Carriage and homology of carbapenemase genes of multidrugresistant Acinetobacter baumannii in Wujiang

Abstract:

ObjectiveTo investigate the carriage and homology of carbapenemase genes of multidrugresistant Acinetobacter baumannii (MDRAB) in Wujiang area.MethodsA total of 44 nonduplicated MDRAB isolated from patients in 3 general hospitals in Wujiang area from January 2010 to December 2013 were collected. Minimum inhibitory concentrations(MICs) were detected, carbapenemase genes OXA51, OXA23, OXA24, OXA58, IMP, TEM, SHV, and GES were amplified with polymerase chain reaction(PCR), homology of strains was detected with pulsedfield gel electrophoresis(PFGE).Results44 MDRAB strains were mainly collected from sputum (93.18%), mainly distributed in intensive care unit (ICU), department of respiratory diseases, and department of neurosurgery, accounting for 45.45%, 27.27%, and 13.64% respectively; MDRAB were both sensitive to minocycline and polymyxin B, resistance rates to piperacillin, ampicillin/sulbactam, ceftazidime, gentamicin, amikacin, and ciprofloxacin were all 100.00%, resistance rates to imipenem and meropenem were both 97.73%. 44 MDRAB strains were all detected OXA51, OXA23 and TEM genes, 12 strains were positive for GES gene, 1 strain was positive for OXA58 and SHV respectively, OXA24 and IMP genes were not found ; MDRAB were divided into 7 types of GA, which included 19, 3, 9, 3, 1, 4, and 5 strains respectively, type A was mainly from two large general hospitals in Wujiang area (Wujiang First People’s Hospital and Shengze Hospital), type B, D and E strains were not detected in Wujiang First People’s Hospital, type E strain was only 1 isolate and was from Yongding Hospital, the other types were sporadically distributed.ConclusionMultidrug resistance of clinically isolated Acinetobacter baumannii is serious in Wujiang area, OXA23 and TEM genes are major causes of multidrug resistance in Acinetobacter baumannii, the main types are A and C, which present clonal spread.