Which is the most likely organism to cause a UTI?

Correct Answer: B

Rationale: E. coli is the most likely UTI organism ~80% of uncomplicated cases (e.g., adheres via fimbriae), dominant in community settings. Staph saprophyticus ranks second young women, ~10-15%. Pseudomonas and Klebsiella occur in complicated UTIs hospitalized/catheterized, less common. E. coli's prevalence distinguishes it, key to UTI etiology, unlike secondary or nosocomial pathogens.

Correct Answer: A

Rationale: Prostatitis isn't usually STD-related E. coli (enteric) dominates acute bacterial cases, incorrect. Tender/enlarged prostate classic sign, true. IV gentamicin/ampicillin for severe cases appropriate. Co-trimoxazole concentrates well effective, correct. Non-STD etiology distinguishes the error, key to bacterial prostatitis, unlike physical, severe, or treatment truths.

Correct Answer: D

Rationale: 10 cm kidneys (normal size) suggest ARF CRF shrinks kidneys (<9 cm) from scarring, not chronic. Anemia (erythropoietin loss), osteodystrophy (phosphate retention), and polyuria/nocturia (tubular damage) are CRF hallmarks chronic adaptation. Normal size distinguishes ARF, key to differentiating acuity, unlike chronic signs.

Correct Answer: D

Rationale: Increased erythropoietin isn't CRF levels drop, causing anemia (e.g., renal failure), incorrect. Secondary hyperparathyroidism (phosphate retention), hypocalcemia (low vitamin D), and hyperphosphatemia (excretion loss) all classic. Erythropoietin deficiency distinguishes the error, key to CRF's anemia, unlike metabolic shifts.

Correct Answer: D

Rationale: Iron doesn't typically cause ARF unlike rhabdomyolysis (myoglobin), NSAIDs (perfusion drop), and ethylene glycol (oxalate crystals), all established. Iron overload affects liver renal toxicity rare. Lack of nephrotoxicity distinguishes it, key to ARF differential, unlike proven renal insults.