Phage ZCSS1 from isolation to application against Staphylococcus sciuri and biofilm: A prospect of utilizing temperate phage and its products

Following the spread of the multi-drug resistant bacteria and the huge demand on public health, various alternatives were pursued. Bacteriophages (virulent phages) are among the potential antibacterial agents that have shown promising applications in medicine, veterinary and industry. However, the vast majority of bacteriophages in the environment (temperate phages) are under-looked because of the concerns surrounding them. Here, we have isolated and characterized a promising bacteriophage (has both lytic and lysogenic-related genes) with high specificity and potential activity against Staphylococcus sciuri (S. sciuri), then highlighted the gene products (endolysin, holin, protease and hydrolase) that are responsible for its tremendous lytic activity. Phage ZCSS1 was isolated from raw milk to act against multidrug-resistant S. sciuri that is considered pathogenic to humans and animals. The stability of phage ZCSS1 at different concentrations of salts, chemicals, temperatures, and pH values was exanimated and the results showed a great persistence against harsh physical and chemical conditions. The entire structural parts of the phage were characterized using transmission electron microscopy (TEM), which revealed that ZCSS1 belongs to Myoviridae, Caudovirales. The whole-genome sequencing of ZCSS1 produced a complete DNA sequence of 139,743 bp, with 208 coding genes. Moreover, the lysogenic and lyticrelated genes were identified in the sequence data, making ZCSS1 a good candidate for studying the switching between lysogenic and lytic life cycles. The activity of ZCSS1 to inhibit and clear the biofilms was tested in various titers (MOI & LE; 1), where it presented a remarkable ability against S. scuiri biofilms, even at low titers. In this work a promising temperate phage was characterized and its gene products was highlighted to be utilized in various further applications.