Title: Molecular subtyping methods for campylobacter Authors
Submitted to: USDA Annual Food Safety Research Planning Meeting
Publication Type: Proceedings
Publication Acceptance Date: February 22, 2007
Publication Date: February 22, 2007
Citation: Frye, J.G., Englen, M.D., Meinersmann, R.J., Cray, P.J. 2007. Molecular subtyping methods for campylobacter. USDA Annual Food Safety Research Planning Meeting. February 21-23, 2007. Shepherdstown, WV. Technical Abstract: 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. The purpose of this study was the development of a novel microarray-based typing method for C. jejuni. Thirty-six geographically diverse C. jejuni isolated from 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. The typing method was compared directly to PFGE and flaA typing using the Bionumerics analysis package. CGI typing was found to be more discriminatory than PFGE or flaA typing. Over 100 genes were found that varied among the isolates and were also associated with the different sources and regions of the U.S. from which they were isolated. CGI provides a unique tool for genotypic and population studies of C. jejuni. The identification of genomic regions with high diversity including source and virulence specific marker genes forms the basis for development of a novel, more efficient typing method for C. jejuni.