Risk factors for the carriage of antimicrobial-resistant Escherichia coli in puppies and adult dogs

  • Kezia Wareham

Student thesis: Master's ThesisMaster of Science (MSc)


Antimicrobial resistance (AMR) is a major worldwide issue with severe implications on human and animal health as well as global food security. For this study, 223 (41 locally recruited and 182 through the Dog’s Trust Generation Pup study) 16-week-old puppies, 64 locally recruited 12-week-old puppies and 25 adult dogs (14 locally recruited and 11 recruited from the Oxfordshire area) were screened and their owners provided a faecal sample from their dog and completed a questionnaire. The E. coli (Escherichia coli) carried by these puppies were tested for resistance to five different antimicrobials (ciprofloxacin, streptomycin, tetracycline, cephalexin and amoxicillin). Univariable and multivariable logistic regression analyses were used to explore possible risk factors for AMR in E. coli carried by the puppies. Puppies that were fed raw meat had a greater risk of ciprofloxacin resistance (multivariable: 12.42 (5.01 to 30.78) <0.001), tetracycline resistance (multivariable: 4.47 (2.21 to 9.05) <0.001), amoxicillin resistance (multivariable: 3.18 (1.57 to 6.42) 0.001) and streptomycin resistance (multivariable: 8.23 (3.95 to 17.15) <0.001). Autocoprophagia was found to be protective against resistance in the Generation Pup cohort to tetracycline (multivariable: 0.10 (0.01 to 0.80) 0.03) and amoxicillin (multivariable: 0.18 (0.04 to 0.82) 0.03). The cephalexin resistant E. coli were screened for cefotaxime resistance and further molecular methods were carried out on these. The PCR and whole genome sequence results from the cefotaxime- and ciprofloxacin-resistant E. coli carried by the puppies showed that there were a variety of sequence types (ST’s) identified and provided the mechanism for resistance. For the local cohort of puppies’ samples were collected at 12 and 16 weeks to allow for comparison of resistance. Amoxicillin resistance in the E. coli isolated from the 12-week-old puppies was higher in comparison to the 16-week- old puppies (p<0.001). There was evidence of regional variation in resistance depending on the recruitment area. Tetracycline (p=0.05) and amoxicillin (p=0.04) resistance were more common in E. coli isolated from the 16-week-old puppies that were locally recruited compared to those that were recruited nationally. Furthermore, adult dogs recruited from the Oxfordshire area (n=11) were more likely to have amoxicillin resistance compared to locally recruited dogs (n=14; p=0.02).
Date of Award23 Jan 2019
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorKristen K Reyher (Supervisor) & Tristan A Cogan (Supervisor)

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