An evaluation of conventional and nature-based technologies for controlling antibiotic-resistant bacteria and antibiotic-resistant genes in wastewater treatment plants.

Antibiotic resistance is a globally recognized health concern which leads to longer hospital stays, increased morbidity, increased mortality, and higher medical costs. Understanding how antibiotic resistance persists and exchanges in environmental systems like soil, water, and wastewater are critically important for understanding the emergence of pathogens with new resistance profiles and the subsequent exposure of people who indirectly/directly come in contact with these pathogens. There are concerns about the widespread application of prophylactic antibiotics in the clinical and agriculture sectors, as well as chemicals/detergents used in food and manufacturing industries, especially the quaternary ammonium compounds which have been found responsible for the generation of resistant genes in water and soil. The rates of horizontal gene transfer increase where there is a lack of proper water/wastewater infrastructure, high antibiotic manufacturing industries, or endpoint users - such as hospitals and intensive agriculture. Conventional wastewater treatment technologies are often inefficient in the reduction of ARB/ARGs and provide the perfect combination of conditions for the development of antibiotic resistance. The wastewater discharged from municipal facilities may therefore be enriched with bacterial communities/pathogens and provide a suitable environment (due to the presence of nutrients and other pollutants) to enhance the transfer of antibiotic resistance. However, facilities with tertiary treatment (either traditional/emerging technologies) provide higher rates of reduction. This review provides a synthesis of the current understanding of wastewater treatment and antibiotic resistance, examining the drivers that may accelerate their possible transmission to a different environment, and highlighting the need for tertiary technologies used in treatment plants for the reduction of resistant bacteria/genes.

Exploring the use of water resource recovery facility instrument data to visualise dynamic resilience to environmental stressors.

Water resource recovery facilities (WRRF) face increasingly dynamic stressors, such as higher rainfall intensity and extended dry periods, which can exert stress on ageing water infrastructure and processes. These events can generate process stresses, which lead to wastewater process failures which result in pollution events that could be identified from instrument data used for operational/compliance monitoring. This extraction can be performed on two levels (1) for discrete processes that generate data to monitor process control variables and (2) at the WRRF process boundary (global), which is mainly used for compliance. Both levels of data hold valuable information on the dynamic influence of environmental stressors (cause) and the resulting process stress or resilience (effect) as 'dynamic resilience'. This paper proposes a novel methodology that uses actual water company instrument data to evaluate the 'discrete' (unit processes) and 'global' (WRRF boundary) dynamic resilience of a WRRF in the south of the UK. Dynamic resilience is presented as a four-stage methodology, which; (1) cleans WRRF data and extracts a standard operating condition; (2) identifies dynamic high and low flow environmental stressor events (one in five years); (3) models the process stresses and resilience generated by the imposed dynamic stressor before; (4) generating a contoured heat map of process-related stresses or resilience as a self ordering window. These methods demonstrate the possibility of visualising the dynamics of WRRF resilience (dynamic stressors and process stresses/resilience) resulting from high and low flow dynamic environmental stressors. Despite some challenges experienced with self ordering window scaling, the results demonstrate the possibility of identifying zones of process stress and resilience. It may also be possible to expand the methods developed to incorporate storm flows and combined sewer discharges.

Antibiotics and antibiotic resistant bacteria/genes in urban wastewater: A comparison of their fate in conventional treatment systems and constructed wetlands.

There is a growing concern that the use and misuse of antibiotics can increase the detection of antibiotic resistant genes (ARGs) in wastewater. Conventional wastewater treatment plants provide a pathway for ARGs and antibiotic resistant bacteria (ARB) to be released into natural water bodies. Research has indicated that conventional primary and secondary treatment systems can reduce ARGs/ARB to varying degrees. However, in developing/low-income countries, only 8-28% of wastewater is treated via conventional treatment processes, resulting in the environment being exposed to high levels of ARGs, ARB and pharmaceuticals in raw sewage. The use of constructed wetlands (CWs) has the potential to provide a low-cost solution for wastewater treatment, with respect to removal of nutrients, pathogens, ARB/ARGs either as a standalone treatment process or when integrated with conventional treatment systems. Recently, CWs have also been employed for the reduction of antibiotic residues, pharmaceuticals, and emerging contaminants. Given the benefits of ARG removal, low cost of construction, maintenance, energy requirement, and performance efficiencies, CWs offer a promising solution for developing/low-income countries. This review promotes a better understanding of the performance efficiency of treatment technologies (both conventional systems and CWs) for the reduction of antibiotics and ARGs/ARB from wastewater and explores workable alternatives.

