Objective: To analyze the genus, drug resistance/virulence and phylogenetic characteristics of Brucella strains isolated from brucellosis surveillance sentinels in Henan Province from 2013 to 2022, and provide baseline data for the surveillance, early warning and outbreak tracing of brucellosis. Methods: Blood samples were collected from patients with Brucella infection for strain isolation, culture and species identification, drug susceptibility test, whole genome sequencing, splicing and assembly, functional/virulence/resistance gene prediction analysis and phylogenetic tree drawing based on single nucleotide polymorphism (SNP). Results: In 36 brucellosis patients, the majority were men (86.11%, 31/36), young adults aged 18-50 (88.89%, 32/36) and farmers/herdsmen (72.22%, 26/36). A total of 36 strains of Brucella melitensis were isolated, and average 1 305 functional proteins of 21 categories were predicted by strain genome; all the strains carried four main virulence factors (pmm, VirB group, BtpA/BtpB, BvrS/BvrR). The drug sensitivity rate was 100.00% to six types of antibiotics including levofloxacin, rifampicin, doxycycline, streptomycin, tetracycline and gentamicin, they showed different resistances to three antibiotics including compound trimethoprim-sulfamethoxazole, ciprofloxacin and ampicillin. The strains carried four types of resistance genes and two clusters of resistance genes, with four combinations of genotypes, the resistance mechanisms included antibiotic degradation/modification enzymes, resistant nodular cell differentiation (RND) efflux pumps, 16S/23S ribosomal rRNA binding site mutations, etc. The number of SNP differed in the genomes of 36 Brucella melitensis strains ranged from 0 to 454 and phylogenetic tree was divided into three major branches, with relative branch distances between 0.000 0 and 0.498 6 for each strain. Conclusions: Human Brucella melitensis strains isolated from surveillance sentinels in Henan from 2013 to 2022 carried multiple virulence and antibiotic resistance genes and had different drug resistance phenotypes. Single nucleotide polymorphism analysis and phylogenetic tree analysis showed significant differences in phylogenetic relationships among different strains.
目的： 分析2013-2022年分离自河南省监测哨点布鲁氏菌病（布病）患者的菌株属种、耐药/毒力及亲缘进化特征，为布病的监测预警和暴发溯源提供参考依据。 方法： 采集布病患者血液进行分离培养、属种鉴定，菌株药物敏感性试验，全基因组序列测定、拼接组装、功能/毒力/耐药基因检测分析及基于单核苷酸多态性（SNP）的系统发育树绘制。 结果： 在36例布病患者中，以男性（86.11%，31/36）、18~50岁青壮年（88.89%，32/36）和农/牧民（72.22%，26/36）为主。36株病原菌均为羊种布鲁氏菌。菌株基因组预测功能蛋白21类，平均数量1 305个；均携带4类主要毒力因子（pmm、VirB组、BtpA/BtpB、BvrS/BvrR）。菌株对6种抗生素（左氧氟沙星、利福平、多西环素、链霉素、四环素和庆大霉素）药物敏感性均为100.00%；对3种抗生素（复方新诺明、环丙沙星和氨苄西林）存在不同程度的耐药。菌株携带4种耐药基因和2种耐药基因簇，存在4种基因型组合；耐药机制包括抗生素降解/修饰酶类、抗性结瘤细胞分裂外排泵、16S/23S核糖体rRNA抗生素结合位点突变等。36株布鲁氏菌基因组总SNP差异数在0~454个之间，系统发育树分析共分为3个分支，各菌株相对分支间进化距离在0.000 0~0.498 6之间。 结论： 2013-2022年河南省监测哨点分离的人感染羊种布鲁氏菌携带多种毒力、耐药基因，呈现不同的耐药表型；其SNP分析和系统发育树显示不同菌株间亲缘进化关系差异性较大。.