Resapath observations: the decline in antibiotic resistance continues
Since 2001, the Network for the Epidemiological Surveillance of Antimicrobial Resistance in Animal Pathogenic Bacteria (Resapath) has been monitoring the evolution of the spread of bacteria resistant to antibiotics, including those of critical importance for humans, in populations of sick animals. breeding and companionship. These bacteria are detected by a network of 71 veterinary analysis laboratories. During 2019, 53,469 tests were carried out. The bacterium Escherichia coli is the main bacterial species identified and constitutes the main indicator for monitoring trends in antibiotic resistance.
In general, a decrease or stabilization of the rate of resistant bacteria is observed. More specifically for the bacterium Escherichia coli:
- resistance to two families of antibiotics, 3rd and 4th generation cephalosporins and fluoroquinolones, is particularly monitored, as these are crucial for human health and have few or no alternatives. For these two families of antibiotics, the proportion of resistant bacteria is low and the decline observed in recent years continues: the rate of bacteria resistant to cephalosporins is between 1% in pigs and poultry and 4% for cats. The proportion of bacteria resistant to fluoroquinolones is between 3% for pigs, turkeys and horses and 8% for cattle;
- colistin is another closely monitored antibiotic. Resistance to this antibiotic has been under control for the past 15 years and concerns fewer and fewer strains of bacteria;
- for other antibiotics, the general trend is a slight decrease or stabilization of resistance. The situation varies according to the sector: poultry, for which a very marked decrease in antibiotic resistance had been observed before 2014, has the lowest rate of bacteria resistant to antibiotics. Thus, this rate is at most 30% in hens and chickens, for the antibiotics responsible for the most resistance. It is a maximum of 40% for turkeys. The decrease in antibiotic resistance was less clear for pigs and the situation is stable for cattle: the highest rate of resistant bacteria is 65% in pigs and 75% in cattle;
- multi-resistant bacteria, that is to say which are insensitive to more than three antibiotics, are on the decline in all sectors combined. In 2019, the proportion of multi-resistant strains was highest in cattle, with 15.5% of multi-resistant bacteria, and lowest in turkeys (2%).
Furthermore, resistance to methicillin, another major indicator of antibiotic resistance, mainly concerns the bacterium Staphylococcus pseudintermedius, a species of staphylococcus causing pathologies in domestic carnivores. This resistance is present in 15 to 20% of the strains tested. This phenomenon is comparable to what is observed in humans for Staphylococcus aureus. Note that S. pseudintermedius only very rarely affects humans.
Monitoring the use of veterinary drugs: animals generally less exposed to antibiotics
ANSES, through the National Agency for Veterinary Medicinal Products (ANSES/ANMV), monitors the sale of antibiotics for veterinary use and the exposure of animals to them. For this, it relies on the sales of veterinary medicinal products declared by the marketing authorization holders. The quantity of antibiotics sold is constantly decreasing, with 422 tonnes of antibiotics sold in 2019, i.e. 10.5% less than in 2018.
However, the tonnage of antibiotics sold does not reflect the real exposure of animals to antibiotics: this depends on the dosage of the drug, the duration of administration and the evolution of the populations of the different animal species considered. Taking into account the recommendations for use of the drugs studied and the estimate of the mass of the animal populations, the Agency determined the level of exposure of the animals to antibiotics.
Principle results :
- the level of exposure is the lowest since monitoring began in 1999. to antibiotics, all animal species combined, decreased by 45.3%;
- this decrease continues in 2019, with an overall reduction of 10.9% compared to the previous year;
- this trend varies according to the species: exposure has decreased in cattle, pigs and poultry, which record a respective decrease of 9.9%, 16.4% and 12.8% in one year, but we observe for the year 2019 a slight rebound for rabbits and domestic carnivores such as dogs and cats: + 1.5% for rabbits and +2.1% for carnivores. This increase should not overshadow the downward trend recorded since 2011;
- since 2013, animal exposure to critically important antibiotics has decreased sharply and has stabilized over the past three years: between 2013 and 2019, it decreased by 86% for fluoroquinolones and by 94.1% for cephalosporins of the last generations;
- colistin, for which transferable resistance mechanisms have been described, saw its exposure rate decrease by 64.2% compared to the average reference level between 2014 and 2015. The objective of a 50% reduction in five years set in 2017 by the second Ecoantibio plan was achieved for the pig, poultry and beef sectors.
In conclusion, the dynamic for the prudent and responsible use of antibiotics carried out in recent years is a success, which must be maintained by the continuous efforts of each of the actors.