AbstractsBiology & Animal Science

Campylobacter jejuni is the most common causative agent of bacterial gastroenteritis in the world and is frequently carried in many food animals. In order to better prevent human infections a better understanding of the epidemiology and genetics of this organism is needed. The development of comparative genome indexing (CGI) as a molecular typing tool for C. jejuni offers a new means to meet many of these needs. To evaluate the CGI as a typing tool, comparisons to two standard methods, pulsed-field gel electrophoresis (PFGE) and flaA short variable region sequencing (flaA SVR) typing were preformed using isolates obtained from cattle and chicken sources. The results demonstrated that CGI provided the highest discrimination among the isolates. Since CGI produces considerable amounts of data this method also allows for a more in depth study of C. jejuni at the genomic level. One hundred and thirty-one geographically diverse C. jejuni strains were selected from a collection of human, beef cattle and chicken isolates. Statistical analyses identified 134 genes specific for isolate source and geographic origin. Using this reduced gene set, all 131 isolates were further analyzed via the ®BioNumerics software program to determine the usefulness of the reduced dataset to differentiate among the isolates. The reduced dataset was sufficient to discriminate all of the isolates as unique types and differentiated strains by host source more effectively compared to the whole genome dataset. Overall, the results of these studies indicate the value of CGI as a molecular typing tool for C. jejuni and its potential to provide new insights into this organism on many levels.