Examination of the Anaerobic Growth ofCampylobacter concisusStrains

Abstract

Campylobacter concisusis an oral bacterium that is associated with intestinal diseases.C. concisuswas previously described as a bacterium that requires H2-enriched microaerobic conditions for growth. The level of H2in the oral cavity is extremely low, suggesting thatC. concisusis unlikely to have a microaerobic growth there. In this study, the anaerobic growth ofC. concisuswas investigated. The growth of fifty-seven oralC. concisusstrains and six entericC. concisusstrains under various atmospheric conditions including anaerobic conditions with and without H2was examined. The atmospheric conditions were generated using commercially available gas-generation systems.C. concisusputative virulence proteins were identified using mass spectrometry analysis. Under anaerobic conditions, 92% of the oralC. concisusstrains (52/57) and all six enteric strains grew without the presence of H2and the presence of H2greatly increasedC. concisusgrowth. An oralC. concisusstrain was found to express a number of putative virulence proteins and the expression levels of these proteins were not affected by H2. The levels of H2appeared to affect the optimal growth ofC. concisus. This study provides useful information in understanding the natural colonization site and pathogenicity ofC. concisus.