Anaerobic bacteria in suppurative genitourinary infections

Bacterial growth was obtained from specimens of 55 male and 48 female patients with localized suppurative genitourinary tract infections. The 55 male patients had abscesses of the genitalia (15), scrotal cyst (3), penis (7), testis (6), prostate (3), kidney (4), perinephric area (2) and periurethral area (4), wounds of the scrotum (3) and penis (6), and infected hydrocele (2). The 48 female patients had abscesses of Bartholin's cyst (26), vulva (4), vagina (4), labial cyst (2), kidney (2), perinephric area (1), periurethral area (3) and bladder (2), and a labial wound (4). Anaerobic bacteria only were present in 34 specimens (33 per cent), aerobic bacteria only in 7 (7 per cent), and mixed aerobic and anaerobic flora in 62 (60 per cent). A total of 275 isolates (189 anaerobic and 86 aerobic) was recovered, for an average of 2.6 isolates per specimen (1.8 anaerobes and 0.8 aerobes). The predominant anaerobes recovered were Bacteroides species (103 isolates) and anaerobic cocci (54). The most frequently recovered aerobes were Escherichia coli (26 isolates), Staphylococcus aureus (10) and Proteus species (8). These data illustrate that most suppurative genitourinary infections involve anaerobic bacteria. These findings have important implications regarding the culturing techniques of these infections and for the selection of antimicrobials for their management.