Abstract
An agar dilution technique and the 'E' test were used to compare the antimicrobial activities of ticarcillin, ticarcillin-clavulanate, ampicillin, ampicillin-sulbactam, piperacillin, piperacillin-tazobactam, meropenem, biapenem, imipenem, levofloxacin, ofloxacin, ciprofloxacin, ceftazidime and cefepime against 97 clinical isolates of Xanthomonas maltophilia. Intermediate susceptibility breakpoints for members of the family Enterobacteriaceae were used. Results were analysed as minimum inhibitory concentrations for 50 and 90% of the strains tested and as percentages of strains susceptible at the breakpoint. Good correlation between the two techniques was observed, with ticarcillin-clavulanate clearly the most active agent by both methods with 64 to 66% followed by levofloxacin with 63 to 65% of the strains being susceptible. Biapenem and imipenem showed weak activity with none of the strains being susceptible. Ceftazidime had better activity than cefepime when they were compared by the two methods. There was no significant difference in the results between the two susceptibility techniques used.