The food application of a novel Staphylococcus aureus bacteriophage vB_SA_STAP152 and its endolysin LysP152 with high enzymatic activity under cold temperature

Abstract

Staphylococcus aureus, a foodborne bacterial pathogen, poses a serious challenge due to antibiotic resistance, highlighting the urgent need for effective and alternative antimicrobial agents. Undoubtedly, bacteriophages and bacteriophage-encoded antibacterial proteins have been considered effective biopreservatives. Herein, we report the isolation and characterization of a novel lytic bacteriophage, vB_SA_STAP152, along with its endolysin LysP152. Morphological and genomic analysis revealed that vB_SA_STAP152 could be considered as a new species in the Rosenblumvirus genus. Stability tests demonstrated that vB_SA_STAP152 can withstand a range of temperatures (∼65 °C) and pH values (4–11). Moreover, we successfully cloned and expressed the bacteriophage-encoded protein, endolysin LysP152, which exhibited optimal activity at temperatures between 4 and 35 °C and within a broad pH range (4–11). The antibacterial spectrum experiments revealed that phage vB_SA_STAP152 effectively targeted 76.15% of S. aureus strains across 14 different sequence types (STs), particularly including community-associated methicillin-resistant S. aureus (CA-MRSA) ST59. Furthermore, endolysin LysP152 demonstrated complete lysis all tested S. aureus strains spanning 17 STs. Subsequently, the efficacy of vB_SA_STAP152 and LysP152 against MRSA in pork was evaluated, revealing a significant reduction of bacterial counts by 4.27–4.42 log₁₀ CFU/mL with phage vB_SA_STAP152 at room temperature and by 3.31 log₁₀ CFU/mL with endolysin LysP152 at refrigerator temperature. Overall, the in-vitro studies and favorable physical and chemical properties suggested that phage vB_SA_STAP152 and endolysin LysP152 have the potential to be developed as antimicrobial agents against S. aureus in the food industry.