Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, People's Republic of China.
Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.
Emerg Microbes Infect. 2020 Dec;9(1):2562-2570. doi: 10.1080/22221751.2020.1850182.
Shiga toxin (Stx)-producing (STEC) can cause a wide range of symptoms from asymptomatic carriage, mild diarrhea to bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). Intimin, encoded by the gene, also plays a critical role in STEC pathogenesis. Herein, we investigated the prevalence and genetic diversity of among clinical STEC isolates from patients with diarrhea, BD, HUS as well as from asymptomatic STEC-positive individuals in Sweden with whole-genome sequencing. We found that 173 out of 239 (72.4%) of clinical STEC strains were positive. Six subtypes (1, 1, 3, , and ) were identified and its subtype 1 were significantly overrepresented in O157:H7 strains isolated from BD and HUS patients. 1 was associated with O121:H19 and O103:H2 strains, and 3 to O26:H11 strains. The combination of subtype 1 and subtype ( or + ) is more likely to cause severe disease, suggesting the possibility of using genotypes in risk assessment of STEC infection. In summary, this study demonstrated a high prevalence of in clinical STEC strains and considerable genetic diversity of in STEC strains in Sweden from 1994 through 2018, and revealed association between subtypes and disease severity.
产志贺毒素（Stx）的（STEC）可引起从无症状携带、轻度腹泻到血性腹泻（BD）和溶血性尿毒综合征（HUS）等各种症状。由基因编码的紧密素在 STEC 发病机制中也起着关键作用。在此，我们通过全基因组测序研究了来自瑞典腹泻、BD、HUS 患者的临床 STEC 分离株以及无症状 STEC 阳性个体中基因的流行率和遗传多样性。我们发现，239 株临床 STEC 株中有 173 株（72.4%）为阳性。鉴定出 6 种 亚型（1、1、3、、和 ），从 BD 和 HUS 患者分离的 O157:H7 菌株中明显过度表达 1 型。1 型与 O121:H19 和 O103:H2 菌株有关，而 3 型与 O26:H11 菌株有关。1 型和 3 型（或+）的组合更可能导致严重疾病，这表明有可能在 STEC 感染的风险评估中使用基因型。总之，本研究表明，在瑞典，临床 STEC 菌株中基因的流行率很高，STEC 菌株中的基因多样性很大，并且揭示了亚型与疾病严重程度之间的关联。
