Novel Phage StaphC_127 Specific to Both Staphylococcus capitis and Staphylococcus caprae and Representing a New Genus of Staphylococcal Siphoviruses

Coagulase-negative staphylococci, including Staphylococcus capitis and Staphylococcus caprae can be causative agents of various nosocomial infections. A novel Staphylococcus phage StaphC_127, active against both S. caprae and S. capitis, was isolated from the surface of a spoiled tomato. All susceptible Staphylococcus strains were isolated from clinical samples collected from the irritated skin surface. StaphC_127 has low lytic activity against the host strain S. caprae CEMTC 1849 and is possibly a temperate phage as its genome encodes the repressor, antirepressor, and site-specific DNA recombinase. In addition, the StaphC_127 genome was detected in bacteriophage insensitive mutants (BIMs) obtained from at least two sensitive S. caprae strains after StaphC_127 infection. Notably, the StaphC_127 genome encodes the Tad2 protein belonging to the Tad2 phage protein family, which inhibits the Thoeris antiphage defense system. The obtained results of the genome analysis indicated that StaphC_127 is the first member of a new supposed Staphcevirus genus that, in turn, is part of a putative Estebevirinae subfamily containing phages capable of infecting coagulase-negative staphylococci.