Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Influence of Plant Root Exudates on the Mobility of Fuel Volatile Compounds in Contaminated Soils

<div><p>Vegetation and its associated microorganisms play an important role in the behaviour of soil contaminants. One of the most important elements is root exudation, since it can affect the mobility, and therefore, the bioavailability of soil contaminants. In this study, we evaluated the influence of root exudates on the mobility of fuel derived compounds in contaminated soils. Samples of humic acid, montmorillonite, and an A horizon from an alumi-umbric Cambisol were contaminated with volatile contaminants present in fuel: oxygenates (MTBE and ETBE) and monoaromatic compounds (benzene, toluene, ethylbenzene and xylene). Natural root exudates obtained from <i>Holcus lanatus</i> and <i>Cytisus striatus</i> and ten artificial exudates (components frequently found in natural exudates) were added to the samples, individually and as a mixture, to evaluate their effects on contaminant mobility. Fuel compounds were analyzed by headspace-gas chromatography-mass spectrometry. In general, the addition of natural and artificial exudates increased the mobility of all contaminants in humic acid. In A horizon and montmorillonite, natural or artificial exudates (as a mixture) decreased the contaminant mobility. However, artificial exudates individually had different effects: carboxylic components increased and phenolic components decreased the contaminant mobility. These results established a base for developing and improving phytoremediation processes of fuel-contaminated soils.</p> </div

Rhizobacterial communities associated with the flora of three serpentine outcrops of the Iberian Peninsula

Aim Plant -associated bacteria can improve phytoextraction by increasing plant growth and/or metal uptake. This study aimed to characterise the culturable rhizobacterial community associated with two Nihyperaccumulators and to obtain a collection of isolates for application in Ni phytomining. Methods Non-vegetated and rhizosphere soil samples were collected from the Ni-hyperaccumulator Alyssum serpyllifolium ssp. lusitanicum (three populations) and Alyssum serpyllifolium ssp. malacitanum (one population), as well as from non-hyperaccumulating plants (Dactylis glomerata, Santolina semidentata and Alyssum serpyllifolium ssp. serpyllifolium). Rhizobacteria were isolated and characterised genotypically (BOX-PCR, 16S rDNA sequencing) and phenotypically (Ni tolerance, plant growth promoting (PGP) traits, biosurfactant production). Results Hyperaccumulating Alyssum subspecies hosted higher densities of bacteria compared to either nonhyperaccumulators or non-vegetated soil. In some cases hyperaccumulators showed selective enrichment of Nitolerant bacteria. Most bacterial strains belonged to the Actinobacteria phylum and presented Ni resistance. Phosphorus-solubilisers were mostly associated with the hyperaccumulators, siderophore-producers with D. glomerata, and IAA-producers with both these species. Conclusion Taxonomic diversity and phenotypic characteristics were soil-, plant species- and plant population- specific. Moreover, differences were observed between the two Ni-hyperaccumulating subspecies and amongst plant populations. Several strains presented PGP characteristics which could be useful when selecting microorganisms for bioaugmentation trials.This research was supported by the Spanish Ministerio de Economía y Competitividad (CTM2012-39904- C02-01) and FEDER, and by the 7th Framework Program of the European Commission (FP7-KBBE-266124, GREENLAND)

Implementing nickel phytomining in a serpentine quarry in NW Spain

In Galicia (NW Spain), ultramafic outcrops represent approximately 5% of the land surface and several mining and quarrying activities take place in these areas.Resulting mine-soils present physical, chemical and biological properties which limit plant growth and soil functioning. Nickel phytomining, an eco-friendly strategy for metal recovery, could potentially be applied to these areas.A one-year field experiment was carried out in a serpentine quarry to evaluate the performance of four Ni hyperaccumulating plant species, comparing the Mediterranean spp. Bornmuellera emarginata and Odontarrhena muralis with the native populations of Noccaea caerulescens and Odontarrhena serpyllifolia. Field plots were established and amended with inorganic NPK fertilisers or composted sewage sludge. Three replicate plots (4 m(2)) were planted for each plant species and fertilisation regime. Amending with compost reduced pH from 7.8 to 6.6, and increased soil cation exchange capacity (CEC), nutrient concentrations and Ni availability. Moreover, compost-amended mine-soil presented higher microbial density and activity, parameters which were further stimulated by plant growth.Plant biomass production of all plant species was significantly higher in compost-amended soils than that after NPK fertilisation, being most pronounced for O. muralis and B. emarginata. Despite the reduction in shoot Ni concentrations observed in plants (except O. muralis) grown in compost-amended plots, the increased biomass production led to significantly higher Ni yields (in kg ha(-1)) in B. emarginata (2.9), N. caerulescens (1.9) and O. muralis (2.3). All plant species were able to establish and grow in the mine-soil (with the Mediterranean species showing a higher capacity for adaptation) and to generate moderate Ni yields.Nonetheless, the results highlight the need for further optimisation in order to enhance the Ni phytoextraction efficiency.Finally, the improvement in soil quality after compost amendment and plant growth support the idea that phytomining systems can be effective approaches for the rehabilitation of soils affected by quarrying operations after mine closure

Evidence for nickel mobilisation in rhizosphere soils of Ni hyperaccumulator Odontarrhena serpyllifolia

Purpose: Rhizosphere processes are known to modify uptake of elements from soil, but limited information is available for hyperaccumulators. We investigated labile Ni fractions and their kinetics of replenishment in the rhizospheres of the Ni-hyperaccumulator Odontarrhena serpyliffolia, the Ni-excluder Holcus lanatus and in bulk soils collected at the same serpentine outcrop. Methods: Labile Ni fractions in rhizosphere and bulk soil were evaluated using conventional extractions and also by the Diffusive Gradients in Thin Films (DGT) technique. DGT data were used to predict the kinetics of Ni resupply using DIFS modelling. Chemical imaging of Ni distribution along roots using DGT coupled with laser-ablation was conducted. Results: Labile Ni forms were higher in both rhizosphere than in bulk soils, together with an increase in dissolved organic C, cation exchange capacity and the Ca/Mg ratio. Ni fractionation indicated a shift towards less stable Ni fractions in the rhizosphere, particularly in the hyperaccumulator. DIFS modelling showed that the rhizosphere of the excluder was able to sustain the initially lower soluble Ni concentration through replenishment from the solid phase, while Ni resupply in the rhizosphere of the hyperaccumulator was not sufficient to maintain the initially high concentrations of soluble Ni. However, the amount of DGT-labile Ni was higher in the rhizosphere of the hyperaccumulator compared to the excluder in all deployment times. Conclusion: Our data suggest that compounds derived from root activity, in particular DOC, are important controls of Ni availability to plants growing on serpentine soil