Evolution of antibiotic resistance at low antibiotic concentrations including selection below the minimal selective concentration

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: The datasets associated with Figs. 1–6 are included in this published article as a Supplementary Data file. Metagenome sequence files have been deposited in the European Nucleotide Archive. Accession number: PRJEB38942.Code availability: Code used for metagenome analysis: FastQC; MultiQC; FLASH2; Metaphlan2; Hclust2 and ARGs-OAP v2.Determining the selective potential of antibiotics at environmental concentrations is critical for designing effective strategies to limit selection for antibiotic resistance. This study determined the minimal selective concentrations (MSCs) for macrolide and fluoroquinolone antibiotics included on the European Commission's Water Framework Directive's priority hazardous substances Watch List. The macrolides demonstrated positive selection for ermF at concentrations 1-2 orders of magnitude greater (>500 and 7.8 and <15.6 µg/L). This highlights the need for compound specific assessment of selective potential. In addition, a sub-MSC selective window defined by the minimal increased persistence concentration (MIPC) is described. Differential rates of negative selection (or persistence) were associated with elevated prevalence relative to the no antibiotic control below the MSC. This increased persistence leads to opportunities for further selection over time and risk of human exposure and environmental transmission.Biotechnology and Biological Sciences Research Council (BBSRC)Natural Environment Research Council (NERC

Emulsifying properties of sugar beet pectin microgels

Particle stabilized (‘Pickering’) oil-in-water (O/W) emulsions were fabricated using sugar beet pectin (SBP) microgel particles (SBPM) that differed in their crosslinking density and therefore elasticity. Droplet size distributions and emulsion microstructures were investigated via light scattering and complimentary imaging techniques: light microscopy, confocal laser scanning microscopy and scanning electron microscopy. Comparisons to emulsions stabilized by native (i.e., non-microgelled) SBP at equivalent overall SBP content were made throughout. The SBPM-stabilized emulsions (20 and 40 vol% oil) were shown to have an improved physical stability compared to those stabilized by SBP. For example, droplet coarsening on prolonged (9 week) storage at ambient temperature (25 °C) and on temperature cycling (75 °C) was substantially reduced for SBPM-stabilized emulsions. This is attributed to the greater steric barrier provided by SBPM particles and their higher energy of displacement. Furthermore, the higher viscoelasticity of the SBPM-stabilized emulsions (particularly at 40 vol% oil) retarded droplet creaming. This higher viscoelasticity could be due to weak flocculation of the SBPM-stabilized droplets or the strong influence of the SBPM on the viscoelasticity of the intervening aqueous phase, even at relatively low SBPM concentrations

Predicting selection for antimicrobial resistance in UK wastewater and aquatic environments: Ciprofloxacin poses a significant risk.

This is the final version. Available from Elsevier via the DOI in this record. Data access statement: The research data supporting this publication are provided within this paper and the supplementary information accompanying this publication.Antimicrobial resistance (AMR) is a threat to human and animal health, with the environment increasingly recognised as playing an important role in AMR evolution, dissemination, and transmission. Antibiotics can select for AMR at very low concentrations, similar to those in the environment, yet their release into the environment, e.g., from wastewater treatment plants, is not currently regulated. Understanding the selection risk antibiotics pose in wastewater and receiving waters is key to understanding if environmental regulation of antibiotics is required. We investigated the risk of selection occurring in UK wastewater and receiving waters by determining where measured environmental concentration data (n = 8187) for four antibiotics (ciprofloxacin, azithromycin, clarithromycin, and erythromycin) collected in England and Wales 2015-2018 (sites n = 67) exceeded selective concentration thresholds derived from complex microbial community evolution experiments undertaken previously. We show that selection for AMR by ciprofloxacin is likely to have occurred routinely in England and Wales wastewater during the 2015-2018 period, with some seasonal and regional trends. Wastewater treatment reduces the selection risk posed by ciprofloxacin significantly, but not completely, and predicted risk in surface waters remains high in several cases. Conversely, the potential risks posed by the macrolides (azithromycin, clarithromycin, and erythromycin) were lower than those posed by ciprofloxacin. Our data demonstrate further action is needed to prevent selection for AMR in wastewater, with environmental quality standards for some antibiotics required in the future, and that selection risk is not solely a concern in low/middle income countries.FRESH CDT/AstraZenecaBBSRC/ AstraZenecaNatural Environment Research CouncilNatural Environment Research Counci

The ‘SELection End points in Communities of bacTeria’ (SELECT) Method: A Novel Experimental Assay to Facilitate Risk Assessment of Selection for Antimicrobial Resistance in the Environment

