The zoonotic bacterium Leptospira interrogans is the aetiological agent of leptospirosis, a re-emerging infectious disease that is a growing public health concern. Most human cases of leptospirosis result from environmental infection. Biofilm formation and its contribution to the persistence of virulent leptospires in the environment or in the host have scarcely been addressed. Here, we examined spatial and time-domain changes in biofilm production by L. interrogans. Our observations showed that biofilm formation in L. interrogans is a highly dynamic process and leads to a polarized architecture. We notably found that the biofilm matrix is composed of extracellular DNA, which enhances the biofilm’s cohesiveness. By studying L. interrogans mutants with defective diguanylate cyclase and phosphodiesterase genes, we show that biofilm production is regulated by intracellular levels of bis-(3′–5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) and underpins the bacterium’s ability to withstand a wide variety of simulated environmental stresses. Our present results show how the c-di-GMP pathway regulates biofilm formation by L. interrogans, provide insights into the environmental persistence of L. interrogans and, more generally, highlight leptospirosis as an environment-borne threat to human health.

人畜共患病钩端螺旋体是钩端螺旋体病的病原体，钩端螺旋体病是一种重新出现的传染病，引起了公众健康的日益关注。人类钩端螺旋体病的大多数病例是由环境感染引起的。几乎没有解决生物膜形成及其对环境或宿主中强毒钩端螺旋体持久性的贡献。在这里，我们检查了问询人生物膜生产中的空间和时域变化。我们的观察结果表明，询问豆中的生物膜形成是一个高度动态的过程，并导致极化的结构。我们特别发现生物膜基质由细胞外DNA组成，从而增强了生物膜的凝聚力。通过研究询问乳杆菌具有缺陷的双鸟苷酸环化酶和磷酸二酯酶基因的突变体，我们表明生物膜生产受细胞内双-（3'-5'）-环二聚鸟苷单磷酸鸟嘌呤单磷酸鸟苷（c-di-GMP）的调节，并增强了细菌抵御广泛细菌的能力各种模拟环境压力。我们目前的结果表明，C-二GMP通路如何调节由生物膜形成钩端螺旋体，提供深入的环境持久性L.问号，更普遍，突出钩端螺旋体病对人类健康的环境中传播的威胁。