Bartonella spp. in bats from the Brazilian Amazon Forest.

Despite the great diversity of bats (64 species) in the State of Acre, northwestern Brazil, there are no studies on occurrence and diversity of Bartonella spp. in bats in this region. The present study investigated the occurrence and molecular identity of Bartonella spp. in spleen samples (n = 271) from bats of 30 different species from this region, within the Amazon biome. Twenty-one out of 208 (10.1%) samples positive in the PCR for the mammalian gapdh endogenous genes were positive in the qPCR for Bartonella spp. based on the nuoG gene. The two gltA Bartonella genotypes detected grouped with those previously identified in bats from other locations, expanding the diversity of genotypes associated with bats. This study provided the first molecular evidence of the presence of Bartonella spp. in bats in the state of Acre and in bats of the species Lophostoma silvicolum, Vampyressa thyone, Tonatia saurophila and Phyllostomus elongatus.

Advancements in Surfactant Carriers for Enhanced Oil Recovery: Mechanisms, Challenges, and Opportunities.

Enhanced oil recovery (EOR) techniques are crucial for maximizing the extraction of residual oil from mature reservoirs. This review explores the latest advancements in surfactant carriers for EOR, focusing on their mechanisms, challenges, and opportunities. We delve into the role of inorganic nanoparticles, carbon materials, polymers and polymeric surfactants, and supramolecular systems, highlighting their interactions with reservoir rocks and their potential to improve oil recovery rates. The discussion includes the formulation and behavior of nanofluids, the impact of surfactant adsorption on different rock types, and innovative approaches using environmentally friendly materials. Notably, the use of metal oxide nanoparticles, carbon nanotubes, graphene derivatives, and polymeric surfacants and the development of supramolecular complexes for managing surfacant delivery are examined. We address the need for further research to optimize these technologies and overcome current limitations, emphasizing the importance of sustainable and economically viable EOR methods. This review aims to provide a comprehensive understanding of the emerging trends and future directions in surfactant carriers for EOR.

Groundwater quality evaluation of the weathering mantle in crystalline basement aquifer system, southern Brazil.

Groundwater is the main source of water for more than 2 billion people worldwide. In southern Brazil, the Crystalline Basement Aquifer System is composed of strategic groundwater reservoirs. Groundwater is mostly taken from shallow wells, and it is often used without any treatment, which poses a risk to public health. The present study aims to evaluate shallow groundwater quality and the geochemistry of shallow and deep groundwater located in the municipality of Canguçu, southern Brazil. The physicochemical and microbiological parameters of groundwater samples collected from shallow wells were monitored and analyzed using ANOVA variance analysis and water quality index (CCME WQI) approaches. Also, the results were compared with secondary data from deep wells. The monitored shallow wells had thermotolerant coliforms, Escherichia coli, pH, potassium, manganese, iron, and nitrate in disagreement with the guidelines of the World Health Organization. Moreover, variance analysis showed that the parameters temperature, dissolved oxygen, pH, chloride, and magnesium were the most influenced by seasonal variations. According to the CCME WQI, most samples had good quality (60%), 28% had fair quality, and 12% had poor quality. In addition, the field campaigns with higher precipitation rates also presented fair quality. Therefore, most of the shallow groundwater quality is affected by surface pollutants from the urban area, aggravated in rainy periods. Whereas deep groundwater is influenced by geochemistry mechanisms. The results revealed the risk of water consumption for public health and the urgent need for better maintenance of these wells and water treatment implementation.

Clinical and radiographic outcomes of a two-piece ceramic implant: one year results from a prospective clinical trial.

