Lactobacillus is widely used as a probiotic, and many researchers have focused on its stress response to improve its functionality and survival. However, studies on persister cells, dormant cells that aid bacteria in surviving general stress, have focused on pathogenic bacteria that cause infection, not Lactobacillus. Thus, understanding Lactobacillus persister cells will provide essential clues for understanding how Lactobacillus survives and maintains its function under various environmental conditions. We treated Lactobacillus strains with various antibiotics to determine the conditions required for persister formation using kill curves and transmission electron microscopy. In addition, we observed the resuscitation patterns of persister cells using single-cell analysis. Our results show that Lactobacillus creates a small population of persister cells (0.0001-1% of the bacterial population) in response to beta-lactam antibiotics such as ampicillin and amoxicillin. Moreover, only around 0.5-1% of persister cells are heterogeneously resuscitated by adding fresh media; the characteristics are typical of persister cells. This study provides a method for forming and verifying the persistence of Lactobacillus and demonstrates that antibiotic-induced Lactobacillus persister cells show characteristics of dormancy, sensitivity of antibiotics, same as exponential cells, multi-drug tolerance, and resuscitation, which are characteristics of general persister cells. This study suggests that the mechanisms of formation and resuscitation may vary depending on the characteristics, such as the membrane structure of the bacterial species.

中文翻译：

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乳酸杆菌持续形成和复苏。

乳酸菌被广泛用作益生菌，许多研究人员都关注其应激反应，以提高其功能和存活率。然而，对持久细胞（帮助细菌抵御一般压力的休眠细胞）的研究主要集中在引起感染的病原菌上，而不是乳酸菌。因此，了解乳杆菌持久细胞将为了解乳杆菌如何在各种环境条件下生存并维持其功能提供重要线索。我们用各种抗生素处理乳杆菌菌株，以使用杀灭曲线和透射电子显微镜确定持久形成所需的条件。此外，我们使用单细胞分析观察了持续细胞的复苏模式。我们的结果表明，乳杆菌响应氨苄西林和阿莫西林等 β-内酰胺抗生素，会产生一小群持久细胞（占细菌群的 0.0001-1%）。此外，只有大约 0.5-1% 的持续细胞通过添加新鲜培养基得到异质复苏；这些特征是持续细胞的典型特征。本研究提供了一种形成和验证乳酸菌持久性的方法，并证明抗生素诱导的乳酸菌持久性细胞表现出休眠、与指数细胞相同的抗生素敏感性、多药耐受性和复苏等一般持久性细胞的特征。细胞。这项研究表明，形成和复苏的机制可能会根据细菌种类的特性（例如膜结构）而有所不同。