A conceptual framework for a multi-criteria decision support tool to select technologies for resource recovery from urban wastewater.

In the context of circular economy, wastewater can be used to address some of the 21st century's challenges regarding the transition to renewable resources for water, energy, and nutrients. Despite all the research, development, and experience with resource recovery from urban wastewater, its implementation is still limited. The transition from treatment to resource recovery is complex due to the difficulty of selecting unit processes from a large number of candidate processes considering the operational limitations of each process, and sustainability objectives. Presently, a multi-criteria decision support tool that deals with the difficulty of unit process selection for resource recovery from wastewater has not been developed. Therefore, this paper presents the conceptual framework of a decision support tool to find the optimum treatment train consisting of compatible unit processes which can recover water, energy and/or nutrients from a specified influent composition. The framework presents the relationship between the user input, the knowledge library of technologies and a weighted multi-objective nonlinear programming model to aid process selection. The model presented here shows, not only how the processes are selected, but also the four-dimensional sustainability impact of the generated treatment train while considering the weight provided by the user. Thus, this study presents a reproducible framework which can support private and public decision-makers in transparent evidence-based decision making and eventually the systematic implementation of resource recovery from urban wastewater.

Interleukin-1 receptor antagonist: An exploratory plasma biomarker that correlates with disability and provides pathophysiological insights in relapsing-remitting multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disorder. Interleukin-1 receptor antagonist (IL-1RA) is an endogenous soluble antagonist of the IL-1 receptor and blocks the pro-inflammatory effects of IL-1ß known to contribute to MS pathology. The objectives of this study were to determine whether IL-1RA is associated with disability in MS and how this correlates with neurofilament light (NfL) levels in cerebrospinal fluid (CSF). METHODS: Peripheral blood and CSF were collected from consenting MS patients. Patient demographic and clinical variables, including past relapse activity, were also collected. Circulating levels of IL-1RA, IL-18, and IL-1ß were measured in plasma; IL-1RA and NfL were measured in the CSF via Bio-plex multiplex immunoassay kits and ELISA, respectively. IL-1RA expression was investigated in vitro using primary human macrophages and microglia, and in situ using post-mortem MS tissue. RESULTS: Following a multiple regression analysis, IL-1RA levels in plasma correlated with expanded disability status scale score independent of all other variables. In a separate cohort, CSF IL-1RA significantly correlated with NfL. In vitro, induction of the NLRP3 inflammasome, a pathological hallmark within MS lesions, led to increased release of IL-1RA from primary human microglia and macrophages. In the CNS, IL-1RA+ macrophages/microglia were present at the rim of mixed active/inactive MS lesions. CONCLUSIONS: Results presented in this study demonstrate that IL-1RA is a novel exploratory biomarker in relapsing-remitting MS, which correlates with disability and provides mechanistic insights into the regulatory inflammatory responses within the demyelinated CNS.

Male sex chromosomal complement exacerbates the pathogenicity of Th17 cells in a chronic model of central nervous system autoimmunity.

