title: Plasmid-mediated antimicrobial resistance in Haemophilus pleuropneumoniae.
abstract: Haemophilus pleuropneumoniae, isolated from the lungs of pig, was resistant to ampicillin, streptomycin, and sulfadiazine. This isolate, SD-1, possessed 1 plasmid (pVM105) coded for resistance to ampicillin and sulfadiazine, and the other (pVM104) for resistance to streptomycin and sulfadiazine. A 2nd isolate of H pleuropneumoniae, SD-2, recovered from a pig in a different outbreak of porcine pleuropneumonia, was resistant to streptomycin and sulfadiazine. These resistance determinants were on 1 plasmid (pVM106). All 3 patients were nontransmissible and small (pVM105 = 3.6 x 10(6) daltons, pVM104 and pVM106 = 2.3 x 10(6) daltons. The basis for resistance to ampicillin, encoded on plasmid pVM105, was due to a beta-lactamase. This beta-lactamase was highly active on penicillin G and ampicillin, moderately active on cephalothin, and inactive on oxacillin, indicating a TEM type of beta-lactamase.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003227:Conjugation, Genetic; D004196:Disease Outbreaks / Q000662:veterinary*; D004926:Escherichia coli / Q000235:genetics; D006190:Haemophilus / Q000187:drug effects / Q000235:genetics*; D006192:Haemophilus Infections / Q000382:microbiology / Q000662:veterinary*; D009175:Mycoplasma Infections / Q000662:veterinary*; D011002:Pleuropneumonia, Contagious / Q000382:microbiology*; D011815:R Factors; D013307:Streptomycin / Q000494:pharmacology; D013411:Sulfadiazine / Q000494:pharmacology; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D014169:Transformation, Bacterial
chemical_list: D000900:Anti-Bacterial Agents; D013411:Sulfadiazine; D000667:Ampicillin; D013307:Streptomycin