Abstract
Antimicrobial resistance (AMR) is a significant threat to global health. Both human and veterinary medicine depend on the availability of effective antibiotics. With pets currently residing in nearly 50% of UK households, human and animal health are more closely connected than ever. A One Health approach that encourages prudent use of antibiotics, and development of alternatives, is of increasing importance and was adopted in this project to investigate the social, psychological and biological challenges of producing and implementing an alternative antimicrobial, phage therapy, into companion animal medicine.
Semi-structured interviews and thematic analyses were used to obtain vets and pet owners’ views and experiences of antibiotic use in pets. A quantitative survey involving 157 UK vets and pet owners was also developed to assess views on phage therapy and identify potential barriers to its implementation. Concurrently, laboratory studies were undertaken to find phage(s) appropriate for treating canine E. coli infections. Phage were isolated from environmental samples and screened for their ability to kill E. coli isolates found in canine wound and urinary tract infections. Promising candidates were characterised for their host range, burst size and stability.
Interviews with UK vets and pet owners revealed complexities in vet-owner interactions, including differing perceptions of responsibility for prudent antimicrobial use, suggesting that antibiotic use in companion animals is vulnerable to the same human behaviours as those seen in human medicine. We found that 71% of UK vets and pet owners were open to using phage therapy as an alternative antimicrobial to treat companion animals. Of 200 phages isolated from soil and sewage samples, five candidates were selected and showed varying degrees of lytic activity against E. coli. The most promising candidates were effective against four out of ten clinical isolates.
In conclusion, UK vets and pet owners displayed positive attitudes to alternative therapies, although larger scale surveys are needed to confirm this. Environmental samples were abundant in lytic phage; however, labour-intensive processing and limited host-ranges of selected phage highlighted the practical challenges associated with developing effective phage therapy treatments.