Antimicrobial activity and phytochemical screening of buchenavia tetraphylla (aubl.) R. A. Howard (combretaceae: combretoideae)

This study evaluated the antimicrobial and hemolytic activities and phytochemical constituents of hydroalcoholic extract and its fractions from Buchenavia tetraphylla leaves. Cyclohexane (BTCF), ethyl acetate (BTEF), and n-butanol-soluble (BTSBF) and non-soluble (BTNBF) fractions were obtained from a liquid-liquid partition of hydroalcoholic extract (BTHE) from B. tetraphylla leaves. The hemolytic activity of active fractions was checked. The BTHE inhibited the growth of Micrococcus luteus (MIC: 0.10 mg/mL), Pseudomonas aeruginosa (MIC: 0.20 mg/mL), Mycobacterium smegmatis (MIC: 0.39 mg/mL), Proteus vulgaris, and Staphylococcus aureus(MIC: 0.78 mg/mL for both). The more active fractions were BTCF and BTBSF. BTCF showed better potential to inhibit M. luteus (0.10 mg/mL), P. aeruginosa (0.20 mg/mL), S. enteritidis (0.39 mg/mL), and S. aureus (1.56 mg/mL). BTBSF showed the best results for M. luteus (0.10 mg/mL), M. smegmatis, B. subtilis (0.39 mg/mL for both), and P. vulgaris (0.10 mg/mL). The HC50 were greater than observed MIC: 20.30, 4.70 and 2.53 mg/mL, respectively, to BTBF, BTHE and BTCF, which. The phytochemical analysis detected the presence of flavanoids, triterpene, carbohydrate, and tannin. Our work showed for the first time the broad-spread antimicrobial activity of B. tetraphylla, which has nonhemolytic action, creating a new perspective on the interesting association of traditional and scientific knowledge

Effects of Alterations in Staphylococcus aureus Cell Membrane and Cell Wall in Antimicrobial Resistance

Staphylococcus aureus is one of the most successful opportunistic pathogen able to cause serious infections due to its ability to produce virulence factors and acquire antimicrobial resistance. Recent reports indicate that the phenotypic changes in the cell wall and cell membrane are essential mechanisms related to the resistance to several antibacterial drugs (such as daptomycin and vancomycin). These alterations involve changes in cell wall composition and chemical modifications of some components (point mutation leading to modification in phosphatidylglycerol molecule, in the production of the aberrations in peptidoglycan structure and decrease in autolytic activity of the components of the cell envelope), leading to changes in electric charge of the cell surface, cell membrane fluidity and cell morphology. In fact, S. aureus develops several multifactorial and strain-specific adaptive mechanisms to survival in host. The study of such mechanisms is very important. The aim of this chapter is to review the phenotypic mechanisms related to drug resistance in S. aureus

SOS Response and Staphylococcus aureus: Implications for Drug Development

Damage in genetic material is induced through the action of several drugs (directly or indirectly). Specially, antimicrobials from quinolone class (such as ciprofloxacin) induce DNA damage that promotes the formation of the RecA filament leading to auto-cleavage of LexA and allows the expression of SOS genes, including the error-prone polymerase (like umuC). The SOS pathway plays a critical role in the acquisition of mutations that lead to the emergence of antibiotic-resistant bacteria and the spread of virulence factors. This chapter provides a comprehensive review about the SOS response of Staphylococcus aureus and the modulatory effects of new compounds (natural or synthetics) on this pathway. The effects of some SOS inhibitors are highlighted such as baicalein and aminocoumarins. Compounds able to prevent SOS response are extremely important to develop new combinatory approaches to inhibit S. aureus mutagenesis. The study of new SOS inductors could reveal new insights into the pathways used by S. aureus to acquire drug resistance; examples of these compounds are the lysine-peptoid hybrid LP5, cyclic peptide inhibitors, etc. These studies can impact the development of new drugs. In conclusion, we hope to provide essential information about the effects of compounds on SOS response from S. aureus

Deaths by COVID-19 in a hospital from a city from Legal Amazon region: what lessons could be learned?