OBJECTIVE: To describe the clinical and radiographic performance and survival rate of a new two-piece ceramic implant system after at least 12 months of follow-up. MATERIALS AND METHODS: Sixty-five implants were placed and followed up for at least 12 months (12.3 ± 1.5), in 50 patients. The implants were installed both in fresh extraction sockets and in healed sites and received provisional restoration when the clinical insertion torque was greater than 35Ncm. The primary results describe the survival rate of these implants. Clinical performance was evaluated through the evaluation of the Pink Esthetic Score (PES) and the degree of satisfaction of the patients. Bone loss was measured through radiographic measurements of the marginal bone loss in the mesial (MBLM) and distal (MBLD) sites. RESULTS: The survival rate was 98.5%. The average MBLM was 0.24 mm (± 0.53) and the MBLD was 0.27 mm (± 0.57). A statistical difference was observed only when comparing immediate implants with delayed ones (MBLM - p = 0.046 and MBLD - p = 0.028) and when they received immediate provisionalization or not (MBLM - p = 0.009 and MBLD - p = 0.040). The PES before the intervention (T0) was 13.4 (± 0.8) and the PES at T2 (12-month follow-up) was 12.9 (± 1.5) (p = 1.14). CONCLUSION: The new two-piece ceramic implant used in the present study showed predictable and reliable results, similar to those found with titanium implants after one year of follow-up. CLINICAL RELEVANCE: These implants can be used as an alternative to titanium implants in terms of the marginal bone loss and the degree of patient satisfaction.

Inspiratory Muscle Training in Phase 1 and 2 Postoperative Cardiac Rehabilitation Following Coronary Artery Bypass Graft Surgery: Systematic Review With Meta-Analysis.

OBJECTIVE: This study aimed to determine the effects of inspiratory muscle training (IMT) on exercise capacity, respiratory muscle strength, length of hospital stay (LOS), and quality of life (QOL) following coronary artery bypass graft surgery. METHODS: The search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook and included the databases MEDLINE, EMBASE, CINAHL, Scopus, and CENTRAL. The review included randomized controlled trials utilizing IMT during phase 1 or 2 postoperative cardiac rehabilitation (PoCR) versus alternative treatment (active or passive control) in patients following coronary artery bypass graft surgery. RESULTS: Fifteen studies were included (11 phase 1 studies, 4 phase 2 studies) with no reported adverse events. In phase 1 PoCR, IMT reduced the LOS (-1.02 days; 95% CI = -2.00 to -0.03) and increased exercise capacity (6-minute walk distance) (+75.46 m; 95% CI = 52.34 to 98.57), and maximal inspiratory pressure (MIP) (10.46 cm H2O; 95% CI = 2.83 to 18.10), but had no effect on maximal expiratory pressure. In phase 2 PoCR, IMT increased 6-minute walk distance (45.84 m; 95% CI = 10.89 to 80.80), MIP (-23.19 cm H2O; 95% CI = -31.31 to -15), maximal expiratory pressure (20.18 cm H2O; 95% CI = 9.60 to 30.76), and QOL (-11.17; 95% CI = -17.98 to -4.36), with no effect on peak oxygen uptake. There was a high risk of bias for MIP (75% of the phase 1 studies) and 6MWT (1 of 4 phase 2 studies). The quality of the evidence ranged from very low to moderate. CONCLUSION: IMT significantly improves exercise capacity, respiratory muscle strength, LOS, and QOL in phase 1 and 2 PoCR. IMPACT: IMT may benefit patients during phase 1 and 2 of PoCR, considering the safety, low cost, and potential benefits.

Substâncias psicoativas: consumo pelos trabalhadores de saúde do sistema de atendimento móvel de urgência / Psychoactive substances: consumption among workers from themobile urgency care system

Objetivo:Avaliar o consumo de substâncias psicoativas por trabalhadores de saúde do Serviço de Atendimento Móvel de Urgência. Métodos: Estudo transversal realizado em um serviço público de saúde localizado numa cidade do Piauí. A coleta de dados se deu de janeiro a março de 2019 por meio da aplicação dos instrumentos em entrevistas pessoais, um com características ocupacionais, sociodemográficas e econômicas e o Alcohol, Smoking and Substance Involvement Screening Test(ASSIST). Os dados foram organizados e processados no software Statistical Package for the Social Sciences(SPSS)(versão 19.0). Resultados:Dos 68 profissionais de saúde,42 eram do sexo masculino, com média de idade de 49,8 anos. Destes, 44 eram casados e 48 católicos. A categoria profissional mais presente foi a de técnicos de enfermagem (46,2%). Dentre estes trabalhadores, o álcool foi a substância psicoativa mais utilizada por 54 profissionais, seguido pelo consumo de tabaco por 25 e de hipnóticos por 8. Destaca-se que o tabaco foi a substância mais utilizada diariamente. Conclusão:O consumo de substâncias psicoativas entre profissionais da saúde mostrou-se presente e pode estar relacionado com a pressão proveniente desses cargos. Chama-se atenção para a importância de ampliar esse debate e discutir a saúde mental de trabalhadores da saúde

