Characterization of blaAFM-1-positive carbapenem-resistant strains isolated in Guangzhou, China

Author:

Qin Yingcheng,Peng Yuan,Duan Xiaonv,Song Zhenli,Huang Rong,Rui Yongyu

Abstract

Abstract Background Carbapenemase-producing makes a great contribution to carbapenem resistance in Gram-negative bacilli. BlaAFM-1 gene was first discovered by us in Alcaligenes faecalis AN70 strain isolated in Guangzhou of China and, was submitted to NCBI on 16 November 2018. Methods Antimicrobial susceptibility testing was performed by broth microdilution assay using BD Phoenix 100. The phylogenetic tree of AFM and other B1 metallo-β-lactamases was visualized by MEGA7.0. Whole-genome sequencing technology was used to sequence carbapenem-resistant strains including the blaAFM-1 gene. Cloning and expressing of blaAFM-1 were designed to verify the function of AFM-1 to hydrolyze carbapenems and common β-lactamase substrates. Carba NP and Etest experiments were conducted to evaluate the activity of carbapenemase. Homology modeling was applied to predict the spatial structure of AFM-1. A conjugation assay was performed to test the ability of horizontal transfer of AFM-1 enzyme. The genetic context of blaAFM-1 was performed by Blast alignment. Results Alcaligenes faecalis strain AN70, Comamonas testosteroni strain NFYY023, Bordetella trematum strain E202, and Stenotrophomonas maltophilia strain NCTC10498 were identified as carrying the blaAFM-1 gene. All of these four strains were carbapenem-resistant strains. Phylogenetic analysis revealed that AFM-1 shares little nucleotide and amino acid identity with other class B carbapenemases (the highest identity (86%) with NDM-1 at the amino acid sequence level). The spatial structure of the AFM-1 enzyme was predicted to be αβ/βα sandwich structure, with two zinc atoms at its active site structure. Cloning and expressing of blaAFM-1 verified AFM-1 could hydrolyze carbapenems and common β-lactamase substrates. Carba NP test presented that the AFM-1 enzyme possesses carbapenemase activity. The successful transfer of pAN70-1(plasmid of AN70) to E.coli J53 suggested that the blaAFM-1 gene could be disseminated by the plasmid. The genetic context of blaAFM indicated that the downstream of the blaAFM gene was always adjacent to trpF and bleMBL. Comparative genome analysis revealed that blaAFM appeared to have been mobilized by an ISCR27-related mediated event. Conclusions The blaAFM-1 gene is derived from chromosome and plasmid, and the blaAFM-1 gene derived from the pAN70-1 plasmid can transfer carbapenem resistance to susceptible strains through horizontal transfer. Several blaAFM-1-positive species have been isolated from feces in Guangzhou, China.

Funder

Natural Science Foundation of Guangdong Province

Guangdong Province Science and Technology Project

Guangzhou City Science and Technology

Publisher

Springer Science and Business Media LLC

Subject

Infectious Diseases,Microbiology (medical),General Medicine

Cited by 3 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3