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The incidence of syphilis has increased alarmingly over the years. Its diagnosis continues to be a challenge, leading to the search for new alternative and effective methods. The objective of this study was to select and evaluate threeThe online version contains supplementary material available at 10.1007/s12088-022-01017-w.

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. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-022-00698-1.

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

In order to develop a more sensitive and reliable method for detection of serum antibodies against Mycoplasma hyopneumoniae infection in pigs, six recombinant proteins of M. hyopneumoniae (P102, P95, P46, P97 like, Lppt, and hypothetical P987) were used for the standardization of an indirect enzyme-linked immunosorbent assay (ELISA). The proteins were evaluated against 50 sera of the specific pathogen-free and 50 sera of pigs with lesions suggestive of infection. The sensitivity was 88%, 86%, 78%, 74%, 66%, and 60% for the proteins P102, P95, P46, P97 like, Lppt, and hypothetical protein P987, respectively. Moreover, the proteins were used to establish the seroprevalence in two different commercial herds (254 sera pigs from farm considered free of M. hyopneumoniae and 246 from farm with clinical signs of enzootic pneumonia and positive serology for M. hyopneumoniae) and the positive rate was 65.2% for P95, 54.6% for P102, 40.2% for P46, 37.2% for P97 like, 17.4% for the hypothetical P987, and 14% for Lppt protein. In addition, the ELISA with six recombinant proteins was compared to commercial HerdCheck kit using 118 random pig sera samples and the results showed that ELISA with recombinant proteins were more sensitive than the commercial test. These data show that the recombinant proteins P95 and P102 are potential targets to be used in diagnostic tests to detect antibodies against M. hyopneumoniae. Although more studies are necessary, this study provides insights that these recombinant proteins can be useful in epidemiological investigations and as potential biomarkers in differentiating infected animals from those vaccinated.

This study investigated the ability of Staphylococcus aureus isolates from milk to form biofilm, through detection of adhesion genes, investigating exopolysaccharide (EPS) production and biofilm formation on polystyrene (PS) and stainless steel (SS) surfaces, and by quantifying the expression of ebpS and cna genes under different temperatures and culture media. Among the 31 isolates, the adhesion genes ebpS and cna were found in 81% and 61% of the isolates, respectively. The screening tests for phenotype revealed that 58% of the isolates were EPS producers, and 45% showed the ability to produce biofilm on PS. Nine of the 31 isolates were selected to verify their ability to form biofilm on SS, of which 3 were non-biofilm producers, 3 were poor biofilm producers, and 3 were moderate biofilm producers. However, all nine isolates produced biofilm on SS, regardless of their phenotypic profile on PS. Reverse-transcriptase quantitative PCR (RT–qPCR) revealed no variation in the expression levels of ebpS and cna genes at different temperatures, except for isolate S24 at 10 °C, for both genes tested. Moreover, RT–qPCR assays revealed that the expression levels of the adhesion genes ebpS and cna are isolate- and temperature-dependent; however, they are independent of the phenotypic biofilm-formation profile.

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.

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.

The first case of COVID-19 was reported in China in December 2019, and, as the virus has spread worldwide, the World Health Organization declared it a pandemic. Estimates on the number of COVID-19 cases do not reflect it real magnitude as testing is limited. Population based data on the proportion of the population with antibodies is relevant for planning public health policies. We aim to assess the prevalence of SARS-CoV-2 antibodies, presence of signs and symptoms of COVID-19, and adherence to isolation measures. A random sample comprising 133 sentinel cities from all states of the country will be selected. Three serological surveys, three weeks apart, will be conducted. The most populous municipality in each intermediate region of the country, defined by the Brazilian Institute of Geography and Statistics, was chosen as sentinel city. In each city, 25 census tracts will be selected, and 10 households will be systematically sampled in each tract, totaling 33,250 participants. In each household, one inhabitant will be randomly selected to be interviewed and tested for antibodies against SARS-CoV-2, using WONDFO SARS-CoV-2 Antibody Test. By evaluating a representative sample of Brazilian sentinel sites, this study will provide essential information for the design of health policies.

