title: In vitro susceptibilities of feline and canine Escherichia coli and Pseudomonas spp. isolates to ticarcillin and ticarcillin-clavulanic acid.
abstract: OBJECTIVE
  To investigate in vitro susceptibilities of canine and feline Escherichia coli and canine Pseudomonas spp. isolates to ticarcillin and ticarcillin-clavulanic acid (T/C).
  
  
  METHODS
  In vitro susceptibility testing of bacterial isolates collected from infections.
  
  
  METHODS
  We tested 148 (83 canine and 65 feline) E. coli and 61 canine Pseudomonas spp. isolates for susceptibility to T/C using both disc diffusion and Epsilometer tests (E-tests). Additionally, susceptibilities of 96 E. coli and 23 canine Pseudomonas spp. isolates were tested via disc diffusion to ticarcillin alone.
  
  
  RESULTS
  Of the E. coli isolates obtained from canine and feline urine, 92% by disc diffusion and 91% by E-tests were susceptible to T/C. Of the canine Pseudomonas isolates, 90% by disc diffusion and 82% by E-tests were susceptible to T/C. Of the Pseudomonas spp. isolates from the canine ear canal or tympanic bullae, 12% of isolates tested via disc diffusion and 23% via E-tests were found to be resistant to T/C. The 50% minimum inhibitory concentration of T/C for all feline E. coli isolates was significantly lower than that for all canine E. coli isolates (P = 0.0031). The addition of clavulanic acid significantly increased the efficacy of ticarcillin against E. coli (P< 0.0001), but had negligible effect against canine Pseudomonas spp. isolates.
  
  
  CONCLUSIONS
  Ticarcillin-clavulanic acid has reasonable in vitro efficacy against canine and feline E. coli, and canine Pseudomonas spp. isolates. However, decisions to use this drug therapeutically must be made on prudent considerations to minimise selection for bacterial resistance.
authors.affiliation: Faculty of Veterinary Science, The University of Sydney, New South Wales, 2006, Australia.
authors.forename: A B
authors.initials: AB
authors.lastname: Bennett
authors.forename: P A
authors.initials: PA
authors.lastname: Martin
authors.forename: S A
authors.initials: SA
authors.lastname: Gottlieb
authors.forename: M
authors.initials: M
authors.lastname: Govendir
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002371:Cat Diseases / Q000188:drug therapy / Q000382:microbiology; D002415:Cats; D002969:Clavulanic Acids / Q000494:pharmacology; D015169:Colony Count, Microbial / Q000662:veterinary; D004283:Dog Diseases / Q000188:drug therapy / Q000382:microbiology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects*; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000662:veterinary*; D011549:Pseudomonas / Q000187:drug effects*; D013982:Ticarcillin / Q000494:pharmacology*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D002969:Clavulanic Acids; C043215:ticarcillin-clavulanic acid; D013982:Ticarcillin