RESUMO
Leptospirosis, a neglected zoonotic disease, is caused by pathogenic spirochetes belonging to the genus Leptospira and has one of the highest morbidity and mortality rates worldwide. Vaccination stands out as one of the most effective preventive measures for susceptible populations. Within the outer membrane of Leptospira spp., we find the LIC12287, LIC11711, and LIC13259 lipoproteins. These are of interest due to their surface location and potential immunogenicity. Thorough examination revealed the conservation of these proteins among pathogenic Leptospira spp.; we mapped the distribution of T- and B-cell epitopes along their sequences and assessed the 3D structures of each protein. This information aided in selecting immunodominant regions for the development of a chimeric protein. Through gene synthesis, we successfully constructed a chimeric protein, which was subsequently expressed, purified, and characterized. Hamsters were immunized with the chimeric lipoprotein, formulated with adjuvants aluminum hydroxide, EMULSIGEN®-D, Sigma Adjuvant System®, and Montanide™ ISA206VG. Another group was vaccinated with an inactivated Escherichia coli bacterin expressing the chimeric protein. Following vaccination, hamsters were challenged with a virulent L. interrogans strain. Our evaluation of the humoral immune response revealed the production of IgG antibodies, detectable 28 days after the second dose, in contrast to pre-immune samples and control groups. This demonstrates the potential of the chimeric protein to elicit a robust humoral immune response; however, no protection against challenge was achieved. While this study provides valuable insights into the subject, further research is warranted to identify protective antigens that could be utilized in the development of a leptospirosis vaccine. KEY POINTS: ⢠Several T- and B-cell epitopes were identified in all the three proteins. ⢠Four different adjuvants were used in vaccine formulations. ⢠Immunization stimulated significant levels of IgG2/3 in vaccinated animals.
Assuntos
Anticorpos Antibacterianos , Vacinas Bacterianas , Leptospirose , Lipoproteínas , Animais , Leptospirose/prevenção & controle , Leptospirose/imunologia , Lipoproteínas/imunologia , Lipoproteínas/genética , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/genética , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Cricetinae , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito B/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/genética , Adjuvantes Imunológicos/administração & dosagem , Imunoglobulina G/sangue , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/genética , Leptospira interrogans/imunologia , Leptospira interrogans/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/genética , Vacinação , Imunidade Humoral , Leptospira/imunologia , Leptospira/genética , Imunogenicidade da VacinaRESUMO
In the last 20 years, various research groups have endeavored to develop recombinant vaccines against leptospirosis to overcome the limitations of commercially available bacterins. Numerous antigens and vaccine formulations have been tested thus far. However, the analysis of cellular response in these vaccine formulations is not commonly conducted, primarily due to the scarcity of supplies and kits for the hamster animal model. Our research group has already tested the Q1 antigen, a chimeric protein combining the immunogenic regions of LipL32, LemA, and LigANI, in recombinant subunit and BCG-vectored vaccines. In both strategies, 100 % of the hamsters were protected against clinical signs of leptospirosis. However, only the recombinant BCG-vectored vaccine provided protection against renal colonization. Thus, the objective of this study is to characterize the cellular immune response in hamsters immunized with different vaccine formulations based on the Q1 antigen through transcriptional analysis of cytokines. The hamsters were allocated into groups and vaccinated as follows: recombinant subunit (rQ1), recombinant BCG (rBCG:Q1), and saline and BCG Pasteur control vaccines. To assess the cellular response induced by the vaccines, we cultured and stimulated splenocytes, followed by RNA extraction from the cells and analysis of cytokines using real-time PCR. The results revealed that the recombinant subunit vaccine elicited a Th2-type response, characterized by the expression of cytokines IL-10, IL-1α, and TNF-α. This pattern closely resembles the cytokines expressed in severe cases of leptospirosis. On the other hand, the rBCG-vectored vaccine induced a Th1-type response with significant up-regulation of IFN-γ. These findings suggest the involvement of the cellular response and the IFN-γ mediated inflammatory response in the sterilizing immunity mediated by rBCG. Therefore, this study may assist future investigations in characterizing the cellular response in hamsters, aiming to elucidate the mechanisms of efficacy and establish potential correlates of protection.
