Drug resistance and genetic background of New Delhi metallo-β-lactamase ( NDM )-producing bacterial strains in Lishui area of Zhejiang province
10.3760/cma.j.issn.1674-2397.2018.04.007
- VernacularTitle:浙江省丽水地区NDM菌株的耐药特征及基因背景研究
- Author:
Jiansheng HUANG
1
;
Jinglu YU
;
Yan ZHU
;
Xiaolei HU
;
Jianmin REN
;
Yunan ZHAO
;
Hui DING
;
Rongzhen WU
;
Zhigang ZHAO
Author Information
1. 323000,浙江省丽水市中心医院检验科
- Keywords:
Beta-Lactamases;
blaNDM;
Drug-resistance characteristics;
Genetic background
- From:
Chinese Journal of Clinical Infectious Diseases
2018;11(4):287-293
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the drug resistance phenotype and genetic background of New Delhi metallo-β-lactamase (NDM)-producing bacterial strains in Lishui area of Zhejiang province.Methods The imipenem-resistant Enterobacteriaceae strains were isolated from January 2012 to December 2016 in Lishui Municipal Central Hospital of Zhejiang Province.Mrieux Vitek 2 Compact system was used to identified strains and PCR was used to screen for blaNDMgene.Susceptibility was detected by K-B method and MICs were obtained by Vitek 2 with GN13 cards.Plasmids typing was carried out by DNA sequencing of the replication initiator with the transconjugates as templates.The blaNDMgenetic contexts were detected by PCR and complete genome sequencing.Results A total of 102 strains of carbapenem-resistant enterobacteria (CRE), mainly Escherichia coli and Enterobacter cloacae, were isolated, of which 15 were positive for blaNDMwith a positive detection rate of 14.7%.The resistance rate to β-lactam antibiotics was 100%, and the resistance rates to aztreonam, compound sulfamethoxazole , tobramycin and gentamicin were all ＞80%;and the resistance rate to quinolones was ＞50%.Among the 15 NDM-producing strains , 12 strains were positive for Hodge test, and 2 strains of Enterobacter cloacae and 1 strain of Escherichia coli were negative. There were 11 strains of blaNDM-1and 4 strains of blaNDM-1.A variety of plasmid types such as IncX 3, IncFIIγ and IncA/C were detected, and 4 blaNDM-5genes were located in the IncX3 plasmid.Four blaNDMsurrounding gene structures were found, of which 8 blaNDM-1genes were located in ISAb125-hyp-blaNDM-1-bleMBL-TrpF-DsbC-IS26, while blaNDM-5was located in IS3000-IS5-blaNDM-5-bleMBL-TrpF-DsbC-IS26 structure, and the former was reported for the first time in China.Conclusion NDM-producing bacterial strains in Lishui area are prevalent at a low level and have high sensitivity to fosfomycin and polymyxin .The blaNDMgene may have multiple sources, but IncX3 plasmid is still the main source for gene transfer.Some new types of blaNDM-1 gene structure have been also found in this study.
