Department of Food Science and Technology, Oregon State University, Corvallis, OR, USA.
Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea.
Microb Pathog. 2024 Sep;194:106793. doi: 10.1016/j.micpath.2024.106793. Epub 2024 Jul 14.
Genetically, Listeria monocytogenes is closely related to non-L. monocytogenes (L. innocua, L. welshimeri, L. grayi, L. aquatica, and L. fleischimannii). This bacterium is well known for its resistance to harsh conditions including acidity, low temperatures, and high salt concentrations. This study explored the responses of 65 Listeria strains to stress conditions and characterized the prevalence of stress-related genes. The 65 Listeria strains were isolated from different environments and their viability was assessed in four different tests: independent tests for pH 3, 1 °C, and 5 % salt concentration and multiple resistance tests that combined pH 3, 1 °C, 5 % salt. From the data, the 65 strains were categorized into stress-resistant (56) or stress-sensitive groups (9), with approximately 4 log CFU/mL differences. The PCR assay analyzed the prevalence of two virulence genes prfA and inlA, and eight stress-related genes: three acid (gadB, gadC, and atpD), two low temperature (betL and opuCA) and three salt resistance genes (flaA, cysS, and fbp). Two low temperature (bet and opuCA) and salt resistance (fbp) genes were more prevalent in the stress-resistant strains than in the stress-sensitive Listeria group.
从遗传学角度来看，李斯特菌与非李斯特菌（无害李斯特菌、威氏李斯特菌、格氏李斯特菌、海生李斯特菌和费氏李斯特菌）密切相关。这种细菌以其对恶劣条件的抵抗力而闻名，包括酸度、低温和高盐浓度。本研究探讨了 65 株李斯特菌对胁迫条件的反应，并对与应激相关的基因的流行情况进行了特征描述。这 65 株李斯特菌是从不同环境中分离出来的，其在四项不同测试中的生存能力进行了评估：pH3、1°C 和 5%盐浓度的独立测试，以及 pH3、1°C、5%盐浓度组合的多重耐药测试。从数据中，将 65 株菌株分为抗应激（56 株）或应激敏感（9 株）组，其差异约为 4 个对数 CFU/mL。PCR 分析了两种毒力基因 prfA 和 inlA 以及八种与应激相关的基因的流行情况：三个酸应激（gadB、gadC 和 atpD）、两个低温应激（betL 和 opuCA）和三个盐应激基因（flaA、cysS 和 fbp）。应激抗性菌株中两种低温（bet 和 opuCA）和盐抗性（fbp）基因比应激敏感李斯特菌组更为普遍。
