Characterization of the role of global regulator FliA in the pathophysiology of Pseudomonas aeruginosa infection

Publication date: April 2018Source: Research in Microbiology, Volume 169, Issue 3Author(s): Yi-Ling Lo, Chyi-Liang Chen, Lunda Shen, Ying-Ching Chen, Yi-Hsin Wang, Chung-Chan Lee, Lian-Chen Wang, Chih-Hsien Chuang, Rajendra Prasad Janapatla, Cheng-Hsun Chiu, Hwan-You ChangAbstractFliA is known to be a sigma factor that regulates bacterial flagella gene expression. Accumulating evidence suggests that FliA is involved in bacterial behavior other than motility. To elucidate the contribution of FliA to Pseudomonas aeruginosa pathophysiology, we analyzed the biological properties and gene expression profiles of a ΔfliA mutant. Transcriptome analysis results demonstrated that the expression levels of flagella biogenesis genes decreased dramatically in the mutant; consequently, the ΔfliA mutant failed to synthesize flagella and exhibited reduced motility. The ΔfliA mutant displayed stronger hemolytic and caseinolytic activities, as well as pyocyanin production. The expression of type 6 secretion system-II genes and interbacterial competition activity was decreased in the ΔfliA mutant. Direct evidence of fliA participation in virulence was obtained from analysis of hypervirulent strain B136-33. Adhesion to and cytotoxicity toward mammalian cells and penetration through cell layers were noted; furthermore, the colonization ability of the fliA::Tn5 mutant in the intestines of laboratory mice was compromised. Notably, the fliA-overexpressing strain displayed phenotypes similar to th...
Source: Research in Microbiology - Category: Microbiology Source Type: research