Antibiotics: Salmonella and Campylobacter Show High Levels of Antibiotic Resistance in Humans and Animals

Data from 2013 on antibiotic resistance in zoonotic bacteria, provided by 28 EU member states, were jointly analyzed by two European agencies. This new report* highlights the continued spread of multidrug resistance in Europe. For the first time, the European Food Safety Authority (EFSA) and the ECDC have used similar criteria to interpret levels of antimicrobial resistance in humans and animals, making the comparison of data more meaningful. Campylobacter and Salmonella bacteria show high levels of antibiotic resistance in humans and animals, leading to fewer treatment options for some of the most common foodborne infections. For example, multidrug-resistant Salmonella isolates continue to spread across Europe. Similarly, several countries have reported significant resistance of Campylobacter isolates to ciprofloxacin, a critically important antibiotic, both in humans (54.6% of C. jejuni and 66.6% of C. coli were resistant) and in animals (54.5% of C. jejuni and 68.8% of C. coli in broiler chickens, 35.8% of C. jejuni in cattle, and 31.1% of C. coli in pigs). Furthermore, many human Campylobacter infections originate from the handling, preparation, and meat consumption of chicken. Yet high levels of resistance to fluoroquinolones are found in Campylobacter isolates from both humans and broiler chickens. Such levels of resistance further limit the options for effectively treating campylobacteriosis. Salmonella resistance to multiple antibiotics is high (31.8% in humans, 56% in broiler chickens, 73% in turkeys, 38% in fattening pigs), and the persistent spread of multidrug-resistant clones, as well as the emergence of resistance genes within these clones, in both humans and animals (broiler chickens, pigs, and cattle), is a cause for concern. The only encouraging finding is that co-resistance to critically important antimicrobials for both bacteria remains low. Levels of co-resistance in Salmonella are approximately 0.2% in humans, 0.3% in broiler chickens, and zero in fattening pigs and turkeys. For Campylobacter , rates of multidrug resistance and co-resistance to critically important antibiotics are low in humans (1.7% for C. jejuni and 4.1% for C. coli ) and low to moderate in animals (0.5% of C. jejuni in broiler chickens and 1.1% in cattle, 12.3% of C. coli in broiler chickens and 19.5% in pigs). The report also includes data on resistance in bacteria such as Escherichia coli , enterococci, and methicillin-resistant Staphylococcus aureus (MRSA) in animals and in food. It thus adds another building block to the “Action Plan to Combat the Growing Threat of Antimicrobial Resistance” presented in 2011 by the European Commission.  

Resistance, multidrug resistance, co-resistance

> Antimicrobial resistance: This refers to a bacterium’s resistance to an antibiotic to which it was previously susceptible. > Multidrug-resistant bacteria: These bacteria are resistant to at least three different classes of antimicrobials. • Examples of multidrug-resistant bacteria: - Methicillin-resistant Staphylococcus aureus (MRSA); - vancomycin-resistant enterococci (VRE); - ESBL-producing Enterobacteriaceae (e.g., Escherichia coli and Klebsiella pneumoniae); - carbapenemase-producing Enterobacteriaceae (CPE), such as Klebsiella pneumoniae; - Pseudomonas aeruginosa; - Clostridium difficile. > Co-resistance: combined resistance to two specific antimicrobials of critical importance.  

* EFSA-ECDC European Union Summary Report on Antimicrobial Resistance in Zoonotic and Indicator Bacteria from Humans, Animals, and Food,