Population-based data on COVID-19 are urgently needed. We report on three rounds of probability sample household surveys in the state of Rio Grande do Sul (Brazil), carried out in nine large municipalities using the Wondfo lateral flow point-of-care test for immunoglobulin M and G antibodies against SARS-CoV-2 (https://en.wondfo.com.cn/product/wondfo-sars-cov-2-antibody-test-lateral-flow-method-2/). Before survey use, the assay underwent four validation studies with pooled estimates of sensitivity (84.8%; 95% confidence interval (CI) = 81.4-87.8%) and specificity (99.0%; 95% CI = 97.8-99.7%). We calculated that the seroprevalence was 0.048% (2/4,151; 95% CI = 0.006-0.174) on 11-13 April (round 1), 0.135% (6/4,460; 95% CI = 0.049-0.293%) on 25-27 April (round 2) and 0.222% (10/4,500; 95% CI = 0.107-0.408) on 9-11 May (round 3), with a significant upward trend over the course of the surveys. Of 37 family members of positive individuals, 17 (35%) were also positive. The epidemic is at an early stage in the state, and there is high compliance with social distancing, unlike in other parts of Brazil. Periodic survey rounds will continue to monitor trends until at least the end of September, and our population-based data will inform decisions on preventive policies and health system preparedness at the state level.

The aim of this study was to investigate the prevalence of thermophilic Campylobacter in the broiler production chain of southern Brazil, by evaluating broiler farms and slaughter line samples, and to determine the genetic diversity, antimicrobial resistance, and virulence genes of the isolates. Of the 140 samples investigated in this study, 75 (53.6%) were positive for thermophilic Campylobacter, and all isolates were identified by phenotypic and molecular tests as C. jejuni. The resistance to nalidixic acid was the most common (74%), followed by resistance to enrofloxacin (67.3%) and ciprofloxacin (37.1%). However, there was no resistance to the macrolides tested which are recommended for the treatment of human campylobacteriosis. The PFGE showed that the isolates were grouped in eight macrorestriction patterns (P1 to P8). A representative isolate of each macrorestriction pattern was investigated for the presence of virulence genes and all isolates carried the cadF, ciaB, cdtA, cdtB, cdtC, and flaA genes. The dnaJ gene was detected in 87.5% (7/8) of the isolates. The flhA and racR genes were detected in 75% (6/8), while the pldA gene was present in 62.5% (5/8) and the wlaN gene in 25% (2/8). The presence of C. jejuni in broiler farms and in the slaughterhouse is a hazard to consumer given that this pathogen can be maintained throughout the broiler production chain and contaminates the final product. Moreover, the presence of the major virulence genes in the isolates demonstrates that they have the ability to develop campylobacteriosis in humans.

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.

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 most prevalent serovars worldwide, even though they are not prevalent in the specific region. This study aimed to evaluate the prevalence of specific antibodies against Leptospira serogroups, reproductive disorders and the risk factors in dairy herds from 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 for leptospirosis 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 conducted with the owners with questions about the health of the animals, management, habitat, feeding and reproduction. Chi-square tests univariate analysis with the SPSS® version 20.0 were performed to estimate the association of serogroup Djasiman seroreactivity with the occurrence of reproductive problems and related risk factors. The mean prevalence of antibodies against leptospires was 78.7% (MR1, 74.9 %; MR2, 84.1 %; and MR3, 80.2 %). Serogroup prevalence was different in each mesoregion evaluated and varied with vaccination status tested of the animals. The most prevalent serogroups in MR1 were Djasiman and Icterohaemorrhagiae. In MR2 and MR3, Djasiman was the most prevalent serogroup, regardless of vaccination status. Other prevalent serogroups in vaccinated animals were Icterohaemorrhagiae (MR1), Sejroe (MR2), Pomona, Sejroe, and Icterohaemorrhagiae (MR3). The other serovars tested had a prevalence of less or equal than 2%. The occurrence of reproductive problems with abortions and estrus repetition, was associated with reactivity to the serogroup Djasiman (P > 0.05). The results showed that the access of animals to flooded areas and the presence of rodents were significant risk factors, according to the literature.Discussion: The prevalence of antibodies against Leptospira in the studied areas was higher than expected, with a high prevalence of Djasiman serogroup. It is important to note that this serogroup is not present in current vaccine formulations. The presence of wetlands and rodents as risk factors in association with Djasiman is consistent with the scientific literature, since wild rodents are natural hosts, and swampy areas may allow Leptospira to survive for up to 180 days in the environment. Due to the presence and high prevalence found of the serogroup Djasiman in the experiment, new studies are being carried out to improve our knowledge about this serogroup and its possible inclusion in a commercial vaccine. Prophylaxis and control measures were recommended to rural producers in the analyzed properties.Keywords: bovine leptospirosis, herds, zoonosis, antibodies, reproductive disorders, leptospires, Djasiman.