Objective:To evaluate the consumption of psychoactive substances by health workers from the Mobile Urgency Care Service. Methods:A cross-sectional study conducted at a Public Health service located in a city in Piauí. Data collection took place from January to March2019 by applying the following instruments in personal interviews: one with occupational, sociodemographic and economic characteristics; and the Alcohol, Smoking and Substance Involvement Screening Test(ASSIST). The data were organized and processed inthe Statistical Package for the Social Sciences(SPSS) software (version19.0). Results:Of the 68 health professionals, 42 were male, with a mean age of 49.8 years old. Among them, 44 were married and 48 were Catholics. The most prevalent professional category was Nursing Technician, accounting for 46.2%. Among these workers, alcohol was themost used psychoactive substance (54 professionals), followed by tobacco consumption (25) and hypnotics (8). It is noted that tobacco was the substance most commonly used on a daily basis. Conclusion:Consumption of psychoactive substances among health professionals was evident and can be related to the pressure resulting from these positions. Attention is drawn to the importance of expanding this debate and addressing health workers' mental health

Silk fibroin-derived electrospun materials for biomedical applications: A review.

Electrospinning is a versatile technique for fabricating polymeric fibers with diameters ranging from micro- to nanoscale, exhibiting multiple morphologies and arrangements. By combining silk fibroin (SF) with synthetic and/or natural polymers, electrospun materials with outstanding biological, chemical, electrical, physical, mechanical, and optical properties can be achieved, fulfilling the evolving biomedical demands. This review highlights the remarkable versatility of SF-derived electrospun materials, specifically focusing on their application in tissue regeneration (including cartilage, cornea, nerves, blood vessels, bones, and skin), disease treatment (such as cancer and diabetes), and the development of controlled drug delivery systems. Additionally, we explore the potential future trends in utilizing these nanofibrous materials for creating intelligent biomaterials, incorporating biosensors and wearable sensors for monitoring human health, and also discuss the bottlenecks for its widespread use. This comprehensive overview illuminates the significant impact and exciting prospects of SF-derived electrospun materials in advancing biomedical research and applications.

Space-time patterns and drivers of migrant bird communities in coastal Piauí State, Brazil

Introduction: Migration is a natural phenomenon that includes annual movements of many bird species in response to seasonal cycles. With approximately one third of all living bird species, South America has an important avifauna, and many migrants land in Brazil at stopping points and wintering sites. Objective: To identify associations between migrant birds and coastal vegetation, and environmental influence of on migration. Methods: At 10 points along the coast of Piauí State, Brazil, we made visual censuses and mist net captures, between April 2009 and February 2016. Results: We identified 82 migrant bird species (13 orders; 28 families) that represented 41 intracontinental migrating species, 26 northern visiting species, 14 nomad species and one vagrant species. The richness peaks were at the beginning and end of both dry and rainy seasons, matching insolation and atmospheric pressure. There were spatial pattern differences among vegetation complexes. Chrysolampis mosquitus is an indicator of caatinga vegetation, Numenius phaeopus of wetland, Charadrius collaris of non-flooding fields, Rostrhamus sociabilis of forest-grassland transition, and Columbina picui of orchards. Despite differences in number and species composition within vegetation types, the temporal pattern in species richness was similar among flooded fields, non-flooded fields, and transition grassland categories. Conclusions: Migrant birds occupy specific environments during their permanence along the coast of Piauí State, with richness matching insolation and atmospheric pressure.

