Xanthogranulomatous pyelonephritis is most often due to: (A) E. coli, (B) Proteus, (C) Pseudomonas, (D) Klebsiella
Answer is B. Xanthogranulomatous pyelonephritis occurs when a chronic urinary obstruction (often by staghorn calculi), together with chronic infection, leads to the suppurative destruction of renal tissue.Proteus infection is associated with staghorn formation.Ref: Harrison; 19th edition; Page no: 1033