Mobilization of the penicillinase gene in Enterococcus faecalis.

Enterococcus faecalis SF4855 is a beta-lactamase-producing isolate resistant to high levels of gentamicin, with determinants for these resistances on the chromosome. SF4855 transferred both determinants into E. faecalis FA2-2 and UV202 at a frequency of 10(-9) in the presence of the MLS plasmid pYN120. Beta-Lactamase and gentamicin resistance probes hybridized to three locations on the chromosome of FA2-2 transconjugants on contour-clamped homogeneous electric field electrophoresis. The study results suggest mobilization of the beta-lactamase determinant.