A novel chimeric endolysin with enhanced lytic and binding activity against Clostridium perfringens

Clostridium perfringens is a gram-positive, anaerobic, and spore-forming bacterium that produces toxins causing various diseases in humans and livestock animals. With the growth in antibiotic resistance, finding alternative biocontrol agents against C. perfringens is necessary for food safety and animal health. Here, we isolated a C. perfringens-infecting bacteriophage CPD9 and characterized its endolysin LysCPD9. Although LysCPD9 has specific lytic activity against C. perfringens over a wide range of environmental conditions, its activity was lower than expected. To improve its lytic activity, we generated chimeric endolysins by shuffling the domains of LysCPD9 with those of thermostable C. perfringens endolysin, LysCPS2. Among the chimeras, a novel chimeric endolysin, ClyY, showed higher antimicrobial activity than its parental endolysin LysCPD9. In addition, ClyY significantly reduced C. perfringens cells in artificially contaminated milk and beef by 4-log CFU/ml and 3-log CFU/cm², respectively, within 2 h. This enhanced lytic activity might be due to the increased cell wall binding because ClyY showed at least 3-fold higher binding activity than LysCPD9. ClyY could be utilized as an effective therapeutic as well as diagnostic tool for C. perfringens.