Some bacteria prey upon other bacteria. Bdellovibrio-like bacteria are obligatory predators, as such they must consume live bacteria. Some Bdellovibrio-like species eat their prey from the outside (epibiotic predation), while others squeeze into the periplasm and devour the prey from within (periplasmic predation). Here we identified initial interaction genes of Bdellovibrio by using transcriptome data, comparative genome analyses, and experimental microbiology. Our screen found a conserved region that is expressed when the Bdellovibrio is searching for its prey. This region is homologous to 'tight adherence’ (TAD) loci. TAD locus is crucial for attachment of bacteria onto surfaces and eukaryotic hosts. Knockout of TAD components abolishes Bdellovibrio predation. Moreover, these TAD components were found to be controlled by the flagellar sigma factor FliA. To our knowledge, this is the first incident where FliA regulates non-flagellar related genes.
