Staphylococcus aureus lytic bacteriophage: isolation and application evaluation

Staphylococcus aureus is a significant pathogen associated with various illnesses, including food poisoning. The development of effective treatments is challenging, necessitating the exploration of novel antimicrobial options. Bacteriophages (phages) have emerged as promising candidates in this regard. In this study, a virulent phage called mSA4 was isolated and characterized. Furthermore, its efficacy in combating S. aureus biofilms and growth in various food products was evaluated. Phage mSA4 demonstrated a broad host range, targeting both S. aureus and methicillin-resistant S. aureus strains. Belonging to the Myoviridae family, it exhibited rapid adsorption (over 50% in 3 min), a short latent period (20 min), and a burst size of 97 phage particles per infected bacterial cell. Furthermore, phage mSA4 displayed stability across a wide range of pH values and temperatures, and effectively degraded established biofilms. Its performance was evaluated in chocolate milk, beef meat, and iceberg lettuce, resulting in significant reductions in bacterial counts (2.1 log CFU/mL, 2.8 log CFU/cm², and 3.2 log CFU/cm², respectively). These findings underscore the potential of phage mSA4 as a natural biocontrol agent against S. aureus.