Zhang Xing-Xing, Huang Xin, Li Xue-Qin, Wang Zhen-Yu, Jiang Yue, Jiao Xinan, Li Qiuchun, Wang Jing, Zhong Fa-Gang
State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Institute of Animal Husbandry and Veterinary, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, Xinjiang, China; Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China.
State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Institute of Animal Husbandry and Veterinary, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, Xinjiang, China.
J Glob Antimicrob Resist. 2025 Jul 3;44:207-210. doi: 10.1016/j.jgar.2025.06.020.
Salmonella enterica serovar Kentucky ST198 has been increasingly reported in diverse sources worldwide, emerging as a globally epidemic clone. In this study, we aim to characterise the first isolated S. Kentucky ST198 strain from a horse in China.
Twelve faecal samples were collected from horses at a farm in Shihezi, Xinjiang Province, China, and investigated for the presence of Salmonella. The minimum inhibitory concentrations of 15 antimicrobial agents were determined using the broth microdilution method. The whole genome of Sal140 was sequenced using the Illumina Hiseq platform and assembled into contigs with SPAdes 3.10.0. Phylogenetic analysis was performed using Parsnp based on core-genome single-nucleotide polymorphisms.
A single S. Kentucky strain, designated Sal140, was isolated. This strain carried 15 antimicrobial resistance genes and exhibited resistance to ampicillin, ceftazidime, cefuroxime, cefotaxime, gentamicin, streptomycin, tetracycline, tigecycline, florfenicol, nalidixic acid, ciprofloxacin, azithromycin, and sulfamethoxazole/trimethoprim. Co-resistance to ciprofloxacin and third-generation cephalosporins was attributed to mutations in gyrA (S83F and D87G) and parC (T57S and S80I), and the production of CTX-M-55, respectively. Phylogenetic analysis revealed that Sal140 clustered within the subclade ST198.2-2, showing close genetic similarity (15-24 SNPs) to isolates from a patient and chicken meat in other regions of China, suggesting a potential epidemiological link among these S. Kentucky ST198 isolates from different sources.
In conclusion, the emergence of extensively drug-resistant (XDR) S. Kentucky ST198 in a horse is concerning. Continuous surveillance of this particular clone in horses is strongly recommended.
肠炎沙门氏菌肯塔基血清型ST198在全球范围内不同来源中的报道日益增多，已成为一种全球流行的克隆菌株。在本研究中，我们旨在对中国一匹马身上首次分离出的肯塔基沙门氏菌ST198菌株进行特征分析。
从中国新疆石河子某农场的马匹中采集了12份粪便样本，检测其中沙门氏菌的存在情况。采用肉汤微量稀释法测定了15种抗菌药物的最低抑菌浓度。使用Illumina Hiseq平台对Sal140的全基因组进行测序，并利用SPAdes 3.10.0组装成重叠群。基于核心基因组单核苷酸多态性，使用Parsnp进行系统发育分析。
分离出一株单一的肯塔基沙门氏菌菌株，命名为Sal140。该菌株携带15个抗菌耐药基因，对氨苄西林、头孢他啶、头孢呋辛、头孢噻肟、庆大霉素、链霉素四环素、替加环素、氟苯尼考、萘啶酸、环丙沙星、阿奇霉素以及磺胺甲恶唑/甲氧苄啶耐药。对环丙沙星和第三代头孢菌素的共同耐药分别归因于gyrA基因（S83F和D87G）和parC基因（T57S和S80I）的突变以及CTX-M-55的产生）。系统发育分析表明，Sal140聚集在亚分支ST198.内，与中国其他地区一名患者和鸡肉中的分离株显示出密切的遗传相似性（15 - 24个单核苷酸多态性），这表明这些来自不同来源的肯塔基沙门氏菌ST198分离株之间可能存在流行病学联系。
总之，一匹马身上出现广泛耐药（XDR）的肯塔基沙门氏菌ST198令人担忧。强烈建议持续监测马匹中这种特定的克隆菌株。
