Identifying skin bacteriophages of Staphylococcus to determine population and community dynamics
Samah Alsaadi 1*, Hanshuo Lu 1, Heather E. Allison 1, Malcolm J. Horsburgh 1
- Institute of Infection, Veterinary and Ecological Sciences
- University of Liverpool
- Liverpool
- UK
Samah Alsaadi. Email: s.alsaadi@liverpool.ac.uk
Human skin is colonised by diverse microbial communities that are important for skin health. Species of coagulase-negative Staphylococcus are highly abundant and vary across the different skin regions, with S. epidermidis being the most frequent. We seek to investigate how the skin virome influences the dynamics of staphylococcal populations in bacterial communities of the skin microbiome, with focus on skin bacteriophages infecting Staphylococcus spp. We collected swabs from >80 healthy volunteers across different skin sites to isolate cutaneous phages that infect different Staphylococcus spp. From the swabs we isolated, purified and sequenced the genomes of 42 phages that infect 8 different Staphylococcus species, including multiple isolates of a novel phage. We assessed qualitatively the degree of phage resistance using a wide host range of 138 Staphylococcus strains of the 8 species. Among the coagulase-negative staphylococci tested, S. hominis exhibits broad resistance to phage infection. We hypothesise that S. hominis encodes pathways to limit phage infection and have explored its mechanisms using experimental evolution by selecting for phage resistance. We also determined that S. aureus was resistant to every phage isolated from the skin that infects coagulase- negative staphylococci. The phages that infect staphylococci will inform our studies of their potential contributions to skin population dynamics and dysbiosis and will enable interrogation of metagenomic datasets to explore relationships with skin health.