Clostridium perfringens Virulent Bacteriophage CPS2 and Its Thermostable Endolysin LysCPS2

Clostridium perfringens is one of the most common causes of food-borne illness. The increasing prevalence of multidrug-resistant bacteria requires the development of alternatives to typical antimicrobial treatments. Here, we isolated and characterized a C. perfringens-specific virulent bacteriophage CPS2 from chicken feces. The CPS2 phage contains a 17,961 bp double-stranded DNA genome with 25 putative ORFs, and belongs to the Picovirinae, subfamily of Podoviridae. Bioinformatic analysis of the CPS2 genome revealed a putative endolysin, LysCPS2, which is homologous to the endolysin of Clostridium phage phiZP2 and phiCP7R. The enzyme showed strong lytic activity against C. perfringens with optimum conditions at pH 7.5–10, 25–65 °C, and over a broad range of NaCl concentrations. Interestingly, LysCPS2 was found to be highly thermostable, with up to 30% of its lytic activity remaining after 10 min of incubation at 95 °C. The cell wall binding domain in the C-terminal region of LysCPS2 showed a binding spectrum specific to C. perfringens strains. This is the first report to characterize highly thermostable endolysin isolated from virulent C. perfringens bacteriophage. The enzyme can be used as an alternative biocontrol and detection agent against C. perfringens.