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.

Babesiosis is a disease caused by tickborne hemoprotozoan apicomplexan parasites of the genus Babesia that negatively impacts public health and food security worldwide. Development of effective and sustainable vaccines against babesiosis is currently hindered in part by the absence of definitive host correlates of protection. Despite that, studies in Babesia microti and Babesia bovis, major causative agents of human and bovine babesiosis, respectively, suggest that early activation of innate immune responses is crucial for vertebrates to survive acute infection. Trained immunity (TI) is defined as the development of memory in vertebrate innate immune cells, allowing more efficient responses to subsequent specific and non-specific challenges. Considering that Mycobacterium bovis bacillus Calmette-Guerin (BCG), a widely used anti-tuberculosis attenuated vaccine, induces strong TI pro-inflammatory responses, we hypothesize that BCG TI may protect vertebrates against acute babesiosis. This premise is supported by early investigations demonstrating that BCG inoculation protects mice against experimental B. microti infection and recent observations that BCG vaccination decreases the severity of malaria in children infected with Plasmodium falciparum, a Babesia-related parasite. We also discuss the potential use of TI in conjunction with recombinant BCG vaccines expressing Babesia immunogens. In conclusion, by concentrating on human and bovine babesiosis, herein we intend to raise awareness of BCG TI as a strategy to efficiently control Babesia infection.

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.

In this study, we describe the characterization of a new lectin, BfL-II, purified from the seeds of Bauhinia forficata, which is distinct, at sequence-level, from the previously reported lectin from the same specie (BfL). In addition, the gene for this lectin was cloned and expressed in Escherichia coli and its antiproliferative activity was evaluated against human breast and colorectal cancer cells (MCF-7 and HT-29, respectively). The treatment with 100 μg/μL of either native or recombinant BfL (nBfL or rBfL) significantly reduced the proliferation of both cancer cell lines (p

Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic Leptospira species. The vaccines that are currently available are bacterins, with limited human use, that confer short-term, serovar-specific immunity. Lig proteins are considered to be the best vaccine candidates to date. Here, we aimed to construct a recombinant Lig chimera (LC) comprised of LigAni and LigBrep fragments, and to evaluate it as subunit or DNA vaccine using different administration strategies. Vaccines were formulated with 50 µg of recombinant LC associated with different adjuvants or with 100 µg of pTARGET/LC. Four-week-old hamsters received two doses of vaccine with different strategies and were challenged with 5 × DL50Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130. The immune response generated by Lig chimera conferred 100% protection to hamsters treated with at least one dose of recombinant LC. Despite the high levels of antibodies that vaccinated animals produced, a sterilizing immunity was not achieved. The lack of a sterilizing immunity could indicate the importance of a mixed humoral and cellular immune response. The present study generated insights that will be useful in the future development of improved subunit vaccines against leptospirosis.

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 Saude” initiative, Instituto Serrapilheira, Brazilian Ministry of Health, Brazilian Collective Health Association (ABRASCO) and the JBS S.A. initiative ‘Fazer o Bem Faz Bem’.

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.