Objetivo: Descrever a epidemiologia de mortes por COVID-19 em um hospital na região da Amazônia em um período de 64 dias, que corresponde à curva de crescimento da primeira onda da pandemia de COVID-19 em 2020. Métodos: Os dados foram obtidos de 152 óbitos registrados em prontuários de adultos e idosos hospitalizados. Os dados foram também comparados com o número de óbitos em anos anteriores, no mesmo período estudado, de forma a avaliar o impacto da pandemia neste hospital. O estudo também avalia o impacto das transferências intra-hospitalares, contabilizando o número de vezes que os pacientes que faleceram realizaram transferências entre setores do hospital. Resultados: No período analisado, houve aumento de óbitos em relação aos anos anteriores. A maioria dos pacientes mortos era do sexo masculino, com idade entre 34 e 96 anos. Os óbitos foram associados a comorbidades como hipertensão arterial, diabetes mellitus e doença renal. A infecção por SARS-CoV-2 foi confirmada em 91 casos. Entre eles, 15 indivíduos foram internados sem condições relacionadas à infecção por SARS-CoV-2; eles tiveram um número três vezes maior de transferências hospitalares do que aqueles admitidos com sintomas de infecção por SARS-CoV-2. Dezesseis pacientes com infecção por SARS-CoV-2 desenvolveram sintomas respiratórios logo após a hospitalização. O exame diagnóstico para infecção por SARS-CoV-2 foi realizado em média 4 (± 6) dias após o início dos sintomas e 6 (± 6) dias após a admissão, e o tempo médio do início dos sintomas respiratórios até o óbito foi de 4 ( ± 6) dias. Conclusões: Esses dados sugerem alta presença de infecção hospitalar por SARS-CoV-2 na região amazônica brasileira, o que pode estar relacionado ao número de transferências setoriais, demora na confirmação do diagnóstico e falta de manejo. Relatamos um grave problema de saúde pública, pois demonstra a fragilidade das instituições de saúde no ambiente hospitalar.Objectives: Describe the epidemiology of COVID-19 deaths within a hospital in the Amazon region in a period of 64 days, which corresponds to the growth curve of the COVID-19 first-wave pandemic in 2020. Methods: The data were obtained from medical records of 152 deaths registered for adults and elderly hospitalized. The data were also compared with the number of deaths in previous years during the same period studied to assess the impact of the pandemic on this hospital. The study also assesses the impact of intra-hospital transfers, accounting for the number of times patients who died performed transfers between sectors of the hospital. Results: During the period analyzed, there was an increase in deaths compared to the previous years. The majority of dead patients were male, aged between 34 and 96 years. The deaths were associated comorbidities such as arterial hypertension, diabetes mellitus, and kidney disease. The SARS-CoV-2 infection was confirmed in 91 cases. Among them, 15 individuals were admitted without conditions related to SARS-CoV-2 infection; they had a three-fold higher number of hospital transfers than those admitted with SARS-CoV-2 infection symptoms. Sixteen patients with SARS-CoV-2 infection developed respiratory symptoms just after hospitalization. The diagnostic exam for SARS-CoV-2 infection was performed on average 4 (± 6) days after the onset of symptoms and 6 (± 6) days after admission, and the average time from the onset of respiratory symptoms to death was 4 (± 6) days. Conclusions: These data suggest the high presence of hospital infection by SARS-CoV-2 in the Brazilian Amazon region, which may be related to the number of sectorial transfers, delay in confirming the diagnosis, and lack of management. We report a serious public health problem, as it demonstrates the fragility of healthcare institutions in the hospital environment

Correlação entre mediadores inflamatórios e marcadores bioquímicos em pacientes com tuberculose pulmonar ativa

