Antimicrobial resistance of bovine Salmonella enterica ssp. enterica isolates from the Alberta Agriculture and Forestry Disease Investigation Program (2006-2014).

The objectives of this study were to describe the antimicrobial susceptibility and serotypes of clinical Salmonella spp. isolates from Alberta cattle, to inform antimicrobial stewardship decisions for Alberta bovine veterinarians and to provide data for national surveillance. Isolates were collected from cattle and serotyped by Alberta Agriculture and Forestry from 2006 to 2014. Susceptibility testing was completed using Canadian surveillance breakpoints. There were 81 unique Salmonella isolates from 72 visits to 27 farms. The majority of isolates were S. Typhimurium (66.7%) and S. Dublin (19.8%). The prevalence of multidrug resistance was high in S. Typhimurium (89.1%) and S. Dublin (93.8%), including ceftiofur resistance (43.6% and 68.8%, respectively), while there was no resistance in other serotypes. As ceftiofur is a recommended treatment option for enteritis and septicemia caused by Salmonella in cattle, these results reinforce that obtaining bacterial culture and susceptibility results is critical for suspected cases of bovine salmonellosis in Alberta.