Sex differences in multiple sclerosis (MS) incidence and severity have long been recognized. However, the underlying cellular and molecular mechanisms for why male sex is associated with more aggressive disease remain poorly defined. Using a T cell adoptive transfer model of chronic experimental autoimmune encephalomyelitis (EAE), we find that male Th17 cells induce disease of increased severity relative to female Th17 cells, irrespective of whether transferred to male or female recipients. Throughout the disease course, a greater frequency of male Th17 cells produce IFNγ, a hallmark of pathogenic Th17 responses. Intriguingly, XY chromosomal complement increases the pathogenicity of male Th17 cells. An X-linked immune regulator, Jarid1c, is downregulated in pathogenic male murine Th17 cells, and functional experiments reveal that it represses the severity of Th17-mediated EAE. Furthermore, Jarid1c expression is downregulated in CD4+ T cells from MS-affected individuals. Our data indicate that male sex chromosomal complement critically regulates Th17 cell pathogenicity.

Vigorous cool room treadmill training to improve walking ability in people with multiple sclerosis who use ambulatory assistive devices: a feasibility study.

BACKGROUND: Aerobic training has the potential to restore function, stimulate brain repair, and reduce inflammation in people with Multiple Sclerosis (MS). However, disability, fatigue, and heat sensitivity are major barriers to exercise for people with MS. We aimed to determine the feasibility of conducting vigorous harness-supported treadmill training in a room cooled to 16 °C (10 weeks; 3times/week) and examine the longer-term effects on markers of function, brain repair, and inflammation among those using ambulatory aids. METHODS: Ten participants (9 females) aged 29 to 74 years with an Expanded Disability Status Scale ranging from 6 to 7 underwent training (40 to 65% heart rate reserve) starting at 80% self-selected walking speed. Feasibility of conducting vigorous training was assessed using a checklist, which included attendance rates, number of missed appointments, reasons for not attending, adverse events, safety hazards during training, reasons for dropout, tolerance to training load, subjective reporting of symptom worsening during and after exercise, and physiological responses to exercise. Functional outcomes were assessed before, after, and 3 months after training. Walking ability was measured using Timed 25 Foot Walk test and on an instrumented walkway at both fast and self-selected speeds. Fatigue was measured using fatigue/energy/vitality sub-scale of 36-Item Short-Form (SF-36) Health Survey, Fatigue Severity Scale, modified Fatigue Impact Scale. Aerobic fitness (maximal oxygen consumption) was measured using maximal graded exercise test (GXT). Quality-of-life was measured using SF-36 Health Survey. Serum levels of neurotrophin (brain-derived neurotrophic factor) and cytokine (interleukin-6) were assessed before and after GXT. RESULTS: Eight of the ten participants completed training (attendance rates ≥ 80%). No adverse events were observed. Fast walking speed (cm/s), gait quality (double-support (%)) while walking at self-selected speed, fatigue (modified Fatigue Impact Scale), fitness (maximal workload achieved during GXT), and quality-of-life (physical functioning sub-scale of SF-36) improved significantly after training, and improvements were sustained after 3-months. Improvements in fitness (maximal respiratory exchange ratio and maximal oxygen consumption during GXT) were associated with increased brain-derived neurotrophic factor and decreased interleukin-6. CONCLUSION: Vigorous cool room training is feasible and can potentially improve walking, fatigue, fitness, and quality-of-life among people with moderate to severe MS-related disability. TRIAL REGISTRATION: The study was approved by the Newfoundland and Labrador Health Research Ethics Board (reference number: 2018.088) on 11/07/2018 prior to the enrollment of first participant (retrospectively registered at ClinicalTrials.gov: NCT04066972. Registered on 26 August 2019.

miR-223 promotes regenerative myeloid cell phenotype and function in the demyelinated central nervous system.

In the injured central nervous system, myeloid cells, including macrophages and microglia, are key contributors to both myelin injury and repair. This immense plasticity emphasizes the need to further understand the precise molecular mechanisms that contribute to the dynamic regulation of myeloid cell polarization and function. Herein, we demonstrate that miR-223 is upregulated in multiple sclerosis (MS) patient monocytes and the alternatively-activated and tissue-regenerating M2-polarized human macrophages and microglia. Using miR-223 knock-out mice, we observed that miR-223 is dispensable for maximal pro-inflammatory responses, but is required for efficient M2-associated phenotype and function, including phagocytosis. Using the lysolecithin animal model, we further demonstrate that miR-223 is required to efficiently clear myelin debris and promote remyelination. These results suggest miR-223 constrains neuroinflammation while also promoting repair, a finding of important pathophysiological relevance to MS as well as other neurodegenerative diseases.

