Comparison Of Biapenem In Combination With Other Antimicrobial Agents

Objectives:To evaluate the in vitro activity of biapenem respectively combined with sulbactam,amikacin,ciprofloxacin and fosfomycin against psendomonas aeruginosa(PAE) and acinetobacter baumanii(ABA), so as to discuss the feasibility of combined use of antimicrobial agents and seek effective combined strategy to treat the infection of PAE or ABA in clinical.Methods:1. PAE and ABA were isolated and identified by routine procedure and VITEK-32automatic bacterial identification instrument;2. K-B paper method was used to test routine susceptibility of biapenem, sulbactam, amikacin, ciprofloxacin and fosfomycin,also combined drug susceptibility of biapenem with sulbactam, amikacin, ciprofloxacin and fosfomycin; 3. The protocol was designed by checkerboard method, and the minmium inhibitory concentration (MIC) of antibiotics was admitted by microdilution broth method, and the fractional inhibitory concentration (FIC) index was calcutated according to MIC results.Results:1. The resistant rates of18strains of PAE to biapenem, sulbactam, amikacin, ciprofloxacin and fosfomycin respectively were33.3%,11.1%,16.7%,38.9%,44.4%;and the resistant rates of23strains of ABA respectively were87.0%,87.0%,87.0%,100%,78.3%;2. The synergys of biapenem plus amikacin, ciprofloxacin fosfomycin or sulbactam against18strains of PAE respectively were16.7%.11.1%,72.2%,61.1%; against23strains of ABA respectively were0.0%、0.0%、30.4%、65.2%;3. FIC indexs of biapenem combined with amikacin, ciprofloxacin, fosfomycin and sulbactam against No.112PAE respectively were0.75,1.0,0.375and0.125;against No.112PAE respectivrly were1.0,1.0,0.5and0.25; against No.213ABA respectively were1.0,0.75,1.0and0.5; against No.209ABA respectively were1.0,1.5,1.0and0.375.Conclusions: The resistance of PAE and ABA separated from clinical specimens was increasing,and the problem of ABA was much more serious.Some bateria probably owned kinds of resistant mechanism. There was no antagonistic effect observed in the experiment of biapenam combined with sulbactam, amikacin, ciprofloxacin or fosfomycin,of which the most effective was biapenam plus sulbactam and the second was biapenam plus fosfomycin.In the experiment most piapenam plus amikacin showed unrelated effect, which was different from used to be. Biapenam was suggested to treat the infection with multiple drug resistant PAE or ABA in combination with composite including enzyme inhibitor(sulbactam or tazobactam),in order to improve treatment and control the infection effectively.