Detection and antibiotic resistance analysis of NDM-1 producing Acinetobacter isolated from sewage of hospitals in Beijing

Objective To investigate the prevalence of New Delhi Metallo-beta-lactamase-1(NDM-1)producing Acinetobacter isolated from sewage samples of hospitals in Beijing and to analyze its antibiotic resistance.Methods Sewage samples were collected from several comprehensive hospitals in Beijing and the isolated strains with suspicious resistance to imipenem were screened with biochemical identification and 16S rRNA sequencing.Polymerase chain reaction(PCR)technique was used to detect the blaNDM-1 gene from the isolated bacterial colonies.Antibiotic susceptibility testing of all the blaNDM-1 positive strains was performed by using the Sensititre instrument.Results Twenty blaNDM-1 positive Acinetobacter strains were detected,including 10 A.baumannii,4 A.calcoaceticus,4 A.lwoffi,and 2 A.junii.All strains were resistant to ceftriaxone,cefepime,cefepime,cefepime,cefoperazone,cefazolin,cefoxitin,and ampicillin and 85%of them to imipenem.Conclusion Isolation rate of the blaNDM-1 positive Acinetobacter in hospital sewage in Beijing is high and the blaNDM-1 positive bacteria are multidrug resistance.Hospital sewage may be one of main medium facilitating the emergence and spread of the blaNDM-1 positive bacteria.