title: Antimicrobial resistance patterns of bacteria isolated from canine urinary samples submitted to a New Zealand veterinary diagnostic laboratory between 2005-2012.
abstract: OBJECTIVE
  To identify and describe culture and antimicrobial resistance (AMR) patterns in bacteria isolated from canine urinary samples submitted to a New Zealand veterinary diagnostic laboratory.
  
  
  METHODS
  Records from a veterinary diagnostic laboratory were examined for bacterial isolates cultured from canine urine samples between January 2005 and December 2012. Culture and susceptibility results were compiled with information on the age, sex and breed of dog. Repeat submissions were removed. Susceptibility was assessed using results of the Kirby-Bauer disk diffusion method, for a standard panel including amoxicillin-clavulanic acid (AMC), cefovecin (from 2010-2012), cephalothin, clindamycin, enrofloxacin and trimethoprim-sulphonamide (TMS).
  
  
  RESULTS
  A total of 5,786 urine samples were submitted for analysis, and 3,135 bacterial isolates were cultured from 2,184 samples. Of these 3,135 isolates, 1,104 (35.2%) were Escherichia coli, 442 (14.1%) were Staphylococcus spp., 357 (11.4%) Proteus mirabilis and 276 (8.8%) were Enterococcus spp. The frequency of culture-positive samples increased with increasing age in both female and male dogs (p<0.001). The percentage of E. coli isolates resistant to AMC and cephalothin increased between 2005 and 2012 (p<0.001), as did resistance to enrofloxacin (p=0.022), but there was no change in resistance to TMS (p=0.696). Enrofloxacin was the antimicrobial with the least resistance shown by the four most common bacteria isolated during the course of the study.
  
  
  CONCLUSIONS
  The results of this study provide important regional information regarding the prevalence of bacterial uropathogens and their susceptibility patterns. There was an increase in resistance to some commonly used antimicrobials in the treatment of urinary tract infections. Having access to regional antimicrobial susceptibility results is crucial when forming guidelines for the use of antimicrobials for the treatment of urinary tract infections. Given changes in practising habits and antimicrobial usage over time, ongoing monitoring and surveillance of resistance in pathogens is needed.
authors.affiliation: a Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand.
authors.forename: C H
authors.initials: CH
authors.lastname: McMeekin
authors.affiliation: a Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand.
authors.forename: K E
authors.initials: KE
authors.lastname: Hill
authors.affiliation: b New Zealand Veterinary Pathology/IDEXX NZ , PO Box 944, Hamilton , New Zealand.
authors.forename: I R
authors.initials: IR
authors.lastname: Gibson
authors.affiliation: a Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand.
authors.forename: J P
authors.initials: JP
authors.lastname: Bridges
authors.affiliation: a Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Private Bag 11222, Palmerston North 4442 , New Zealand.
authors.forename: J
authors.initials: J
authors.lastname: Benschop
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004283:Dog Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000652:urine; D004285:Dogs; D024881:Drug Resistance, Bacterial; D005260:Female; D007753:Laboratories; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D013997:Time Factors; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D014730:Veterinary Medicine
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antimicrobials; E. coli; resistance; susceptibility; urinary tract infection