Analysis of Type IV pilin in Vibrio parahaemolyticus
University of Delaware
Vibrio parahaemolyticus is a Gram-negative bacterium that is ubiquitous in the marine environment and is also a human pathogen that when ingested induces gastroenteritis. This bacterium expresses on its surface rod like hair-like appendages called pili. Pili are important for bacterial adherence to surfaces such as shellfish and human cells. The V. parahaemolyticus genome contains several different pili, but the most common class of pili is the type IV. In V. parahaemolyticus, four type IV pili have been identified, two of which are TAD Caulobacter Pilin Assembly (CPA) type IV pilins, as well as the mannose-sensitive hemagglutinin (MSHA), and the chitin regulated pilus (ChiRP/Pil). MSHA pilin is required for adherence, biofilm production, and twitching motility. CHiRP is required for adherence to chitin surfaces and natural transformation for DNA uptake. This study focused on the characterization of one of the two TAD CPA type IV pilins, the TAD1 CPA type IV pilin. In this work, a non-functional TAD1 mutant strain was constructed by deleting the pilin protein encoded by the VP2423 gene creating a ∆VP2423 mutant. The mutant strain was then characterized using growth pattern analysis and phenotypic assays: swimming and swarming assays, capsule polysaccharide production, and biofilm formation. The mutant strain grew similar to wild type in all these assays.
Bacterium, Pili, Mutant strain