In vitro susceptibility of Stenotrophomonas maltophilia isolates to antimicrobial agents

Objective To compare the in vitro activity of moxifloxacin with other antimicrobial agents (gatifloxacin. levofloxa-cin, ciprofloxacin, ceftazidime, cefepime, cefoperazone-sulbactam, piperacillin-tazobactam. ticarcillin-clavulanic acid, trime-thoprim-sulfamethoxazole) against the clinical isolates of Stenotrophomonas maltophilia. Methods The MICs of ten antimicrobial agents for 200 strains of S. maltophilia collected from three hospitals in Beijing were determined by two-fold agar dilution test. The data were analyzed by WHONET 5. 3 software. Results The ranking of susceptibility rates from high to low was: moxifloxacin (84.5%), gatifloxacin (79.5%), levofloxacin (76%), trimethoprim-sulfamethoxazole (72.5%), cefoperazone-sulbactam (41.5%), ticarcillin-clavulanic acid (34%), ceftazidime (23%), ciprofloxacin (15%) , cefepime (7%) and piperacillin-tazobactam (4. 5%). New fluoroquinolones, such as moxifloxacin, have high in vitro activity against S. maltophilia. They may be good choice for the treatment of infections caused by S. maltophilia.