In vitro genomic and proteomic evidence of a type IV pili-like structure in the fish pathogen Piscirickettsia salmonis. Issue 16 (6th July 2018)

• Record Type: Journal Article
• Authors: Sánchez, Patricio; Oliver, Cristian; Hernández, Mauricio; Cortés, Marcos; Cecilia Rauch, María; Valenzuela, Karla; Garduño, Rafael A; Avendaño-Herrera, Rubén; Yáñez, Alejandro J
• Is Part Of: FEMS microbiology letters. Volume 365:Issue 16(2018:Aug.)
• Publication Date: 2018-07-06
• Subjects: Piscirickettsia salmonis -- SRS -- piscirickettsiosis -- type IV pilus -- pili; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fny169
• Languages: English
• ISSNs: 0378-1097

Abstract

ABSTRACT: Piscirickettsia salmonis is an intracellular γ-proteobacteria and the etiological agent of piscirickettsiosis, which causes massive economic losses in the Chilean salmon industry. The type IV pili (T4P) play an important role in adherence to host cell surfaces and bacterial pathogenicity. T4P contains a variable number of components, as predicted in P. salmonis genomes. However, no studies have determined if P. salmonis possesses T4P. The aims of this investigation were to identify T4P components in the P. salmonis type strain LF-89 T, evaluate respective transcript expressions, and analyze the main putative T4P proteins using bioinformatics and proteomic approaches. Two main clusters of P. salmonis T4P genes were found. Expression of the pilA gene was upregulated at 4 h post-infection (hpi), while pilQ was upregulated 4 days post-infection. At 16 hpi, pilB and pilD were strongly upregulated. The PilA amino acid sequence analysis showed a conserved N-terminal domain and sequence motifs critical for T4P biosynthesis. MudPIT analysis revealed PilA in the P. salmonis LF-89 T proteome, and TEM showed pili-like filamentous structures on the P. salmonis surface. These results strongly suggest the presence of a T4P-like structure in P. salmonis . Abstract : Fish pathogen Piscirickettsia salmonis present type IV pili-like structures that are differentially modulated during infectious processes, likely aiding in adherence to host cells and in pathogenicity.