In order to develop a more sensitive and reliable method for detection of serum antibodies against Mycoplasma hyopneumoniae infection in pigs, six recombinant proteins of M. hyopneumoniae (P102, P95, P46, P97 like, Lppt, and hypothetical P987) were used for the standardization of an indirect enzyme-linked immunosorbent assay (ELISA). The proteins were evaluated against 50 sera of the specific pathogen-free and 50 sera of pigs with lesions suggestive of infection. The sensitivity was 88%, 86%, 78%, 74%, 66%, and 60% for the proteins P102, P95, P46, P97 like, Lppt, and hypothetical protein P987, respectively. Moreover, the proteins were used to establish the seroprevalence in two different commercial herds (254 sera pigs from farm considered free of M. hyopneumoniae and 246 from farm with clinical signs of enzootic pneumonia and positive serology for M. hyopneumoniae) and the positive rate was 65.2% for P95, 54.6% for P102, 40.2% for P46, 37.2% for P97 like, 17.4% for the hypothetical P987, and 14% for Lppt protein. In addition, the ELISA with six recombinant proteins was compared to commercial HerdCheck kit using 118 random pig sera samples and the results showed that ELISA with recombinant proteins were more sensitive than the commercial test. These data show that the recombinant proteins P95 and P102 are potential targets to be used in diagnostic tests to detect antibodies against M. hyopneumoniae. Although more studies are necessary, this study provides insights that these recombinant proteins can be useful in epidemiological investigations and as potential biomarkers in differentiating infected animals from those vaccinated.

This study investigated the ability of

Whole-cell inactivated vaccines remain the only licensed vaccines used to control human and animal leptospirosis worldwide. Although they are protective against lethal infections, the efficacy of these vaccines has been divergent. The manufacturing process often involves the use of standard bacterial strains subjected to serial in vitro passages, with a risk of loss of virulence, and may affect the immunogenicity and consequently decrease protection. Thus, the objective of this study was to perform a comparative analysis of the efficacy of in-house bacterins produced with standard (avirulent) and virulent strains. Hamsters were immunized with killed bacteria produced using avirulent and virulent strains of L. interrogans serovars Copenhageni and Canicola. Vaccine efficacy was determined in terms of protection against lethal homologous or heterologous challenges. The results showed that immunization with both avirulent and virulent Canicola strains resulted in 100% protection against homologous challenge. Conversely, Copenhageni bacterins produced using an avirulent strain conferred only 25-37.5% protection against homologous challenge (P > 0.05), while virulent Copenhageni bacterin conferred 100% protection (P < 0.001). A single vaccine dose was sufficient to induce protection, and administration of a prime boost significantly reduced the bacterial load in the kidneys and improved the humoral immune response to the virulent Copenhageni strain. These findings suggest that the maintenance of virulent strains in bacterin formulations is essential for improving the immunogenicity and efficacy of leptospirosis vaccines.

The aim of this study was to estimate neosporosis seroprevalence and its associated risk factors in milk herds (Bos taurus taurus) located in the northwestern region of Rio Grande do Sul State, Brazil. Three hundred twenty-two blood samples were collected from dairy cows on 18 farms in 17 cities of this region. An epidemiologic questionnaire was completed for each farm. It consisted of questions about the general characteristics of the herd, reproduction, and animal management. Serum samples were tested for Neospora caninum using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Results indicated a seroprevalence of Neospora in 88.9% (16/18) of herds and 31.1% (100/322) of individuals. Risk factor analyses demonstrated that culling by reproductive disorder (OR = 0.6), flooding (OR = 0.5), and commercial sale (OR = 0.4) were associated with seroprevalence. Nevertheless, the purchase of replacement animals in the herd played an important role in disease occurrence (OR = 2.2). Results of this study suggested that Neospora caninum was present in the studied herds under investigation and that there are risk factors associated with its seroprevalence on the farms of the northwestern of Rio Grande do Sul. RESUMO - O objetivo desse estudo foi estimar a soroprevalência da neosporose e os possíveis fatores de risco em rebanhos (Bos taurus taurus) localizados na mesorregião Noroeste do Rio Grande do Sul, Brasil. Foram coletadas 322 amostras de sangue de bovinos leiteiros, em 18 propriedades localizadas em 17 munícipios desta mesorregião. Um questionário epidemiológico foi aplicado em cada propriedade, contendo questões relacionadas às características gerais dos rebanhos, dados reprodutivos e manejo animal. As amostras de soro foram testadas através do teste de imunoensaio enzimático (ELISA) para Neospora caninum. Os resultados demonstraram uma soroprevalência de Neospora de 88,9% (16/18) entre os rebanhos e 31,1% (100/322) entre os indivíduos. Entre os fatores de risco analisados foi observado que descarte por problemas reprodutivos (OR=0,6), presença de áreas alagadiças (OR=0,5) e venda comercial (OR=0,4) estavam associados a soroprevalência. No entanto, a compra de animais substituídos no rebanho desempenhou um papel significativo na ocorrência da doença (OR=2,2). Os resultados desse estudo sugerem que o Neospora caninum esteve presente nos rebanhos estudados, bem como, existem fatores associados com a soroprevalência nas propriedades da mesorregião do Noroeste do Rio Grande do Sul. Made available in DSpace on 2018-12-21T23:40:13Z (GMT). No. of bitstreams: 1 ArtigoCienciaRuralGuilhermeSeroprevalence.pdf: 773587 bytes, checksum: 56704b4fed9266b4bc27ccd9f2d526ab (MD5) Previous issue date: 2018-12-19

