Characterization of a bacteriocin that targets Clostridioidies difficile

Clostridioidies difficile is a bacterium of concern for anyone undergoing antibiotic treatment. C. difficile can resist most antibiotics and is currently only treated with Metronidazole and Vancomycin. Both antibiotics are non-specific to C. difficile and have the side effect of killing the normal microbiome of the gut. This microbiome helps to keep the body resistant to C. difficile infections. The lack of specific treatment options perpetuates the problem of infection and can lead to relapses of disease. Clostridium butyricum, a non-pathogenic probiotic, has been shown to produce a highly specific antimicrobial product called a bacteriocin that targets C. difficile. Previously, the gene encoding for the C. butyricum bacteriocin (CBMB) was cloned into E. coli and purified as recombinant protein. The recombinant CBMB was shown to exhibit potent activities in multiple strains of C. difficile. In my project, I continue the characterization of CBMB by performing disk agar diffusion assays, growth curve analysis showing the antimicrobial effect of CBMB on C. difficile. In silico analysis using the new AI system, Alphafold 2 was performed to predict the 3-dimension structure of CBMB. Based on this analysis, we also designed peptide fragments derived from the different regions of CBMB to determine the site of catalysis. Furthermore, we are also working on determining the minimal residues required for CBMB to still retain antimicrobial activity. The ultimate goal of my project is to generate potentially novel alternative treatment of C. difficile infections.