Between July 2018 and May 2019, Corynebacterium diphtheriae was isolated from eight patients with non-respiratory infections, seven of whom experienced homelessness and had stayed at shelters in King County, WA, USA. All isolates were microbiologically identified as nontoxigenic C. diphtheriae biovar mitis. Whole-genome sequencing confirmed that all case isolates were genetically related, associated with sequence type 445 and differing by fewer than 24 single-nucleotide polymorphisms (SNPs). Compared to publicly available C. diphtheriae genomic data, these WA isolates formed a discrete cluster with SNP variation consistent with previously reported outbreaks. Virulence-related gene content variation within the highly related WA cluster isolates was also observed. These results indicated that genome characterization can readily support epidemiology of nontoxigenic C. diphtheriae .

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2018 年 7 月至 2019 年 5 月美国华盛顿州金县无毒白喉棒状杆菌的基因组流行病学

2018 年 7 月至 2019 年 5 月期间，从 8 名非呼吸道感染患者中分离出白喉棒状杆菌，其中 7 名无家可归，曾住在美国华盛顿州金县的收容所。所有分离株在微生物学上被鉴定为无毒白喉杆菌生物变种。全基因组测序证实，所有病例分离株都具有遗传相关性，与序列类型 445 相关，并且差异少于 24 个单核苷酸多态性 (SNP)。与公开可用的白喉棒状杆菌相比 根据基因组数据，这些 WA 分离株形成了一个离散的簇，其 SNP 变异与先前报道的暴发一致。还观察到高度相关的 WA 簇分离株内的毒力相关基因含量变化。这些结果表明基因组特征可以很容易地支持无毒白喉杆菌的流行病学。