The Study Of Distribution About Carbapenemase OXA-51 In Acinetobacter Baumannii And Nosocomial Infection

Objective:To analyze the epidemiological characteristics and clinical distribution of OXA-51 enzyme in Carbapenem resistance Acinetobacter baumannii in Yanbian University Hospital,and to provide the basis for effective clinical control of nosocomial infection.Methods:A total of 206 isolates of Acinetobacter peculiar were cultured in our hospital from October 2015 to September 2016.The following methods were used to study:1.the phenotypic identification:using BD automatic bacterial、K-B paper diffusion method and 42 ℃ culture method to identify 206 strains of Acinetobacter baumannii.The phenotypic detection of metallogenic enzymes was carried out by EDTA co-trial.2.Genotype identification:Genomic analysis was performed by polymerase chain reaction(PCR)and agarose gel electrophoresis.Genotype analysis was used to analyze the genotype distribution of epidemic drug-resistant strains in our hospital.3.According to the antimicrobial susceptibility of bacteria analysis the drug resistance of Acinetobacter baumannii in our hospital.Results:1.82.2%strains of isolated Acinetobacter baumannii were derived from the type of sputum specimens,77.0%were from the intensive care unit.63.5%of carbapenem resistant patients are older than 60 years old,significantly more than young people and children;2.Resistance rate:there are 174 strains of carbapenem resistant strains from 206 strains of Acinetobacter baumannii,accounting for 84.5%,32 strains are carbapenem sensitive.Resistant strains to imipenem and meropenem accounts to 73.8%and 72.1%,and no strains resistant to polymyxin.3.Phenotypic identification:206 strains of AB were identified from 230 strains of Acinetobacter according to bacterial identification and 42 ℃ culture method;Using EDTA collaborative test 23 strains of E.coli;4.Genotype identification:The results of PCR showed that all the blaOXA-51 genotypes of Acinetobacter baumannii were positive,48 were blaOXA-51 gene and blaOXA-23 gene positive strains.blaOXA.24 and blaOXA-58 genotypes were not detected;5.The strains of blaOXA-51 genotype were divided into three groups,group 1:blaOXA-51 positive and ISA bal negative are 51 strains,group 2:blaOXA-51 and ISA bal both positive are 75strains,group 3:25 strains of blaOXA-51,blaOXA-23 and ISA bal were positive.3 groups of imipenem,meropenem resistant rates were 75%,99%and 100%.The presence of the ISA bal sequence increased the resistance rate of the blaOXA-51 genotype,and the increased susceptibility of the ISA bal gene to the imipenem group was 74%and 75%,resistance to meropenem increased by 25%and 26%;6.The results of pulsed-field gel electrophoresis showed that CR-AB was mainly type 1 and type 6,which were positive for blaOXA-51 and ISA bal genes.Conclusions:1.The resistance rate of carbapenems in Acinetobacter baumannii was higher,but it still had high sensitivity to polymyxin.The main department of the control of Acinetobacter baumannii in the hospital was Intensive care unit.2.The genotype of Acinetobacter baumannii,which is popular in our hospital,is mainly blaOXA-51 and blaOXA-23,and no blaOXA-24 and blaOXA-58 genotypes are detected.The presence of inserted sequence ISA bal increases the blaOXA-51 gene Type of resistance,blaOXA-51 and ISA bal genes were positive in the group of type 1 and 6 were the main subtypes of the hospital.