The Gratia Polyvalent Staphylococcal Bacteriophage

Summary

Lytic spectra of the Gratia staphylococcal bacteriophage have been determined both against the standard international typing strains of Staphylococcus aureus and against “wild” strains. The broad range of lytic capability of the Gratia phage is remarkable. The substrain of Gratia phage propagated on Serotype I lysed more than half of the standard typing strains and 31% of 279 “wild” strains. Inhibition of lytic activity by pooled human serum was not complete in the majority of instances even in 80% serum. These data we believe to be compatible with the supposition that direct lysis of infecting staphylococci may be a factor in the therapeutic efficacy of the staphylococcal bateriophage lysate under appropriate conditions.