title: Linkage of serum resistance, aerobactin production, and resistance to antimicrobial agents on conjugal plasmids in some strains of Escherichia coli isolated from septic foals.
abstract: Fifteen isolates of Escherichia coli obtained from the blood and tissues of septic foals had plasmid DNA of size ranging from 2.5 to 93 megadaltons. These isolates grew in normal equine serum (serum resistant), a trait previously documented to be expressed by isolates obtained from blood and tissues of septic foals, but not by isolates obtained from the feces of clinically normal horses. Of these isolates, 3 contained conjugal plasmids that encoded resistance to multiple antimicrobial agents linked to serum resistance and, in 1 isolate, to production of aerobactin as well. Serum resistance and production of aerobactin are related to virulence of septicemic E coli from non-equine sources.
authors.affiliation: Department of Veterinary Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: D C
authors.initials: DC
authors.lastname: Hirsh
authors.forename: C
authors.initials: C
authors.lastname: Kirkham
authors.forename: W D
authors.initials: WD
authors.lastname: Wilson
mesh_terms: D000818:Animals; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D008040:Genetic Linkage; D006734:Horse Diseases / Q000382:microbiology*; D006736:Horses; D006877:Hydroxamic Acids / Q000378:metabolism; D010957:Plasmids / Q000235:genetics*; D018805:Sepsis / Q000382:microbiology / Q000662:veterinary*; D017262:Siderophores / Q000096:biosynthesis; D014774:Virulence / Q000235:genetics
chemical_list: D006877:Hydroxamic Acids; D017262:Siderophores; C031819:aerobactin