| 1. |
- Larsson, D. G. Joakim, 1969, et al.
(författare)
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Critical knowledge gaps and research needs related to the environmental dimensions of antibiotic resistance
- 2018
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 117, s. 132-138
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Forskningsöversikt (refereegranskat)abstract
- There is growing understanding that the environment plays an important role both in the transmission of antibiotic resistant pathogens and in their evolution. Accordingly, researchers and stakeholders world-wide seek to further explore the mechanisms and drivers involved, quantify risks and identify suitable interventions. There is a clear value in establishing research needs and coordinating efforts within and across nations in order to best tackle this global challenge. At an international workshop in late September 2017, scientists from 14 countries with expertise on the environmental dimensions of antibiotic resistance gathered to define critical knowledge gaps. Four key areas were identified where research is urgently needed: 1) the relative contributions of different sources of antibiotics and antibiotic resistant bacteria into the environment; 2) the role of the environment, and particularly anthropogenic inputs, in the evolution of resistance; 3) the overall human and animal health impacts caused by exposure to environmental resistant bacteria; and 4) the efficacy and feasibility of different technological, social, economic and behavioral interventions to mitigate environmental antibiotic resistance.(1)
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| 2. |
- Wernersson, Ann-Sofie, 1969, et al.
(författare)
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The European technical report on aquatic effect-based monitoring tools under the water framework directive
- 2015
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Ingår i: Environmental Sciences Europe. - : Springer Science and Business Media LLC. - 2190-4715 .- 2190-4707. ; 27:11 March 2015
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Tidskriftsartikel (refereegranskat)abstract
- The Water Framework Directive (WFD), 2000/60/EC, requires an integrated approach to the monitoring and assessment of the quality of surface water bodies. The chemical status assessment is based on compliance with legally binding Environmental Quality Standards (EQSs) for selected chemical pollutants (priority substances) of EU-wide concern. In the context of the mandate for the period 2010 to 2012 of the subgroup Chemical Monitoring and Emerging Pollutants (CMEP) under the Common Implementation Strategy (CIS) for the WFD, a specific task was established for the elaboration of a technical report on aquatic effect-based monitoring tools. The activity was chaired by Sweden and co-chaired by Italy and progressively involved several Member States and stakeholders in an EU-wide drafting group. The main aim of this technical report was to identify potential effect-based tools (e.g. biomarkers and bioassays) that could be used in the context of the different monitoring programmes (surveillance, operational and investigative) linking chemical and ecological status assessment. The present paper summarizes the major technical contents and findings of the report.
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| 5. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Can branding and price of pharmaceuticals guide informed choices towards improved pollution control during manufacturing?
- 2018
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Ingår i: Journal of Cleaner Production. - 0959-6526. ; 171, s. 137-146
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Tidskriftsartikel (refereegranskat)abstract
- Pharmaceutical manufacturing can lead to substantial discharges of active pharmaceutical ingredients into the environment, with local consequences to the environment and, in the case of antibiotics, potentially global implications in terms of increasing risks for resistance development. In this study, we used Swedish sales data for pharmaceuticals combined with data on the origin of the active ingredients to determine if price pressure and generic substitution are related to the estimated general environmental performance and the perceived corruption levels of the production countries. In line with the general perception, India was the largest producer of generics, while Europe and the USA dominated for branded products. We found that the price and environmental performance index of the production countries were linked, but that this relationship was largely explained by whether the product was original or generic. Although this relationship would allow buyers to select products that are more likely to originate from countries that, in general terms, have better pollution control, it lacks resolution. We conclude that to better allow consumers, hospitals and pharmacies to influence the environmental impact of their product choices, there is need for regulation as well as transparency in the production chain. To this end, emissions from manufacturing need to be measured, allowing for control and follow-up on industry commitments towards sustainable manufacturing of pharmaceuticals.
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| 6. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Concentrations of antibiotics predicted to select for resistant bacteria: Proposed limits for environmental regulation
- 2016
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 86, s. 140-149
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Tidskriftsartikel (refereegranskat)abstract
- There are concerns that selection pressure from antibiotics in the environment may accelerate the evolution and dissemination of antibiotic-resistant pathogens. Nevertheless, there is currently no regulatory system that takes such risks into account. In part, this is due to limited knowledge of environmental concentrations that might exert selection for resistant bacteria. To experimentally determine minimal selective concentrations in complex microbial ecosystems for all antibiotics would involve considerable effort. In this work, our aim was to estimate upper boundaries for selective concentrations for all common antibiotics, based on the assumption that selective concentrations a priori need to be lower than those completely inhibiting growth. Data on Minimal Inhibitory Concentrations (MICs) were obtained for 111 antibiotics from the public EUCAST database. The 1% lowest observed MICs were identified, and to compensate for limited species coverage, predicted lowest MICs adjusted for the number of tested species were extrapolated through modeling. Predicted No Effect Concentrations (PNECs) for resistance selection were then assessed using an assessment factor of 10 to account for differences between MICs and minimal selective concentrations. The resulting PNECs ranged from 8 ng/L to 64 μg/L. Furthermore, the link between taxonomic similarity between species and lowest MIC was weak. This work provides estimated upper boundaries for selective concentrations (lowest MICs) and PNECs for resistance selection for all common antibiotics. In most cases, PNECs for selection of resistance were below available PNECs for ecotoxicological effects. The generated PNECs can guide implementation of compound-specific emission limits that take into account risks for resistance promotion.