Introducción: La migración es un fenómeno natural que incluye los movimientos anuales de muchas especies de aves en respuesta a los ciclos estacionales. Con aproximadamente un tercio de todas las especies de aves conocidas, América del Sur tiene una avifauna importante y muchas aves migratorias tienen puntos de parada e invernada en Brasil. Objetivo: Identificar asociaciones entre las aves migratorias y la vegetación costera, y la influencia del medio ambiente en la migración. Métodos: En 10 puntos a lo largo de la costa del Estado de Piauí, Brasil, realizamos censos visuales y capturas con redes de niebla, entre abril 2009 y febrero 2016. Resultados: Identificamos 82 especies de aves migratorias (13 órdenes; 28 familias) que representaron 41 especies migratorias intracontinentales, 26 especies visitantes del norte, 14 especies nómadas y una especie vagante. Los picos de riqueza se dieron al principio y al final de las estaciones seca y lluviosa, coincidiendo con la insolación y la presión atmosférica. Hubo diferencias en el patrón espacial entre los complejos de vegetación. Chrysolampis mosquitus es un indicador de vegetación de caatinga, Numenius phaeopus de humedales, Charadrius collaris de campos que no se inundan, Rostrhamus sociabilis de transición bosque-pastizales y Columbina picui de huertos. A pesar de las diferencias en el número y composición de especies dentro de los tipos de vegetación, el patrón temporal en la riqueza de especies fue similar entre las categorías de campos inundados, campos no inundados y pastizales de transición. Conclusiones: Las aves migratorias ocupan ambientes específicos durante su permanencia a lo largo de la costa del estado de Piauí, con una riqueza acorde con la insolación y la presión atmosférica.

Patient-specific modeling for guided rehabilitation of stroke patients: the BrainX3 use-case.

BrainX3 is an interactive neuroinformatics platform that has been thoughtfully designed to support neuroscientists and clinicians with the visualization, analysis, and simulation of human neuroimaging, electrophysiological data, and brain models. The platform is intended to facilitate research and clinical use cases, with a focus on personalized medicine diagnostics, prognostics, and intervention decisions. BrainX3 is designed to provide an intuitive user experience and is equipped to handle different data types and 3D visualizations. To enhance patient-based analysis, and in keeping with the principles of personalized medicine, we propose a framework that can assist clinicians in identifying lesions and making patient-specific intervention decisions. To this end, we are developing an AI-based model for lesion identification, along with a mapping of tract information. By leveraging the patient's lesion information, we can gain valuable insights into the structural damage caused by the lesion. Furthermore, constraining whole-brain models with patient-specific disconnection masks can allow for the detection of mesoscale excitatory-inhibitory imbalances that cause disruptions in macroscale network properties. Finally, such information has the potential to guide neuromodulation approaches, assisting in the choice of candidate targets for stimulation techniques such as Transcranial Ultrasound Stimulation (TUS), which modulate E-I balance, potentiating cortical reorganization and the restoration of the dynamics and functionality disrupted due to the lesion.

Redefining stroke rehabilitation: Mobilizing the embodied goal-oriented brain.

Advancements in stroke rehabilitation remain limited and call for a reorientation. Based on recent results, this study proposes a network-centric perspective on stroke, positing that it not only causes localized deficits but also affects the brain's intricate network of networks, transiting it into a pathological state. Translating these system-level insights into interventions requires brain theory, and the Distributed Adaptive Control (DAC) theory offers such a framework. When applied in the rehabilitation gaming system, these principles demonstrate superior results over conventional methods. This impact stems from activating extensive brain networks, particularly the executive control network, focused motor learning, and maintaining excitatory-inhibitory balance, which is essential for neural repair and functional reorganization. The analysis stresses uniting preclinical and clinical research and placing the architecture of the embodied volitional brain at the centre of rehabilitation approaches.

Recent Progress in Stimuli-Responsive Antimicrobial Electrospun Nanofibers.

