PARMA, Italy – Two European Union agencies' scientists combined their expertise to analyze member-state data and compile the first joint EU study on antimicrobial resistance in zoonotic bacteria affecting humans, animals and food. The study, compiled by the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC), indicates resistance to antimicrobials was observed in zoonotic bacteria, such as Salmonella and Campylobacter, which may cause infectious diseases transmissible between animals and humans and which can be found in foods.

Antimicrobial resistance data for non-disease causing bacteria such as indicator E. coli and Enterococci, that usually do not cause disease in humans, is also presented in the study. Findings will be considered by the European Commission as it develops its forthcoming proposals for action to fight antimicrobial resistance.

Antimicrobials are used in human and veterinary medicine to eliminate micro-organisms causing infections, such as bacteria. In food-producing animals, the antimicrobials used to treat various infectious diseases may be the same or similar to those used for humans.

Resistance to antimicrobials occurs when the micro-organisms develop mechanisms that reduce their effectiveness or render their use ineffective. Resistant bacteria can spread through many routes. When antimicrobial resistance occurs in zoonotic bacteria present in animals and food it can also compromise the effective treatment of infectious diseases in humans.

Based on 2009 data, the study shows a high or moderate proportion of Salmonella (in chickens), Campylobacter and non-disease-causing E. coli was also found to be resistant to this antibiotic.

A low proportion of Salmonella and non-disease-causing E. coli in animals was found to be resistant to third-generation cephalosporins, a type of antibiotic, considered by the World Health Organization (WHO) to be critically important in human medicine.

Other key study findings include:

  • Campylobacter — In animals, this showed high levels of resistance to ciprofloxacin. This was in particular the case for chickens (46 percent in Campylobacter jejuni and 78 percent in the Campylobacter coli) and also pigs (50 percent in Campylobacter coli).
  • Salmonella — In animals, high levels of resistance were recorded for ampicillin, tetracycline and sulphonamide in pigs and pig meat (47-60 percent), cattle (37-40 percent) and chicken meat (27-33 percent). A moderate level of resistance to ciprofloxacin was recorded in chickens and chicken meat (around 20 percent).
  • Non-disease causing E. coli showed high levels of resistance to tetracycline, ampicillin and sulphonamide in pigs and chicken; and E. coli was found to be resistant to ciprofloxacin in chicken (47 percent) and also in pigs (12 percent). The occurrence of third-generation cephalosporin resistance was still low.