Induction of a viable but non-culturable state by stringent response in Escherichia coli O157:H7 during macrophage interaction enables immune evasion

IF 6.6 1区农林科学 Q1 FOOD SCIENCE & TECHNOLOGY

LWT - Food Science and Technology Pub Date : 2025-10-14 DOI:10.1016/j.lwt.2025.118621

Haoqing Zhao, Yuanyuan Liu, Jingfeng Zhang, Hanying Xie, Huiting Huang, Lichao Zhao

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引用次数: 0

Abstract

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major foodborne pathogen. It can survive harsh conditions in the gastrointestinal tract and macrophages, contributing to its pathogenicity. This study aimed to investigate how E. coli O157:H7 enters the Viable But Non-Culturable (VBNC) state within macrophages to evade immune recognition. First, we assessed bacterial survival under simulated gastrointestinal conditions to exclude potential confounding effects. Next, we examined bacterial viability, growth, and gene expression in macrophages using wild-type and relA-deficient strains. Results showed that macrophage ingestion triggers reactive oxygen species (ROS), activating the stringent response and inducing the VBNC state. VBNC state E. coli O157:H7 significantly reduced expression of pathogen-associated molecular patterns (PAMPs), helping them evade immune detection. Furthermore, VBNC state E. coli O157:H7 exhibited enhanced resistance to ROS stress. This study provides insights into bacterial survival strategies in host environments and underscores the health risks associated with VBNC pathogens.

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在巨噬细胞相互作用期间，大肠杆菌O157:H7通过严格反应诱导存活但不可培养的状态，从而实现免疫逃避

肠出血性大肠杆菌（EHEC） O157:H7是一种主要的食源性病原体。它可以在胃肠道和巨噬细胞的恶劣条件下生存，有助于其致病性。本研究旨在探讨大肠杆菌O157:H7如何在巨噬细胞内进入可存活但不可培养（Viable But non - culable， VBNC）状态以逃避免疫识别。首先，我们评估了模拟胃肠道条件下的细菌存活率，以排除潜在的混杂效应。接下来，我们使用野生型和rela缺陷菌株检测巨噬细胞中的细菌活力、生长和基因表达。结果表明，巨噬细胞摄取可触发活性氧（reactive oxygen species， ROS），激活严格反应，诱导VBNC状态。VBNC表明，大肠杆菌O157:H7显著降低病原体相关分子模式（pathogen associated molecular patterns, PAMPs）的表达，帮助它们逃避免疫检测。此外，VBNC状态的大肠杆菌O157:H7对ROS胁迫表现出增强的抗性。这项研究提供了宿主环境中细菌生存策略的见解，并强调了与VBNC病原体相关的健康风险。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

LWT - Food Science and Technology 工程技术-食品科技

CiteScore

11.80

自引率

6.70%

发文量

1724

审稿时长

65 days

期刊介绍： LWT - Food Science and Technology is an international journal that publishes innovative papers in the fields of food chemistry, biochemistry, microbiology, technology and nutrition. The work described should be innovative either in the approach or in the methods used. The significance of the results either for the science community or for the food industry must also be specified. Contributions written in English are welcomed in the form of review articles, short reviews, research papers, and research notes. Papers featuring animal trials and cell cultures are outside the scope of the journal and will not be considered for publication.