Campylobacter Pathogenomics: Genomes and Beyond

Members of the genus Campylobacter are defined as fastidious, microaerophilic, oxidase positive, nonfermentative, gram-negative bacteria. All predicted proteins from the five Campylobacter genomes were compared with data from other published microbial genomes by BLASTP. The chromosomes of all five Campylobacter strains in this comparative study were examined for the presence or absence of clustered regularly interspaced short palindromic repeats (CRISPR) elements in intergenic regions. In this study, a strain is considered CRISPR positive when it contains two or more direct repeats of a 21-bp or larger DNA segment separated by unique spacer sequences of a similar size. The Campylobacter species strains analyzed in this study have the Sec-dependent and Sec-independent protein export pathways for the secretion of proteins across the inner or periplasmic membrane. Of the 580 open reading frames (ORFs) conserved between the Campylobacter and Helicobacter species included in this study, 27 ORFs involved in flagellar biosynthesis and function were conserved between Campylobacter and Helicobacter. A research group applied in vitro mariner-based transposition system to identify genes involved in motility in C. jejuni 81-176. They followed up this work to show that flagellar genes were regulated by σ54, but not σ28. Although some proteomic studies have been conducted for C. jejuni, these were limited to differential analysis of specific mutations, planktonic versus biofilm growth, and on NCTC 11168 stocks with different amounts of passaging.