RNA-based regulation mechanism of phage-encoded AbiF system in Clostridioides difficile

During its infection cycle, Clostridioides difficile pathogen survives in phage-rich intestinal communities by relying on several defense systems, some of which have identified RNAs as key components. Here, we study the putative abiF-like gene (abortive infection system) found in the phi-027 prophage and conserved in ribotype 027 C. difficile isolates. We show that it is mediated by a non-coding RNA, RCd22, which lies just upstream of the abiF-like gene.