阿拉丘沙门菌的遗传特征及耐药基因初步研究  

Preliminary examination of the genetic characteristics and antimicrobial resistance genes of Salmonella Alachua

作　　者：刘玥[1] 许学斌[1] 胡屹[2] 顾其芳[1] 刘诚[1] 袁政安[1] 陈敏[1] LIU Yue;XU Xue-bin;HU Yi;GU Qi-fang;LIU Cheng;YUAN Zhen-an;CHEN Min(Department of Microbiology,Shanghai Municipal Center for Disease Control and Prevention,Shanghai 200336,China;School of Public Health,Fudan University,Shanghai 200032,China)

机构地区：[1]上海市疾病预防控制中心病原生物检定所,上海200336 [2]复旦大学公共卫生学院流行病教研室,上海200032

出　　处：《中国人兽共患病学报》2025年第2期164-170,共7页Chinese Journal of Zoonoses

基　　金：上海市加强公共卫生体系建设三年行动计划(2023-2025);重点学科项目(No.GWVI-11.1-09)资助。

摘　　要：目的 基于阿拉丘沙门菌分离株的全基因组分析,初步探讨其遗传特征及耐药基因分布。方法 收集并鉴定5株来自不同来源(人源与非人源)的阿拉丘沙门菌,对其进行表型和血清型验证、抗菌药物敏感性测定以及全基因组测序分析。利用全球公开数据库的阿拉丘沙门菌基因组数据,对这些菌株的毒力基因、耐药基因和质粒复制子进行预测,并构建系统发育树以探讨其遗传背景。结果 我国阿拉丘沙门菌的首例报告出现于2015年的上海,临床特征主要为腹泻,菌株主要集中在东部和南部沿海地区。本次研究的5株菌株中,4株归属于序列型ST2061,1株归属于ST1298。所有菌株对大多数临床常用抗菌药物敏感。全基因组分析结果显示,2株ST2061菌株携带bla KPC-2基因,1株ST1298菌株携带fosA7基因。在全球阿拉丘沙门菌群体的5个遗传进化群(C1~C5)中,本研究的ST2061克隆位于C1群,与英国菌株高度同源;而ST1298克隆位于C4群,为携带磷霉素耐药基因fosA7的全球流行克隆。结论 本研究初步呈现我国阿拉丘沙门菌分离株的遗传和耐药特征,提示存在携带bla_(KPC-2)和fosA7基因的菌株出现。为后续在更大范围内开展的分子流行病学监测与溯源分析提供参考,并强调加强阿拉丘沙门菌耐药性监测的重要性。This study was aimed at preliminarily investigating the genetic and antimicrobial resistance characteristics of Salmonella Alachua isolates through whole-genome analyses.Five Salmonella Alachua isolates from various sources(both human and non-human)were collected and identified.Phenotype and serotype verification,antimicrobial susceptibility testing,and whole-genome sequencing were performed.Virulence genes,antimicrobial resistance genes,and plasmid replicons were predicted according to globally available Salmonella Alachua genomic data.A phylogenetic tree was constructed to explore the genetic background.The first report of Salmonella Alachua in China emerged in Shanghai in 2015,and patients presented primarily with diarrhea.The isolates have been found predominantly in the eastern and southern coastal regions.Among the five isolates analyzed,four belonged to sequence type(ST)2061,and one belonged to ST1298.All isolates were susceptible to most commonly used clinical antibiotics.Whole-genome analyses revealed that two ST2061 strains carried the bla KPC-2 gene,and one ST1298 strain carried the fosA7 gene.Phylogenetic analysis of global Salmonella Alachua populations indicated that the ST2061 clone belonged to the C1 clade,which was closely related to strains from the UK,whereas the ST1298 clone was found in the C4 clade,a globally disseminated fosA7-positive lineage.This study provides initial insights into the genetic and antimicrobial resistance characteristics of Salmonella Alachua in China,highlighting the presence of strains carrying bla_(KPC-2) and fosA7 genes.These findings may provide a reference for future large-scale molecular epidemiological surveillance and source-tracing efforts,and they underscore the importance of enhanced resistance monitoring for Salmonella Alachua.

关 键 词：阿拉丘沙门菌 bla KPC-2 fosA7 系统发育进化 

分 类 号：R378.2[医药卫生—病原生物学]