Objective: Correlate inflammatory mediators and biochemical parameters in patients with active pulmonary tuberculosis (TB) treated at a public hospital in São Luís, MA. Methods: This is a case-control study of patients with a positivediagnosis of active pulmonary TB. Serum samples from patients and the control group were collected for the clinical trials, and epidemiological data were collected through medical records and interviews. The control group consisted of healthy volunteers with no previous contact with TB cases, matched by age and sex to the clinical group. To measureinflammatory cytokines, we used the Human IL-6 ELISA Set and Human IFN-γ ELISA Set kits. Oxidative stress was measured by quantification of thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO). In biochemistry, the levels of uric acid, anti-streptolysin “O” (AEO), alanine aminotransferase (ALT), amylase, aspartate aminotransferase (AST), calcium, total cholesterol, gamma-glutamyl transferase (Gamma GT), glucose, alkaline phosphatase, high-density lipoprotein (HDL), C-reactive protein (CRP) and triglycerides were measured. Results: The clinical group consisted of 53 patients. There was a substantial decrease in IFN-γ (p<0.0001) and a significant increase in IL-6 (p<0.0001). TBARS production increased significantly (p= 0.0414). There was no significant difference in NO production (p= 0.3194). In biochemistry, there was a significant increase in ALT (p= 0.0072), AST (p= 0.0016), Gamma GT (p= 0.0011), alkaline phosphatase (p<0.0001), CRP (p<0. .0001) and triglycerides (p= 0.0343), and a significant decrease in calcium (p<0.0001). A significant positive correlation was found between IL-6 and IFN-γ (p= 0.0448), as well as AST and ALT (p<0.0001); CRP and gamma GT (p<0.0001); Gamma GT and ALT (p= 0.0016); Gamma GT and AST (p=0.0004); triglycerides and cholesterol (p= 0.0002); alkaline phosphatase and gamma GT (p<0.0001); CRP and alkaline phosphatase (p<0.0001); triglycerides and calcium (p= 0.0121); cholesterol and calcium (p= 0.0261); glucose and cholesterol (p= 0.0373); and triglycerides and glucose (p= 0.0127) in biochemistry, with a significant negative correlation between glucose and uric acid (p= 0.0092); and CRP and HDL (p=0.0037). The correlation between inflammatory mediators and biochemical markers was positive between IL-6 and gamma GT (p= 0.0011); IL-6 and CRP (p<0.0001); IL-6 and alkaline phosphatase (p=0.0076); and NO and triglycerides (p= 0.0016), and significant negative correlation between IFN-γ and cholesterol (p= 0.0171) and TBARS and cholesterol (p= 0.0138). Conclusion: Immunosuppression of IFN-γ activity was observed. A correlation was found between IL-6 and inflammatory biochemical markers, indicating damage and injury caused by M. tuberculosis.Objetivo: Correlacionar mediadores inflamatórios e parâmetros bioquímicos em pacientes com tuberculose (TB) pulmonar ativa atendidos em um hospital público, em São Luís, MA. Métodos: Trata-se um caso-controle de pacientes com diagnóstico positivo para TB pulmonar ativa. Amostras de soro dos pacientes e grupo controle foram coletadas para os experimentos clínicos e os dados epidemiológicos foram coletados por meio de prontuários e entrevistas. O grupo controle foi formado por voluntários saudáveis sem contato prévio com casos de TB, pareados com idade e sexo ao grupo clínico. Para dosar citocinas inflamatórias, utilizaram-se os kits Human IL-6 ELISA Set e Human IFN-γ ELISA Set. Mediu-se o estresse oxidativo pela quantificação das espécies reativas do ácido tiobarbitúrico (TBARS) e óxido nítrico (ON). Na bioquímica, mediram-se os níveis de ácido úrico, anti-estreptolisina-O (AEO),alanina aminotransferase (ALT), amilase, aspartato aminotransferase (AST), cálcio, colesterol total, gama glutamil transferase (Gama GT), glicose, fosfatase alcalina, lipoproteína de alta densidade (HDL), proteína C reativa (PCR) e triglicerídeos. A análise estatística foi realizada pelo software GraphPad Prism 8, com p<0,05 significativo. Resultados:O grupo clínico foi formado por 53 pacientes. Houve uma diminuição significativa de IFN-γ (p<0,0001),e aumento significativo de IL-6 (p<0,0001). A produção de TBARS aumentou significativamente (p= 0,0414). Não houve diferença significativa na produção de ON (p= 0,3194). Na bioquímica, houve aumento significativo em ALT (p= 0,0072), AST (p= 0,0016), gama GT (p= 0,0011), fosfatase alcalina (p<0,0001), PCR (p<0,0001) e triglicerídeos (p= 0,0343), e diminuição significativa de cálcio (p<0,0001). Encontrou-se correlação positiva significativa entre IL-6 e IFN-γ (p= 0,0448), assim como AST e ALT (p<0,0001); PCR e gama GT (p<0,0001); gama GT e ALT (p= 0,0016); gama GT e AST (p= 0,0004); triglicerídeos e colesterol (p= 0,0002); fosfatase alcalina e gama GT (p<0,0001); PCR e fosfatase alcalina (p<0,0001); triglicerídeos e cálcio (p= 0,0121); colesterol e cálcio (p= 0,0261); glicose e colesterol (p= 0,0373); e triglicerídeos e glicose (p= 0,0127) na bioquímica, sendo negativa significativa entre glicose e ácido úrico (p= 0,0092); e PCR e HDL (p= 0,0037). A correlação entre marcadores inflamatório e bioquímicos foi positiva entre IL-6 e gama GT (p= 0,0011); IL-6 e PCR (p<0,0001); IL-6 e fosfatase alcalina (p= 0,0076); e ON e triglicerídeos (p= 0,0016), e negativa significativa entre IFN-γ e colesterol (p= 0,0171) e TBARS e colesterol (p= 0,0138). Conclusões: Observou-se imunossupressão da atividade de IFN-γ. Encontrou-se correlação entre IL-6 e marcadores bioquímicos inflamatórios, indicando dano e lesão causados por M. tuberculosis

