Location: Warmwater Aquaculture Research UnitTitle: Salmonella enterica serovar Kentucky flagella are required for broiler skin adhesion and Caco-2 cell invasion
|SALEHI, SANAZ - Mississippi State University|
|HOWE, KEVIN - Mississippi State University|
|LAWRENCE, MARK - Mississippi State University|
|BAILEY, H - Mississippi State University|
|KARSI, ATTILA - Mississippi State University|
Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2016
Publication Date: 10/28/2016
Citation: Salehi, S., Howe, K., Lawrence, M., Brooks, J.P., Bailey, H., Karsi, A. 2016. Salmonella enterica serovar Kentucky flagella are required for broiler skin adhesion and Caco-2 cell invasion. Applied and Environmental Microbiology. 83:2.
Interpretive Summary: Salmonella enterica serovar Kentucky is among the most prominent serovars on carcasses in poultry-processing plants. Previous studies showed that flagella contribute to bacterial attachment to broiler skin. In this work, we deleted flagellar structural (flgK, fliC, and fljB) and motor (motA) genes to differentiate the role of flagella in the colonization of broiler skin and cellular attachment. Results indicated that flagellin subunit fliC, flagellar assembly, and a functional flagellar motor are required for optimal attachment of S. Kentucky on chicken skin and for cellular attachment and invasion.
Technical Abstract: Nontyphoidal Salmonella strains are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella enterica serovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry-processing plants. Previous studies showed that flagella are one of the main factors that contribute to bacterial attachment to broiler skin. However, the precise role of flagella and the mechanism of attachment are unknown. There are two different flagellar subunits (fliC and fljB) expressed alternatively in Salmonella enterica serovars using phase variation. Here, by making deletions in genes encoding flagellar structural subunits (flgK, fliC, and fljB), and flagellar motor (motA), we were able to differentiate the role of flagella and their rotary motion in the colonization of broiler skin and cellular attachment. Utilizing a broiler skin assay, we demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate tight attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild type. S. Kentucky with deletions in all three structural genes, fliC, fljB, and flgK, as well as a flagellar motor mutant (motA), exhibited less adhesion and invasion of Caco-2 cells, while an fljB mutant was as adherent and invasive as the wild-type strain.