Due to the high rate of transmissibility, Brazil became the new COVID-19 outbreak epicenter, being a reference region to monitor how SARS-CoV-2 is mutating and spreading. Here, we combined genomic and structural biology analysis evaluate genomes isolated from different regions of Brazil. We showed 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, helping studies of structure-based drug discovery and vaccine development.

Background: Rio Grande do Sul, the southernmost state in Brazil, had a slow start in the pandemic compared to other regions of the country, but the number of new cases rose sharply in December 2020, with a huge spike in March 2021, when the number of new cases was close to 800 per million people. In this article, we describe the pandemic in the State through the lens of 10 consecutive surveys conducted between April 2020 and April 2021. Methods: We used a sentinel city approach, covering all regions of the State. In each city we selected 50 urban census tracts with probability proportional to size. In each tract, 10 households were selected using a systematic approach. Within each selected household, all residents were listed, and one was selected randomly. In the first rounds of the study, we used the rapid point-of-care lateral- flow WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds nine and 10, we used an in-house direct ELISA test that identifies the presence of IgG to the viral spike (S) protein from dried blood spot samples (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score through principal components analysis. Findings: Antibody prevalence in early April 2020 was 0.07 (95% CI 0.01-0.32), increasing to 10.0% (95% CI 9.1-11.0) in February 2021, and to 18.2% (95% CI 16.9-19.5) in April 2021. Self-reported whites showed the lowest seroprevalences (9.3%, 95% CI 8.3–10.4 in round 9 and 17.3%, 95% CI 15.9–18.8 in round 10), while indigenous individuals presented the highest levels (20.0%, 95% CI 8.5– 40.3 in round 9 and 44.4%, 95% CI 22.5–68.7 in round 10), followed by blacks (14.4%, 95% CI 11.3– 18.1 in round 9 and 21.6%, 95% CI 17.4–26.4 in round 10). We found an increase in seropositivity in relation to our exposure score; the most exposed 10% of the population presented a 40% higher seropositivity. Interpretation: The proportion of the population already infected by SARS-Cov-2 in the State is still far from any perspective of herd immunity, suggesting that herd immunity will only be achieved through vaccination. Funding: the Brazilian Ministry of Health, Banco do Estado do Rio Grande do Sul (BANRISUL), Instituto Cultural Floresta, UNIMED Porto Alegre, “Todos pela Saude” Group, Instituto Serrapilheira, Brazilian Collective Health Association (ABRASCO) and the JBS S.A. initiative “Fazer o Bem Faz Bem”. Declaration of Interest: None to declare. Ethical Approval: Ethical approval was obtained from the Brazilian’s National Ethics Committee (30415520.2.0000.5313), and we obtained written informed consent from all participants.

