According to a multi-agency analysis, a decline in antimicrobial consumption in Europe has been associated with a dro in overall antimicrobial resistance (AMR).

Findings come from a report looking at the usage of antimicrobial agents and the occurrence of antimicrobial resistance in bacteria from humans and food-producing animals, such as broilers, turkeys, cattle under one year of age, and pigs.

It included data from 2019 and 2021 on antibiotic consumption and AMR in Europe. It was published by the European Centre for Disease Prevention and Control (ECDC), the European Food Safety Authority (EFSA), and the European Medicines Agency (EMA).

Additional data will be released shortly in another EFSA and ECDC report covering AMR in bacteria affecting humans, animals, and food.

Impact of cutting antibiotic usage on farms
ECDC, EFSA, and EMA analyzed trends of antimicrobial consumption and AMR in E. coli from humans and food-producing animals. They also looked at changes between 2014 and 2021 and discovered antibiotic consumption in food-producing animals decreased by 44 percent but remained stable in humans.

The agencies said high levels of antimicrobial consumption and AMR were still being reported in several EU countries. Reducing use in food-producing animals is likely to benefit human health, such as impacting resistance in foodborne pathogens such as Campylobacter.

An analysis found that E. coli bacteria in animals and humans became less antibiotic-resistant as the overall antibiotic consumption was reduced. The agencies say that trends in antibiotic resistance can be reversed with the right actions and policies.

“Using fewer antibiotics in livestock production pays off: in most countries that reduced antibiotic use, we observed a corresponding decrease in resistance levels. This means that national efforts work,” said EFSA’s executive director Bernhard Url.

Bacterial isolates from humans were from clinically ill individuals sampled in healthcare settings, while isolates from food-producing animals came from domestically produced healthy animals at slaughter.

Associated resistance
The report covered seven antimicrobial groups (carbapenems, third- and fourth-generation cephalosporins, fluoroquinolones and other quinolones, aminopenicillins, polymyxins, macrolides, and tetracyclines). It focused on resistance to these antimicrobials in E. coli and Campylobacter, while some data on Salmonella is included.

In humans, using essential groups of antibiotics, such as carbapenems, third- and fourth-generation cephalosporins, and quinolones, was associated with resistance to these antibiotics in E. coli from human infections.

Using quinolones, polymyxins, aminopenicillins, and tetracyclines in food-producing animals was associated with resistance to these antibiotics occurring in indicator E. coli in food-producing animals.

Bacterial resistance in humans may be linked to such resistance in food-producing animals. Two examples are Campylobacter jejuni and Campylobacter coli, which may be found in food-producing animals and spread to people through food.

Overall findings suggest that measures to reduce antimicrobial consumption in food-producing animals and in humans have been effective in many countries, said experts.

“Nevertheless, these measures need to be reinforced so that reductions in antimicrobial consumption are retained and further continued, wher necessary. This also highlights the importance of measures promoting human and animal health, such as vaccination and better hygiene, thereby reducing the need for antimicrobials.”