Chemical Constituents and Evaluation of Antimicrobial and Cytotoxic Activities of Kielmeyera coriacea

Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL−1). The outer bark and wood EOs showed MICs of 100 µg mL−1 for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest

Evaluation of in vitro Antifungal Activity of Xylosma prockia (Turcz.) Turcz. (Salicaceae) Leaves Against Cryptococcus spp.

Cryptococcus species are responsible for important systemic mycosis and are estimated to cause millions of new cases annually. The available therapy is limited due to the high toxicity and the increasing rates of yeast resistance to antifungal drugs. Popularly known as “sucará,” Xylosma prockia (Turcz.) Turcz. (Salicaceae) is a native plant from Brazil with little information on its pharmacological potential. In this work, we evaluated in vitro anticryptococcal effects of the leaf ethanolic extract of X. prockia and its fractions against Cryptococcus gattii and Cryptococcus neoformans. We also evaluated phenotypic alterations caused by ethyl acetate fraction (EAF) (chosen according to its biological results). The liquid chromatography–mass spectrometry (LC-MS) analysis of EAF demonstrated the presence of phenolic metabolites that belong to three structurally related groups as majority compounds: caffeoylquinic acid, coumaroyl-glucoside, and caffeoyl-glucoside/deoxyhexosyl-caffeoyl glucoside derivatives. The minimum inhibitory concentration (MIC) values against C. gattii and C. neoformans ranged from 8 to 64 mg/L and from 0.5 to 8 mg/L, for ethanolic extract and EAF, respectively. The EAF triggered an oxidative burst and promoted lipid peroxidation. EAF also induced a reduction of ergosterol content in the pathogen cell membrane. These effects were not associated with alterations in the cell surface charge or in the thermodynamic fingerprint of the molecular interaction between EAF and the yeasts evaluated. Cytotoxic experiments with peripheral blood mononuclear cells (PBMCs) demonstrated that EAF was more selective for yeasts than was PBMCs. The results may provide evidence that X. prockia leaf extract might indeed be a potential source of antifungal agents.Fil: Folly, Mariany L. C.. Universidade Federal de Juiz de Fora; BrasilFil: Ferreira, Gabriella F.. Universidade Federal de Juiz de Fora; BrasilFil: Salvador, Maiara R.. Universidade Federal de Juiz de Fora; BrasilFil: Sathler, Ana A.. Universidade Federal de Juiz de Fora; BrasilFil: da Silva, Guilherme F.. Universidade Federal de Juiz de Fora; BrasilFil: Santos, Joice Castelo Branco. Ceuma University; BrasilFil: Santos, Julliana R. A. dos. Ceuma University; BrasilFil: Nunes Neto, Wallace Ribeiro. Ceuma University; BrasilFil: Rodrigues, João Francisco Silva. Ceuma University; BrasilFil: Fernandes, Elizabeth Soares. Ceuma University; BrasilFil: da Silva, Luís Cláudio Nascimento. Ceuma University; BrasilFil: de Freitas, Gustavo José Cota. Universidade Federal de Minas Gerais; BrasilFil: Denadai, Ângelo M.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Rodrigues, Ivanildes V.. Universidade Federal de Juiz de Fora; BrasilFil: Mendonça, Leonardo M.. Universidade Federal de Juiz de Fora; BrasilFil: Monteiro, Andrea Souza. Ceuma University; BrasilFil: Santos, Daniel Assis. Universidade Federal de Minas Gerais; BrasilFil: Cabrera, Gabriela Myriam. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Siless, Gastón Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Lang, Karen L.. Universidade Federal de Juiz de Fora; Brasi

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio