More Timely Antimicrobial Susceptibility Testing as a Tool in Combatting Antimicrobial Resistance in Clinically Relevant Microorganisms: Is There More than One Way to Skin a Cat?

Why do veterinarians ask for antimicrobial susceptibility testing? A qualitative study exploring determinants and evaluating the impact of antibiotic reduction policy

For public health reasons, increasing attention has focused on more rational use of antimicrobials in farm animals. Guidance concerning the prescription of antibiotics and antimicrobial susceptibility testing (antibiograms in this case) are beneficial tools to help control the development of antimicrobial resistance. Nevertheless, even though there are already several qualitative studies analysing the determinants of antimicrobial prescription and use in veterinary medicine, little is known about decision-making concerning the use of antibiograms. The aim of this study was to provide a better understanding of veterinarians' motivations and role-players' influence concerning the choice of whether to ask for an antibiogram in the bovine, porcine, poultry and equine sectors in France. We concurrently evaluated the impact of a new French decree (2016) requiring an antibiogram before certain critically important antimicrobial agents can be used in veterinary medicine. Semi-structured interviews with veterinarians were conducted in France. Thematic analysis was used to analyse transcripts. In all, we surveyed 66 veterinarians. Use of antibiograms in veterinary medicine was multifactorial - 46 factors grouped into 11 categories were identified - and differed between animal sectors: use was almost systematic in poultry, frequent in pigs and rare in both the bovine and equine sectors. The decree has not increased the use of antibiograms but has induced a change in prescriptions due to field constraints and the time needed to obtain the results of antibiograms. Respondents see the decree as an aid in promoting responsible and rational use of antibiotics, fostering the use of alternatives. Our findings provide the basis of veterinarians' position regarding antibiogram use and antimicrobial resistance, pointing out levers to facilitate the use of antibiograms in veterinary medicine (for example communication on the benefits of this test and external financial support). Furthermore, the evaluation of the impact of the decree aimed at reducing the use of critically important antibiotic highlights key factors for a successful change in regulations, such as advance planning, precise and adapted communication, and demonstration of the measure's legitimacy. These results will be useful in guiding representative veterinary bodies and regulatory authorities during their decision-making, communication, and policy and regulation choices to combat antimicrobial resistance.

Understanding the culture of antimicrobial prescribing in agriculture: a qualitative study of UK pig veterinary surgeons

OBJECTIVES

The use of antimicrobials in food-producing animals has been linked with the emergence of antimicrobial resistance in bacterial populations, with consequences for animal and public health. This study explored the underpinning drivers, motivators and reasoning behind prescribing decisions made by veterinary surgeons working in the UK pig industry.

METHODS

A qualitative interview study was conducted with 21 veterinary surgeons purposively selected from all UK pig veterinary surgeons. Thematic analysis was used to analyse transcripts.

RESULTS

Ensuring optimum pig health and welfare was described as a driver for antimicrobial use by many veterinary surgeons and was considered a professional and moral obligation. Veterinary surgeons also exhibited a strong sense of social responsibility over the need to ensure that antimicrobial use was responsible. A close relationship between management practices, health and economics was evident, with improvements in management commonly identified as being potential routes to reduce antimicrobial usage; however, these were not always considered economically viable. The relationship with clients was identified as being a source of professional stress for practitioners due to pressure from farmers requesting antimicrobial prescriptions, and concern over poor compliance of antimicrobial administration by some farmers.

CONCLUSIONS

The drivers behind prescribing decisions by veterinary surgeons were complex and diverse. A combination of education, improving communication between veterinary surgeons and farmers, and changes in regulations, in farm management and in consumer/retailer demands may all be needed to ensure that antimicrobial prescribing is optimal and to achieve significant reductions in use.

Rapid bacterial antibiotic susceptibility test based on simple surface-enhanced Raman spectroscopic biomarkers

Rapid bacterial antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) measurement are important to help reduce the widespread misuse of antibiotics and alleviate the growing drug-resistance problem. We discovered that, when a susceptible strain of Staphylococcus aureus or Escherichia coli is exposed to an antibiotic, the intensity of specific biomarkers in its surface-enhanced Raman scattering (SERS) spectra drops evidently in two hours. The discovery has been exploited for rapid AST and MIC determination of methicillin-susceptible S. aureus and wild-type E. coli as well as clinical isolates. The results obtained by this SERS-AST method were consistent with that by the standard incubation-based method, indicating its high potential to supplement or replace existing time-consuming methods and help mitigate the challenge of drug resistance in clinical microbiology.