Genomic Surveillance of Streptococcus pyogenes Strains Causing Invasive Disease, United States, 2016–2017

Frontiers in Microbiology

Paula Snippes-Vagnone¹  Ruth Lynfield¹  Bernard Beall²  Yuan Li²  Chris A. Van Beneden²  Srinivasan Velusamy²  Sopio Chochua²  Lesley McGee²  Benjamin J. Metcalf²  Joy Rivers²  Saundra Mathis²  Zhongya Li²  Srinivas A. Nanduri² 

[1] Minnesota Department of Health, St Paul, MN, United States;Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States;

关键词: group A streptococcus;    genomics;    surveillance studies;    vaccines;    antibiotic resistance;    virulence;   

DOI  :  10.3389/fmicb.2020.01547

来源: DOAJ

【 摘 要 】

BackgroundStreptococcus pyogenes is a major cause of severe, invasive infections in humans. The bacterial pathogen harbors a wide array of virulence factors and exhibits high genomic diversity. Rapid changes of circulating strains in a community are common. Understanding the current prevalence and dynamics of S. pyogenes lineages could inform vaccine development and disease control strategies.MethodsWe used whole-genome sequencing (WGS) to characterize all invasive S. pyogenes isolates obtained through the United States Center for Disease Control and Prevention’s Active Bacterial Core surveillance (ABCs) in 2016 and 2017. We determined the distribution of strain features, including emm type, antibiotic resistance determinants, and selected virulence factors. Changes in strain feature distribution between years 2016 and 2017 were evaluated. Phylogenetic analysis was used to identify expanding lineages within emm type.ResultsSeventy-one emm types were identified from 3873 isolates characterized. The emm types targeted by a 30-valent M protein-based vaccine accounted for 3230 (89%) isolates. The relative frequencies of emm types collected during the 2 years were similar. While all isolates were penicillin-susceptible, erythromycin-resistant isolates increased from 273 (16% of 2016 isolates) to 432 (23% of 2017 isolates), mainly driven by increase of the erm-positive emm types 92 and 83. The prevalence of 24 virulence factors, including 11 streptococcal pyrogenic toxins, ranged from 6 to 90%. In each of three emm types (emm 49, 82, and 92), a subgroup of isolates significantly expanded between 2016 and 2017 compared to isolates outside of the subgroup (P-values < 0.0001). Specific genomic sequence changes were associated with these expanded lineages.ConclusionsWhile the overall population structure of invasive S. pyogenes isolates in the United States remained stable, some lineages, including several that were antibiotic-resistant, increased between 2016 and 2017. Continued genomic surveillance can help monitor and characterize bacterial features associated with emerging strains from invasive infections.

【 授权许可】

Unknown