Effect of peptide and amino acid catabolism on the growth dynamic and colonization efficiency of Campylobacter jejuni

• Applicant: Professor Dr. Dirk Hofreuter
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens ; Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 186883334

Campylobacter jejuni is a common cause of gastrointestinal infections in humans and little is known about the physiological requirements essential for C. jejuni to thrive efficiently in its hosts. We are interested in identifying growth substrates that allow C. jejuni to persist in its different environments. C. jejuni is unable to metabolize carbohydrates, the major energy source of many commensal and pathogenic intestinal bacteria. Instead, glucogenic amino acids seem to be the preferred source of carbon and nitrogen for C. jejuni. Because peptides are abundant in the intestine, we hypothesize that the catabolism of these peptides by C. jejuni contributes to its growth. With targeted mutagenesis we will decipher the importance of specific peptidases, peptide transporters and amino acid transporters for the growth of C. jejuni. We will further analyze the significance of putative growth factors of C. jejuni by testing specific mutants for their in vivo colonization capability using different animal models of infection. These studies will be complemented by metabolomic analyses of peptide-containing growth media during the cultivation of C. jejuni in vitro to identify which peptides that can be utilized by C. jejuni for growth. With completion of this project we will not only discover essential metabolic pathways in C. jejuni that could serve as potential drug targets, but we will also gain a better general understanding of how pathogens access nutrients during infection.

• DFG Programme: Research Grants