Antibiotic-resistant genes and bacteria as evolving contaminants of emerging concerns (e-CEC): is it time to include evolution in risk assessment?

The pressing issue of the abundance of antibiotic resistance genes and resistant bacteria in the environment (ARGs and ARB, respectively) requires procedures for assessing the risk to health. The chemo-centric environmental risk assessment models identify hazard(s) in a dose–response manner, obtaining exposure, toxicity, risk, impact and policy. However, this risk assessment approach based on ARGs/ARB evaluation from a quantitative viewpoint shows high unpredictability because ARGs/ARB cannot be considered as standard hazardous molecules: ARB duplicate and ARGs evolve within a biological host. ARGs/ARB are currently listed as Contaminants of Emerging Concern (CEC). In light of such characteristics, we propose to define ARGs/ARB within a new category of evolving CEC (or e-CEC). ARGs/ARB, like any other evolving determinants (e.g., viruses, bacteria, genes), escape environmental controls. When they do so, just one molecule left remaining at a control point can form the origin of a new dangerous and selection-responsive population. As a consequence, perhaps it is time to acknowledge this trait and to include evolutionary concepts within modern risk assessment of e-CEC. In this perspective we analyze the evolutionary responses most likely to influence risk assessment, and we speculate on the means by which current methods could measure evolution. Further work is required to implement and exploit such experimental procedures in future risk assessment protocols

The bacterial urban resistome: recent advances

Cities that are densely populated are reservoirs of antibiotic resistant genes (ARGs). The overall presence of all resistance genes in a specific environment is defined as a resistome. Spatial proximity of surfaces and different hygienic conditions leads to the transfer of antibiotic resistant bacteria (ARB) within urban environments. Built environments, public transportation, green spaces, and citizens’ behaviors all support persistence and transfer of antimicrobial resistances (AMR). Various unique aspects of urban settings that promote spread and resilience of ARGs/ARB are discussed: (i) the role of hospitals and recreational parks as reservoirs; (ii) private and public transportation as carriers of ARGs/ARB; (iii) the role of built environments as a hub for horizontal gene transfer even though they support lower microbial biodiversity than outdoor environments; (iv) the need to employ ecological and evolutionary concepts, such as modeling the fate of a specific ARG/ARB, to gain enhanced health risk assessments. Our understanding and our ability to control the rise of AMR in an urban setting is linked to our knowledge of the network connecting urban reservoirs and the environment

Antifungals, arthropods and antifungal resistance prevention: lessons from ecological interactions

Arthropods can produce a wide range of antifungal compounds, including specialist proteins, cuticular products, venoms and haemolymphs. In spite of this, many arthropod taxa, particularly eusocial insects, make use of additional antifungal compounds derived from their mutualistic association with microbes. Because multiple taxa have evolved such mutualisms, it must be assumed that, under certain ecological circumstances, natural selection has favoured them over those relying upon endogenous antifungal compound production. Further, such associations have been shown to persist versus specific pathogenic fungal antagonists for more than 50 million years, suggesting that compounds employed have retained efficacy in spite of the pathogens' capacity to develop resistance. We provide a brief overview of antifungal compounds in the arthropods' armoury, proposing a conceptual model to suggest why their use remains so successful. Fundamental concepts embedded within such a model may suggest strategies by which to reduce the rise of antifungal resistance within the clinical milieu

Time to Clinical Stability in Patients with Ventilator-Associated Pneumonia due to Methicillin-Resistant Staphylococcus aureus Treated with Linezolid versus Vancomycin: Results from the IMPACT-HAP Study

