The Recombinant Bacteriophage Endolysin HY-133 Exhibits In Vitro Activity against Different African Clonal Lineages of the Staphylococcus aureus Complex, Including Staphylococcus schweitzeri

HY-133 is a recombinant bacteriophage endolysin with bactericidal activity against Staphylococcus aureus. Here, HY-133 showed in vitro activity against major African methicillin-susceptible and methicillin-resistant S. aureus lineages and ceftaroline/ceftobiprole- and borderline oxacillin-resistant isolates. HY-133 was also active against Staphylococcus schweitzeri, a recently described species of the S. aureus complex. The activity of HY-133 on the tested isolates (MIC50, 0.25 mu g/ml; MIC90, 0.5 mu g/ml; range, 0.125 to 0.5 mu g/ml) was independent of the species and strain background or antibiotic resistance.