Phenotypic, genotypic and proteomic variations between poor and robust colonizing Campylobacter jejuni strains

Area of Science:

• Microbiology
• Food Safety
• Bacterial Pathogenesis

Background:

• Campylobacter jejuni is a leading cause of human bacterial gastrointestinal illness globally.
• Poultry consumption is a primary transmission route for this foodborne pathogen.
• Understanding C. jejuni colonization factors is crucial for food safety.

Purpose of the Study:

• To investigate phenotypic, genotypic, and proteomic differences between robust and poor C. jejuni colonizing strains in chickens.
• To identify specific proteins and pathways associated with differential colonization potential.

Main Methods:

• Oral challenge of chicks with two distinct C. jejuni strains (A74/C robust, A74/O poor).
• Phenotypic characterization including growth, biofilm, adherence, invasion, and survival assays.
• Genotypic analysis using whole genome alignment, core genome, and various typing methods (MLST, PFGE).
• Quantitative proteomic analysis via UHPLC-MS/MS, followed by COG and KEGG pathway analysis.

Main Results:

• Genotypically similar strains exhibited significant phenotypic differences in colonization and virulence-associated traits.
• Proteomic analysis identified distinct protein profiles, with overexpression of carbon metabolism and motility proteins in the robust colonizer (A74/C).
• The robust strain showed increased expression of proteins involved in adhesion, invasion, energy metabolism, stress response, and regulation.

Conclusions:

• Phenotypic and proteomic variations, particularly in metabolism and virulence-related proteins, contribute to differential C. jejuni colonization in chickens.
• These findings highlight the complex interplay of factors mediating bacterial colonization potential.
• Understanding these variations can inform strategies to control C. jejuni in poultry and prevent human infections.