Assuntos
Vacina BCG , Leptospirose , Cricetinae , Animais , Antígenos de Bactérias/genética , Leptospirose/prevenção & controle , Proteínas Recombinantes/genética , Vacinas Sintéticas/genética , Citocinas/metabolismo , Imunidade Celular , Proteínas Recombinantes de Fusão/genéticaRESUMO
Seroprevalence of bovine alphaherpesvirus type 1 (BoAHV1) infections may be contaminated by crossreactive antibodies to bovine alphaherpesvirus type 5 (BoAHV5). To avoid such crossreactivity, an indirect enzyme-linked immunosorbent assay prepared with a recombinant glycoprotein C (gC) antigen (ELISA-gC1) was developed, aiming the detection of antibodies to BoAHV1, with no crossreactivity with BoAHV5 antibodies. The antigen for the ELISA-gC1 was the product of the expression of 219 bp from the N-terminal portion of the BoAHV1 gC gene, which bears low homology between the two virus types. The test was validated on 131 bovine serum samples, including 26 sera from BoAHV1-experimentally immunized, 38 sera from BoAHV5-experimentally infected or immunized calves, and 67 sera from calves seronegative for both BoAHV1 and BoAHV5, as determined by serum neutralization (SN). When compared to SN for BoAHV1, the ELISA-gC1 presented 100% sensitivity, 95.5 % specificity, 100 % negative predictive value, 89.6 % positive predictive value, 98.8 % precision, and a kappa correlation coefficient (κ) 0.95. None of the 38 BoAHV5-seropositive calves was detected by the ELISA-gC1. The ELISA-gC1 proved highly effective for the identification of BoAHV1-positive sera, with no crossreactivity with anti-BoAHV5 antibodies, thus able to distinguish serological responses from BoAHV1- and BoAHV5-seropositive cattle. Its capacity to detect BoAHV1-specific antibodies should allow the determination of the actual BoAHV1 prevalence in herds, which cannot be serologically determined in countries where BoAHV5 is also prevalent due to antibody crossreactivity. Apart from recognizing exclusively BoAHV1-infected cattle, the ELISA-gC1 may also be used in support of BoAHV5 epidemiological studies by allowing the exclusion of BoAHV1-seropositive animals.
Assuntos
Doenças dos Bovinos , Herpesvirus Bovino 1 , Animais , Bovinos , Estudos Soroepidemiológicos , Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática/veterinária , Valor Preditivo dos Testes , Doenças dos Bovinos/diagnóstico , Sensibilidade e EspecificidadeRESUMO
The first leptospiral recombinant vaccine was developed in the late 1990s. Since then, progress in the fields of reverse vaccinology (RV) and structural vaccinology (SV) has significantly improved the identification of novel surface-exposed and conserved vaccine targets. However, developing recombinant vaccines for leptospirosis faces various challenges, including selecting the ideal expression platform or delivery system, assessing immunogenicity, selecting adjuvants, establishing vaccine formulation, demonstrating protective efficacy against lethal disease in homologous challenge, achieving full renal clearance using experimental models, and reproducibility of protective efficacy against heterologous challenge. In this review, we highlight the role of the expression/delivery system employed in studies based on the well-known LipL32 and leptospiral immunoglobulin-like (Lig) proteins, as well as the choice of adjuvants, as key factors to achieving the best vaccine performance in terms of protective efficacy against lethal infection and induction of sterile immunity.
