Abstract：
Listeria monocytogenes exhibits varying levels of pathogenicity when entering the host through contaminated food. However, little is known regarding the stress response and environmental tolerance mechanism of different virulence strains to host gastrointestinal (GI) stimuli. This study analyzed the differences in the survival and genes of stress responses among two strains of L. monocytogenes 10403S (serotype 1/2a, highly virulent strain) and M7 (serotype 4a, low-virulence strain) during simulated gastrointestinal digestion. The results indicated that L. monocytogenes 10403S showed greater acid and bile salt tolerance than L. monocytogenes M7, with higher survival rates and less cell deformation and cell membrane permeability during the in vitro digestion. KEGG analysis of the transcriptomes indicated that L. monocytogenes 10403S displayed significant activity in amino acid metabolism, such as glutamate and arginine, associated with acid tolerance. Additionally, L. monocytogenes 10403S demonstrated a higher efficacy in promoting activities that preserve bacterial cell membrane integrity and facilitate flagellar protein synthesis. These findings will contribute valuable practical insights into the tolerance distinctions among different virulence strains of L. monocytogenes in the GI environment.
摘要：
单核细胞增生李斯特菌通过受污染的食物进入宿主时表现出不同水平的致病性。然而,关于不同毒力菌株对宿主胃肠道（GI）刺激的应激反应和环境耐受机制知之甚少。本研究分析了两株单核细胞增生李斯特菌10403S（血清型1/2a，高毒力菌株)和M7(血清型4a，低毒力菌株）在模拟胃肠道消化过程中。结果表明，单核细胞增生李斯特菌10403S比单核细胞增生李斯特菌M7表现出更高的耐酸和胆盐能力，在体外消化过程中存活率更高，细胞变形和细胞膜通透性更小。对转录组的KEGG分析表明，单核细胞增生李斯特菌10403S在氨基酸代谢中显示出显着的活性，如谷氨酸和精氨酸，与耐酸有关。此外,单核细胞增生李斯特菌10403S在促进保持细菌细胞膜完整性和促进鞭毛蛋白合成的活性方面表现出更高的功效。这些发现将为GI环境中单核细胞增生李斯特菌的不同毒力菌株之间的耐受性区别提供有价值的实践见解。
