Polyvalent Phage CoNShP-3 as a Natural Antimicrobial Agent Showing Lytic and Antibiofilm Activities against Antibiotic-Resistant Coagulase-Negative Staphylococci Strains

Synthetic antimicrobials have a negative impact on food quality and consumer health, which is why natural antimicrobials are urgently needed. Coagulase-negative staphylococci (CoNS) has gained considerable importance for food poisoning and infection in humans and animals, particularly in biofilms. As a result, this study was conducted to control the CoNS isolated from food samples in Egypt. CoNS isolates were selected on the basis of their antibiotic susceptibility profiles and their biofilm-associated behavior. In this context, a total of 29 different bacteriophages were isolated and, in particular, lytic phages (6 isolates) were selected. The host range and physiological parameters of the lytic phages have been studied. Electron microscopy images showed that lytic phages were members of the familiesMyoviridae(CoNShP-1, CoNShP-3, and CoNSeP-2 isolates) andSiphoviridae(CoNShP-2, CoNSsP-1, and CoNSeP-1 isolates). CoNShP-1, CoNShP-2, and CoNShP-3 were found to be virulent toStaphylococcus haemolyticus, CoNSsP-1 toStaphylococcus saprophyticusand CoNSeP-1 and CoNSeP-2 toStaphylococcus epidermidis. Interestingly, the CoNShP-3 exhibited a typical polyvalent behavior, where not only lysis CoNS, but also other genera includeStaphylococcus aureus, methicillin-resistantStaphylococcus aureus(MRSA), vancomycin-resistantStaphylococcus aureus(VRSA),Bacillus cereusandBacillus subtilis. In addition, CoNShP-3 phage showed high stability at different temperatures and pH levels. Indeed, CoNShP-3 phage showed an antibiofilm effect againstStaphylococcus epidermidisCFS79 andStaphylococcus haemolyticusCFS43, respectively, whileStaphylococcus saprophyticusCFS28 biofilm was completely removed. Finally, CoNShP-3 phage demonstrated a high preservative efficacy over short and long periods of storage against inoculated CoNS in chicken breast sections. In conclusion, this study highlights the control of CoNS pathogens using a polyvalent lytic phage as a natural antibacterial and antibiofilm agent from a food safety perspective.