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Dogs are highly susceptible to leptospirosis and are a public health concern due to their important role as a source of spreading disease, particularly in urban settings. In this study, we present the pathogenesis, serological characterization, and complete genome sequencing of a virulent Brazilian strain (NEG7) of L. interrogans serovar Copenhageni isolated from the urine of a dog that died due to acute leptospirosis. Clinical investigation showed that the dog was presented with icteric mucous membranes, weakness, dehydration, anorexia, and kidney and liver failures. Necropsy followed by histopathological evaluation revealed lesions compatible with liver and kidney leptospirosis. The leptospires recovered from the urine were further characterized by genome analysis, which confirmed that the isolate belonged to L. interrogans serogroup icterohaemorrhagiae serovar Copenhageni. Multiple bioinformatics tools were used to characterize the genomic features, and comparisons with other available Copenhageni strains were performed. Characterization based on absence of an INDEL in the gene lic12008, associated with phylogenetic and ANI (99.99% identity) analyses, confirmed the genetic relatedness of the isolate with L. interrogans serovar Copenhageni. A better understanding of the diversity of the pathogenic Leptospira isolates could help in identifying genotypes responsible for severe infections. Moreover, it can be used to develop control and prevention strategies for Leptospira serovars associated with particular animal reservoirs.
RESUMO
Leptospirosis is a neglected disease of man and animals that affects nearly half a million people annually and causes considerable economic losses. Current human vaccines are inactivated whole-cell preparations (bacterins) of Leptospira spp. that provide strong homologous protection yet fail to induce a cross-protective immune response. Yearly boosters are required, and serious side-effects are frequently reported so the vaccine is licensed for use in humans in only a handful of countries. Novel universal vaccines require identification of conserved surface-exposed epitopes of leptospiral antigens. Outer membrane ß-barrel proteins (ßb-OMPs) meet these requirements and have been successfully used as vaccines for other diseases. We report the evaluation of 22 constructs containing protein fragments from 33 leptospiral ßb-OMPs, previously identified by reverse and structural vaccinology and cell-surface immunoprecipitation. Three-dimensional structures for each leptospiral ßb-OMP were predicted by I-TASSER. The surface-exposed epitopes were predicted using NetMHCII 2.2 and BepiPred 2.0. Recombinant constructs containing regions from one or more ßb-OMPs were cloned and expressed in Escherichia coli. IMAC-purified recombinant proteins were adsorbed to an aluminium hydroxide adjuvant to produce the vaccine formulations. Hamsters (4-6 weeks old) were vaccinated with 2 doses containing 50 - 125 µg of recombinant protein, with a 14-day interval between doses. Immunoprotection was evaluated in the hamster model of leptospirosis against a homologous challenge (10 - 20× ED50) with L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni strain Fiocruz L1-130. Of the vaccine formulations, 20/22 were immunogenic and induced significant humoral immune responses (IgG) prior to challenge. Four constructs induced significant protection (100%, P < 0.001) and sterilizing immunity in two independent experiments, however, this was not reproducible in subsequent evaluations (0 - 33.3% protection, P > 0.05). The lack of reproducibility seen in these challenge experiments and in other reports in the literature, together with the lack of immune correlates and commercially available reagents to characterize the immune response, suggest that the hamster may not be the ideal model for evaluation of leptospirosis vaccines and highlight the need for evaluation of alternative models, such as the mouse.
Assuntos
Leptospira , Leptospirose , Cricetinae , Humanos , Camundongos , Animais , Hidróxido de Alumínio , Reprodutibilidade dos Testes , Leptospirose/prevenção & controle , Vacinas Bacterianas , Antígenos de Bactérias/genética , Proteínas Recombinantes , Escherichia coli , Imunoglobulina G , EpitoposRESUMO
Different approaches are in use to improve our knowledge about the causative agent of coronavirus disease (COVID-19). Cell culture-based methods are the better way to perform viral isolation, evaluate viral infectivity, and amplify the virus. Furthermore, next-generation sequencing (NGS) have been essential to analyze a complete genome and to describe new viral species and lineages that have arisen over time. Four naso-oropharyngeal swab samples, collected from April to July of 2020, were isolated and sequenced aiming to produce viral stocks and analyze the mutational profile of the found lineage. B.1.1.33 was the lineage detected in all sequences. Although the samples belong to the same lineage, it was possible to evaluate different mutations found including some that were first described in these sequences, like the S:H655Y and T63N. The results described here can help to elicit how the pandemic started to spread and how it has been evolving in south Brazil.
