Review of the comparative in vitro susceptibilities of lower female genital tract pathogens to older and newer fluoroquinolones

Appraising and rearranging a variety of susceptibility studies that used the same methodology performed in our laboratory, we reviewed and compared the in vitro activities of the newer fluoroquinolones (gatifloxacin, grepafloxacin, moxifloxacin, sitafloxacin and trovafloxacin) to those of the older fluoroquinolones (ciprofloxacin, ofloxacin, sparfloxacin, and levofloxacin) against potentially pathogenic, anaerobic bacterial species of the lower female genital tract. At a concentration of 2 mug/ml, moxifloxacin (89% inhibition) and gatifloxacin (83% inhibition) had comparable anti-anaerobic activity to trovafloxacin (88% inhibition). Sitafloxacin, which is under clinical development in Japan was also highly active against the anaerobes tested. Comparatively, the older fluoroquinolones and grepafloxacin demonstrated less anti-anaerobe activity. Sitafloxacin, moxifloxacin and trovafloxacin were the most active agents tested with 237/243 (97%), 217/ 243 (89%) and 319/367 (88%), of the strains inhibited at 2 mug/ml, respectively. While the older fluoroquinolones required the addition of a second drug to be useful in mixed gynaecological infections, the newer fluoroquinolones have improved anti-anaerobic activity and could potentially be useful as monotherapy. (C) 2000 Academic Press.