Expanding the repertoire of conservative site-specific recombination in Clostridioides difficile.

We report the finding of one novel inversion site for which we demonstrate the inversion potential and quantify inversion frequencies during exponential and stationary growth in both historic and modern isolates of the same ribotype. We then employ a computational approach to assess the prevalence of all sites identified so far in a large collection of sequenced C. difficile isolates. We show that phase-variable loci are widespread with some sites being present in virtually all analyzed strains. Furthermore, in our small subset of RT017 and RT078 strains, we detect no evidence of gain or loss of invertible sites in historic versus modern isolates demonstrating the relative stability of those genomic elements. Overall, our results support the idea that C. difficile has adopted phase variation mediated by DNA inversions as its major generator of diversity which could be beneficial during the pathogenesis process. PMID: 31323290 [PubMed - as supplied by publisher]
Source: Anaerobe - Category: Microbiology Authors: Tags: Anaerobe Source Type: research