Kong Ximei, Wang Jian, Lei Gaopeng, Yang Yang, Huang Weifeng, Leng Yun, Miao Yanfang, Li Ming, Yuan Qiwu, Zhao Yuanyuan, Xu Xin, Zuo Haojiang, Tian Lvbo
Chengdu Center for Disease Control and Prevention (Chengdu Institute of Health Supervision), Chengdu, China.
West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China.
J Glob Antimicrob Resist. 2025 Jun;43:264-270. doi: 10.1016/j.jgar.2025.05.009. Epub 2025 May 13.
The study aimed to investigate the prevalence, antimicrobial resistance profiles, and virulence characteristics of Salmonella isolates from clinical cases in Sichuan, China, collected from 2019 to 2021.
A total of 153 Salmonella isolates from 19 regions in Sichuan Province were analysed. Sequence types (STs) were identified using multi-locus sequence typing. Antimicrobial susceptibility testing was conducted to assess resistance profiles, while whole-genome sequencing was used to detect antimicrobial resistance genes (ARGs) and virulence genes.
Among the 153 Salmonella isolates, 49 STs were identified. ST11 (S. Enteritidis) was the most prevalent, while S. Kentucky comprised 3.27% (5/153) of isolates, significantly higher than the national average (0.33%, P < 0.05). All S. Kentucky ST198 isolates were extensively drug-resistant, exhibiting resistance to at least seven antimicrobial classes, including fluoroquinolones and extended-spectrum cephalosporins. S. Kentucky ST198 harboured significantly more ARGs (P < 0.001) and virulence genes (P < 0.001) than other strains. ARGs such as CTX-M-55, TEM-216, TEM-90, and TEM-150 were significantly more prevalent (P < 0.05), conferring resistance to extended-spectrum cephalosporins and β-lactams. Additionally, the absence of sifA (16.7% vs. 91.8%, P < 0.001) and shdA (0.0% vs. 68.7%, P = 0.001), suggesting that these genes may influence the reduced risk of human infection by ST198.
These findings highlight the emergence of extensively drug-resistant Salmonella Kentucky ST198 in Southwest China and underscore the urgent need for ongoing surveillance in this region due to its significant public health impact.
本研究旨在调查2019年至2021年期间从中国四川临床病例中分离出的沙门氏菌的流行情况、抗菌药物耐药谱和毒力特征。
对四川省19个地区的153株沙门氏菌分离株进行了分析。使用多位点序列分型鉴定序列类型（STs）。进行抗菌药物敏感性测试以评估耐药谱，同时使用全基因组测序检测抗菌药物耐药基因（ARGs）和毒力基因。
在153株沙门氏菌分离株中，鉴定出49种STs。ST11（肠炎沙门氏菌）最为常见，而肯塔基沙门氏菌占分离株的3.27%（5/153），显著高于全国平均水平（0.33%，P<0.05）。所有肯塔基沙门氏菌ST198分离株均为广泛耐药，对至少七种抗菌药物类别表现出耐药性，包括氟喹诺酮类和超广谱头孢菌素。肯塔基沙门氏菌ST198携带的ARGs（P<0.001）和毒力基因（P<0.001）明显多于其他菌株。CTX-M-55、TEM-216、TEM-90和TEM-150等ARGs更为普遍（P<0.05），赋予对超广谱头孢菌素和β-内酰胺类的耐药性。此外，sifA（16.7%对91.8%，P<0.001）和shdA（0.0%对68.7%，P=0.001）的缺失，表明这些基因可能影响ST198感染人类的风险降低。
这些发现突出了中国西南部广泛耐药的肯塔基沙门氏菌ST198的出现，并强调由于其对公共卫生的重大影响，该地区迫切需要持续监测。
