Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou 510515, China.
Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institutet, 141 52 Stockholm, Sweden.
Toxins (Basel). 2021 Jan 19;13(1):71. doi: 10.3390/toxins13010071.
Shiga toxin (Stx)-producing (STEC) is an important foodborne pathogen with the ability to cause bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). Little is known about enterohemolysin-encoded by . Here we investigated the prevalence and diversity of in 239 STEC isolates from human clinical samples. In total, 199 out of 239 isolates (83.26%) were positive, and was significantly overrepresented in isolates carrying + ( < 0.001) and ( < 0.001). The presence of was significantly associated with BD and serotype O157:H7. Five subtypes were identified, among which, subtypes B, C, and F were overrepresented in -positive isolates. All O157:H7 isolates carried subtype B, which was related to BD and HUS. Three groups were observed in the phylogenetic analysis, namely, group Ⅰ ( subtype A), group Ⅱ ( subtype B, C, and F), and group Ⅲ ( subtype D). Most BD- and HUS-associated isolates were clustered into group Ⅱ, while group Ⅰ was associated with non-bloody stool and individuals ≥10 years of age. The presence of + and + was significantly associated with HUS and O157:H7 isolates. In summary, this study showed a high prevalence and the considerable genetic diversity of among clinical STEC isolates. The genotypes (subtype B and phylogenetic group Ⅱ) could be used as risk predictors, as they were associated with severe clinical symptoms, such as BD and HUS. Furthermore, , together with and can be used as a risk predictor for HUS in STEC infections.
产志贺毒素(Stx)的 (STEC)是一种重要的食源性病原体,能够引起血性腹泻(BD)和溶血尿毒综合征(HUS)。目前对于 编码的肠出血性大肠杆菌(enterohemolysin)知之甚少。在这里,我们调查了 239 个人类临床样本中 STEC 分离株的流行率和多样性。在 239 株分离株中,共有 199 株(83.26%)为 阳性,携带 + 的分离株中显著过度表达 (<0.001)和 (<0.001)。 的存在与 BD 和血清型 O157:H7 显著相关。鉴定出 5 种 亚型,其中,-阳性分离株中 B、C 和 F 亚型过度表达。所有 O157:H7 分离株均携带 亚型 B,与 BD 和 HUS 相关。在系统发育分析中观察到 3 个 组,即第 Ⅰ组(亚型 A)、第 Ⅱ组(亚型 B、C 和 F)和第 Ⅲ组(亚型 D)。大多数与 BD 和 HUS 相关的分离株聚类到第 Ⅱ组,而第 Ⅰ组与非血性腹泻和年龄≥10 岁的个体相关。 + 和 + 的存在与 HUS 和 O157:H7 分离株显著相关。总之,本研究表明临床 STEC 分离株中 高度流行且具有相当大的遗传多样性。 基因型(亚型 B 和系统发育组 Ⅱ)可用作严重临床症状(如 BD 和 HUS)的风险预测因子。此外, 与 和 一起可作为 STEC 感染中 HUS 的风险预测因子。