[Transduction of streptomycin resistance in group A streptococci by virulent streptococcal phage CA1].

The author studied the Smr transduction in hemolytic streptococci, group A, by the virulent CA1 phage. This phage differed from the A12 and A25 by the spectrum of lytic activity and was affiliated to them serologically. In comparable experiments CA1 phage exceeded A25 phage by the transducing activity. Phage CA1 transduced the cultures of various serological types. The efficiency of transduction depended on the multiplicity of the infection (the optimum--0.1--0.03), the age of the recipient culture (the optimum--1--2-day) and the time of phenotypical expression (the optimum--2--3 hours). It was possible to increase the frequency of transduction by one order with the aid of UV irradiation. Still a theoretically possible output of the transducers determined by calculation was not reached because of some abortiveness of the process.