Wastewater treatment plants as critical reservoirs for resistance genes





Research Project: 2017-01-01 - 2019-12-31
Total sum awarded: €1 525 102

Multiresistant bacteria are a severe problem to modern healthcare. The problem is increasing and development of novel technologies to cope with this critical situation is a necessity. Solutions include novel antibiotic drugs as well as reducing the spread of resistance genes in the environment. Wastewater treatment plants (WWTP) are nodal points where much of the contaminated material is passing. When processing the sludge, biogas is produced, followed by a residue, biofertilizer. Sanitation of biofertilizer is usually performed via treatment at 70°C for 1 hour. However, other strategies need to be developed to assure that the frequency of resistance genes in the sludge is drastically reduced.So far, very few reports are present on the abundance of resistance genes, and even less information is available concerning possible treatments to reduce the content. The present program addresses both of these aspects, the frequency and means to reduce resistance genes by e.g. converting the nucleic acids into biogas. The project involves monitoring of the fate of resistance genes, both in the conventional processing in WWTPs and in subsequent anaerobic digestion. An organism carrying a reporter gene will be added to a model of a WWTP, and the “survival” of that gene will be monitored. Based on the results obtained, a model will be developed concerning the effect of new treatment methods and their impact on spreading of resistance genes. Both bacteria and bacteriophages are carrying resistance genes, and will be monitored to evaluate the effect of different treatments.

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  • Rolf Lood, Lund University, Sweden (Coordinator)
  • Bo Mattiasson, Lund University, Sweden (Partner)
  • Kurt Fuurstedt, Statens Serum Institute, Denmark (Partner)
  • Roald Kommedal, University of Stavanger, Norway (Partner)

Antimicrobial resistance is a worldwide problem, and many bacteria have now developed resistance towards even last-resort antibiotics. Despite significant attempts to limit this development more and more infections are identified as resistant to the treatment in hospitals. Much effort has been put into understanding the spread of resistance, and treatment thereof, within a hospital setting. It is only quite recently that an understanding that we need to also take in the environment, and development of resistance in such a setting in what now is called a One Health Approach has dawned. Not only is the presence of resistance in hospitals important, but of equal importance is the presence of free antibiotics in nature, usage of antibiotics for food industry, handling of wastewater etc for the spread of antibiotic resistance. The wastewater treatment plants have been shown to be a hotspot for development of antibiotic resistance due to the high prevalence of bacteria and viruses there, as well as high levels of antibiotics. This will favor resistant bacteria, and exchange of resistance between microbes. A key player in this perspective are the bacterial viruses (bacteriophages) that can act as a transmission vehicle and transfer resistance between different bacteria. Our research aims at understanding the mechanisms underlying these transmission dynamics, and develop means to limit it.