Salmonella enterica and extended-spectrum cephalosporin-resistant Escherichia coli recovered from Holstein dairy calves from 8 farms in New Brunswick, Canada

Abstract

This study was carried out to determine the frequency of fecal carriage, antimicrobial susceptibility, and resistance genes in Salmonella enterica and Escherichia coli with reduced susceptibility to extended-spectrum cephalosporins (ESC) isolated from 488 dairy calves from 8 farms in New Brunswick, Canada. Both S. enterica and E. coli with reduced susceptibility to ESC were isolated using selective culture. Minimum inhibitory concentrations to a panel of antimicrobial drugs were determined for randomly selected E. coli isolates and all of the Salmonella isolates. Multiplex PCR were conducted on the selected ESC-resistant E. coli to assess the β-lactamase resistance genes (bla, bla, bla, and bla) and plasmid-mediated qnrB and qnrS resistant genes. Information on ceftiofur use and other farm management practices were collected by the use of a questionnaire to determine the risk factors for the fecal recovery of E. coli with reduced susceptibility to ESC. Salmonella enterica frequency in calves' fecal samples was 3.3%, and all were pansusceptible. Salmonella isolates belonged to 3 serovars namely Salmonella Senftenberg, Salmonella Typhimurium, and Salmonella Derby. The frequency of fecal carriage of E. coli with reduced susceptibility to ESC in calves was 81.2%. Of the selected isolates (n = 100), all were multi-drug resistant, whereas 88% were ESC resistant based on minimum inhibitory concentration testing. From the selected ESC-resistant E. coli isolates, bla was detected in 84.1%, bla was detected in 52.2%, bla groups were detected in 30.7%, and bla was detected in 1.1% of isolates. Plasmid-mediated quinolone resistance genes were identified in 7 of 9 isolates resistant to quinolones. Five isolates were positive for qnrB, whereas 2 isolates were positive for both qnrB and qnrS. Whereas neonatal calves [odds ratio (OR) = 2.42, 95% confidence interval (CI): 1.87-3.12], regular ceftiofur use on the farm (OR = 3.83, 95% CI: 2.29-6.39), feeding of unpasteurized nonsalable milk (OR = 1.6, 95% CI: 1.18-2.18), and use of florfenicol (OR = 2.02, 95% CI: 1.43-2.86) were statistically associated with fecal recovery of E. coli with reduced susceptibility to ESC, use of ceftiofur for the treatment of respiratory diseases (OR = 0.57, 95% CI: 0.41-0.79) was statistically associated with decreased recovery of E. coli with reduced susceptibility to ESC. This study has provided information on the resistance genes associated with the occurrence of ESC and fluoroquinolone resistance in dairy calves within this region.

Determination of antimicrobial resistance to extended-spectrum cephalosporin, quinolones, and vancomycin in selected human enteric pathogens from Prince Edward Island, Canada

“…These genes can be transferred through mobile genetic elements to other commensal flora and/or to more pathogenic resistant strains (Hannah et al 2009), and in some cases cause multi-drug resistant extra-intestinal infections (Johnson et al 2001). The bla TEM and bla CMY-2 genes were the most prevalent β-lactamases in this study, which are similar to the D r a f t genotypes present in dairy calves (Awosile et al 2018) and in retail meats within Atlantic Canada (Forward et al 2004) as well as other parts of North America (Daniels et al 2007;Martin et al 2012). Previous studies from the Netherlands have reported on the genetic similarities of AMR resistance genes in Dutch patients, poultry and retail meat (Leverstein-van Hall et al 2011;Overdevest et al 2011).…”

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in cattle production – a threat around the world

“…CTX ND-ESBL were described in E-ESBL in cattle in Canada, which was the country where the largest variety of CTX-M's types were described (Awosile et al, 2018;Cormier et al, 2016;Lussier, 2010). All E-ESBLs were E. coli of faecal origin.…”

Prevalence and trend analysis of antimicrobial resistance in clinical Escherichia coli isolates collected from diseased pigs in the USA between 2006 and 2016

“…The problem of AMR is further compounded by the phenomena of co-resistance, which enables an isolate to be resistant against mul- antimicrobial and use of an unrelated antimicrobial in animal production systems (Awosile et al, 2018;Gibbons et al, 2016).…”