title: Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from turkeys.
abstract: One hundred fifty-three isolates of Pasteurella multocida, representing the causative agent of 95% of all known outbreaks of fowl cholera occurring in California meat and breeder turkeys from August 1985 through February 1987, were examined for susceptibility to antimicrobial agents. Of the 153 isolates, 6 were shown to be resistant to one or more antimicrobial agents. Of the six resistant isolates, five contained R plasmids. All but one of the R plasmids were small (6 to 7 megadaltons) and nonconjugative, encoding resistance to tetracycline or kanamycin, streptomycin, and sulfonamides; the other was large (70 megadaltons) and conjugative, transferring resistance to kanamycin, streptomycin, sulfonamides, and tetracycline to P. multocida and Escherichia coli. The three plasmids encoding resistance to tetracycline alone appeared identical.
authors.affiliation: Department of Veterinary Microbiology, School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: D C
authors.initials: DC
authors.lastname: Hirsh
authors.forename: L M
authors.initials: LM
authors.lastname: Hansen
authors.forename: L C
authors.initials: LC
authors.lastname: Dorfman
authors.forename: K P
authors.initials: KP
authors.lastname: Snipes
authors.forename: T E
authors.initials: TE
authors.lastname: Carpenter
authors.forename: D W
authors.initials: DW
authors.lastname: Hird
authors.forename: R H
authors.initials: RH
authors.lastname: McCapes
mesh_terms: D000818:Animals; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D008826:Microbial Sensitivity Tests; D010325:Pasteurella / Q000187:drug effects* / Q000235:genetics; D010326:Pasteurella Infections / Q000662:veterinary; D010957:Plasmids; D011201:Poultry Diseases / Q000382:microbiology; D011815:R Factors; D014422:Turkeys / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial