Evaluation of Antibacterial Activity of Bismuth Ferrites Nanoparticles in the inhibition of E. coli and S. aureus bacteria.

In this work, bismuth ferrites (BFO) nanoparticles were produced in the form of using sol-gel technique, followed by annealing in a tube furnace in temperatures from 400 °C to 650 ºC. X-ray diffraction (XRD) results showed the formation of small sizes nanoparticles (NPs) with high purity. Structural analysis displayed that annealing at 600 ºC could make BFO NPs be fitted to rhombohedral space group (R3c), with small quantity of spurious phases. The sizes of the BFO nanoparticles determined by transmission electron microscopy (HRTEM) are between 50 to 100 nm. To evaluate the efficiency of BFO in antimicrobial susceptibility tests, the nanoparticles were dispersed through nanoemulsion and tested agar diffusion method and dilution in a 96 well plate using a Gram positive strains (Staphylococcus aureus) and Gram negative strain (Escherichia coli). The antibacterial activity of the BFO NPs was partially tested at concentrations of 2 mg/mL with MIC greater than 60 µg/mL for both bacteria.

Synthesis, characterization, and evaluation of antibacterial activity of transition metal oxyde nanoparticles.

Nanoparticles (NPs) have a wide range of applications in various areas. For health application, cytotoxicity tests are used to ensure its efficiency and safety. In this paper, ZnFe2O4, CoFe2O4, Zn0.5Co0.5Fe2O4 NPs were synthesized, characterized and their antibacterial properties were evaluated. The Sol-Gel method was used to synthesize the NPs. Their electronic and crystallographic structures were characterized by Fourier Transform Infrared Spectroscopy Analysis (FTIR), X-ray fluorescence (XRF), X-Ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). To perform the antibacterial evaluation, ferrites were dispersed through nanoemulsion to prevent the crystals from accumulating together. Then the evaluation was performed through microdilution in a 96-well plate and diffusion in agar disc in contact with 3 different strains of Staphylococcus aureus and Escherichia coli. It demonstrated that the Sol-Gel method was efficient to synthesize NPs with suitable sizes for health application. All synthesized NPs showed the inhibition of bacterias with different concentrations used.

The emergence of SARS, MERS and novel SARS-2 coronaviruses in the 21st century.

At the beginning of the 21st century, a new deadly infectious disease known as severe acute respiratory syndrome (SARS) was recognized as a global public health threat. Subsequently, ten years after the initial SARS cases occurred in 2002, new cases of another atypical respiratory disease caused worldwide concern. This disease became known as Middle East respiratory syndrome (MERS) and was even more lethal than SARS. Currently, history has repeated itself with the emergence of a new Chinese epidemic at the end of 2019. For this respiratory disease, called COVID-19, a novel coronavirus (SARS-CoV-2) was identified as the etiologic agent. In sum, SARS, MERS and COVID-19 are caused by recently discovered coronaviruses that cause flu-like illnesses, but with a clinical outcome that tends to be more severe. As a result of the current importance of coronaviruses in global public health, we conducted a review to summarize and update, above all, the epidemiological historical aspects of the three major diseases in humans caused by coronaviral infection.

The role of mitochondrial DNA damage at skeletal muscle oxidative stress on the development of type 2 diabetes.

Reduced cellular response to insulin in skeletal muscle is one of the major components of the development of type 2 diabetes (T2D). Mitochondrial dysfunction involves in the accumulation of toxic reactive oxygen species (ROS) that leads to insulin resistance. The aim of this study was to verify the involvement of mitochondrial DNA damage at ROS generation in skeletal muscle during development of T2D. Wistar rats were fed a diet containing 60% fat over 8 weeks and at day 14 a single injection of STZ (25 mg/kg) was administered (T2D-induced). Control rats received standard food and an injection of citrate buffer. Blood and soleus muscle were collected. Abdominal fat was quantified as well as glucose, triglyceride, LDL, HDL, and total cholesterol in plasma and mtDNA copy number, cytochrome b (cytb) mRNA, 8-hydroxyguanosine, and 8-isoprostane (a marker of ROS) in soleus muscle. T2D-induced animal presented similar characteristics to humans that develop T2D such as changes in blood glucose, abdominal fat, LDL, HDL and cholesterol total. In soleus muscle 8-isoprostane, mtDNA copy number and 8-hydroxyguanosine were increased, while cytb mRNA was decreased in T2D. Our results suggest that in the development of T2D, when risks factors of T2D are present, intracellular oxidative stress increases in skeletal muscle and is associated with a decrease in cytb transcription. To overcome this process mtDNA increased but due to the proximity of ROS generation, mtDNA remains damaged by oxidation leading to an increase in ROS in a vicious cycle accounting to the development of insulin resistance and further T2D.

First complete genome sequence and molecular characterization of Canine morbillivirus isolated in Central Brazil.

The Brazilian regions are still highly endemic areas for Canine morbillivirus [canine distemper virus (CDV)]. However, little is known regarding the genetic variability of the strain circulating in several Brazilian regions. Here, we report the first full-length genome and molecular characterization of CDV isolated from domestic dogs in the Brazilian Center-West region. Sequence alignment and phylogenetic analyses based on deduced amino acid and nucleotide sequences showed that the isolated strain is characterized as the South America-I/Europe genotype. However, it segregates into a CDV subgenotype branch. Interestingly, both H and F proteins have a gain of a potential N-glycosylation sites compared to the Onderstepoort vaccine strain. Therefore, this study provides a reference to further understand the epidemic and molecular characteristics of the CDV in Brazil.

Rocio Virus: An Updated View on an Elusive Flavivirus.

Rocio virus (ROCV) is a mosquito-borne flavivirus and human pathogen. The virus is indigenous to Brazil and was first detected in 1975 in the Sao Paulo State, and over a period of two years was responsible for several epidemics of meningoencephalitis in coastal communities leading to over 100 deaths. The vast majority of ROCV infections are believed to be subclinical and clinical manifestations can range from uncomplicated fever to fatal meningoencephalitis. Birds are the natural reservoir and amplification hosts and ROCV is maintained in nature in a mosquito-bird-mosquito transmission cycle, primarily involving Psorophora ferox mosquitoes. While ROCV has remained mostly undetected since 1976, in 2011 it re-emerged in Goiás State causing a limited outbreak. Control of ROCV outbreaks depends on sustainable vector control measures and public education. To date there is no specific treatment or licensed vaccine available. Here we provide an overview of the ecology, transmission cycles, epidemiology, pathogenesis, and treatment options, aiming to improve our ability to understand, predict, and ideally avert further ROCV emergence.

Association of -308G/A polymorphism in the tumor necrosis factor-alpha gene promoter with susceptibility to development of hantavirus cardiopulmonary syndrome in the Ribeirão Preto region, Brazil.

Activation of the immune response in hantavirus cardiopulmonary syndrome (HCPS) leads to a high TNF production, probably contributing to the disease. The polymorphic TNF2 allele (TNF -308G/A) has been associated with increased cytokine production. We investigated the association of the TNF2 allele with the outcome of hantavirus infection in Brazilian patients. A total of 122 hantavirus-exposed individuals (26 presenting HCPS and 96 only hantavirus seroconversion) were studied. The TNF2 allele was more frequently found in HCPS patients than in individuals with positive serology for hantavirus but without a history of HCPS illness, suggesting that the TNF2 allele could represent a risk factor for developing HCPS.

Comparative epidemiology between the 2009 H1N1 influenza and COVID-19 pandemics.

In a short time, humanity has experienced two pandemics: the influenza A virus pandemic (pH1N1) in 2009 and the coronavirus disease 2019 (COVID-19) pandemic in 2020. Therefore, it is likely that the general population will erroneously seek to compare the two pandemics and adopt similar attitudes in facing them. However, the two pandemics have their intrinsic characteristics that distinguish them considerably; for example, the virulence of the infectious agents and the availability of treatment and vaccine. Consequently, given this knowledge gap between the pH1N1 and COVID-19 pandemics, we conducted this review to clarify and summarize, above all, the epidemiological historical aspects of these two viruses of great importance to global public health.

Dynamic behavior of Dengue and Zika viruses NS1 protein reveals monomer-monomer interaction mechanisms and insights to rational drug design.

Communicated by Ramaswamy H. Sarma.

Glutathione s-transferase variants in a brazilian population.

Recent pharmacogenomic studies have revealed significant interethnic differences in glutathione S-transferase (GST) allelic frequencies among various ethnic groups. Therefore, we have investigated GSTM1 (gene deletion), GSTT1 (gene deletion) and GSTP1 (rs1695) polymorphism frequencies in 3 Brazilian ethnic groups (n = 203). GSTM1 and GSTT1 polymorphism analyses were performed by multiplex polymerase chain reaction, and GSTP1 (rs1695) analysis was done by polymerase chain reaction restriction fragment length polymorphism. GSTM1- polymorphism frequency was 33.2%, while GSTT1 null (GSTT1-) was 30.2%. The valine GSTP1*B (rs1695) allele was present in 35.1% subjects, while the heterozygous form (isoleucine/valine) was the most prevalent genotype (46.6%). We found a statistically significant difference in genotype frequency among Amerindians versus Caucasians (p = 0.016) and among Amerindians versus African-Americans (p = 0.033). Considerable frequency variation was found in our study, even when compared with other studies showing phylogeographical heterogeneity to the genes studied in Brazilian populations.

Mutation of critical residues reveals insights of yellow fever virus nonstructural protein 1 (NS1) stability and its formation.

Communicated by Ramaswamy H. Sarma.

Prediction of MAYV peptide antigens for immunodiagnostic tests by immunoinformatics and molecular dynamics simulations.

The Mayaro virus is endemic to South America, and the possible involvement of Aedes spp. mosquitoes in its transmission is a risk factor for outbreaks of greater proportions. The virus causes a potentially disabling illness known as Mayaro fever, which is similar to that caused by the chikungunya virus. The cocirculation of both viruses, with their clinical and structural similarities, and the absence of prophylactic and therapeutic measures highlight the need for studies that seek to understand the Mayaro virus. Using approaches in silico, we identified an antigenic and specific epitope (p_MAYV4) in domain A of the E2 glycoprotein of the Mayaro virus. This epitope was theoretically predicted to be stable and exposed on the surface of the protein, where it showed key properties that enable its interaction with neutralizing antibodies. These characteristics make it an interesting target for the development of immunodiagnostic platforms. Molecular dynamics simulation-based structural analysis showed that the PHE95 residue in the E1 fusion loop region is conserved among Alphavirus family members. PHE95 interacts with the hydrophobic residues of the E2 glycoprotein to form a cage-shaped structure that is critical to assemble and stabilize the E1/E2 heterodimer. These results provide important insights useful for the advancement of diagnostic platforms and the study of therapeutic alternatives.

Molecular and serological surveys of canine distemper virus: A meta-analysis of cross-sectional studies.

BACKGROUND: Canine morbillivirus (canine distemper virus, CDV) persists as a serious threat to the health of domestic dogs and wildlife. Although studies have been conducted on the frequency and risk factors associated with CDV infection, there are no comprehensive data on the current epidemiological magnitude in the domestic dog population at regional and national levels. Therefore, we conducted a cross-sectional study and included our results in a meta-analysis to summarize and combine available data on the frequency and potential risk factors associated with CDV infection. METHODS: For the cross-sectional study, biological samples from dogs suspected to have canine distemper (CD) were collected and screened for viral RNA. Briefly, the PRISMA protocol was used for the meta-analysis, and data analyses were performed using STATA IC 13.1 software. RESULTS: CDV RNA was detected in 34% (48/141) of dogs suspected to have CD. Following our meta-analysis, 53 studies were selected for a total of 11,527 dogs. Overall, the pooled frequency of CDV positivity based on molecular and serological results were 33% (95% CI: 23-43) and 46% (95% CI: 36-57), respectively. The pooled subgroup analyses of clinical signs, types of biological samples, diagnostic methods and dog lifestyle had a wide range of CDV positivity (range 8-75%). Free-ranging dogs (OR: 1.44, 95% CI: 1.05-1.97), dogs >24 months old (OR: 1.83, 95% CI: 1.1-3) and unvaccinated dogs (OR: 2.92, 95% CI: 1.26-6.77) were found to be positively associated with CDV infection. In contrast, dogs <12 months old (OR: 0.36, 95% CI: 0.20-0.64) and dogs with a complete anti-CDV vaccination (OR: 0.18, 95% CI: 0.05-0.59) had a negative association. CONCLUSION: Considering the high frequency of CDV positivity associated with almost all the variables analyzed in dogs, it is necessary to immediately and continuously plan mitigation strategies to reduce the CDV prevalence, especially in determined endemic localities.

