Antimicrobial resistance in Burkholderia pseudomallei

Four strains of Burkholderia pseudomallei were used to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill curves with 13 single antimicrobial agents: ceftazidime, piperacillin, imipenem, amoxicillin/clavulanic acid, doxycycline, cotrimoxazole, kanamycin, rifampicin, ciprofloxacin, trovafloxacin, clarithromycin, azithromycin and meropenem. The time-kill studies were also performed with 33 pairs of combinations of the above antimicrobial agents: 15 combinations which would be expected to be used for acute therapy and 18 combinations for maintenance therapy. The results show that the single and combination antimicrobial agents with bactericidal effects against the four strains of B. pseudomallei which should be used for clinical trials in acute melioidosis are: imipenem, meropenem, and imipenem + azithromycin. The combination antimicrobial agents which should be further studied for the ability to eliminate biofilm and intracellular killing effect are ciprofloxacin + clarithromycin, ciprofloxacin + azithromycin, and imipenem + azithromycin.