title: Resistance to gentamicin and amikacin of gram-negative organisms isolated from horses.
abstract: Resistance of gram-negative bacteria to gentamicin has become an increasingly common problem among clinical isolates from human beings. Susceptibility of isolates from horses to gentamicin and amikacin was evaluated for the period from July, 1983 to June, 1985. All isolates of Escherichia coli, and species of Enterobacter, Klebsiella, Proteus, and Pseudomonas examined were susceptible to amikacin, except 2 of the 46 Pseudomonas isolates. In contrast, 13 to 50% of isolates were resistant to gentamicin. Escherichia coli, and Klebsiella, Proteus, and Enterobacter species isolates were highly significantly more susceptible to amikacin (P less than 0.01) than to gentamicin. Pseudomonas spp (P = 0.13) were not significantly different in susceptibility to the 2 drugs. There was significant variation among genera in their susceptibility to gentamicin (P = 0.002), primarily because of the frequency of resistance in isolates of Klebsiella spp and Proteus spp, compared with the other 3 organisms (E coli, Enterobacter spp, and Pseudomonas spp). There was no significant difference of susceptibility to amikacin among the genera studied (P = 0.06).
authors.affiliation: Department of Clinical Studies, University of Pennsylvania, School of Veterinary Medicine, Kennett Square 19348.
authors.forename: J A
authors.initials: JA
authors.lastname: Orsini
authors.forename: C E
authors.initials: CE
authors.lastname: Benson
authors.forename: P A
authors.initials: PA
authors.lastname: Spencer
authors.forename: E
authors.initials: E
authors.lastname: Van Miller
mesh_terms: D000583:Amikacin / Q000494:pharmacology*; D000818:Animals; D004352:Drug Resistance, Microbial; D004754:Enterobacter / Q000187:drug effects / Q000302:isolation & purification; D004755:Enterobacteriaceae / Q000187:drug effects*; D004756:Enterobacteriaceae Infections / Q000382:microbiology / Q000662:veterinary; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005839:Gentamicins / Q000494:pharmacology*; D006734:Horse Diseases / Q000382:microbiology*; D006736:Horses; D007709:Klebsiella / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D011511:Proteus / Q000187:drug effects / Q000302:isolation & purification; D011549:Pseudomonas / Q000187:drug effects* / Q000302:isolation & purification; D011552:Pseudomonas Infections / Q000382:microbiology / Q000662:veterinary
chemical_list: D005839:Gentamicins; D000583:Amikacin