MOLECULAR CHARACTERIZATION OF PATHOGENS AND THEIR RESPONSES TO ENVIRONMENTAL FACTORS
Location: Molecular Characterization of Foodborne Pathogens
Title: Gyr B versus 16s rDNA sequencing for the identification of Campylobacter jejuni, Campylobacter coli, and Campylobacter lari
Submitted to: Journal of Nucleic Acids Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 13, 2010
Publication Date: January 1, 2011
Citation: Gunther, N.W., Almond, J.T., Yan, X., Needleman, D.S. 2011. Gyr B versus 16s rDNA sequencing for the identification of Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. Journal of Nucleic Acids Investigation. DOI: 101089/fpd.2010.0773.
Interpretive Summary: The three main human disease causing Campylobacter species, Campylobacter jejuni, Campylobacter coli, and Campylobacter lari are very closely related to one another. They are so closely related that a genetic method often used to differentiate one bacterial species from another is ineffective in differentiating these three Campylobacter species. The 16s rDNA gene has stretches of sequence that are unique for different bacterial species, unfortunately these stretches of sequence in the 16s rDNA genes of C. jejuni, C. coli, and C. lari are almost identical and therefore insufficient for differentiation of the bacteria. We have adapted an alternative method using the sequencing of a portion of the gyrase B gene that gives excellent differentiation of these three Campylobacter species. Our method has the advantages of requiring fewer steps in the amplification and sequencing of the target gene, as well as simplifying the analyses while maintaining the excellent differentiating quality of the gyrase B gene. This research provides a useful tool for identifying and organizing clinically relevant strains for use in research laboratories.
Species of the genus Campylobacter are the causative agents of a sizable number of the cases of food-borne illness in the developed world. The majority of this disease is caused by three of the thermotolerant Campylobacter species: Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. The inability to fully differentiate these three species using the commonly employed 16s rDNA sequencing procedure has led to the development of alternative methods to properly identify these bacteria. Some of these methods include the utilization of the gyrB gene. A simple method was developed for the differentiation of C. jejuni, C. coli, and C. lari employing the gyrB gene. It involves amplification and sequencing of a species-variable region of the gene with a single pair of DNA primers. The method works well for the separation and organization of the three Campylobacter strains as well as satisfying the suggested guidelines for sequence based identification for most strains investigated.