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| 7. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Elucidating selection processes for antibiotic resistance in sewage treatment plants using metagenomics
- 2016
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 572, s. 697-712
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Tidskriftsartikel (refereegranskat)abstract
- Sewage treatment plants (STPs) have repeatedly been suggested as “hotspots” for the emergence and dissemination of antibiotic-resistant bacteria. A critical question still unanswered is if selection pressures within STPs, caused by residual antibiotics or other co-selective agents, are sufficient to specifically promote resistance. To address this, we employed shotgun metagenomic sequencing of samples from different steps of the treatment process in three Swedish STPs. In parallel, concentrations of selected antibiotics, biocides and metals were analyzed. We found that concentrations of tetracycline and ciprofloxacin in the influent were above predicted concentrations for resistance selection, however, there was no consistent enrichment of resistance genes to any particular class of antibiotics in the STPs, neither for biocide and metal resistance genes. The most substantial change of the bacterial communities compared to human feces occurred already in the sewage pipes, manifested by a strong shift from obligate to facultative anaerobes. Through the treatment process, resistance genes against antibiotics, biocides and metals were not reduced to the same extent as fecal bacteria. The OXA-48 gene was consistently enriched in surplus and digested sludge. We find this worrying as OXA-48, still rare in Swedish clinical isolates, provides resistance to carbapenems, one of our most critically important classes of antibiotics. Taken together, metagenomics analyses did not provide clear support for specific antibiotic resistance selection. However, stronger selective forces affecting gross taxonomic composition, and with that resistance gene abundances, limit interpretability. Comprehensive analyses of resistant/non-resistant strains within relevant species are therefore warranted.
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| 8. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Environmental factors influencing the development and spread of antibiotic resistance
- 2018
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Ingår i: FEMS Microbiology Reviews. - : Oxford University Press (OUP). - 0168-6445 .- 1574-6976. ; 42:1, s. 68-80
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Forskningsöversikt (refereegranskat)abstract
- Antibiotic resistance and its wider implications present us with a growing healthcare crisis. Recent research points to the environment as an important component for the transmission of resistant bacteria and in the emergence of resistant pathogens. However, a deeper understanding of the evolutionary and ecological processes that lead to clinical appearance of resistance genes is still lacking, as is knowledge of environmental dispersal barriers. This calls for better models of how resistance genes evolve, are mobilized, transferred and disseminated in the environment. Here, we attempt to define the ecological and evolutionary environmental factors that contribute to resistance development and transmission. Although mobilization of resistance genes likely occurs continuously, the great majority of such genetic events do not lead to the establishment of novel resistance factors in bacterial populations, unless there is a selection pressure for maintaining them or their fitness costs are negligible. To enable preventative measures it is therefore critical to investigate under what conditions and to what extent environmental selection for resistance takes place. In addition, understanding dispersal barriers is not only key to evaluate risks, but also to prevent resistant pathogens, as well as novel resistance genes, from reaching humans.
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| 9. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Metaxa2: Improved identification and taxonomic classification of small and large subunit rRNA in metagenomic data
- 2015
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 15:6, s. 1403-1414
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Tidskriftsartikel (refereegranskat)abstract
- The ribosomal rRNA genes are widely used as genetic markers for taxonomic identification of microbes. Particularly the small subunit (SSU; 16S/18S) rRNA gene is frequently used for species- or genus-level identification, but also the large subunit (LSU; 23S/28S) rRNA gene is employed in taxonomic assignment. The metaxa software tool is a popular utility for extracting partial rRNA sequences from large sequencing data sets and assigning them to an archaeal, bacterial, nuclear eukaryote, mitochondrial or chloroplast origin. This study describes a comprehensive update to metaxa – metaxa2 – that extends the capabilities of the tool, introducing support for the LSU rRNA gene, a greatly improved classifier allowing classification down to genus or species level, as well as enhanced support for short-read (100 bp) and paired-end sequences, among other changes. The performance of metaxa2 was compared to other commonly used taxonomic classifiers, showing that metaxa2 often outperforms previous methods in terms of making correct predictions while maintaining a low misclassification rate. metaxa2 is freely available from http://microbiology.se/software/metaxa2/
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| 10. |
- Bengtsson-Palme, Johan, 1985, et al.
(författare)
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Protection goals must guide risk assessment for antibiotics
- 2018
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Ingår i: Environment international. - : Elsevier BV. - 1873-6750 .- 0160-4120. ; 111, s. 352-353
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Tidskriftsartikel (refereegranskat)abstract
- In a recent paper published in Environment International, Le Page et al. (2017) stress that discharge limits for antibiotics need to consider their potency to affect both environmental and human health, a very sound standpoint also from our point of view. It is reasoned that predicted no-effect concentrations for resistance selection (PNECs) derived from the minimal inhibitory concentrations (MICs) of the most sensitive studied human-associated bacteria (Bengtsson-Palme and Larsson, 2016a), may not be sufficiently protective as environmental cyanobacteria in many cases appear to be more sensitive, according to the authors. The antibiotic resistance health crisis, and the growing understanding of the contribution of the environment in this development, indicates an urgent need for discharge limits for antibiotics, particularly for industrial sources (Bengtsson-Palme and Larsson, 2016b). Such limits would have tremendous value in regulation efforts (Government of India, 2017), for initiatives from the industry themselves (IFPMA, 2016), and for development of environmental criteria within public procurement and generic exchange programs (Bengtsson-Palme et al., 2018; Laurell et al., 2014; SPHS Secreteriat, UNDP Istanbul Regional Hub, 2015). However, somewhat in contrast to what the authors conclude, we do not think there is evidence that cyanobacteria would often be more sensitive to antibiotics than the most sensitive human-associated bacteria. Importantly, we also think that it is a bit unclear from the paper which protection goals are considered (protecting microbial diversity in ecosystems, protecting ecosystem functions and services, or protecting from risks for resistance selection) and particularly in what ways ecotoxicological test data could inform each of these targets.
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