Lessons learned from volar plate fixation of scaphoid fracture nonunions.

Treating scaphoid nonunions presents difficulties particularly when there is bone loss, significant humpback deformity or avascular necrosis. We describe a new type of fixation with a volar scaphoid plate that adds to the methods of internal fixation that are available for the treatment of recalcitrant scaphoid nonunions. We will also discuss 'lessons learned' from a cases series. The case series includes 20 consecutive patients treated with volar buttress plating and a pedicled vascularized bone graft from the ipsilateral volar distal radius. There was clinical and radiographic evidence of union in 18 of 20 patients, 13 of which were verified by computed tomographic scan. The range of motion was improved in all patients post-operatively. Four patients with radiographic union experienced intermittent clicking with maximal wrist flexion, believed to be due to the impingement of the plate on the volar aspect of the radioscaphoid articulation and underwent removal at approximately 1 year after the index procedure. Volar scaphoid plating is a useful alternative to headless scaphoid screw fixation in the treatment of unstable scaphoid waist fractures and nonunions. LEVEL OF EVIDENCE: IV.

Effects of fumarates on inflammatory human astrocyte responses and oligodendrocyte differentiation.

OBJECTIVE: Dimethyl fumarate (DMF) is a fumaric acid ester approved for the treatment of relapsing-remitting multiple sclerosis (RRMS). In both the brain and periphery, DMF and its metabolite monomethyl fumarate (MMF) exert anti-inflammatory and antioxidant effects. Our aim was to compare the effects of DMF and MMF on inflammatory and antioxidant pathways within astrocytes, a critical supporting glial cell in the central nervous system (CNS). Direct effects of fumarates on neural progenitor cell (NPC) differentiation toward the oligodendrocyte lineage were also assessed. METHODS: Primary astrocyte cultures were derived from both murine and human brains. Following pretreatment with MMF, DMF, or vehicle, astrocytes were stimulated with IL-1ß for 24 h; gene and microRNA expression were measured by qPCR. Cytokine production and reactive oxygen species (ROS) generation were also measured. NPCs were differentiated into the oligodendrocyte lineage in the presence of fumarates and immunostained using early oligodendrocyte markers. RESULTS: In both murine and human astrocytes, DMF, but not MMF, significantly reduced secretion of IL-6, CXCL10, and CCL2; neither fumarate promoted a robust increase in antioxidant gene expression, although both MMF and DMF prevented intracellular ROS production. Pretreatment with fumarates reduced microRNAs -146a and -155 upon stimulation. In NPC cultures, DMF increased the number of O4+ and NG2+ cells. INTERPRETATION: These results suggest that DMF, and to a lesser extent MMF, mediates the anti-inflammatory effects within astrocytes. This is supported by recent observations that in the inflamed CNS, DMF may be the active compound mediating the anti-inflammatory effects independent from altered antioxidant gene expression.

Pro-inflammatory activation of primary microglia and macrophages increases 18 kDa translocator protein expression in rodents but not humans.

The 18kDa Translocator Protein (TSPO) is the most commonly used tissue-specific marker of inflammation in positron emission tomography (PET) studies. It is expressed in myeloid cells such as microglia and macrophages, and in rodent myeloid cells expression increases with cellular activation. We assessed the effect of myeloid cell activation on TSPO gene expression in both primary human and rodent microglia and macrophages in vitro, and also measured TSPO radioligand binding with 3H-PBR28 in primary human macrophages. As observed previously, we found that TSPO expression increases (∼9-fold) in rodent-derived macrophages and microglia upon pro-inflammatory stimulation. However, TSPO expression does not increase with classical pro-inflammatory activation in primary human microglia (fold change 0.85 [95% CI 0.58-1.12], p = 0.47). In contrast, pro-inflammatory activation of human monocyte-derived macrophages is associated with a reduction of both TSPO gene expression (fold change 0.60 [95% CI 0.45-0.74], p = 0.02) and TSPO binding site abundance (fold change 0.61 [95% CI 0.49-0.73], p < 0.0001). These findings have important implications for understanding the biology of TSPO in activated macrophages and microglia in humans. They are also clinically relevant for the interpretation of PET studies using TSPO targeting radioligands, as they suggest changes in TSPO expression may reflect microglial and macrophage density rather than activation phenotype.

Fate of hydrocarbon pollutants in source and non-source control sustainable drainage systems.

Sustainable drainage (SuDs) is an established method for managing runoff from developments, and source control is part of accepted design philosophy. However, there are limited studies into the contribution source control makes to pollutant removal, especially for roads. This study examines organic pollutants, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), in paired source and non-source control full-scale SuDs systems. Sites were selected to cover local roads, trunk roads and housing developments, with a range of SuDs, including porous asphalt, swales, detention basins and ponds. Soil and water samples were taken bi-monthly over 12 months to assess pollutant loads. Results show first flush patterns in storm events for solids, but not for TPH. The patterns of removal for specific PAHs were also different, reflecting varying physico-chemical properties. The potential of trunk roads for pollution was illustrated by peak runoff for TPH of > 17,000 µg/l. Overall there was no significant difference between pollutant loads from source and non-source control systems, but the dynamic nature of runoff means that longer-term data are required. The outcomes of this project will increase understanding of organic pollutants behaviour in SuDs. This will provide design guidance about the most appropriate systems for treating these pollutants.

Impact of prior irregular infliximab dosing on performance of long-term infliximab maintenance therapy in Crohn's disease.

BACKGROUND: Infliximab is efficacious in the management of moderate to severe Crohn's disease (CD). There are limited data regarding performance of infliximab in patients who require reinitiation of maintenance dosing following previous irregular exposure. METHODS: This was a retrospective, observational study of CD patients treated with maintenance infliximab beyond 3 years. Maintenance infliximab infusion regimens were categorized as scheduled maintenance (SM) (maintenance infusions q < or =8 weeks after loading) or prior irregular (PI) (no loading, gap in therapy >8 weeks prior to or during maintenance therapy). We examined differences in need for medical and surgical hospitalizations as well as associated healthcare costs between the 2 groups. RESULTS: In all, 104 CD patients met criteria for 3-year maintenance infliximab treatment (SM n = 64; PI n = 40). The rates of CD-related surgeries (60.9% and 55.0%, P = not significant [N.S.]) and medical hospitalizations (35.9% and 37.5%, P = N.S.) prior to infliximab initiation was similar between the 2 groups. However, the rate of medical (26.5% versus 47.5%, P = 0.035) and surgical hospitalizations (21.8% versus 48.7%, P = 0.009) were significantly lower in the SM compared to the PI group. During the third year of treatment the excess costs per patient for the PI group compared to the SM group amounted to $11,464 in spite of both cohorts being on SM therapy. CONCLUSIONS: Patients who begin and continue an uninterrupted maintenance dosing regimen had a lower incidence of hospitalization and surgery than those who received an irregular or interrupted regimen prior to beginning an SM regimen.

MRI detection of macrophages labeled using micrometer-sized iron oxide particles.

PURPOSE: To evaluate cellular labeling of immune cells using micron-sized iron oxide particles (MPIOs) and evaluate the MR relaxivity and MRI detection of the labeled cells. MATERIALS AND METHODS: Immune cells isolated from mice and rats were labeled with three different sizes of MPIO particles (0.35, 0.90, or 1.63 microm). These labeled cells were characterized using transmission electron microscopy (TEM), fluorescence microscopy, flow cytometry, MR relaxometry, and MRI. RESULTS: Macrophage uptake of MPIOs was found to be highest for the 1.63-microm size particles. MR relaxivity measurements indicated greater spin-spin relaxation for MPIO-labeled cells relative to cells labeled with nanometer-sized ultra-small superparamagnetic iron oxide (USPIO) particles with similar iron content. TEM and fluorescence microscopy indicated cellular uptake of multiple MPIO particles per cell. Macrophages labeled with 1.63-microm MPIOs had an average cellular iron uptake of 39.1 pg/cell, corresponding to approximately 35 particles per cell. CONCLUSION: Cells labeled with one or more MPIO particles could be readily detected ex vivo at 11.7 Tesla and after infusion of the MPIO-labeled macrophages into the kidney of a rat, hypointense regions of the outer cortex are observed, in vivo, by MRI at 4.7 Tesla.

In situ labeling of immune cells with iron oxide particles: an approach to detect organ rejection by cellular MRI.

In vivo cell tracking by MRI can provide means to observe biological processes and monitor cell therapy directly. Immune cells, e.g., macrophages, play crucial roles in many pathophysiological processes, including organ rejection, inflammation, autoimmune diseases, cancer, atherosclerotic plaque formation, numerous neurological disorders, etc. The current gold standard for diagnosing and staging rejection after organ transplantation is biopsy, which is not only invasive, but also prone to sampling errors. Here, we report a noninvasive approach using MRI to detect graft rejection after solid organ transplantation. In addition, we present the feasibility of imaging individual macrophages in vivo by MRI in a rodent heterotopic working-heart transplantation model using a more sensitive contrast agent, the micrometer-sized paramagnetic iron oxide particle, as a methodology to detect acute cardiac rejection.

Matrix-assisted laser desorption/ionization mass spectrometry of discrete mass poly(butylene glutarate) oligomers.

The mass dependency of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) response has been studied using equimolar mixtures of synthetic discrete mass poly(butylene glutarate) (PBG) oligomers of known structure having degrees of polymerization of 8, 16, 32, and 64. Mass discrimination observed was attributed to choice of matrix and detector saturation caused by higher laser intensity and inclusion of matrix ions in the MALDI spectra. Optimization of sample preparation and instrumental parameters provided uniform response over the mass ranged spanned by these four oligomers. The oligomer mixture was shown to serve as a model of more complex polymer distributions in the mass range 780-6000 Da, and application of the discrete mass oligomers as internal and calibration standards was demonstrated. Inclusion of PBG discrete mass oligomers as an internal standard in a quasi-equimolar mixture with polydispersed poly(butylene adipate) (PBA) indicated that some diminution of response occurred during the analysis of this mixture of materials. Reasons for differences in the corrected molecular weight averages of the polydispersed PBA obtained from measurements using MALDI and GPC were studied using individual discrete mass oligomers as calibration standards for GPC. The data indicated that differences in hydrodynamic volumes of PBG oligomers and PEG standards at similar masses resulted in an overestimation by GPC of the molecular weight averages of the PBA distribution.

Hemodynamic response profile predicts susceptibility to cocaine-induced toxicity.

Cocaine evokes pressor responses due either to a large increase in systemic vascular resistance despite a decrease (>8%) in cardiac output (vascular responders) or to small increases in both cardiac output and vascular resistance (mixed responders) in conscious rats. These studies were designed to determine (1) if the hemodynamic response pattern to cocaine correlates with relative sensitivity to toxicity and (2) if altering the hemodynamic response pattern to cocaine using propranolol enhances toxicity. Rats were instrumented for determination of cardiac output and arterial pressure. After recovery, rats were classified as vascular or mixed responders to cocaine (5 mg/kg, i.v., four to six trials). Two weeks later, cocaine was infused (1.5 mg/kg/min) until death after pretreatment with saline or propranolol (1 mg/kg). Saline-pretreated mixed responders (n=6) had greater tolerance to cocaine toxicity compared to vascular responders (n=11). Furthermore, saline-pretreated vascular responders were less sensitive than propranolol-pretreated vascular responders (n=9) to cocaine toxicity. Therefore, we propose that the initial hemodynamic response pattern to cocaine predicts sensitivity to cocaine toxicity. In addition, propranolol, a drug that enhances the increase in vascular resistance to cocaine, also increases toxicity to cocaine in vascular responders.