Wirth Joseph S, Leeper Molly M, Smith Peyton A, Vasser Michael, Katz Lee S, Vidyaprakash Eshaw, Carleton Heather A, Chen Jessica C
Emerg Infect Dis. 2025 May;31(13):109-116. doi: 10.3201/eid3113.240686.
In the United States, Shiga toxin-producing Escherichia coli (STEC) outbreaks cause >265,000 infections and cost $280 million annually. We investigated REPEXH01, a persistent strain of STEC O157:H7 associated with multiple sources, including romaine lettuce and recreational water, that has caused multiple outbreaks since emerging in late 2015. By comparing the genomes of 729 REPEXH01 isolates with those of 2,027 other STEC O157:H7 isolates, we identified a highly conserved, single base pair deletion in espW that was strongly linked to REPEXH01 membership. The biological consequence of that deletion remains unclear; further studies are needed to elucidate its role in REPEXH01. Additional analyses revealed that REPEXH01 isolates belonged to Manning clade 8; possessed the toxins stx2a, stx2c, or both; were predicted to be resistant to several antimicrobial compounds; and possessed a diverse set of plasmids. Those factors underscore the need to continue monitoring REPEXH01 and clarify aspects contributing to its emergence and persistence.
在美国，产志贺毒素大肠杆菌（STEC）疫情每年导致超过26.5万例感染，造成2.8亿美元的损失。我们调查了REPEXH01，这是一种与包括长叶生菜和娱乐用水在内的多种来源相关的持续性STEC O157:H7菌株，自2015年末出现以来已引发多次疫情。通过将729株REPEXH01分离株的基因组与2027株其他STEC O157:H7分离株的基因组进行比较，我们在espW中鉴定出一个高度保守的单碱基对缺失，该缺失与REPEXH01成员身份密切相关。该缺失的生物学后果尚不清楚；需要进一步研究以阐明其在REPEXH01中的作用。额外分析显示，REPEXH01分离株属于曼宁进化枝8；携带毒素stx2a、stx2c或两者皆有；预计对几种抗菌化合物具有抗性；并拥有多种质粒。这些因素强调了继续监测REPEXH01并阐明其出现和持续存在的相关因素的必要性。
