E. coli involved in 80% of cases
Other: Pseudomonas, Klebsiella, Enterobacter, Serratia, Staph
Urinary Tract Obstruction
Epididymitis
Urethritis
Unprotected rectal intercourse
Phimosis
Indwelling urethral catheter
"UTI" frequently refers specifically to acute cystitis, but may also be used as a general term for all urinary infections; use location-specific diagnosis.
Renal/perirenal
Pyelonephritis
Emphysematous pyelonephritis
Renal abscess
Perinephric abscess
Ureteral
Infected urolithiasis
Bladder
Acute cystitis ("UTI")
Chronic cystitis
Urethra/periurethra
Urethritis<unk> 
Pyelonephritis
Emphysematous pyelonephritis
Renal abscess
Perinephric abscess
Emphysematous pyelonephritis
Infected urolithiasis
Acute cystitis ("UTI")
Chronic cystitis
Urethritis<unk>
Prostatitis
Genitourinary infection
Proctitis
Acute cystitis 
Acute cystitis
Pyelonephritis
Pelvic inflammatory disease
Urethritis