Qu Mei, Huang Ying, Lyu Bing, Zhang Xin, Tian Yi, Feng Zhaomin, Gao Zhiyong, Zhang Daitao
Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing, China.
China CDC Wkly. 2024 Aug 16;6(33):825-833. doi: 10.46234/ccdcw2024.179.
Highly fluoroquinolone-resistant serovar Kentucky ( Kentucky) of sequence type (ST) 198 has emerged as a global multidrug-resistant (MDR) clone, posing a threat to public health.
Whole genome sequencing and antibiotic susceptibility testing was used to characterize the population structure and evolutionary history of 54 Kentucky isolates recovered from food and human clinical cases in Beijing from 2016 to 2023.
All 54 Kentucky ST198 isolates exhibited resistance to quinolones, carrying point mutations in the quinolone resistance-determining regions (_S83F and _S80I). Resistance to other antibiotics (folate pathway inhibitors, cephems, aminoglycosides, phenicols, rifamycin, fosfomycin, macrolides, and tetracyclines), mediated by the , , , , , , , , , , , , , , , and genes, was also observed in different combinations. The Beijing Kentucky ST198 evolutionary tree was divided into clades 198.2-1 and 198.2-2, which were further differentiated into three subclades: 198.2-2A, 198.2-2B, and 198.2-2C. Compared with the extended-spectrum β-lactamase-encoding gene in 198.2-1, the co-existence of and , as well as chromosomally located , was detected in most 198.2-2 isolates, which showed more complex MDR phenotypes. Kentucky ST198 outbreak isolates derived from two predominant clonal sources: 198.2-1 with cgST236434 and 198.2-2A with cgST296405.
The Kentucky population in Beijing is genetically diverse, consisting of multiple co-circulating lineages that have persisted since 2016. Strengthening surveillance of food and humans will aid in implementing measures to prevent and control the spread of AMR.
序列型（ST）198的高氟喹诺酮耐药血清型肯塔基（Kentucky）已成为全球多重耐药（MDR）克隆株，对公共卫生构成威胁。
采用全基因组测序和抗生素敏感性试验对2016年至2023年从北京食品和人类临床病例中分离出的54株肯塔基菌株的群体结构和进化历史进行表征。
所有54株肯塔基ST198菌株均对喹诺酮类药物耐药，在喹诺酮耐药决定区携带点突变（_S83F和_S80I）。还观察到由 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 和 基因介导的对其他抗生素（叶酸途径抑制剂、头孢菌素、氨基糖苷类、酚类、利福霉素、磷霉素、大环内酯类和四环素类）的不同组合耐药情况。北京肯塔基ST198进化树分为198.2-1和198.2-2两个分支，进一步分化为三个亚分支：198.2-2A、198.2-2B和198.2-2C。与198.2-1中的超广谱β-内酰胺酶编码基因 相比，在大多数198.2-2分离株中检测到 和 的共存以及位于染色体上的 ，这些分离株表现出更复杂的多重耐药表型。肯塔基ST198暴发菌株来自两个主要克隆来源：具有cgST236434的198.2-1和具有cgST296405的198.2-2A。
北京的肯塔基菌株群体在基因上具有多样性，由自201６年以来持续共存的多个谱系组成。加强对食品和人类的监测将有助于实施预防和控制抗菌药物耐药性传播的措施。
