Changes in the phage-typing patterns of Staphlococci following lysogenization with a related group of Staphylococcus bacteriophages.

Abstract

Strains of phage type 52/52A/80 are appearing with increasing frequency in Canada, in conjunction with type '80/81' strains. To investigate the possibility of a relationship between these strains, attempts were made to lysogenize each of the propagating strains of phages 80, 81, 82, and KS6 with their homologous phages.No lysogenic systems could be established with phage 80. The typing pattern of strains lysogenized with phages 81, 82, and KS6 differed from that of the parent strain. Three types of variants were observed. One type showed a loss in sensitivity to one or more of the phages. In the second, there was a concurrent loss in sensitivity to some of the phages and a gain in sensitivity to phages 52 and 52A; phages 81 and especially KS6 induced this type of variant. The third variant was either non-typable or typable only with other phages used undiluted. The change in phage sensitivity was not accompanied by a change in antibiotic sensitivity.The possibility that strains of type 52/52A/80, as well as non-typable strains, may be derived in nature from type 80/81 strains by lysogenization with phage KS6, or one related to it, is discussed.