Electrospun nanofibrous membranes have garnered significant attention in antimicrobial applications, owing to their intricate three-dimensional network that confers an interconnected porous structure, high specific surface area, and tunable physicochemical properties, as well as their notable capacity for loading and sustained release of antimicrobial agents. Tailoring polymer or hybrid-based nanofibrous membranes with stimuli-responsive characteristics further enhances their versatility, enabling them to exhibit broad-spectrum or specific activity against diverse microorganisms. In this review, we elucidate the pivotal advancements achieved in the realm of stimuli-responsive antimicrobial electrospun nanofibers operating by light, temperature, pH, humidity, and electric field, among others. We provide a concise introduction to the strategies employed to design smart electrospun nanofibers with antimicrobial properties. The core section of our review spotlights recent progress in electrospun nanofiber-based systems triggered by single- and multi-stimuli. Within each stimulus category, we explore recent examples of nanofibers based on different polymers and antimicrobial agents. Finally, we delve into the constraints and future directions of stimuli-responsive nanofibrous materials, paving the way for their wider application spectrum and catalyzing progress toward industrial utilization.

Zwitterionic "Solutions" for Reversible CO2 Capture.

The zwitterions resulting from the covalent attachment of 3- or 4-hydroxy benzene to the 1,3-dimethylimidazolium cation represent basic compounds (pKa of 8.68 and 8.99 in aqueous solutions, respectively) that chemisorb in aqueous solutions 0.58 mol/mol of carbon dioxide at 1.3 bar (absolute) and 40 °C. Equimolar amounts of chemisorbed CO2 in these solutions are obtained at 10 bar and 40 °C. Chemisorption takes place through the formation of bicarbonate in the aqueous solution using imidazolium-containing phenolate. CO2 is liberated by simple pressure relief and heating, regenerating the base. The enthalpy of absorption was estimated to be -38 kJ/mol, which is about 30 % lower than the enthalpy of industrially employed aqueous solutions of MDEA (estimated at -53 kJ/mol using the same experimental apparatus). The physisorption of CO2 becomes relevant at higher pressures (>10 bar) in these aqueous solutions. Combined physio- and chemisorption of up to 1.3 mol/mol at 40 bar and 40 °C can be attained with these aqueous zwitterionic solutions that are thermally stable and can be recycled at least 20 times.

Single laboratory evaluation of umbilical cord blood units processing methodologies for banking.

OBJECTIVE: To compare the efficiency of 3 different processing methods (Sepax, AutoXpress [AXP], and manual processing with hydroxyethyl starch [HES] sedimentation) used at Stemlab during a 10-year period. METHODS: Historical data were compiled and the analytical results obtained for the 3 different methods were compared. RESULTS: The manual processing (HES) method yielded the highest level of total nucleated cell recovery after processing, and the AXP system yielded the highest CD34+ cell number. The red blood cell reduction was also significantly higher with the HES method. Also, HES showed comparable results to Toticyte technology for umbilical cord blood (UCB) processing. CONCLUSION: These results show that the HES method is as effective as automated technologies for UCB volume reduction; hence, it is a suitable methodology for private and public UCB banks. The HES method also proved to be superior to Toticyte technology for medical applications, with higher recovery yields of total nucleated cells after thawing and equivalent CD34+ cell recovery and functionality.

Multiscale effects of excitatory-inhibitory homeostasis in lesioned cortical networks: A computational study.

Stroke-related disruptions in functional connectivity (FC) often spread beyond lesioned areas and, given the localized nature of lesions, it is unclear how the recovery of FC is orchestrated on a global scale. Since recovery is accompanied by long-term changes in excitability, we propose excitatory-inhibitory (E-I) homeostasis as a driving mechanism. We present a large-scale model of the neocortex, with synaptic scaling of local inhibition, showing how E-I homeostasis can drive the post-lesion restoration of FC and linking it to changes in excitability. We show that functional networks could reorganize to recover disrupted modularity and small-worldness, but not network dynamics, suggesting the need to consider forms of plasticity beyond synaptic scaling of inhibition. On average, we observed widespread increases in excitability, with the emergence of complex lesion-dependent patterns related to biomarkers of relevant side effects of stroke, such as epilepsy, depression and chronic pain. In summary, our results show that the effects of E-I homeostasis extend beyond local E-I balance, driving the restoration of global properties of FC, and relating to post-stroke symptomatology. Therefore, we suggest the framework of E-I homeostasis as a relevant theoretical foundation for the study of stroke recovery and for understanding the emergence of meaningful features of FC from local dynamics.

