Liu Qian, Yang Xi, Sun Hui, Wang Hua, Sui Xinxia, Zhang Peihua, Bai Xiangning, Xiong Yanwen
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Division of Laboratory Medicine, Oslo University Hospital, 0372 Oslo, Norway.
Microorganisms. 2023 Nov 23;11(12):2843. doi: 10.3390/microorganisms11122843.
() is an emerging diarrheagenic pathogen associated with sporadic infections and human gastroenteric outbreaks. The gene, which encodes intimin in the locus of enterocyte effacement (LEE) operon, contributes to the establishment of the attaching and effacing (A/E) lesion. Increasing collection of strains from various sources has resulted in a rapid increase in the number of subtypes. This study systematically investigated the prevalence and genetic diversity of among strains isolated from humans, animals, and food. The gene was present in 452/459 (98.5%) strains and 23 subtypes were identified including two novel subtypes, named -α11 and η3. The -σ subtype was the most predominant among humans, animals, and food-derived strains, while -γ3, τ, and α11 were unique in human-derived strains. Additionally, the LEE island was also analyzed at genomic, transcriptional, and functional levels through genomic analysis, quantitative reverse transcription PCR, and HEp-2 cell adherence assays, respectively. The transcript levels were variable and associated with subtypes. Three different adherence patterns, including localized adherence-like (LAL), diffuse adherence (DA), and detachment (DE), were observed among strains. This study demonstrated a high diversity of functional intimin in strains isolated from humans, animals, and food. Further in vivo and in vitro studies are warranted to better elucidate the role of intimin or LEE in different genetic backgrounds.
（）是一种新兴的致腹泻病原体，与散发性感染和人类胃肠疾病暴发相关。编码紧密黏附素的基因位于肠细胞脱落位点（LEE）操纵子中，有助于形成紧密黏附并脱落（A/E）损伤。从各种来源收集的菌株数量不断增加，导致菌株亚型数量迅速增加。本研究系统地调查了从人类、动物和食物中分离出的菌株中（）的流行情况和遗传多样性。在459株菌株中有452株（98.5%）存在该基因，共鉴定出23种亚型，包括两种新亚型，分别命名为-α11和η3。-σ亚型在人类、动物和食物来源的菌株中最为常见，而-γ3、τ和α11仅在人类来源的菌株中出现。此外，还分别通过基因组分析、定量逆转录PCR和HEp-2细胞黏附试验，在基因组、转录和功能水平上对LEE岛进行了分析。（）的转录水平各不相同，且与（）亚型相关。在菌株中观察到三种不同的黏附模式，包括局部黏附样（LAL）、弥漫性黏附（DA）和脱落（DE）。本研究表明，从人类、动物和食物中分离出的菌株中功能性紧密黏附素具有高度多样性。有必要进一步开展体内和体外研究，以更好地阐明紧密黏附素或LEE在不同遗传背景中的作用。
