[Characteristics of the conjugation transfer of the R plasmids in bacteria of the intestinal group to Erwinia cells].

The conjugal transfer of seven R factors with different genes of drug resistance from Escherichia coli bacteria to twenty Erwinia strains was studied. Seven Erwinia strains were able to accept R plasmids, however the frequency of R factors transfer from E. coli to Erwinia was about 10(-6)-10(-4), and as a rule was higher when the cross was made at optimum temperature for the donor. The most of R- exconjugants showed higher degree of resistance to streptomycin and lower degrees of resistance to tetracycline and chloramphenicol than donor E. coli strains. R plasmids which were transferred to Erwinia from enteric bacteria were characterized by low genetical stability and in some cases were eliminated at first generations of recipient bacteria. Some R- strains of Erwinia exconjugants were able to transfer the accepted plasmids by conjugation into E. coli cells, but were not able to do it in homologous systems.