Abstract
The plasmid content, antibiotic susceptibilities, and biochemical traits of fecal streptococci isolated from pigs during a tylosin feeding experiment were analyzed. The presence of tylosin in the feed did not select for a particular streptococcal strain or biochemical type but did select for multiple antibiotic resistance. A DNA probe obtained from Escherichia coli and containing a cloned macrolide-lincosamide-streptogramin B (MLS) resistance determinant from a streptococcal strain of human origin hybridized primarily to large plasmids among MLS-resistant streptococci from antibiotic-fed pigs. Patterns of hybridization were similar among MLS-resistant clinical isolates from human infections and isolates from other antibiotic-fed animals. The results of mating experiments indicated that tylosin selected for localization of the MLS determinants to large conjugative plasmids. These data established (1) a strong sequence homology between MLS resistance genes in isolates from humans and those from farm animals and (2) an increased potential for dissemination of MLS resistance as a consequence of tylosin feeding.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 74-82 |
| Number of pages | 9 |
| Journal | Journal of Infectious Diseases |
| Volume | 149 |
| Issue number | 1 |
| DOIs | |
| State | Published - 1984 |
Bibliographical note
Funding Information:This work was supported by the US Food and Drug Administration and grant 5 ROI AI 1910-02 from the National Institutes of Health.