In Genitourinary TB, True is -

Sterile pyuria is the rule" - But about 15-20% of patients with tuberculosis have a secondary pyogenic infection, obscuring the clue - sterile pyuria. The tubercle bacilli can be identified on AFB staining of 24 hr urine specimen or the first-morning urine sample collected on 3 successive days." AFB staining is positive in about 60% of cases - Smith' Urology Most common site of genitourinary tuberculosis is - kidney The commonest cause of pyelonephritis is - E. coli Ref : Smith's Urology 17/e p195, 219