Assuntos
COVID-19 , SARS-CoV-2 , Brasil , Genoma Viral , Humanos , Mutação , Filogenia , SARS-CoV-2/genéticaRESUMO
Mycobacterium bovis BCG has been used for a century as the only licensed vaccine against tuberculosis. Owing to its strong adjuvant properties, BCG has also been employed as an oncological immunotherapeutic as well as a live vaccine vector against other pathogens. However, BCG vaccination has limited efficacy in protecting against adult forms of tuberculosis (TB), raises concerns about its safety in immunocompromised populations, compromises the diagnosis of TB through the tuberculin test and lacks predictability for successful antigen expression and immune responses to heterologous antigens. Together, these factors propelled the construction and evaluation of auxotrophic BCG strains. Auxotrophs of BCG have been developed from mutations in the genes required for their growth using different approaches and have shown the potential to provide a model to study M. tuberculosis, a more stable, safe, and effective alternative to BCG and a vector for the development of recombinant live vaccines, especially against HIV infection. In this review, we provide an overview of the strategies for developing and using the auxotrophic BCG strains in different scenarios.
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Leptospirosis is a zoonotic disease caused by pathogenic species of Leptospira. Due to the similarity with clinical signs of other febrile diseases, early diagnosis remains challenging. Real-time PCR has been used for direct detection of Leptospira, but it requires thermocyclers and highly trained personnel. Loop-mediated isothermal amplification (LAMP) is a simple and rapid DNA-based assay. Therefore, here we have developed PCR and LAMP assays targeting two novel genes, lic13162 and lic20239, and also lipL32 gene to detect pathogenic Leptospira. Analytical and diagnostic performances were compared with bacterial isolates (including different Leptospira species and serovars) and clinical samples. The results demonstrated that PCR assays targeting lic13162 and lic20239 were successful to amplify Leptospira, but LAMP not. However, both PCR and LAMP targeting lipL32 could detect pathogenic Leptospira. LAMP lipL32 could be performed in 30 min with a detection limit of 156 cells/mL. Diagnostic performance of lipL32-LAMP presented 84.2% sensitivity and 93.2% specificity. In conclusion, lipL32 PCR and LAMP are effective methods to detect pathogenic Leptospira directly from clinical samples.
Assuntos
Leptospira , Leptospirose , Humanos , Leptospira/genética , Leptospirose/diagnóstico , Leptospirose/microbiologia , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e EspecificidadeRESUMO
Leptospirosis is a bacterial zoonotic disease with significant impact on health all over the world. Currently, bacterins are the only vaccines available for prevention of this disease, despite several drawbacks. In an effort to develop a more effective vaccine against leptospirosis, reverse and structural vaccinology have been applied to design recombinant constructions composed of leptospiral surface-exposed antigens. Herein, we describe a protocol for design and development of Leptospirosis recombinant vaccines using immunoinformatic approaches.