Role of mixed Th1 and Th2 serum cytokines on pathogenesis and prognosis of hantavirus pulmonary syndrome.

The hantavirus pulmonary syndrome (HPS) is an emerging syndrome in the Americas. The disease results from intense immune activation and changes in vascular permeability. The aim of this study was to determine the profile of serum cytokines in HPS patients looking for correlation with the clinical parameters, severity and outcome of illness. Studying 21 HPS patients, we found that IL-6 may have an important role in the pathogenesis of HPS, being associated with fatal outcome. Our results also support a mixed Th1/Th2 immune response during the course of HPS and that the magnitude of Th1 response effector cytokines is correlated to HPS severity. The decreased levels of TGF-beta observed in HPS patients suggest that immunoregulatory activity could be damaged in these patients.

Natural host relationships and genetic diversity of rodent-associated hantaviruses in southeastern Brazil.

OBJECTIVE: Hantaviruses are rodent-borne RNA viruses that have caused hantavirus cardiopulmonary syndrome in several Brazilian regions. In the present study, geographical distribution, seroprevalence, natural host range, and phylogenetic relations of rodent-associated hantaviruses collected from seven counties of Southeastern Brazil were evaluated. METHODS: ELISA, RT-PCR and phylogenetic analysis were used in this study. RESULTS: Antibodies to hantavirus were detected in Bolomys lasiurus, Akodon sp. and Oligoryzomys sp., performing an overall seroprevalence of 5.17%. All seropositive rodents were associated with grasslands or woods surrounded by sugar cane fields. Phylogenetic analysis of partial S- and M-segment sequences showed that viral sequences isolated from B. lasiurus specimens clustered with Araraquara virus. However, a sequence from Akodon sp. shared 100% similarity with Argentinian/Chilean viruses based on the partial S-segment amino acid sequence. CONCLUSION: These results indicate that there are associations between rodent reservoirs and hantaviruses in some regions of Southeastern Brazil, and suggest the existence of additional hantavirus genetic diversity and host ecology in these areas.

Epidemiological and clinical profile of HIV-infected patients from Southwestern Goias State, Brazil.

Knowledge about epidemiological distribution patterns of HIV infection in different geographic regions is relevant to understand the dynamics of the disease in Brazil. This study aims to characterize the epidemiological and clinical profile of HIV-infected patients from Southwestern Goias State, from 2005 to 2015. A standardized questionnaire was used to collect clinical-epidemiological, virological, and immunological data from the medical records of all HIV-infected patients (n=539) who were followed at the regional reference center of Jatai, Goias State, Brazil, from 2005 to 2015. We detected the prevalence of male patients and the heterosexual route of transmission, as well as an expressive number of young women infected with HIV. The HIV infection was more prevalent in reproductive ages (55.3%). Most patients presented clinical manifestations related to HIV infection at the time of diagnosis. Twenty-four patients presented coinfection with hepatitis C virus, syphilis, hepatitis B virus, leprosy or Chagas disease. Pneumonia caused by Pneumocystis jirovecii was the most common opportunistic infection, followed by neurotoxoplasmosis, tuberculosis, and neurocryptococcosis. Combined antiretroviral therapy improved CD4+ T-cell counts: the mean CD4+ T-cell counts after treatment was twice as high as those found at the first medical appointment; and highly active antiretroviral therapy promoted viral suppression in a significant number of patients. Considering the increasing distribution of HIV infection to the interior of Brazil, this descriptive study outlines the clinical-epidemiological characteristics of HIV infection in Southwestern Goias and contributes to develop local prevention strategies and public service plans.

