The effects of antimicrobial therapy on faecal Escherichia coli and Mucosal Staphylococci in dogs

Vanessa Schmidt
2014
Canine infections with antimicrobial resistant (AMR), particularly multi-drug resistant (MDR) bacteria are increasing, severely limiting therapeutic options, and representing an animal health issue. In addition, with potential transfer of AMR bacteria between dogs, their environment, humans and other animals, there may also be a public health risk. Commensal isolates can be a source of clinical infections and studies reporting the prevalence of AMR and risk factors for such isolates are
more » ... t. Furthermore, one of the most significant impacts upon commensal bacterial populations is antimicrobial therapy that may select for pre-existing AMR organisms or transmission of resistance determinants. The aim of this work was to investigate AMR amongst canine commensal bacterial populations and the effects of five different antimicrobials, authorised to treat dogs in the UK, on these populations both during and after therapy. Three groups of dogs were enrolled: healthy non-antimicrobial treated, non-vet visiting dogs (n = 28), to investigate longitudinal carriage of faecal E. coli; healthy non-antimicrobial treated, non-vet visiting, dogs (n = 73) and antimicrobial treated, non-hospitalised dogs (n = 127) to investigate longitudinal carriage of mucosal staphylococci and faecal E. coli. Staphylococci and E. coli isolated from swabs (nose/perineum) and faecal samples respectively, were tested for phenotypic AMR and carriage of resistance genes by PCR assay. Staphylococci were assigned to species by PCR assay (nuc gene), MALDI-TOF-MS and sequencing (tuf gene). Healthy dog E. coli underwent phylo-typing, and a selection of longitudinal healthy dog E. coli isolates were genotyped. Questionnaire data were used to formulate independent variables. Statistical analysis included Pearson's Chi-square, survival analysis and multivariable logistic regression; multilevel for clustered data. The prevalence of meticillin-resistant (MR; 42%) and MDR staphylococci (resistant to ≥ 3 antimicrobial classes; 34%) was high amongst healthy do [...]
doi:10.17638/00018715 fatcat:4ycg5ge2qfet7hls2nb6fz7rt4