Resistance of Hemolytic Staphylococci to Bacteriophage Lytic for Non-Hemolytic Staphylococcus Aureus.

A very common infection in Porto Rico is caused by a hemolytic Staphylococcus aureus. These infections are exceedingly virulent as a rule and offer a serious problem in our clinics and hospitals. Pomales has shown that this organism is present in the throat flora of about 19% of supposedly healthy individuals and in pathological cases it predominated in 24%. This organism proved to be the predominating microbe in the crypts and the interior of 65 pairs of tonsils removed at operation. Because of the severity of infections with this organism we have attempted treatment in a few cases with a bacteriophage which is lytic for a non-hemolytic Staphylococcus aureus. The administration of the bacteriophage has had no effect upon the course of the infection. The bacteriophage employed was supplied to us by Larkum, who has reported the efficacious use of this lytic principle in clinical cases. We have attempted to adapt the bacteriophage which is lytic for a non-hemolytic variety of Staphylococcus aureus to 7 strains of hemolytic staphylococci which have been isolated in Porto Rico. Repeated attempts to bring about this adaptation have been made during the past year without success. This is in agreement with the work of Epstein and Fejgin, who have reported the resistance of hemolytic staphylococci to bacteriophage and it may be, as these authors suggest, that such resistance may have some bearing upon the high virulence of hemolytic staphylococci.