Department of Biology, Mendel Hall, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA.
Center for Microbiology and Immunology, School of Medicine, Temple University, Philadelphia, PA 19122, USA.
FEMS Microbiol Lett. 2023 Jan 17;370. doi: 10.1093/femsle/fnad012.
The major biofilm pathway in Salmonella enterica serovar Typhimurium involves specific growth conditions that induce the csgA gene whose product forms surface curli fibers that mediate biofilm formation. We have found that the previously uncharacterized STM1266 gene in S. Typhimurium plays a role in regulating biofilm formation via the curli pathway. S. Typhimurium ΔSTM1266 strains display a biofilm defect, and overexpression of STM1266 results in enhanced biofilm formation. STM1266 deletion resulted in lowered csgA expression using promoter-reporter β-galactosidase assays, and csgA and csgD deletions abrogate the effects of STM1266 overexpression on biofilm formation while deletion of bcsA (encoding an essential enzyme for cellulose formation) has no effect. In a mouse infection model, the ΔSTM1266 strain displayed results similar to those seen for previously reported ΔcsgA strains. The STM1266 gene is predicted to encode a DNA-binding transcriptional regulator of the MerR family and is homologous to the Escherichia coli BluR regulator protein. We respectfully propose to ascribe the name brfS (biofilm regulator for Salmonella Typhimurium) to the STM1266 gene.
鼠伤寒沙门氏菌中生物膜形成的主要途径涉及特定的生长条件，这些条件诱导了 csgA 基因的表达，其产物形成介导生物膜形成的表面卷曲纤维。我们发现，鼠伤寒沙门氏菌中的先前未被表征的 STM1266 基因通过卷曲途径在调节生物膜形成中发挥作用。鼠伤寒沙门氏菌ΔSTM1266 菌株表现出生物膜缺陷，STM1266 的过表达导致生物膜形成增强。通过启动子报告β-半乳糖苷酶测定发现，STM1266 缺失导致 csgA 表达降低，而 csgA 和 csgD 缺失消除了 STM1266 过表达对生物膜形成的影响，而 bcsA（编码纤维素形成所必需的酶）缺失则没有影响。在小鼠感染模型中，ΔSTM1266 菌株的结果与先前报道的ΔcsgA 菌株相似。STM1266 基因预测编码 MerR 家族的 DNA 结合转录调节因子，与大肠杆菌 BluR 调节蛋白同源。我们建议将 STM1266 基因命名为 brfS（鼠伤寒沙门氏菌生物膜调节因子）。
