Antibiotic resistance enters the food chain
Antibiotic resistance constitutes a serious problem in modern societies. Antibiotic misuse certainly accentuates the problem, but the main cause behind the phenomenon is the transfer of antibiotic-resistant genes among microorganisms. So far, the majority of relevant studies have focused on the ability of pathogenic bacteria to transmit these genes. However, equally important are non-pathogenic strains which are used in food fermentation processes. Transmission of antibiotic genes among these bacteria has direct implications for the food chain. In this context, the EU-funded ‘Assessment and critical evaluation of antibiotic resistance transferability in food chain’ (ACE-ART) project concentrated on lactic bacterial strains used as starter cultures in fermented food to evaluate their ability to transfer antibiotic-resistant genes. The ultimate goal was to assess the role of antibiotic use in agriculture and in the prophylaxis and treatment of disease in humans. Bacterial strains were evaluated as a source of antibiotic-resistant genes and their ability to transmit these genes to the environment, animals and humans. Results showed that transfer was more likely to occur in gram-positive pathogens and the presence of antibiotics in the environment enhanced this effect. Experiments performed to delineate the antibiotic resistance pattern identified three different mechanisms, namely natural or intrinsic, mutational and horizontally-acquired resistance. These results came as a support to the position of the European Food Safety Authority (EFSA) that demanded both phenotypic and genetic evaluation of the drug-resistance profiles of strains which applied for EFSA approval. The ACE-ART consortium implemented a dissemination campaign targeting both the European authorities and the greater public, and at the same time fostered cooperation between scientists and industries. Project findings shed light on the occurrence and transmission of antibiotic resistance by non-pathogenic bacteria, with important consequences for the food industry and for future preventive and management strategies.
