The resistance of Salmonella and Campylobacter bacteria to commonly used antimicrobials continues to be frequently observed in both humans and animals, according to a report issued by the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC).

However, combined resistance to critically important antimicrobials for human medicine remains very low, except for certain types of Salmonella and Campylobacter coli in some countries.

Furthermore, there has been an increase in the proportion of Escherichia coli isolates from food-producing animals showing "complete susceptibility" or "zero resistance" to key antimicrobials. This, along with a decrease in the prevalence of E. coli isolates producing ESBL or AmpC enzymes – enzymes that can render some antibiotics ineffective – demonstrates progress in reducing antimicrobial resistance (AMR) in E. coli from food-producing animals in several EU member states.

Carlos Das Neves, EFSA's Chief Scientist, and Mike Catchpole, ECDC's Chief Scientist, stated: "Although we have seen positive outcomes from actions to reduce AMR, continued joint efforts are essential to address this global threat. The One Health approach reminds us that addressing AMR requires collaboration across different sectors, such as human health, animal health, and the environment."

For Salmonella, resistance to carbapenems has been found in isolates from humans but not in animals from which food is obtained; for E. coli, carbapenem resistance has been detected in isolates from food-producing animals.

Although the emergence of carbapenem resistance is currently reported at very low levels in isolates from both humans and animals, a larger number of countries have reported carbapenemase-producing bacteria in different animal species in recent years.

This requires attention and further investigation, as carbapenems are a group of last-resort antibiotics, and any detection of resistance to them is concerning.

Between 2013 and 2022, for humans, at least half of the reporting countries observed increasing trends in resistance to fluoroquinolones in Salmonella Enteritidis and Campylobacter jejuni isolates, typically associated with poultry.

This finding is concerning for public health, as in the rare occasions when Salmonella or Campylobacter infections progress to severe illnesses, fluoroquinolones are among the antimicrobials used for treatment.

One-third of the countries reported decreasing trends in resistance to macrolides in Campylobacter isolates from humans, especially for C. coli. This is noteworthy as increased resistance to fluoroquinolones means that macrolides are becoming increasingly important for treating severe foodborne infections in humans.

In two-thirds of the reporting countries, resistance of human isolates to penicillins and tetracyclines has decreased over time in Salmonella Typhimurium - which is typically associated with pigs and cattle. These antimicrobials are often used to treat bacterial infections in both humans and animals.

Antimicrobial resistance remains a major public health issue that needs to be addressed on multiple fronts and by various stakeholders. Key actions are needed to reduce the emergence and spread of antimicrobial-resistant bacteria.

These include:

- promoting the prudent use of antimicrobials;

- supporting the improvement of infection prevention and control practices;

- strengthening research and innovation in the development of new antimicrobials; and

- ensuring that policies and procedures are in place at the national level.

EFSA also publishes several interactive communication tools. (Photo: Freepik)