Background: Time to clinical stability is a well-defined early clinical outcome in hospitalized patients with community-acquired pneumonia, but it has not been evaluated in patients with ventilator-associated pneumonia (VAP). The objective of this study was to compare time to clinical stability in patients with MRSA VAP treated with linezolid versus vancomycin. Methods: This was a secondary analysis of the IMPACT-HAP study database. VAP was defined according to CDC criteria. MRSA VAP was considered when MRSA was isolated from a tracheal aspirate or bronchoalveolar lavage. A patient was considered to reach clinical stability the day that the following four criteria were met: 1) Afebrile for 24 hours, 2) Decrease in WBC \u3e10% or WBC within normal range, 3) Improving of PaO2/FiO2 ratio of \u3e 20%, or PaO2/FiO2 ratio \u3e 250, or extubation, or FiO2 ≤ 30% if extubated, and 4) Systolic blood pressure \u3e90 mmHg. Time to clinical stability for linezolid and vancomycin were compared using the Chi-Squared and Student’s t-tests. Results: A total of 89 patients treated with linezolid and 75 patients treated with vancomycin met study criteria. From the population of linezolid treated patients, 79% reached clinical stability, compared to 75% of the population of vancomycin treated patients (P=0.463). Median time to clinical stability was 6 days (IQR 8) for patients treated with linezolid, versus 7 days (IQR 12) for patients treated with vancomycin (P=0.490). Conclusions: This study failed to demonstrate a statistically significant difference in time to clinical stability in patients with MRSA VAP treated with linezolid or vancomycin. The number of days for patients to reach clinical stability can be used as an early clinical outcome in patients with VAP

Sepsis in Patients with Ventilator Associated Pneumonia due to Methicillin- Resistant Staphylococcus aureus: Incidence and Impact on Clinical outcomes

Background: Sepsis is a clinical syndrome associated with organ dysfunction due to a dysregulated host response to infection. Methicillin-resistant Staphylococcus aureus (MRSA) Ventilator-associated pneumonia (VAP) is a serious infection frequently associated with sepsis. The objectives of this study were to define the incidence of sepsis and clinical failure in patients with MRSA VAP. Methods: This was a secondary analysis of the Improving Medicine through Pathway Assessment of Critical Therapy in Hospital-Acquired Pneumonia (IMPACT-HAP) study database. VAP was defined according to CDC criteria. MRSA VAP was considered when MRSA was isolated from a tracheal aspirate or bronchoalveolar lavage. We used the 3rd International Consensus Definitions for sepsis. The presence of clinical failure was evaluated at the 14-day follow-up and defined as: 1) progression of baseline signs and symptoms of pneumonia, or 2) death. The Chi- Square Trend Test was utilized to determine the association between the level of organ dysfunction and clinical failure. Results: MRSA VAP was diagnosed in 205 patients with 138 (67%) presenting with sepsis. Clinical failure occurred in 14% (8/57) of patients without sepsis. Clinical failure occurred in 18% (13/73) of patients with sepsis and 1 organ dysfunction, in 28% (12/43) of patients with sepsis and 2 organ dysfunction, in 28% (5/18) of patients with sepsis and 3 organ dysfunction, and in 100% (4/4) of patients with sepsis and 4 organ dysfunction (p= 0.01). Conclusions: Sepsis is a frequent complication of MRSA VAP and the number of organ dysfunction correlates with clinical failure in these patients. Effective prevention and treatment of sepsis and associated organ dysfunction is essential to avoid cumulative burden of disease in MRSA VAP

Scoping Research Report on Assistive Technology - On The Road For Universal Assistive Technology Coverage

Over one billion people – largely disabled people and older people – are currently in need of Assistive Technology (AT). By 2050, this number is predicted to double. Despite the proven advantages of AT for disabled and older people, their families, and society, there is still a vast and stubborn gap between the need and the supply; currently only 10% of those who need AT currently have access to it. This Scoping Research Report on Assistive Technology (AT) seeks to unpick and understand the multi-layered and multifaceted ways in which economic, social, and political factors interplay and interact to create barriers to AT for those who need it the most. Through primary and secondary research, they explore the current landscape, the limitations, and current initiatives, ultimately answering the question: “How best should a target intervention around AT sphere affect positive change for poor, disabled and older people in Global South priority countries?”. To understand this question, the research team asked two specific questions: What are the barriers which prevent access to AT for the people that need it, with a focus on those living in low resource settings within DFID priority Global South countries? How should DFID, in partnership with others best direct its intervention toward overcoming these barriers? The work reveals that, while levels of AT market development vary across countries, key barriers are common. These barriers can be classified into 5 main categories related to both supply and demand factors and across the 5Ps of People, Products, Provision, Personnel, and Policy. This work is part of the ‘Frontier Technology Livestreaming’ programm