative leukocyte esterase but positive symptoms
• all women with acute pyelonephritis

Question 8

Treatment of uncomplicated cystitis and pyelonephritis

Answer 8

• Nitrofurantoin monohydrate
• trimeoprim-sulfamethoxazole (Bactrim)
• Fluoroquinolones

Question 9

Prostatitis: cause, symptoms, treatment

Answer 9

• Cause: reflux of infected urine into glandular prostatic tissue via ejaculatory and prostatic duct. E coli, Enterococcus spp., Proteus
• symptoms: fevers, chills, malaise, dysuria, low back pain, painful ejaculation
• dx: PE has warm tender enlarged prostate
• Rx: depends on gram stain in determining spectrum of antimicrobials, TMP-SMX or fluoroquinolones for gram negative rods. Tetracyclines and macrolide have good penetration into prostatic fluid