Multi-modal and multi-model interrogation of large-scale functional brain networks.

Existing whole-brain models are generally tailored to the modelling of a particular data modality (e.g., fMRI or MEG/EEG). We propose that despite the differing aspects of neural activity each modality captures, they originate from shared network dynamics. Building on the universal principles of self-organising delay-coupled nonlinear systems, we aim to link distinct features of brain activity - captured across modalities - to the dynamics unfolding on a macroscopic structural connectome. To jointly predict connectivity, spatiotemporal and transient features of distinct signal modalities, we consider two large-scale models - the Stuart Landau and Wilson and Cowan models - which generate short-lived 40 Hz oscillations with varying levels of realism. To this end, we measure features of functional connectivity and metastable oscillatory modes (MOMs) in fMRI and MEG signals - and compare them against simulated data. We show that both models can represent MEG functional connectivity (FC), functional connectivity dynamics (FCD) and generate MOMs to a comparable degree. This is achieved by adjusting the global coupling and mean conduction time delay and, in the WC model, through the inclusion of balance between excitation and inhibition. For both models, the omission of delays dramatically decreased the performance. For fMRI, the SL model performed worse for FCD and MOMs, highlighting the importance of balanced dynamics for the emergence of spatiotemporal and transient patterns of ultra-slow dynamics. Notably, optimal working points varied across modalities and no model was able to achieve a correlation with empirical FC higher than 0.4 across modalities for the same set of parameters. Nonetheless, both displayed the emergence of FC patterns that extended beyond the constraints of the anatomical structure. Finally, we show that both models can generate MOMs with empirical-like properties such as size (number of brain regions engaging in a mode) and duration (continuous time interval during which a mode appears). Our results demonstrate the emergence of static and dynamic properties of neural activity at different timescales from networks of delay-coupled oscillators at 40 Hz. Given the higher dependence of simulated FC on the underlying structural connectivity, we suggest that mesoscale heterogeneities in neural circuitry may be critical for the emergence of parallel cross-modal functional networks and should be accounted for in future modelling endeavours.

An Experimental Analysis on Multicepstral Projection Representation Strategies for Dysphonia Detection.

Biometrics-based authentication has become the most well-established form of user recognition in systems that demand a certain level of security. For example, the most commonplace social activities stand out, such as access to the work environment or to one's own bank account. Among all biometrics, voice receives special attention due to factors such as ease of collection, the low cost of reading devices, and the high quantity of literature and software packages available for use. However, these biometrics may have the ability to represent the individual impaired by the phenomenon known as dysphonia, which consists of a change in the sound signal due to some disease that acts on the vocal apparatus. As a consequence, for example, a user with the flu may not be properly authenticated by the recognition system. Therefore, it is important that automatic voice dysphonia detection techniques be developed. In this work, we propose a new framework based on the representation of the voice signal by the multiple projection of cepstral coefficients to promote the detection of dysphonic alterations in the voice through machine learning techniques. Most of the best-known cepstral coefficient extraction techniques in the literature are mapped and analyzed separately and together with measures related to the fundamental frequency of the voice signal, and its representation capacity is evaluated on three classifiers. Finally, the experiments on a subset of the Saarbruecken Voice Database prove the effectiveness of the proposed material in detecting the presence of dysphonia in the voice.

Umbilical-Cord-Derived Mesenchymal Stromal Cells Modulate 26 Out of 41 T Cell Subsets from Systemic Sclerosis Patients.