Assuntos
Leptospira , Leptospirose , Antígenos de Bactérias , Vacinas Bacterianas , Humanos , Leptospira/genética , Leptospira/imunologia , Leptospirose/prevenção & controle , Vacinas Sintéticas/genéticaRESUMO
Leptospirosis is an emerging infectious disease caused by pathogenic Leptospira spp. A universal vaccine against leptospirosis is likely to require highly conserved epitopes from pathogenic leptospires that are exposed on the bacterial surface and that generate a protective and sterilizing immune response. Our group recently identified several genes predicted to encode TonB-dependent receptors (TBDR) in Leptospira interrogans using a reverse vaccinology approach. Three leptospiral TBDRs were previously described and partially characterized as ferric-citrate, hemin, and cobalamin transporters. In the current study, we designed a fusion protein composed of predicted surface-exposed epitopes from three conserved leptospiral TBDRs. Based on their three-dimensional structural models and the prediction of immunogenic regions, nine putative surface-exposed fragments were selected to compose a recombinant chimeric protein. A Mycobacterium bovis BCG strain expressing this chimeric antigen encoded in the pUP500/PpAN mycobacterial expression vector was used to immunize Syrian hamsters. All animals (20/20) vaccinated with recombinant BCG survived infection with an endpoint dose of L. interrogans (p < 0.001). No animal survived in the negative control group. Immunization with our recombinant BCG elicited a humoral immune response against leptospiral TBDRs, as demonstrated by ELISA and immunoblot. No leptospiral DNA was detected by lipL32 qPCR in the kidneys of vaccinated hamsters. Similarly, no growth was observed in macerated kidney cultures from the same animals, suggesting the induction of a sterilizing immune response. Design of new vaccine antigens based on the structure of outer membrane proteins is a promising approach to overcome the impact of leptospirosis by vaccination. KEY POINTS: ⢠Predicted surface-exposed epitopes were identified in three leptospiral TBDRs. ⢠An M. bovis BCG strain expressing a chimeric protein (rTBDRchi) was constructed. ⢠Hamsters vaccinated with rBCG:TBDRchi were protected from lethal leptospirosis.
Assuntos
Leptospira interrogans , Leptospirose , Animais , Antígenos de Bactérias , Vacina BCG , Vacinas Bacterianas , Cricetinae , Epitopos , Leptospira interrogans/genética , Leptospirose/prevenção & controleRESUMO
Background: Cattle are susceptible to chronic leptospirosis infection, that results in reduced milk production and reproductive disorders such as abortions, stillbirths, fetal malformation, and mummified fetuses, causing significant economic losses.Commercially available vaccines against leptospirosis offer limited protection to cattle because they contain only the mostprevalent serovars worldwide, even though they are not prevalent in the specific region. This study aimed to evaluate theprevalence of specific antibodies against Leptospira serogroups, reproductive disorders and the risk factors in dairy herdsfrom different mesoregions of Rio Grande do Sul State, Southern Brazil.Materials, Methods & Results: An epidemiological survey was conducted, and serum samples from the bovine population representative of three mesoregions (MR1, MR2, and MR3) were studied; the samples were collected and tested forleptospirosis using the microscopic agglutination test (MAT) for 12 serogroups checking for the presence of agglutination.A total of 442 blood samples were collected from dairy cattle from November to December 2019 (MR1, 187; MR2, 88;and MR3, 167), including cows vaccinated with different commercial vaccines during the three months before sample collection (n = 295) and non-vaccinated against leptospirosis (n = 147). At the time of collection, an interview was conductedwith the owners with questions about the health of the animals, management, habitat, feeding and reproduction. Chi-squaretests univariate analysis with the SPSS® version 20.0 were performed to estimate the association of serogroup Djasimanseroreactivity with the occurrence of reproductive problems and related risk factors. The mean prevalence of antibodiesagainst leptospires was 78.7% (MR1, 74.9 %; MR2, 84.1 %; and MR3, 80.2 %). Serogroup prevalence was different in...
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Animais , Bovinos , Aborto Animal/etiologia , Fatores de Risco , Leptospirose/epidemiologia , Leptospirose/etiologia , Leptospirose/veterinária , Brasil , Inquéritos Epidemiológicos/métodos , Áreas AlagadasRESUMO
OBJECTIVE: To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS: Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1-8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9-10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS: Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS: The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.
