Submitted to: International Association for Food Protection
Publication Type: Abstract only
Publication Acceptance Date: 3/12/2007
Publication Date: 7/8/2007
Citation: Pittenger, L.G., Englen, M.D., Frye, J.G., Mcnerney, V., Reeves, J., Gay, K.R., Cray, P.J., Harrison, M.A. 2007. Dna micorarrays for genotyping and population studies of campylobacter jejuni. International Association for Food Protection. P5-07:224-225. Interpretive Summary:
Technical Abstract: Introduction: Campylobacter jejuni is a major cause worldwide of foodborne bacterial gastroenteritis. The continued development of more effective and informative typing methods is necessary to improve our understanding of the epidemiology and population dynamics of this important pathogen. Comparative genome indexing (CGI) using whole genome DNA microarrays is a method useful not only for molecular typing, but also to provide considerable strain-specific genetic information unavailable by current typing methods. Purpose: The purpose of this study was to identify genes with a high degree of strain diversity to indicate host source and U.S. region for use in the development of a novel microarray-based typing method for C. jejuni. Methods: One hundred thirty-three geographically diverse C. jejuni isolated from humans, cattle and chickens were typed by CGI. Statistical methods appropriate for data normalization, establishing the presence and absence of genes and highly variable genetic loci were determined. These methods were used to identify C. jejuni genes characteristic of geographic region and host source. Results: A statistical analysis of the CGI data revealed over 100 genes out of the 1927 genes present on the microarray that varied significantly between the test strains and the type strains (NCTC11168 and RM1221). These genes differentiated isolates by source and the U.S. region from which they were isolated. Of these 100 significantly variable genes, approximately one third can be used to determine the geographic region and the remainder can be used to identify the host source. Significance: CGI provides a unique tool for genotypic and population studies of C. jejuni. The identification of genomic regions with high diversity including source and region specific marker genes forms the basis for development of a novel, more efficient typing method for C. jejuni.