Novel plasmid-borne multidrug resistance gene cluster including lsa(E) from a linezolid-resistant Enterococcus faecium isolate of swine origin.

A novel nonconjugative plasmid of 28,489 bp from a porcine linezolid-resistant Enterococcus faecium isolate was completely sequenced. This plasmid harbored a novel type of multiresistance gene cluster that comprised the resistance genes lnu(B), lsa(E), spw, aadE, aphA3, and two copies of erm(B), which account for resistance to macrolides, lincosamides, streptogramins, pleuromutilins, streptomycin, spectinomycin, and kanamycin/neomycin. Structural comparisons suggested that this plasmid might have developed from other enterococcal plasmids by insertion element (IS)-mediated interplasmid recombination processes.