Tetracycline resistance genes in staphylococci from the skin of pigs.

Forty-seven tetracycline-resistant staphylococci from the skin of pigs were examined for genes mediating this resistance. Seventeen isolates were also resistant to minocycline and all hybridized with the tet(M) gene; 23 carried the tet(K) gene and 10 the tet(L) gene. Three carried more than one gene and two did not hybridize with any of the three probes tested. Maps were constructed for two plasmids carrying the tet(K) gene, all were very similar in size (4.35-4.7 kb) and structure and closely resembled the plasmid pT181. Four plasmids which bore the tet(L) gene differed in size, ranging from 4.3 to 11.5 kb, and were dissimilar in structure except for the portion bearing the gene.