Resistance to -lactams and carbapenemases carriage of Acinetibacter baumannii complex in a hospital in Hainan

Objective To investigate the -lactams resistance and carbapenemases carriage of clinical Acinetobacter baumannii complex isolates in Hainan province. Methods A total of 103 of A. baumannii complex isolates were collected in a hospital in Hainan during 2013-2014. Broth microdilution method was used to test the minimal inhibitory concentrations (MICs) of 7 antibiotics for isolates, and PCR was conducted to detect 9 carbapenemases encoded genes. Results In this study, A. baumannii complex isolates shown high resistant rates to piperacilin (n=51, 49.51%), ceftazidime (n=47, 45.63%), and cefotaxime (n=48, 46.60%). The resistant rates to cefepime and piperacilin/tazobactam were 39.81% (n=41) and 40.78% (n=42) respectively. Approximate 20% of the isolates were resistant to imipenem or meropenem. There were 38 isolates carrying blaOXA-58 gene and 62 isolates carrying blaOXA-66 gene and 25 isolates carrying both of blaOXA-58 gene and blaOXA-66 gene. No A. baumannii complex isolates were detected to carry other 7 carbapenemases encoded genes. Conclusion The resistance to -lactams was high among the A. baumannii complex isolates in this study. Carbapenemases encoded genes blaOXA-58 and blaOXA-66 contributed to the carbapenem resistance in A. baumannii complex isolates, while there were other resistant mechanisms.