摘要
目的了解深圳地区耐亚胺培南临床菌株的分布及携带碳青霉烯酶基因的情况,并检测其携带的可移动基因元件。方法 2014—2016年中山大学附属第八医院(深圳)送检标本中分离耐亚胺培南菌株96株,参照美国CLSI的M100S25标准进行药敏分析;采用Carba NP-d试验检测碳青霉烯酶表型;PCR检测碳青霉烯酶基因及可移动基因元件I类整合子、插入序列共同区(Insertion sequence common region,ISCR),对肠杆菌科加测质粒复制子类型。结果 96株耐亚胺培南临床菌株对多种临床常用抗菌药物均耐药;其中52株碳青霉烯酶表型阳性;68株携带碳青霉烯酶基因,其中61株携带D类碳青霉烯酶基因,3株携带bla_(VIM),2株携带blaKPC,1株携带bla_(IMP),1株携带bla_(NDM-1);I类整合子检出率为69.8%,其可变区携带有耐药相关基因盒aad A1、aac A4、dfr A12、aad A5、dfr A17和未知功能的orf F,未发现碳青霉烯是耐药基因;ISCR1检出率为16.7%;肠杆菌科菌株64.3%携带质粒,以Inc F型为主。结论深圳地区耐亚胺培南临床菌株具有多重耐药表型,绝大多数产碳青霉烯酶,碳青霉烯酶基因多存在于细菌染色体上,这类菌株同时携带多种可移动的基因元件及耐药基因,因此,其耐药性具有稳定遗传和水平播散的能力,应密切关注。
Objective To investigate the distribution of carbapenemases-encoding gene and mobile genetic elements of imipenem-resistant clinical strain. Methods A total of 96 isolates of clinical strain were separrated from clinical specimens from January 2014 to December 2016 in the hospital. Bacterial identification and antimicrobial susceptibility test were carried out with VITEK 2 Compact automatic microbiological assay system. The detection of carbapenemase-producing clinical strains were confirmed by Carba NP-d test. Screening of carbapenemase-encoding gene,class 1 integron,ISCR1 and replicon typing of plasmid in Enterobacteriaceae were identified by PCR. Results A total of 96 imipenem-resistant clinical strains showed high-level resistance to multiple antibiotics commonly used,among them 52 isolates（ 76.5%） were phoneype positive for carbapenemase. Carbapenemase-encoding gene was identified in 68 isolates,among them 63 strains confirmed as class D carbapenemase,3 carried blaVIM,2 carried blaKPC,1 carried blaIMPand 1 carried blaNDM-1. The coincidence rate of clinical strains with classⅠintergron was 69.8% in96 strains. Sequencing date of integrons revealed that variable region harbored gene-cassette of aad A1,aac A4,dfr A12,aad A5,dfr A17 and unknown orf F. 16 strains（ 16.7%） were positive in PCR amplification of ISCR1. PCR-based replicon typing showed that 64. 3% of Enterobacteriaceae carried plasmid. The Inc F was the major plasmid incompatibility group.Conclusion The imipenem-resistant clinical strain is multi-drug resistant bacteria in Shenzhen area,majority of them produce carbapenemase,and most of their gene contained on chromasome. Meanwhile,the strains bring mobile genetic elements and mutiple resistence genes. It is a great concern that the resistance gene is able to stablize inheritance and horizontal transfer.
作者
王紫琦
陆学东
蒋利利
杨维青
赵祖国
WANG Zi-qi;LU Xue-dong;JIANG Li-li;YANG Wei-qing;ZHAO Zu-guo(Department of Immunology and Microbiology, Guangdong Medical University, Zhanjiang 524023, Guangdong Province, Chin)
出处
《微生物学免疫学进展》
2018年第3期33-39,共7页
Progress In Microbiology and Immunology
关键词
细菌耐药
碳青霉烯酶
可移动基因元件
Antiroicrobial resistance
Carbapenemase
Mobile genetic elements
