Characterization of Salmonella resistance to bile during biofilm formation

作者：Ming‐Han Tsai, Yihua Liang, Chyi‐Liang Chen, Cheng‐Hsun Chiu · 发表于：Journal of Microbiology Immunology and Infection · 年份：2019 · DOI：10.1016/j.jmii.2019.06.003 · 被引用次数：41 · 研究领域：Salmonella and Campylobacter epidemiology、Bacterial Genetics and Biotechnology、Escherichia coli research studies

BACKGROUND: Non-typhoid Salmonella infection may present as acute gastroenteritis or chronic infection, primarily in the bile-rich gallbladder. Biofilm formation is a mechanism of bile resistance in Salmonella. Our aim was to determine how Salmonella utilizes bile as a signal, and to study the relevance of the interaction between the PhoP-PhoQ two-component system and cyclic diguanosine monophosphate (c-di-GMP) signaling to biofilm formation. METHODS: Two-dimensional (2-D) gel electrophoresis was used to identify genes required for Salmonella biofilm formation in bile. Quantitative real-time PCR (qRT-PCR) was used to clarify the role of the PhoP-PhoQ two-component system and its interaction with genes involved in the c-di-GMP network during biofilm formation. RESULTS: Our result revealed that Salmonella mutants with incomplete outer membrane (△ompA), defective flagella (△flgE), or incomplete PhoP-PhoQ two-component system (△phoP), were unable to develop complete biofilms in the presence of bile. Moreover, PhoP-PhoQ two-component system-related Salmonella mutants (△phoP, △phoQ, △phoP△phoQ) had lower expression of c-di-GMP related genes (csgD, adrA) than the wild-type Salmonella strain had in the bile environment. CONCLUSION: Salmonella may sense and respond to bile through the PhoP-PhoQ two-component system during biofilm formation. Furthermore, the PhoP-PhoQ two-component system might activate regulators of the c-di-GMP signaling network.