Objective:The aim of this study is to detect in vitro the synergetic activity of colistin in combination with imipenem,amikacin or ciprofloxacin,at sub-inhibitory concentrations,against carbapenems-resistant(CR)Acinet...Objective:The aim of this study is to detect in vitro the synergetic activity of colistin in combination with imipenem,amikacin or ciprofloxacin,at sub-inhibitory concentrations,against carbapenems-resistant(CR)Acinetobacter baumannii and Pseudomonas aeruginosa strains isolated from various wards in Annaba teaching hospital in eastern Algeria.Materials and Methods:The minimal inhibitory concentrations(MIC)were determined by broth macrodilution(BMD).Carbapenemase encoding genes were screened using polymerase chain reaction(PCR).The activity of colistin in combination with second antibiotic was evaluated by the Checkerboard Technique.Results:39 CR P.aeruginosa and 21 CR A.baumanni strains where collected.The MIC values ranging from(0.25 to 4μg/ml)to colistin,≥16μg/ml for imipenem,≥4μg/ml to amikacin and≥8μg/ml ciprofloxacin.The PCR reveals the presence of the genes blaOXA23(n=12),blaOXA24(n=6),blaNDM1(n=3)in A.baumannii and blaVIM2(n=12)in P.aeruginosa.The combination of colistin with imipenem showed synergistic effect on 57.14%and 46.15%of A.baumannii and P.aeruginosa isolates,respectively.For colistin and amikacin,the synergistic effect is detected in 28.6%of A.baumannii and 30.8%of P.aeruginosa.While colistin and ciprofloxacin showed synergy on 14.29%and 15.38%of A.baumannii and P.aeruginosa isolates,respectively.Conclusion:CR A.baumannii and P.aeruginosa remain the most prevalent infection agents in patients from high-risk wards at Annaba Hospital.Colistin associated with imipenem or with amikacin at sub-inhibitory concentrations gives very encouraging results allowing better management of infections caused by this type of bacteria.展开更多
文摘Objective:The aim of this study is to detect in vitro the synergetic activity of colistin in combination with imipenem,amikacin or ciprofloxacin,at sub-inhibitory concentrations,against carbapenems-resistant(CR)Acinetobacter baumannii and Pseudomonas aeruginosa strains isolated from various wards in Annaba teaching hospital in eastern Algeria.Materials and Methods:The minimal inhibitory concentrations(MIC)were determined by broth macrodilution(BMD).Carbapenemase encoding genes were screened using polymerase chain reaction(PCR).The activity of colistin in combination with second antibiotic was evaluated by the Checkerboard Technique.Results:39 CR P.aeruginosa and 21 CR A.baumanni strains where collected.The MIC values ranging from(0.25 to 4μg/ml)to colistin,≥16μg/ml for imipenem,≥4μg/ml to amikacin and≥8μg/ml ciprofloxacin.The PCR reveals the presence of the genes blaOXA23(n=12),blaOXA24(n=6),blaNDM1(n=3)in A.baumannii and blaVIM2(n=12)in P.aeruginosa.The combination of colistin with imipenem showed synergistic effect on 57.14%and 46.15%of A.baumannii and P.aeruginosa isolates,respectively.For colistin and amikacin,the synergistic effect is detected in 28.6%of A.baumannii and 30.8%of P.aeruginosa.While colistin and ciprofloxacin showed synergy on 14.29%and 15.38%of A.baumannii and P.aeruginosa isolates,respectively.Conclusion:CR A.baumannii and P.aeruginosa remain the most prevalent infection agents in patients from high-risk wards at Annaba Hospital.Colistin associated with imipenem or with amikacin at sub-inhibitory concentrations gives very encouraging results allowing better management of infections caused by this type of bacteria.
