耐碳青霉烯革兰阴性杆菌耐药性及基因分型

Drug resistance and genotypes of carbapenem-resistant gram-negative bacilli

目的分析住院患者临床分离的耐碳青霉烯类细菌(CPO)类型、耐药机制及耐药基因分型,为临床合理用药提供依据。方法收集天津市第三中心医院2017年11月-2019年10月临床分离的CPO 122株。应用VITEK MS全自动快速微生物质谱检测系统和VITEK-2 Compact全自动微生物药敏系统分别进行细菌鉴定和药敏试验;采用聚合酶链反应(PCR)方法检测碳青霉烯酶耐药基因,采用免疫显色方法检测碳青霉烯酶耐药表型。结果122株细菌包括肺炎克雷伯菌52株,铜绿假单胞菌29株,鲍氏不动杆菌28株,大肠埃希菌、阴沟肠杆菌、氟劳地柠檬酸杆菌、约氏不动杆菌各2株,产酸克雷伯菌、神户肠杆菌、少动鞘胺醇菌、产吲哚金黄杆菌、恶臭假单胞菌各1株。菌株对各类抗菌药物表现出不同程度的耐药,肺炎克雷伯菌、铜绿假单胞菌和鲍氏不动杆菌对亚胺培南、美罗培南、哌拉西林、头孢吡肟的耐药率均高于96%。碳青霉烯酶基因blaKPC和blaOXA-23检出率最高,未检出blaOXA-48。碳青霉烯酶耐药表型KPC和OXA-23检出率最高。以PCR方法检测结果作为金标准,与免疫显色表型检测结果进行McNemar-Bowker法统计学分析,P=0.351。结论碳青霉烯酶肺炎克雷伯菌以KPC型为主,鲍氏不动杆菌以OXA-23型为主。本实验应用的免疫显色法检测结果与PCR方法一致,且操作简便、快速,适合临床微生物实验室常规开展。

OBJECTIVE To analyze the species,drug resistance mechanisms and drug resistance genes of clinical isolates of carbapenem-resistant organisms(CPO)so as to provide guidance for reasonable clinical use of antibiotics.METHODS A total of 122 clinical isolates of CPO were collected from the Third Central Hospital of Tianjin from Nov 2017 to Oct 2019.The clinical isolates were identified by using VITEK-2 Compact automatic microorganism analysis system,the drug susceptibility testing was performed by means of VITEK-2 Compact automatic microorganism analysis system,carbapenemases resistance genes were detected by using polymerase chain reaction(PCR),and drug resistance phenotypes of carbapenemases were detected with the use of immunochromogenic method.RESULTS Among 122 strains of isolated bacteria,there were 52 strains of Klebsiella pneumoniae,29 strains of Pseudomonas aeruginosa,28 strains of Acinetobacter baumannii,2 strains of Escherichia coli,2 strains of Enterobacter cloacae,2 strains of Citrobacter fluraloxidans,2 strains of Acinetobacter yoelii,1 strain of Klebsiella acidogenes,1 strain of Enterobacter Kobe,1 strain of Sphingomonas oligozootica,1 strain of Chrysobacterium indole and 1 strain of Pseudomonas putida.The strains showed various degree of drug resistance.The drug resistance rates of K.pneumoniae,P.aeruginosa and 7 to imipenem,meropenem,piperacillin and cefepime were more than 96%.The detection rates of blaKPC and blaOXA-23 were the highest,but blaOXA-48 was not detected.The detection rates of carbapenemases drug resistance phenotypes KPC and OXA-23 were the highest.Set the result of PCR as gold standards,the statistical analysis that was performed by McNemar Bowker method showed that P=0.351.CONCLUSION KPC is dominant among the carbapenemase-producing K.pneumoniae,OXA-23 is dominant among A.baumannii.The immunochromogenic assay is consistent with PCR method in the result of detection,with the operation simple and rapid,and it is suitable for clinical microbiology laboratory test.