Geographic variations in garenoxacin (BMS284756) activity tested against pathogens associated with skin and soft tissue infections: report from the SENTRY Antimicrobial Surveillance Program (2000)

Abstract

The antimicrobial activity of garenoxacin, a des-(6)F quinolone (formally BMS284756 and T-3811), was evaluated against 2,537 skin and soft tissue infection (SSTI) isolates from the SENTRY Antimicrobial Surveillance Program. Strains isolated in 2000 from Europe, North and Latin America were tested at a central laboratory using reference broth microdilution methods. The rank order of the seven most frequent SSTI pathogens was: Staphylococcus aureus (39.9%), Pseudomonas aeruginosa (12.1%), Escherichia coli (9.7%), Enterococcus spp. (7.7%), Klebsiella spp. (5.8%), Enterobacter spp. (5.6%) and coagulase-negative staphylococci (CoNS; 4.2%). Garenoxacin exhibited a four-fold greater activity (MIC 90, 0.06 μg/ml) compared to levofloxacin (MIC 90, 0.25 μg/ml) against oxacillin-susceptible S. aureus; and oxacillin-resistant staphylococci were more susceptible to garenoxacin (≥90.5%) at ≤4 μg/ml than ciprofloxacin or levofloxacin. Enterococcus spp. were more susceptible to garenoxacin and gatifloxacin (MIC 50, 0.5 μg/ml) than ciprofloxacin or levofloxacin (MIC 50, 2 μg/ml). All tested quinolones inhibited 64.7 to 69.7% of P. aeruginosa isolates, and the rank order of potency slightly favored ciprofloxacin (MIC 50, ≤0.25 μg/ml). Similar susceptibility rates for the four quinolones were observed against E. coli (85.8–87.0%), Enterobacter spp. (90.8–94.3%) and Klebsiella spp. (89.8–95.2%) with the greatest levels of resistance recorded in Latin America for E. coli and Enterobacter spp. The occurrence of extended spectrum β-lactamase-producing isolates (predominantly K. pneumoniae) was documented in all three monitored regions (Latin America > Europe > North America). Continued development of garenoxacin as a treatment of pathogens that commonly cause SSTIs appears to be warranted.