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COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Brasil/epidemiologia , Humanos , Estudos SoroepidemiológicosRESUMO
BACKGROUND: Large-scale epidemiological studies of seroprevalence of antibodies against SARS-CoV-2 often rely on point-of-care tests that provide immediate results to participants. Yet, little is known on how long rapid tests remain positive after the COVID-19 episode, or how much variability exists across different brands and even among batches of the same test. METHODS: In November 2020, we assessed the sensitivity of three tests applied to 133 individuals with a previous positive PCR result between April and October. All subjects provided finger prick blood samples for two batches (A and B) of the Wondfo lateral-flow IgG/IgM test, and dried blood spot samples for the S-UFRJ ELISA test. RESULTS: Overall sensitivity levels were 92.5% (95% CI 86.6-96.3), 63.2% (95% CI 54.4-71.4) and 33.8% (95% CI 25.9-42.5) for the S-UFRJ test, Wondfo A and Wondfo B tests, respectively. There was no evidence of a decline in the positivity of S-UFRJ with time since the diagnosis, but the two Wondfo batches showed sharp reductions to as low as 41.9% and 19.4%, respectively, for subjects with a positive PCR in June or earlier. Positive results for batch B of the rapid test were 35% to 54% lower than for batch A at any given month of diagnosis. INTERPRETATION: Whereas the ELISA test showed high sensitivity and stability of results over the five months of the study, both batches of the rapid test showed substantial declines, with one of the batches consistently showing lower sensitivity levels than the other. ELISA tests based on dried-blood spots are an inexpensive alternative to rapid lateral-flow tests in large-scale epidemiological studies. FUNDING: The study was funded by the "Todos Pela Saúde" initiative, Instituto Serrapilheira, Brazilian Ministry of Health, Brazilian Collective Health Association (ABRASCO) and the JBS S.A. initiative 'Fazer o Bem Faz Bem'.
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COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina M , Sensibilidade e Especificidade , Estudos SoroepidemiológicosAssuntos
COVID-19 , Pandemias , Aniversários e Eventos Especiais , Brasil/epidemiologia , Humanos , SARS-CoV-2RESUMO
Since the beginning of the pandemic of COVID-19, there has been a widespread assumption that most infected persons are asymptomatic. Using data from the recent wave of the EPICOVID19 study, a nationwide household-based survey including 133 cities from all states of Brazil, we estimated the proportion of people with and without antibodies for SARS-CoV-2 who were asymptomatic, which symptoms were most frequently reported, number of symptoms and the association with socio-demographic characteristics. We tested 33,205 subjects using a rapid antibody test previously validated. Information was collected before participants received the test result. Out of 849 (2.7%) participants positive for SARS-CoV-2 antibodies, only 12.1% (95% CI 10.1-14.5) reported no symptoms, compared to 42.2% (95% CI 41.7-42.8) among those negative. The largest difference between the two groups was observed for changes in smell/taste (56.5% versus 9.1%, a 6.2-fold difference). Changes in smell/taste, fever and body aches were most likely to predict positive tests as suggested by recursive partitioning tree analysis. Among individuals without any of these three symptoms, only 0.8% tested positive, compared to 18.3% of those with both fever and changes in smell or taste. Most subjects with antibodies against SARS-CoV-2 are symptomatic, even though most present only mild symptoms.
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Anticorpos Antivirais/sangue , COVID-19 , Portador Sadio/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Adolescente , Adulto , Idoso , Brasil/epidemiologia , COVID-19/epidemiologia , COVID-19/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Adulto JovemRESUMO
Objectives. To evaluate the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) over 6 months in the Brazilian State of Rio Grande do Sul (population 11.3 million), based on 8 serological surveys. Methods. In each survey, 4151 participants in round 1 and 4460 participants in round 2 were randomly sampled from all state regions. We assessed presence of antibodies against SARS-CoV-2 using a validated lateral flow point-of-care test; we adjusted figures for the time-dependent decay of antibodies. Results. The SARS-CoV-2 antibody prevalence increased from 0.03% (95% confidence interval [CI] = 0.00%, 0.34%; 1 in every 3333 individuals) in mid-April to 1.89% (95% CI = 1.36%, 2.54%; 1 in every 53 individuals) in early September. Prevalence was similar across gender and skin color categories. Older adults were less likely to be infected than younger participants. The proportion of the population who reported leaving home daily increased from 21.4% (95% CI = 20.2%, 22.7%) to 33.2% (95% CI = 31.8%, 34.5%). Conclusions. SARS-CoV-2 infection increased slowly during the first 6 months in the state, differently from what was observed in other Brazilian regions. Future survey rounds will continue to document the spread of the pandemic.
