Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
University of Colorado School of Medicine Aurora, Aurora, Colorado, USA.
J Infect Dis. 2022 May 16;225(10):1841-1851. doi: 10.1093/infdis/jiab565.
The genomic features and transmission link of circulating Group A Streptococcus (GAS) strains causing different disease types, such as pharyngitis and invasive disease, are not well understood.
We used whole-genome sequencing to characterize GAS isolates recovered from persons with pharyngitis and invasive disease in the Denver metropolitan area from June 2016 to April 2017.
The GAS isolates were cultured from 236 invasive and 417 pharyngitis infections. Whole-genome sequencing identified 34 emm types. Compared with pharyngitis isolates, invasive isolates were more likely to carry the erm family genes (23% vs 7.4%, P<.001), which confer resistance to erythromycin and clindamycin (including inducible resistance), and covS gene inactivation (7% vs 0.5%, P<.001). Whole-genome sequencing identified 97 genomic clusters (433 isolates; 2-65 isolates per cluster) that consisted of genomically closely related isolates (median single-nucleotide polymorphism=3 [interquartile range, 1-4] within cluster). Thirty genomic clusters (200 isolates; 31% of all isolates) contained both pharyngitis and invasive isolates and were found in 11 emm types.
In the Denver metropolitan population, mixed disease types were commonly seen in clusters of closely related isolates, indicative of overlapping transmission networks. Antibiotic-resistance and covS inactivation was disproportionally associated with invasive disease.
循环 A 组链球菌（GAS）菌株的基因组特征和传播途径导致不同疾病类型，如咽炎和侵袭性疾病，尚不清楚。
我们使用全基因组测序来描述 2016 年 6 月至 2017 年 4 月在丹佛大都市区因咽炎和侵袭性疾病而从患者中分离出的 GAS 分离株。
从 236 例侵袭性和 417 例咽炎感染中培养出 GAS 分离株。全基因组测序鉴定出 34 个 emm 型。与咽炎分离株相比，侵袭性分离株更可能携带 erm 家族基因（23%比 7.4%，P<.001），这赋予了红霉素和克林霉素（包括诱导性耐药）的耐药性，以及 covS 基因失活（7%比 0.5%，P<.001）。全基因组测序鉴定出 97 个基因组簇（433 株分离株；每个簇 2-65 株分离株），由基因组上密切相关的分离株组成（中位数单核苷酸多态性=3 [四分位距，1-4] 簇内）。30 个基因组簇（200 株分离株；所有分离株的 31%）包含咽炎和侵袭性分离株，存在于 11 个 emm 型中。
在丹佛大都市区人群中，密切相关的分离株簇中常见混合疾病类型，表明存在重叠的传播网络。抗生素耐药性和 covS 失活与侵袭性疾病不成比例相关。
