CONJUGATIVE TRANSPOSITION OF TN916-RELATED ELEMENTS FROM ENTEROCOCCUS-FAECALIS TO ESCHERICHIA-COLI AND PSEUDOMONAS-FLUORESCENS

We studied the ability of transposons Tn916, Tn1545, and Tn916-Km, a T n916 derivative expressing kanamycin resistance, to be conjugatively t ransferred from Enterococcus faecalis to various gram-negative bacteri a, Our results demonstrate that these types of elements can carry out conjugative transposition from the chromosome of E. faecalis to those of Escherichia coli and Pseudomonas fluorescens and that the accomplis hment of this event depends on the donor potential of the E. faecalis transposon delivery strain, Since the tet(M) gene does not confer a se lectable level of tetracycline resistance to gram-negative bacteria su ch as E. coli, the presence of another marker(s) readily expressed in these recipients is required for the detection of this type of transfe r, Conjugal transfer of Tn916-Km from E. faecalis to E. coli is not re stricted by the EcoK restriction system, nor does it depend on the pre sence of functional homologous recombination system and integration ho st factor proteins in the recipient bacteria.