Teseptimavirus T7 isolate:IMM-002 Genome sequencing and assembly. Teseptimavirus T7 isolate:IMM-002

Bacteria in their natural habitats are constantly attacked by predatory bacteriophages. Bacterial CRISPR (clustered regularly interspaced short palindromic repeats) systems provide a defense mechanism against predatory phages. The mechanism includes a molecular recording system that retains memory of past encounters with specific phages and thus provides immunity for future invasions. Bacteriphages that target Enterotoxigenic E.coli (ETEC) were not studied thoroughly. Here we report a novel ETEC specific phage IMM-002 that utilizes a colonization factor - CS3 as its receptor. Our findings uncovered a strategy that empowers CRISPR encoded single crRNA to target multiple protospacer sequences within the phage genome. Mutation in one protospacer is therefore not enough for the phage to evade CRISPR mediated host response. These results highlight the past encounters between host ETEC strains with predatory phages.