NDM-1 gene and other carbapenemase genes in Acinetobacter baumannii in Jiangxi area / 中国感染控制杂志

ABSTRACT

Objective To understand the carriage of NDM-1 and other carbapenemases in carbapenem-resistant Acinetobacterbaumannii(CRAB)in Jiangxi area,and provide laboratory basis for the prevention and control of healthcare-associated infection (HAI). Methods Sixty-four strains of CRAB isolated from clinical specimens from 3 tertiary first-class hospitals in Jiangxi area from January 2015 to June 2016 were collected,susceptibility to com-monly used antimicrobial agents were detected with Kirby-Bauer method. Carbapenemases and metalloenzyme in CRAB were screened with modified Hodge test and EDTA-disk synergy test respectively,carbapenems gene was de-tected by polymerase chain reaction (PCR),NDM-1-producing Acinetobacterbaumannii (A. baumannii)were per-formed conjugation test.Results The resistance rates of CRAB to ampicillin/sulbactam,ciprofloxacin,gentamicin, and levofloxacin were up to 95.31% ,98.44% ,90.63% ,and 54.69% respectively. The positive rates of modified Hodge test and EDTA-disk synergy test were 76.56% and 96.88% respectively. PCR amplification result showed that 87.50% (n= 56)of CRAB carried OXA-23 and VIM-1 genes,18.75% (n= 12)carried SIM,3.13% (n= 2)car-ried OXA-24,and 26.56% (n= 17)carried NDM-1 . CRAB carrying NDM-1 gene were all from The First Affilia-ted Hospital of Nanchang University,64.70% (11/17)of which were pandrug-resistant strains. Conjugation test re-sult showed that NDM-1-producing strains could transfer NDM-1 gene to recipient strain Escherichiacoli J53,then acquired resistance to imipenem. Conclusion Antimicrobial resistance rates of clinically isolated CRAB in this area are high,OXA-23 and VIM-1 genes are the main carbapenemase genes,NDM-1 gene positive CRAB is detected, and there may be a clonal spread of NDM-1 gene in hospital,effective measures should be taken as soon as possible to prevent and control the spread of NDM-1 positive CRAB.