Ongoing surveillance of animals in Scotland is providing useful insights into antimicrobial resistance.

Work over several years shows that the rate of resistance remains steady and relatively low, according to experts from Scotland’s Rural College (SRUC).

SRUC Veterinary Services contributed to the ‘Scottish One Health Antimicrobial Use and Antimicrobial Resistance in 2018’ report.

Prepared by Health Protection Scotland, the report looks at information relating to antimicrobial use and antimicrobial resistance in a range of human and animal infections in Scotland.

Dame Sally Davies, the UK’s Special Envoy on Antimicrobial Resistance, has called antibiotic resistance as big a threat to humanity as climate change.

For the second successive year, and in collaboration with Food Standards Scotland, data were collected on commensal E. coli cultured from the faeces of healthy livestock presenting at abattoirs in Scotland.

Once again, the levels of non-susceptible E.coli from poultry and pigs were greater than those detected from cattle and sheep, but levels for each animal species remained relatively stable when compared with 2017.

Over both years, the levels of non-susceptibility to ampicillin and tetracycline were among the highest from the 12 antibiotics tested for all four hosts: both of these are among the antibiotics used most frequently for treatment of infections in livestock. Collection of similar data is continuing in 2019 and annual reviews will give a clearer view of changes in antimicrobial resistance over time.

From farm and companion animal diagnostic services offered by SRUC Veterinary Services and Capital Diagnostics, the following was found:

• Meticillin resistance was not detected in any Staphylococcus aureus from livestock and levels of non-sensitive strains for other antibiotics appear stable and remain relatively low.
• Meticillin resistance was detected in 6% of coagulase positive staphylococci from dogs and cats but levels of non-sensitivity in strains of Staphylococcus pseudintermedius and Staphylococcus aureus from companion animals have fallen for several antibiotics, though remain relatively high for penicillins and fusidic acid.
• Carbapenemases were not detected in any animal diagnostic sample
• Extended spectrum beta-lactamases were identified in two E. coli and two K. pneumoniae from dogs and in single E.coli and Klebsiella pneumoniae isolates from cattle.

Dr Geoff Foster, Microbiology Manager at SRUC Veterinary Services, said: “Reducing the levels of non-sensitive microbes to antibiotics in food producing and companion animals is important to both animal and human health. This is our second year of full data and, while farmers, vets and the wider public should welcome stability in the data, we have a shared responsibility to combat anti-microbial resistance.

Vigilance and best practice in the use of antibiotics remains the key to preserving their future efficacy.

“The advice remains the same: whenever possible use narrow rather than broad spectrum antibiotics, be very careful about when you advise the use of antibiotics as a preventative medicine and promote good husbandry to prevent the spread of disease in the first place. It is also important we continue to invest in research and look at alternatives to antibiotics to minimise the risk of transmission into the environment and the food chain.

“This surveillance, supported by the Scottish Government, will continue. Continuous gathering of data can help inform veterinary practitioners on the most appropriate treatments for their clients, while preserving precious antibiotics.”