Antimicrobial resistance in zoonotic bacteria - ECDC / EFSA report

06 March 2018

Article: 52/901

On 27 February 2048, the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA) published a report covering data on antimicrobial resistance in zoonotic and indicator bacteria in 2016, submitted by 28 EU member states. Resistance in bacterial isolates of zoonotic Salmonella and Campylobacter from humans, animals and food, and resistance in indicator Escherichia coli as well as in meticillin-resistant Staphylococcus aureus from animals and food were addressed and analysed jointly by the two agencies.

The main findings of the report have been identified as follows:

Humans

  • One out of four Salmonella infections in humans are caused by Salmonella bacteria that show resistance to three or more antimicrobials commonly used in human and animal medicine. The proportion is significantly higher in S. Kentucky and S. Infantis (76.3 and 39.4% respectively).
  • For the first time, ESBL-producing S. Kentucky with high resistance to ciprofloxacin was detected in four countries. This type of bacteria cannot be treated with critically important antibiotics.
  • Campylobacter bacteria, which are the most common cause of food-borne disease in the EU, show high resistance to widely used antibiotics (ciprofloxacin resistance 54.6% in C. jejuni and 63.8% in C. coli; tetracyline resistance 42.8% in C. jejuni and 64.8% in C. coli). The levels of resistance increased in two of the three analysed antibiotics (ciprofloxacin and tetracycline), but combined resistance to the critically important antimicrobials is stable and overall low (0.6% in C. jejuni and 8.0% in C. coli). In some countries, however, at least one in three C. coli infections were multidrug-resistant to important antibiotics, leaving very few treatment options for severe infections.

Animals and foods

  • Resistance to carbapenem antibiotics was detected at very low level in poultry and in chicken meat in two member states (15 E. coli bacterial isolates). Carbapenems are used to treat serious infections in humans and are not authorised for use in animals.
  • Two livestock-associated methicillin-resistant Staphylococcus aureus bacterial isolates found in pigs were reported to be linezolid-resistant. Linezolid is one of the last-resort antimicrobials for the treatment of infections caused by highly resistant MRSA.
  • Combined clinical resistance to critically important antimicrobials was observed at low to very low levels in Salmonella (0.2%), Campylobacter (1%) and E. coli (1%) in poultry.
  • Resistance to colistin was observed at low levels (2%) in Salmonella and E. coli in poultry.
  • Prevalence of ESBL-producing E. coli in poultry varies markedly between the member states, from low (less than 10%) to extremely high levels (more than 70%). Bacteria that produce ESBL enzymes show multi-drug resistance to β-lactam antibiotics – a class of broad spectrum antibiotics that includes penicillin derivatives, cephalosporins and carbapenems. This is the first time that the presence of extended-spectrum beta-lactamase (ESBL)-producing E. coli was monitored in poultry and poultry meat.

ECDC and EFSA have expressed concern that the continued detection of multidrug-resistant bacteria means that the situation is not improving. While there is a need to investigate the origins and prevent the spread of highly resistant strains, such as ESBL-producing Salmonella Kentucky, the detection of resistance to carbapenems in poultry and to linezolid in methicillin-resistant Staphylococcus aureus in pigs is alarming because these antibiotics are used in humans to treat serious infections.

Source: ECDC News Release, 27 February 2018