Seropositivity diagnosis for hantavirus in Jataí, Goiás State, Brazil.

INTRODUCTION:: Emerging diseases are of great interest, especially those associated with high mortality rates such as hantaviruses. We aimed to conduct a seroepidemiological survey to determine the levels of hantavirus infection. METHODS:: In-house enzyme-linked immunosorbent assay (ELISA) was used to detect specific antibodies. RESULTS:: Of the 429 samples collected, seropositivity of 3.9% to anti-hantavirus immunoglobulin G (IgG) was observed (CI 95%: 2.3-5.7). Moreover, in three cases, immunoglobulin M (IgM) was detected, of which two were diagnosed as hantavirus cardiopulmonary syndrome (HCPS). CONCLUSIONS:: Our data indicate the considerable occurrence of previous hantavirus infections, highlighting occurrences from sub-clinical cases to HCPS.

Cross-sectional study on case fatality rate due to hantavirus infection in Goiás State, Brazil, 2007-2013. / Estudo transversal da letalidade da hantavirose no estado de Goiás, 2007-2013.

OBJECTIVE: to describe the epidemiological and clinical profile of hantavirus infection and to analyze factors associated with case-fatality in Goiás, Brazil. METHODS: this was a cross-sectional study on case fatality due to hantavirus infection from 2007 to 2013 using data from the Notifiable Diseases Information System (SINAN) for Goiás State. Logistic regression analysis was performed to estimate odds ratios (OR) with 95% confidence intervals (95%CI). RESULTS: 1,171 suspected cases were reported, of which 73 (6.2%) were confirmed. Among the confirmed cases, greater frequency was found among males (n=50), fever was the most common symptom (n=70), and there was a high proportion of hospitalization (n=68). The case-fatality rate was 57.5% . The following factors were associated with death: acute respiratory failure (ARF) (OR=3.6; 95%CI 1.2;10.6), hemoconcentration (OR=3.3; 95%CI 1.1;7.9) and not using a mechanical ventilator (OR=3.4; 95%CI 1.3;9.1). After adjustment, the ARF was still associated with death (OR=3.4; 95%CI 1.0;11.6). CONCLUSION: the case-fatality rate was high, primarily associated with respiratory failure.

Serological evidence of hantavirus infection in an urban area in Mato Grosso State, Brazil.

INTRODUCTION: In Brazil, Mato Grosso (MT) has the highest number of hantavirus cardiopulmonary syndrome cases. Our study aimed to identify anti-hantavirus antibodies in the sera of patients from Sinop, MT, presenting with acute febrile illness. METHODS: A retrospective analysis of data for 198 sera samples assessed using enzyme-linked immunosorbent assay (ELISA) was conducted. RESULTS: Immunoglobulins G (IgGs) against the hantavirus nucleoprotein were found in 13.6% of the tested sera. No sample had immunoglobulin M (IgM) antibodies to hantavirus. Seropositivity occurred mainly in female residents in urban areas who worked around the household. CONCLUSIONS: Our findings suggest circulation of hantavirus in Sinop.

The effect of exercise on skeletal muscle glucose uptake in type 2 diabetes: An epigenetic perspective.

Changes in eating habits and sedentary lifestyle are main contributors to type 2 diabetes (T2D) development, and studies suggest that epigenetic modifications are involved with the growing incidence of this disease. Regular exercise modulates many intracellular pathways improving insulin resistance and glucose uptake in skeletal muscle, both early abnormalities of T2D. Mitochondria dysfunction and decreased expression of glucose transporter (GLUT4) were identified as main factors of insulin resistance. Moreover, it has been suggested that skeletal muscle of T2D subjects have a different pattern of epigenetic marks on the promoter of GLUT4 and PGC1, main regulator of mitochondrial function, compared with nondiabetic individuals. Recent studies have proposed that regular exercise could improve glucose uptake by the attenuation of such epigenetic modification induced at GLUT4, PGC1 and its downstream regulators; however, the exact mechanism is still to be understood. Herein we review the known epigenetic modifications on GLUT4 and mitochondrial proteins that lead to impairment of skeletal muscle glucose uptake and T2D development, and the effect of physical exercise at these modifications.