Leptospirosis has been widely reported in insular environments worldwide, characterizing a major public health threat. Although low-genetic biodiversity is expected in these regions, the introduction of domestic and synanthropic mammals may contribute to the wider diversity of leptospiral strains in insular settings. This study proposes a large-scale seroepidemiological investigation of Leptospira infection in animals from Fernando de Noronha archipelago and describes the characterization of the first leptospiral strain ever isolated from an insular setting in Brazil. A total of 1,265 blood samples from domestic (n = 682), synanthropic (n = 133) and wild (n = 450) animals were collected between 2007 and 2014, totalling 12 species. The presence of anti-Leptospira spp. antibodies was investigated by the microscopic agglutination test (MAT), and kidney samples from 20 synanthropic rodents were collected for the isolation of Leptospira spp. The leptospires recovered were further characterized by serogrouping with polyclonal antibodies, whole-genome sequencing and multilocus sequence typing (MLST). The MAT results revealed the presence of agglutinins in 90 samples (7.1%) and the most frequently found serogroup was Icterohaemorrhagiae (n = 57) in practically all species included. Viable leptospires were recovered from one brown rat, and characterization revealed that the isolate belongs to L. interrogans serogroup Pyrogenes. The results suggest that synanthropic rodents might play an important role in leptospiral infection among wildlife and domestic species in the archipelago.

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. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-021-00477-4.

Leptospirosis is a disease of worldwide importance, both from a veterinarian and a public health point of view. Serological survey through the microscopic agglutination test (MAT) is the standard to diagnose and assess the disease´s distribution in a population. Stray dogs are important urban reservoirs of leptospirosis and studies regarding their seroreactivity in Brazil are few and far apart. This work reports the seroreactivity of stray dogs to the most important serogroups in the Leptospira genus causing urban leptospirosis in dogs and humans in Pelotas, Brazil: Icterohaemorrhagiae and Canicola. All the animals used in this study were female stray dogs, no distinction regarding age or race was made. Blood samples were collected from 221 animals. The MAT was carried out according to the recommendations of the World Health Organization (WHO). Of the 221 tested animals, 64 were positive for agglutinating antibodies, representing a prevalence of 29%. These results are in accordance with those reported for housed dogs in Pelotas in previous studies. This study represents an important epidemiological update for the leptospirosis scenario in southern Brazil. Furthermore, these reports will aid healthcare agents in controlling both canine and human leptospirosis in the region. La leptospirosis es una enfermedad de importancia mundial, tanto desde el punto de vista veterinario como de salud pública. El estudio serológico mediante la prueba de aglutinación microscópica (MAT) es el estándar para diagnosticar y evaluar la distribución de la enfermedad en una población. Los caninos callejeros son importantes reservorios urbanos de leptospirosis y los estudios sobre su serorreactividad en Brasil son pocos y distantes. Este trabajo reporta la serorreactividad de perros callejeros a los serogrupos más importantes del género Leptospira que causan leptospirosis urbana en perros y humanos en Pelotas, Brasil. Todos los animales utilizados en este estudio fueron hembras de perros callejeros, no se hizo distinción en cuanto a edad o raza. Se recolectaron muestras de sangre de 221 animales, se utilizaron Leptospira interrogans serogrupo Icterohaemorrhagiae y serogrupo Canicola. El MAT se ejecutó de acuerdo con las recomendaciones de la Organización Mundial de la Salud (OMS). De los 221 animales probados, 64 fueron positivos para anticuerpos aglutinantes, lo que representa una prevalencia del 29%. Estos resultados concuerdan con los descritos para perros alojados en Pelotas en estudios previos. Este estudio representa una importante actualización epidemiológica para el escenario de la leptospirosis en el sur de Brasil. Además, estos informes ayudarán a los agentes de la salud a controlar la leptospirosis canina y humana en la región. A leptospirose é uma doença de importância mundial, tanto para área veterinária quanto para a saúde pública. O teste de aglutinação microscópica (MAT) é o padrão para diagnosticar e avaliar a distribuição da doença em uma população. No Brasil, caninos não domiciliados são considerados importantes reservatórios urbanos da leptospirose, porém estudos sobre a prevalência da enfermidade são raros ou estão desatualizados. Assim, este trabalho relata a sororeatividade de fêmeas caninas não domiciliadas para dois sorogrupos de Leptospira interrogans, importantes causadores da leptospirose urbana em caninos e humanos no Brasil e no mundo. Todos os animais usados neste estudo foram fêmeas, as quais eram pertencentes ao programa de controle da população canina da Prefeitura de Pelotas, sem a distinção de idade e raça. Amostras de sangue foram coletadas de 221 animais. O MAT foi realizado segundo as recomendações da Organização Mundial da Saúde (OMS). Dos 221 animais testados, 64 foram reagentes, representando uma prevalência de 29%. Esses resultados estão de acordo com os descritos em estudos anteriores para cães no município de Pelotas. Este estudo representa uma importante atualização epidemiológica para o cenário da leptospirose no sul do Brasil. Além disso, estes resultados ajudarão os agentes de saúde no controle da leptospirose canina e humana na região.

