DRUG-RESISTANCE OF ENTERIC BACTERIA

Transmissible drug-resistance (R) factor was transduced in the system of SalmonellaE group with phage epsilon, and its transduction rate was 10-8.The transduction rate of R factor with epsilon phage that had existed as prophage in R+host cell and was induced by UV irradiation increased about 102 times than that of ordinary transduction.The R factor carrying TC resistance marker was consistently segregated by transduction with epsilon phage.The R+transductant was not lysogeniged by transducing epsilon phage, indicating non-lysogenic conversion and non-immunity toward the transducing epsilon phage.The R factor of transductant was non-transmissible by conjugation and not eliminated by acriflavine treatment. But the R factor of transductant was transduced again by epsilon phage that had existed as prophage in R+transductant or that was newly infected to R+transductant.The R factor of R+transductant of S. chittagongwas transmissible by conjugation at 106times lower frequency than that of R factor that was transferred by conjugation, and was eliminated by acriflavine treatment in low frequency.In transduction of R factor R+ transductant with the same epsilon phage that had transduced high frequency transductant (HFT) was obtained and its transduction rate was 10-2.The transmission of R factor to R+transductant was higher than that to R-or R+cell to which R factor was transmitted by conjugation.