Serine Utilization by <i>Campylobacter Jejuni</i> and <i>Campylobacter Coli</i>

The intestinal pathogens <i>Campylobacter jejuni</i> and <i>Campylobacter coli</i> are the most common causes of foodborne bacterial gastroenteritis in humans. In Japan and globally, more than 90% of <i>Campylobacter</i> species isolated from patients with <i>Campylobacter</i> food poisoning are <i>C. jejuni</i>, whereas <i>C. coli</i> accounts for only a small percentage. This difference in isolation rates is considered to be due to differences in the ability of <i>C. jejuni</i> and <i>C. coli</i> to proliferate within the host. However, only a few studies have compared the growth of these two pathogens. To investigate the effect of <i>C. jejuni</i> on the proliferative ability of <i>C. coli</i> and vice versa, co-culture experiments were conducted. Similar strains were selected on the basis of their amino acid requirements for comparative purposes. <i>C. jejuni</i> grew on amino acid-rich media, indicating that its growth was not affected by the presence of <i>C. coli</i>. By contrast, the growth of <i>C. coli</i> was inhibited by <i>C. jejuni</i>. This suggests that the higher detection rate of <i>C. jejuni</i> may be due to its superior growth capacity rather than its initial abundance. Further research on <i>C. coli</i> is required to better understand its role and behavior in the host and in different environments.