Systemic sclerosis (SSc) is an immune-mediated disease wherein T cells are particularly implicated, presenting a poor prognosis and limited therapeutic options. Thus, mesenchymal-stem/stromal-cell (MSC)-based therapies can be of great benefit to SSc patients given their immunomodulatory, anti-fibrotic, and pro-angiogenic potential, which is associated with low toxicity. In this study, peripheral blood mononuclear cells from healthy individuals (HC, n = 6) and SSc patients (n = 9) were co-cultured with MSCs in order to assess how MSCs affected the activation and polarization of 58 different T cell subsets, including Th1, Th17, and Treg. It was found that MSCs downregulated the activation of 26 out of the 41 T cell subsets identified within CD4+, CD8+, CD4+CD8+, CD4-CD8-, and γδ T cells in SSc patients (HC: 29/42) and affected the polarization of 13 out of 58 T cell subsets in SSc patients (HC: 22/64). Interestingly, SSc patients displayed some T cell subsets with an increased activation status and MSCs were able to downregulate all of them. This study provides a wide-ranging perspective of how MSCs affect T cells, including minor subsets. The ability to inhibit the activation and modulate the polarization of several T cell subsets, including those implicated in SSc's pathogenesis, further supports the potential of MSC-based therapies to regulate T cells in a disease whose onset/development may be due to immune system's malfunction.

In vitro and in silico antibacterial evaluation of coumarin derivatives against MDR strains of Staphylococcus aureus and Escherichia coli.

The increase in antibiotic resistance rates has attracted the interest of researchers for antibacterial compounds capable of potentiating the activity of conventional antibiotics. Coumarin derivatives have been reported to develop effective antibacterials with possible new mechanisms of action for treating infectious diseases caused by bacteria with a profile of drug resistance. In this context, the aim of the present study we have now prepared one variety of new synthetic coumarins evaluating the pharmacokinetic and chemical similarity in silico, their antimicrobial activity against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), and potential for the modulation of antibiotic resistance against Staphylococcus aureus (SA10) and Escherichia coli (EC06) clinical isolate bacteria by in vitro assay. The antibacterial activity and antibiotic-enhancing properties were evaluated by the broth microdilution method and pharmacokinetically characterized according to the Lipinsk rule of 5 and had their similarity analyzed in databases such as ChemBL and CAS SciFinder. The results demonstrated that only compound C13 showed significant antibacterial activity (MIC ≤256 µg/mL), and all other coumarins did not display relevant antibacterial activity (MIC ≥1024 µg/mL). However, they did modulate the antibiotics activities to norfloxacin and gentamicin, except, compound C11 to norfloxacin against Staphylococcus aureus (SA10). The in silico properties prediction and drug-likeness results demonstrated that all coumarins presented a good drug-likeness score with no violations and promising in silico pharmacokinetic profiles showing that they have the potential to be developed into an oral drug. The results indicate that the coumarin derivatives showed good in vitro antibacterial activity. These new coumarin derivatives also demonstrated the capacity to modulate antibiotic resistance with potential synergy action for current antimicrobials assayed, as antibiotic adjuvants, to reduce the emergence of antimicrobial resistance.

Photobiological effect of eugenol-derived 3-benzoylcoumarin associated with led lights against MDR microorganisms.

The problem of antibiotic resistance by bacteria threatens human health. Therefore, studies in this area seek alternatives to circumvent it. The study with coumarins and eugenol has already proven that these classes of compounds act against bacteria. In this same aspect, exposure to LED also shows a bactericidal effect. Seeking a possible enhancement of this effect, the present work studied coumarins derived from eugenol in association with LED to investigate the bactericidal effect. Four compounds were tested. For this, minimum inhibitory concentrations (MICs) and modulation with three antibiotics against Escherichia coli and Staphylococcus aureus bacteria were determined. To test the behavior of the activity against exposure to LED, the plates were exposed for 20 min to blue light, 415 nm and then incubated at 37°C for 24 h. For control, duplicates were made, and one of them did not undergo this exposure. C1 exhibited better activity against S. aureus, as synergism prevailed under the conditions tested. C3 and C4 were promising against E. coli as they showed synergism in association with the three antibiotics both with and without LED exposure. Thus, the compounds showed bactericidal activity, and LED was shown to enhance synergism.