This is the final version. Available on open access from NIEHS via the DOI in this recordBackground: Antimicrobial resistance (AMR) is one of the most significant health threats to society. A growing body of research demonstrates selection for AMR likely occurs at environmental concentrations of antibiotics. However, no standardized experimental approaches for determining selective concentrations of antimicrobials currently exist, preventing appropriate environmental and human health risk assessment of AMR. Objectives: We aimed to design a rapid, simple, and cost-effective novel experimental assay to determine selective effect concentrations of antibiotics and to generate the largest experimental data set of selective effect concentrations of antibiotics to date. Methods: Previously published methods and data were used to validate the assay, which determines the effect concentration based on reduction of bacterial community (wastewater) growth. Risk quotients for test antibiotics were generated to quantify risk. Results: The assay (SELection End points in Communities of bacTeria, or the SELECT method) was used to rapidly determine selective effect concentrations of antibiotics. These were in good agreement with quantitative polymerase chain reaction effect concentrations determined within the same experimental system. The SELECT method predicted no effect concentrations were minimally affected by changes in the assay temperature, growth media, or microbial community used as the inoculum. The predicted no effect concentrations for antibiotics tested ranged from 0.05μg/L for ciprofloxacin to 1,250μg/L for erythromycin. Discussion: The lack of evidence demonstrating environmental selection for AMR, and of associated human health risks, is a primary reason for the lack of action in the mitigation of release of antibiotics into the aquatic environment. We present a novel method that can reliably and rapidly fill this data gap to enable regulation and subsequent mitigation (where required) to lower the risk of selection for, and human exposure to, AMR in aquatic environments. In particular, ciprofloxacin and, to a lesser extent, azithromycin, cefotaxime, and trimethoprim all pose a significant risk for selection of AMR in the environment. https://doi.org/10.1289/EHP6635Biotechnology and Biological Sciences Research Council (BBSRC)AstraZeneca Collaborative Awards in Science and Engineering studentshipNatural Environment Research Council (NERC)Nuffield Foundatio

Does environmental exposure to pharmaceutical and personal care product residues result in the selection of antimicrobial‐resistant microorganisms, and is this important in terms of human health outcomes?

This is the final version. Available on open access from Wiley via the DOI in this record. Data Availability Statement: Data, associated metadata, and calculation tools are available from the corresponding author ([email protected]).The environment plays a critical role in the development, dissemination, and transmission of antimicrobial resistance (AMR). Pharmaceuticals and personal care products (PPCPs) enter the environment through direct application to the environment and through anthropogenic pollution. Although there is a growing body of evidence defining minimal selective concentrations (MSCs) of antibiotics and the role antibiotics play in horizontal gene transfer (HGT), there is limited evidence on the role of non-antibiotic PPCPs. Existing data show associations with the development of resistance or effects on bacterial growth rather than calculating selective endpoints. Research has focused on laboratory-based systems rather than in situ experiments, although PPCP concentrations found throughout wastewater, natural water, and soil environments are often within the range of laboratory-derived MSCs and at concentrations shown to promote HGT. Increased selection and HGT of AMR by PPCPs will result in an increase in total AMR abundance in the environment, increasing the risk of exposure and potential transmission of environmental AMR to humans. There is some evidence to suggest that humans can acquire resistance from environmental settings, with water environments being the most frequently studied. However, because this is currently limited, we recommend that more evidence be gathered to understand the risk the environment plays in regard to human health. In addition, we recommend that future research efforts focus on MSC-based experiments for non-antibiotic PPCPS, particularly in situ, and investigate the effect of PPCP mixtures on AM

Drug use in children: cohort study in three European countries

Objective To provide an overview of drug use in children in three European countries

Isotopic and molecular distributions of biochemicals from fresh and buried Rhizophora mangle leaves†

Rhizophora mangle L. (red mangrove) is the dominant species of mangrove in the Americas. At Twin Cays, Belize (BZ) red mangroves are present in a variety of stand structures (tall >5 m in height, transition ~2–4 m and dwarf ~1–1.5 m). These height differences are coupled with very different stable carbon and nitrogen isotopic values[1] (mean tall δ(13)C = -28.3‰, δ(15)N = 0‰; mean tall δ(13)C = -25.3‰, δ(15)N = -10‰). To determine the utility of using these distinct isotopic compositions as 'biomarkers' for paleoenvironmental reconstruction of mangrove ecosystems and nutrient availability, we investigated the distribution and isotopic (δ(13)C and δ(15)N) composition of different biochemical fractions (water soluble compounds, free lipids, acid hydrolysable compounds, individual amino acids, and the residual un-extractable compounds) in fresh and preserved red mangrove leaves from dwarf and tall trees. The distribution of biochemicals are similar in dwarf and tall red mangrove leaves, suggesting that, regardless of stand structure, red mangroves use nutrients for biosynthesis and metabolism in a similar manner. However, the δ(13)C and δ(15)N of the bulk leaf, the biochemical fractions, and seven amino acids can be used to distinguish dwarf and tall trees at Twin Cays, BZ. The data support the theory that the fractionation of carbon and nitrogen occurs prior to or during uptake in dwarf and tall red mangrove trees. Stable carbon and nitrogen isotopes could, therefore, be powerful tools for predicting levels of nutrient limitation at Twin Cays. The δ(13)C and δ(15)N of biochemical fractions within preserved leaves, reflect sedimentary cycling and nitrogen immobilization. The δ(15)N of the immobilized fraction reveals the overlying stand structure at the time of leaf deposition. The isotopic composition of preserved mangrove leaves could yield significant information about changes in ecosystem dynamics, nutrient limitation and past stand structure in mangrove paleoecosystems

