title: Plasmid-encoded trimethoprim resistance in salmonellas isolated in Britain between 1970 and 1981.
abstract: Trimethoprim resistance was plasmid-encoded in all trimethoprim-resistant Salmonella typhimurium and in the majority of trimethoprim-resistant salmonellas of other serotypes isolated since 1970 from humans and food animals in Britain. In S. typhimurium, non-autotransferring plasmids of compatibility group 3 and autotransferring plasmids of group H2 predominated. The predominance of these plasmid types has resulted from the spread of clones of trimethoprim-resistant strains of phage types 18, 170 and 204c. In other salmonellas, a variety of plasmid compatibility groups have been identified. Almost all plasmids which conferred resistance to trimethoprim also coded for sulphonamide resistance.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D011815:R Factors; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics; D012485:Salmonella typhi / Q000187:drug effects / Q000235:genetics; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D014295:Trimethoprim / Q000494:pharmacology*; D006113:United Kingdom
chemical_list: D000900:Anti-Bacterial Agents; D014295:Trimethoprim