全基因组测序分析45株沙门氏菌分子分型、耐药性与毒力携带情况

Analysis of molecular subtyping,drug sensitivity and virulence factors of 45 strains of Salmonella by whole genome sequencing

目的了解沙门氏菌的血清型、分子分型、耐药性及毒力因子特征,探究血清型与耐药性以及毒力之间的关系。方法对吉林省2023年分离到的45株沙门氏菌,采用血清凝集法鉴定血清型;使用微量肉汤稀释法进行17种抗菌药物的耐药性试验;利用全基因组测序及生物信息学对沙门氏菌基因组进行ST型、cgMLST、wgSNP、耐药基因及毒力因子分析。结果45株沙门氏菌分为11种血清型(13种ST型),鼠伤寒沙门氏菌(35.56%,16/45)与肠炎沙门氏菌(31.11%,14/35)为优势血清型,ST以ST11和ST34为主,其中存在1株未知血清型I4,[5],12:d:-(ST279型)沙门氏菌;沙门氏菌对氨苄西林表现出了较高的耐药率(73.33%,33/45),多重耐药菌株占比66.67%(30/45);携带率较高的耐药基因有:TEM-1、aac(6')-Iy、aac(6')-Iaa、aph(6)-Id、sul2,存在11株携带使氟喹诺酮耐药性升高的gyrA变异基因(D87N与D87Y);45株沙门氏菌携带毒力因子以菌毛粘附毒力因子、前噬菌体相关毒力因子、镁离子转运相关毒力因子、非菌毛吸附相关毒力因子、调控毒力因子、分泌系统相关毒力因子为主。结论本研究中沙门氏菌存在多种血清型与ST型,多重耐药严重,同时携带多种毒力因子,应加强监管与监测工作。

Objective To investigate the serotypes,molecular subtyping,drug sensitivity,and virulence factors of Salmonella and to explore the relationship between serotypes and drug sensitivity and virulence.Methods Serotypes of 45 strains of Salmonella isolated in 2023 in Jilin Province were serotyped by serum agglutination;their drug susceptibility to 17 kinds of antimicrobial drugs was performed using broth micro-dilution method;and Salmonella genomes were analyzed for sequence types,cgMLST,wgSNP,resistance genes,and virulence factors.Results The 45 strains of Salmonella were divided into 11 serotypes(13 ST types),with Salmonella typhimurium(35.56%,16/45)and Salmonella enteritidis(31.11%,14/35)as the dominant serotypes,and ST11 and ST34 were the predominant sequence types.A strain of Salmonella with an unknown serotype I4,[5],12:d:-(ST279-type)had been detected;Salmonella showed a high rate of resistance to ampicillin(73.33%,33/45),and the percentage of multidrug resistant strains was 66.67%(30/45);the resistance genes with high carriage rates were TEM-1,aac(6')-Iy,aac(6')-Iaa,aph(6)-Id,sul2,and the presence of 11 strains carrying the gyrA mutated gene(D87N and D87Y)conferring resistance to fluoroquinolones;the 45 strains of Salmonella carried virulence factors:Fimbrial adherence determinants,macrophage inducible genes,magnesium uptake,nonfimbrial adherence determinants,regulation,secretion system.Conclusion In this study,Salmonella has multiple serotypes and ST types,is serious multidrug resistant,and carries multiple virulence factors.Supervision and monitoring should be strengthened.