Methods for conducting systematic reviews of risk factors in low- and middle-income countries.

BACKGROUND: Rates of youth violence are disproportionately high in many low- and middle-income countries [LMICs] but existing reviews of risk factors focus almost exclusively on high-income countries. Different search strategies, including non-English language searches, might be required to identify relevant evidence in LMICs. This paper discusses methodological issues in systematic reviews aiming to include evidence from LMICs, using the example of a recent review of risk factors for child conduct problems and youth violence in LMICs. METHODS: We searched the main international databases, such as PsycINFO, Medline and EMBASE in English, as well as 12 regional databases in Arabic, Chinese, English, French, Spanish, Portuguese and Russian. In addition, we used internet search engines and Google Scholar, and contacted over 200 researchers and organizations to identify potentially eligible studies in LMICs. RESULTS: The majority of relevant studies were identified in the mainstream databases, but additional studies were also found through regional databases, such as CNKI, Wangfang, LILACS and SciELO. Overall, 85% of eligible studies were in English, and 15% were reported in Chinese, Spanish, Portuguese, Russian or French. Among eligible studies in languages other than English, two-thirds were identified only by regional databases and one-third was also indexed in the main international databases. CONCLUSIONS: There are many studies on child conduct problems and youth violence in LMICs which have not been included in prior reviews. Most research on these subjects in LMICs has been produced in the last two-three decades and mostly in middle-income countries, such as China, Brazil, Turkey, South Africa and Russia. Based on our findings, it appears that many studies of child conduct problems and youth violence in LMICs are reported in English, Chinese, Spanish and Portuguese, but few such studies are published in French, Arabic or Russian. If non-English language searches and screening had not been conducted in the current review, 15% of eligible studies would have been missed. Although there are benefits to non-English language searches and the inclusion of non-English studies in meta-analyses, systematic reviewers also need to consider the resources required to incorporate multi-lingual research.We are grateful to the Wellcome Trust [089963/Z/09/Z] and Bernard van Leer Foundation for financial support for the research

Does community-based education increase students' motivation to practice community health care? - a cross sectional study

<p>Abstract</p> <p>Background</p> <p>Community-based education has been introduced in many medical schools around the globe, but evaluation of instructional quality has remained a critical issue. Community-based education is an approach that aims to prepare students for future professional work at the community level. Instructional quality should be measured based on a program's outcomes. However, the association between learning activities and students' attitudes is unknown. The purpose of this study was to clarify what learning activities affect students' attitudes toward community health care.</p> <p>Methods</p> <p>From 2003 to 2009, self-administered pre- and post-questionnaire surveys were given to 693 fifth-year medical students taking a 2-week clinical clerkship. Main items measured were student attitudes, which were: "I think practicing community health care is worthwhile" ("worthwhile") and "I am confident about practicing community health care" ("confidence") using a visual analogue scale (0-100). Other items were gender, training setting, and learning activities. We analyzed the difference in attitudes before and after the clerkships by paired <it>t </it>test and the factors associated with a positive change in attitude by logistic regression analysis.</p> <p>Results</p> <p>Six hundred forty-five students (93.1%), 494 (76.6%) male and 151(23.4%) female, completed the pre- and post-questionnaires. The VAS scores of the students' attitudes for "worthwhile" and "confidence" after the clerkship were 80.2 ± 17.4 and 57.3 ± 20.1, respectively. Both of the scores increased after the clerkship. Using multivariate logistic regression analysis, "health education" was associated with a positive change for both attitudes of "worthwhile" (adjusted RR: 1.71, 95% CI: 1.10-2.66) and "confidence" (1.56, 1.08-2.25).</p> <p>Conclusions</p> <p>Community-based education motivates students to practice community health care. In addition, their motivation is increased by the health education activity. Participating in this activity probably produces a positive effect and improves the instructional quality of the program based on its outcomes.</p