Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
PLoS One. 2023 May 18;18(5):e0284907. doi: 10.1371/journal.pone.0284907. eCollection 2023.
Quorum sensing is a communication strategy that bacteria use to collectively alter gene expression in response to cell density. Pathogens use quorum sensing systems to control activities vital to infection, such as the production of virulence factors and biofilm formation. The Pseudomonas virulence factor (pvf) gene cluster encodes a signaling system (Pvf) that is present in over 500 strains of proteobacteria, including strains that infect a variety of plant and human hosts. We have shown that Pvf regulates the production of secreted proteins and small molecules in the insect pathogen Pseudomonas entomophila L48. Here, we identified genes that are likely regulated by Pvf using the model strain P. entomophila L48 which does not contain other known quorum sensing systems. Pvf regulated genes were identified through comparing the transcriptomes of wildtype P. entomophila and a pvf deletion mutant (ΔpvfA-D). We found that deletion of pvfA-D affected the expression of approximately 300 genes involved in virulence, the type VI secretion system, siderophore transport, and branched chain amino acid biosynthesis. Additionally, we identified seven putative biosynthetic gene clusters with reduced expression in ΔpvfA-D. Our results indicate that Pvf controls multiple virulence mechanisms in P. entomophila L48. Characterizing genes regulated by Pvf will aid understanding of host-pathogen interactions and development of anti-virulence strategies against P. entomophila and other pvf-containing strains.
群体感应是一种细菌用来根据细胞密度集体改变基因表达的通讯策略。病原体利用群体感应系统来控制对感染至关重要的活动，例如毒力因子的产生和生物膜的形成。假单胞菌毒力因子（pvf）基因簇编码一个信号系统（Pvf），存在于超过 500 株变形菌中，包括感染多种植物和人类宿主的菌株。我们已经表明，Pvf 调节昆虫病原体假单胞菌 entomophila L48 中分泌蛋白和小分子的产生。在这里，我们使用不包含其他已知群体感应系统的模型菌株 P. entomophila L48 来鉴定可能受 Pvf 调节的基因。通过比较野生型 P. entomophila 和 pvf 缺失突变体（ΔpvfA-D）的转录组，鉴定出了 Pvf 调节的基因。我们发现，pvfA-D 的缺失影响了大约 300 个与毒力、VI 型分泌系统、铁载体运输和支链氨基酸生物合成有关的基因的表达。此外，我们还鉴定了七个在ΔpvfA-D 中表达减少的推定生物合成基因簇。我们的结果表明，Pvf 控制着 P. entomophila L48 中的多种毒力机制。表征受 Pvf 调节的基因将有助于理解宿主-病原体相互作用，并开发针对 P. entomophila 和其他含有 pvf 菌株的抗毒力策略。
