Development of tools for the genetic manipulation of Campylobacter and their application to the N-glycosylation system of Campylobacter hepaticus, an emerging pathogen of poultry

Campylobacter hepaticus is an emerging pathogen responsible for Spotty Liver Disease (SLD) in poultry, which has considerable economic and animal welfare implications due to increased mortality rates and significant drops in egg production. Although potential virulence genes of C. hepaticus have been identified, further studies have been hindered by the lack of suitable genetic tools and methods for transformation and mutagenesis. This study aimed to develop plasmid vectors and transformation methods and to perform site-specific directed mutagenesis and mutant complementation. These tools enabled the deletion of the pglB gene, an oligosaccharyltransferase central to the N-glycosylation pathway, via allelic exchange, resulting in a C. hepaticus HV10 mutant strain that was unable to N-glycosylate proteins.