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Teste para COVID-19/estatística & dados numéricos , COVID-19/diagnóstico , COVID-19/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Vigilância de Evento Sentinela , Estudos Soroepidemiológicos , Classe Social , Adulto JovemRESUMO
Due to the high rate of transmissibility, Brazil became the new COVID-19 outbreak epicenter and, since then, is being monitored to understand how SARS-CoV-2 mutates and spreads. We combined genomic and structural analysis to evaluate genomes isolated from different regions of Brazil and show that the most prevalent mutations were located in the S, N, ORF3a and ORF6 genes, which are involved in different stages of viral life cycle and its interaction with the host cells. Structural analysis brought to light the positions of these mutations on protein structures, contributing towards studies of selective structure-based drug discovery and vaccine development.
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COVID-19/genética , Mutação/genética , SARS-CoV-2/genética , Proteínas Virais/genética , Brasil , Genoma Viral , Genômica , Humanos , SARS-CoV-2/patogenicidade , Índice de Gravidade de DoençaRESUMO
The occurrence of multidrug-resistant Serratia marcescens strains represents a serious public health threat. The purpose here is to report three cases of carbapenem-resistant S. marcescens infections with unfavorable clinical outcomes and provide a molecular description of the antibiotic resistance determinants at a genomic level. We performed bacterial identification by VITEK 2 and MALDI-TOF. The minimal inhibitory concentrations of antimicrobials were determined according to the Clinical and Laboratory Standards Institute guidelines, except for tigecycline, for which they were determined using Etest strips. Preliminary screening for the presence of carbapenemases was performed by ertapenem hydrolysis using MALDI-TOF MS. Whole-genome sequencing was provided to identify genes responsible for virulence and antimicrobial resistance. Here we report three challenging cases of S. marcescens that were resistant to the most commonly used antibiotics. Otherwise, we performed a genome description, which includes several genes involved in the resistance and virulence. These cases illustrate serious infection due to multidrug-resistant organisms and the complexity of treatment. Our results highlight the need to evaluate isolates regularly during long-term hospital stay to achieve optimal quality of clinical care and thus improve patient outcomes.
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Antibacterianos , Farmacorresistência Bacteriana Múltipla , Serratia marcescens , Antibacterianos/uso terapêutico , Carbapenêmicos , Genoma Bacteriano , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/genética , Virulência , Sequenciamento Completo do GenomaRESUMO
OBJECTIVES: This study aimed to determine whether there are differences in the language used in grant applications submitted to a Southern Brazil Research Support Foundation (FAPERGS) according to the gender, career stage, and the number of publications of applicants. STUDY DESIGN AND SETTING: This observational study also evaluated the relationship between gender, career stage, curriculum, and writing characteristics. Summaries of all research proposals in the biomedical field of FAPERGS during the years of 2013 and 2014 were evaluated according to six language patterns (Positive emotions, Negative emotions, Analytic thinking, Clout, Authenticity, and Emotional tone) defined by the LIWC software. Applicant's gender, career stage, and the number of publications were also collected. RESULTS: Three hundred and forty-four (344) grant proposals met the inclusion criteria and were included in the analysis. No statistical differences were observed in the language pattern used by different gender applicants. In the language used by successful and unsuccessful applicants, we only found a small difference for clout (score 54.5 for not funded and 56.5 for funded grants). However, the principal investigators of successful applications had a significantly higher number of papers published (mean number of papers: 104 versus 58.5). CONCLUSIONS: Gender bias appears to be a more complex problem than just the type of language used; the way society is organized causes several gender biases that may be reflected throughout the women's career.