- E. coli is the most common cause of UTIs: accounts for 85% of community-acquired and 50% of hospital-acquired UTIs.
- Common uropathogens mnemonic: KEEPPS (Klebsiella, E. coli, Enterococcus, Proteus, Pseudomonas, Staph. saprophyticus).
- Proteus and Pseudomonas are always resistant to nitrofurantoin (inherent chromosomal resistance).
- Mechanisms: β-lactams (cell wall), aminoglycosides (ribosomal protein synthesis), quinolones (DNA gyrase), TMP-SMX (dihydrofolate reductase), nitrofurantoin (multiple enzyme systems).
- Antibiotics to avoid in pregnancy: fluoroquinolones (cartilage), TMP/SMX (teratogenicity early, kernicterus late), trimethoprim alone (megaloblastic anemia), nitrofurantoin (3rd trimester — neonatal hemolysis), tetracyclines, chloramphenicol (gray baby), erythromycin (maternal cholestatic jaundice).
- Antibiotics to avoid with warfarin: fluoroquinolones, TMP/SMX, metronidazole, ketoconazole.
- Acute pyelonephritis triad: chills, fever, flank pain with bacteriuria and pyuria — term not used if flank pain absent.
- Renal papillary necrosis mnemonic POSTCARDS: Pyelonephritis, Obstruction, Sickle cell, TB, Cirrhosis, Analgesic abuse, Renal vein thrombosis, Diabetes (most common), Systemic vasculitis.
- Acute ureteral obstruction by sloughed papilla with concomitant UTI is a urologic emergency.
- Uncomplicated cystitis first-line (3): fosfomycin 3g single dose, nitrofurantoin 100mg BID x5d, TMP-SMX DS BID x3d. Fluoroquinolones NOT first-line.
- Sterile pyuria warrants evaluation for TB, stones, or cancer.
- Asymptomatic bacteriuria: screen/treat only pregnant females and patients undergoing elective urologic surgery.
- E. coli is most common cause of emphysematous pyelonephritis/cystitis; usually diabetic; classic triad fever, vomiting, flank pain.
- Renal abscess: <3-5 cm IV antibiotics; ≥5 cm percutaneous drainage. Perinephric abscess: drainage if >3 cm.
- XGP pathogenesis triad: nephrolithiasis (staghorn), chronic obstruction, infection. Most common organism: Proteus. Pathology: lipid-laden foamy macrophages.
- Malacoplakia: von Hansemann cells and Michaelis-Gutmann bodies (pathognomonic); long-term antibiotics (sulfonamides, rifampin, doxycycline, TMP).
- Pregnancy: bacteriuria 4-7%; progression to pyelonephritis 20-40% in pregnant vs 1% non-pregnant. Treatment cuts pyelonephritis risk to 0-5%. Safe agents: penicillins, cephalosporins, fosfomycin, nitrofurantoin (not 3rd trimester).
- Fournier's: superficial/deep fascia (Camper's, Scarpa's/Dartos/Colle's) + skin; spares corpora, urethra, testes, cord; limited posteriorly by Colles' fascia, superiorly by clavicles. Orchiectomy almost never required.
- NIH prostatitis classification: I (acute bacterial), II (chronic bacterial), III (CPPS — IIIA inflammatory, IIIB non-inflammatory), IV (asymptomatic).
- E. coli is most common in bacterial prostatitis (65-80%); ≈5% of acute progress to chronic.
- UPOINT domains: Urinary, Psychosocial, Organ-specific, Infection, Neurologic/systemic, Tenderness (muscle).
- Acute prostatitis 1st-line: TMP/SMX or fluoroquinolone x14 days. ESBL/post-prostate biopsy: carbapenem 10-14d.
- Epididymitis pathogens: pediatric/elderly = E. coli; young sexually active = N. gonorrhoeae + C. trachomatis; MSM = E. coli + Pseudomonas.
- Acute epididymitis if gonorrhea likely: ceftriaxone 1000mg IM/IV + doxycycline.
- Ulcerative genital lesions painful: herpes, chancroid (PAINFUL x2); painless: syphilis, LGV, donovanosis.
- Genital ulcer lymphadenopathy tender: herpes, chancroid, LGV (TENDER x3); non-tender: syphilis; absent: donovanosis.
- HPV: non-oncogenic 6 & 11 (90% anogenital warts); oncogenic 16 & 18 (cervical and penile cancer; 16 more important for penile).
- Bacterial vaginosis mnemonic: "I have no CLUE why there are FISH in my GARDEN" — CLUE cells, FISHY odour, GARDNErella; metronidazole; partner not treated.
- Trichomoniasis: T. vaginalis; sexually transmitted; partner must be treated.
- HIV AIDS-defining cancers: Kaposi sarcoma (HHV-8), non-Hodgkin lymphoma, invasive cervical cancer.
- HIV-associated urologic malignancies: testicular, kidney, penile cancer. NOT associated: prostate, bladder.
- Indinavir stones are radiolucent on plain film and CT (unless mixed with calcium).
- BCG should be used cautiously in HIV-positive patients due to immune dependence.