Disinfectants (DIs) play a key role for prevention and control of pathogens and spoilage bacteria in food production facilities. Effective cleaning and disinfection (C&D) routines can prevent foodborne disease outbreaks and reduce food spoilage. However, the chemical selective pressure by DIs may select for bacterial resistance, and studies have revealed correlations between antibiotic and disinfection resistance. Antibiotic resistance is a global threat that is estimated to cause 10 million deaths annually by 2050. Increased understanding of drivers and transmission routes for antimicrobial resistance (AMR) is fundamental to mitigate this development. New pathways for AMR transmission have emerged, as the waste-flow in food production value chains is altered due to focus on circular economy and increased resource exploitation. This emphasises the need for better control of the processes to prevent AMR development and spread, since AMR bacteria and genes can be reintroduced to new production systems. From a one-health perspective, the whole food production value chain including also feed, sidestream materials, wastewater and sludge, should be considered with respect to food safety and spread of AMR.
The DisinfectAMR project is addressing the role of DIs used in chicken and salmon production facilities and their effect on bacterial loads, microbial community composition, and biofilm prevention. Possible cross-resistance between DIs and antibiotics was also investigated. The risk of AMR dissemination by sidestream materials, waste discharges and processing environments was assessed by analysing the occurrence of AMR bacteria and genes. The study design and sampling protocols were planned in collaboration with the involved industry partners during 3 workshops. The sampling campaigns resulted in a large collection of bacterial strains (>1000) and DNA from production facilities both in Norway and Romania, which formed the basis for further analysis activities in the project. The methodology used for the analyses included advanced technologies such as robotic high-throughput screening, sequence-based mining of resistance genes, metagenomic sequencing, and DI-exposure tests using a microbioreactor.
The results demonstrated that DIs effectively reduce bacterial loads on most production surfaces and alter microbial community compositions. However, areas with insufficient hygiene, high bacterial loads and presence of pathogens were also detected. DI-efficacy varied between different DI-types and concentrations with several biofilms surviving the highest concentrations tested. This knowledge is important for food processing operators to optimise C&D routines. A low prevalence of AMR bacteria was detected in sidestream materials, waste discharges and processing environments. However, several quinolone-resistant Escherichia coli (QREC) were detected in waste discharges from two chicken processing plants, while multi-drug resistant (MDR) E. coli were found in one plant. Additionally, a diverse range of AMR genes, including high-risk genes, were detected in sidestream materials, waste discharges and processing environments. These results highlight the potential of AMR spread to the environment and into new circular production systems and could be recognised as a potential one-health risk. The project have international perspective since similar studies were performed in Romania, where the use of both disinfectants and antibiotics differs from Norwegian practice.
The results from the project are published in peer-reviewed papers, presentations and posters at scientific meetings and conferences, disseminated in popular science channels, and presented and discussed with the group of stakeholders connected to the project, consisting of Animalia, Aquatiq, Sjømatbedriftene and The Norwegian Institute of Public Health. The project has also supported a total of six master students and one PhD student.
With the results and achievements obtained, the DisinfectAMR project contributes to improved knowledge on the effect of disinfectants used in chicken and salmon processing on bacterial loads and surface microbiota, especially with respect to effect against bacterial biofilm which can reduce the effective concentration of DI. Chicken and salmon meat continues to be involved in bacterial disease outbreaks, and our study highlights the importance of effective C&D routines since potential pathogens and spoilage bacteria are found in the surface microbiota in the processing environments. This knowledge is important for food processing operators to optimise C&D routines, which in the long term ensures adequate and sustainable production with low environmental impact at the industry partners. By filling the lack of knowledge on occurrence of AMR bacteria and genes in the food production value chain from processing environments to sidestream materials, feed ingredients, and waste-flow from the factories, the project also demonstrated the potential one-health risk of food production in spread of pathogens and AMR bacteria in a circular perspective to humans, animals and the environment. For the society in general, this new knowledge is important to consider when targeting circular economy and increased resource exploitation using sidestream materials and waste for new feed or food products. The project has established the infrastructure, protocols and competence to efficiently study AMR and disinfectants in the future and to test antibacterial effect in general. The comparable experiments performed in Romania established new research collaboration, and ensured that the outcome also have international relevance. The establishment of the consortium in DisinfectAMR also lead to further collaboration in projects and application initiatives, where the network, competence, and the established methods will be used further.
The project addresses the role of food production and the environment as reservoirs of antimicrobial resistant (AMR) bacteria and the impact of disinfectants (DI) as potential drivers for persistence of AMR in two food production plants, and one process plant for feed. Disinfection products play a key role for prevention and control of pathogenic bacteria in food production facilities. However, such chemical selective pressures may co-select for bacterial resistance in the environment, and studies on bacterial susceptibility to DI in food production pipelines have indicated correlations between bacterial antibiotic and DI resistance. From a One-Health perspective, AMR in humans, animals and the environment cannot be viewed separately, and the whole value chain of food production including also feed, process by-products, wastewater, sludge, etc. should be considered with respect to food safety and spread of AMR. The waste-flow in food production value chains is altered due to focus on circular economy and increased resource exploitation. This emphasise the need for better control on the processes in order to prevent the spread and transfer of AMR, since AMR bacteria and genes may be reintroduced to the circular system. To encounter these challenges, the main goal of the project is to study the effect of prolonged use of DI in Norwegian poultry and salmon production in terms of bacterial resistance towards the DI and potential cross-resistance to antibiotics, with direct impact on a process plant for fish feed ingredients which process raw material from both producers. The fundamental understanding of the drivers and pathways for AMR in other than clinical settings and antibiotics use is limited, and this knowledge gap represents a missing link in the One-Health perspective, thus the project will provide urgently needed knowledge. The outcome will be transferable to similar production facilities both national and international.
