Submitted to: Journal of Medical Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/18/2014
Publication Date: 4/11/2014
Citation: Yeh, H., Hiett, K.L., Line, J.E., Seal, B.S. 2014. Characterization and Antigenicity of Recombinant Campylobacter jejuni Flagellar Capping Protein FliD. Journal of Medical Microbiology. 63(4):602-609. Interpretive Summary: Campylobacter jejuni is an important foodborne pathogen, which causes human acute bacterial gastroenteritis worldwide. Consumption and handling of raw or undercooked poultry meat is the major source of this bacterium for human infection. To prevent human infection, vaccination of chickens is one of powerful means to reduce this bacterium in broiler chicken gut and minimize contamination in poultry. Because the flagellar capping protein (FliD) has been implicated for microorganism adherence and colonization in intestinal mucosa, the role of this FliD protein of Campylobacter jejuni has not been studied. Molecular technique was used to produce a large amount of this protein. Sera from broiler chickens were used to test whether they had anti-FliD antibodies. The results suggest that anti-FliD antibody may be prevalent in the poultry population. These results also provide a rationale for further evaluation of this protein as a vaccine target for chickens and as a tool for investigating the host-Campylobacter jejuni interactions. This study is related to the goal of ARS National Program 108-Food Safety, Component 1D-Intervention and Control Strategies.
Technical Abstract: Campylobacter jejuni, a flagellated, spiral-rod Gram-negative bacterium, is the leading pathogen of human acute bacterial gastroenteritis worldwide, and chickens are regarded as a major reservoir of this microorganism. Bacterial flagella, composed of more than 35 proteins, play important roles in colonization and adhesion to the mucosal surface of chicken ceca. In this communication, the flagellar capping protein, FliD, encoded by the fliD gene, from the Campylobacter jenuni D1-39 isolate was expressed and characterized, and its antigenicity was determined. The fliD gene had 1929 nucleotides, potentially encoding a 642 amino acid peptide with the calculated molecular mass of 69.6 kDa (GenBank accession number KC618388). This gene was PCR amplified and over-expressed in Escherichia coli. The recombinant FliD protein was purified by a cobalt-chelating affinity chromatography, and confirmed by nucleotide sequencing of the expression plasmid, SDS-PAGE analysis, the His tag detection and MALDI-TOF analysis. The immunoblot data showed that the purified recombinant FliD protein reacted strongly to sera from broiler chickens older than four weeks, indicating that this anti-FliD antibody may be prevalent in the poultry population. These results provide a rationale for further evaluation of the FliD protein as a vaccine candidate for broiler chickens to improve food safety for poultry.