title: The adherent abilities of Clostridium perfringens strains are critical for the pathogenesis of avian necrotic enteritis.
abstract: Necrotic enteritis of poultry is an emerging disease of substantial economic importance, but aspects of the pathogenesis of this multi-factorial disease are still unclear. We recently demonstrated that the ability of avian strains of the causative bacterium, Clostridium perfringens, to bind to specific collagen types correlated strongly with their virulence and we postulated that binding of the pathogen to collagen types IV and V and gelatin may involve the putative adhesin-encoding gene cnaA, which is found in the VR-10B locus. In this study we have used site-directed mutagenesis to demonstrate that disruption of the cnaA gene leads to a reduction in the expression of the three genes immediately downstream of cnaA and reduced adherence to collagen types IV and V and gelatin. In addition, a cnaA mutant of strain EHE-NE18 was no longer capable of causing necrotic enteritis in a chicken disease induction model and had a significantly reduced ability to colonise the chicken intestinal mucosa. These results were confirmed by generating and analysing a similar mutant in an independent necrotic enteritis causing C. perfringens strain. This study expands our understanding of the mechanisms involved in necrotic enteritis pathogenesis by demonstrating the importance of C. perfringens adherence to extracellular matrix proteins.
authors.affiliation: CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia; Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia. Electronic address: ben.wade@csiro.au.
authors.forename: Ben
authors.initials: B
authors.lastname: Wade
authors.affiliation: CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia; Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia; Poultry Cooperative Research Centre, Armidale, New South Wales 2350, Australia. Electronic address: anthony.keyburn@csiro.au.
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Keyburn
authors.affiliation: CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia. Electronic address: volker.haring@gmail.com.
authors.forename: Volker
authors.initials: V
authors.lastname: Haring
authors.affiliation: CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia. Electronic address: mark.ford@csiro.au.
authors.forename: Mark
authors.initials: M
authors.lastname: Ford
authors.affiliation: Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia; Poultry Cooperative Research Centre, Armidale, New South Wales 2350, Australia. Electronic address: Julian.rood@monash.edu.au.
authors.forename: Julian I
authors.initials: JI
authors.lastname: Rood
authors.affiliation: CSIRO Biosecurity Flagship, Australian Animal Health Laboratory, Geelong, Victoria 3220, Australia; Infection and Immunity Program, Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia; Poultry Cooperative Research Centre, Armidale, New South Wales 2350, Australia; School of Science, RMIT University, Bundoora, Victoria 3083, Australia. Electronic address: rob.moore@rmit.edu.au.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Moore
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D003015:Clostridium Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D003016:Clostridium perfringens / Q000502:physiology*; D004751:Enteritis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D011201:Poultry Diseases / Q000382:microbiology* / Q000473:pathology
chemical_list: D001426:Bacterial Proteins
keywords: Adherence; Adhesin; Clostridium perfringens; Collagen; Necrotic enteritis; Pathogenesis; Virulence