Analysis on drug-resistant genes and homology in nosocomial infection of carba penem-resistant Acinetobacter baumannii / 国际检验医学杂志

ABSTRACT

Objective To analyze the drug resistance genes and homology in nosocomial infection caused by carbapenem‐resistant Acinetobacter baumannii(CRAB) .Methods Forty strains of CRAB were collected and the minimal inhibitory concentration (MIC) was detected by the agar dilution method .The main carbapenemase genes were detected by PCR .The PCR products were performed the DNA sequencing .The enterobacterial repetitive intergenic consensus (ERIC)‐polymerase chain reaction(PCR) was performed to analyze the genotypes and homology of these strains .The plasmid conjugation experiment was carried out to investigate the trans‐mission of resistant genes .Results Forty strains of CRAB maintained the good sensitivity only to polymyxin B (100% ) and cef‐operazone/sulbactam(57 .5% ) .All of them had different degrees of resistance to other drugs .The OXA‐23 and OXA‐51genes were detected by PCR amplified in all of the CRAB strains .The homology analysis showed that the strains could be divided into 4 types according to 80% of cluster similarity coefficient ,the type A1 (19 strains) was the major epidemic strain ,moreover the various de‐partments had cross infection ;the plasmid conjugation experiment failed .Conclusion There is an endemic spread of CRAB in our hospital and its resistant mechanism is mainly related with OXA‐23 gene expression ;in the rational antibiotics use at the same time , the isolation and prevention measures should be done well for avoiding the hospital cross infection .