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.

Leptospirosis has been widely reported in insular environments worldwide, characterizing a major public health threat. Although low genetic biodiversity is expected in these regions, the introduction of domestic and synanthropic mammals may contribute to the wider diversity leptospiral strains in insular settings. This study proposes a large-scale investigation of Leptospira infection in animals from Fernando de Noronha archipelago, Brazil. A total of 1,265 blood samples from domestic (n=682), synanthropic (n=133) and wild (n=450) animals were collected between 2007 and 2014, totaling 12 species. The presence of anti-Leptospira spp. antibodies was investigated by the Microscopic Agglutination Test (MAT) and kidney samples from synanthropic rodents were collected for the isolation of Leptospira spp. The leptospires recovered were further characterized by MAT with polyclonal antibodies, whole genome sequencing and Multilocus Sequence Typing (MLST). The MAT results revealed the presence of agglutinins in 90 samples (7.1%), and the most frequently found serogroup was Icterohaemorrhagiae (n=57) in practically all species included. Viable leptospires were recovered from one brown rat, and characterization revealed that the isolate belongs to L. interrogans serogroup Pyrogenes. This study stands as the most comprehensive investigation of Leptospira spp. infection in Fernando de Noronha archipelago, also providing the characterization of the first leptospiral strain ever isolated from an insular setting in Brazil. The results suggest that synanthropic rodents play a major role in the transmission of leptospirosis among wildlife and domestic species in the archipelago.

Leptospirosis is a zoonotic disease worldwide and caused by the pathogenic spirochetes of the genus Leptospira. Bacterins make up the vaccines used against leptospirosis, but they only succeed in providing short-term and serovar-specific protection. The use of Mycobacterium bovis BCG as a live vaccine vector expressing leptospiral antigens is a promising alternative, particularly due to its adjuvant properties. Four distinct portions P1 (lipL32), P2 (ligAni), P3 (lemA:ligAni) and P4 (lipL32:lemA) of a recombinant chimera composed of the lipL32, lemA and ligANI genes from Leptospira interrogans were cloned individually according to the BioBricks® strategy in the plasmid pUP500/PpAN. These constructs were individually transformed into a BCG Pasteur strain, and protein expression was detected by Western blot. For vaccination, 5 groups of 10 Golden Syrian hamsters were used, aged 4-6 weeks - group 1, rBCG (LipL32); group 2, rBCG (LigAni); group 3, rBCG (LemA:LigAni); group 4, (LipL32:LemA); group 5, wild-type BCG Pasteur (negative control). Two doses containing 106 CFU of rBCG were administered subcutaneously, the challenge was performed with 5 × LD50 of Leptospira interrogans serovar Copenhageni L1-130, and the animals were observed for a 30-day period until the endpoint was reached. Humoral immunity was assessed via indirect ELISA, while renal colonisation was assessed by culture and quantitative real-time PCR. All vaccinated groups were protected against lethal challenge and renal colonisation, in comparison with negative control group (P < 0.05). Recombinant vaccines were not effective at inducing significant humoral immunity, which suggests the induction of cellular immunity - a characteristic of M. bovis BCG. In conclusion, all formulations provide 100% significant protection against leptospirosis in hamsters with no renal colonisation. The use of rBCG as a vaccine vector represents a promising alternative for the control of animal leptospirosis, allowing for protection against clinical signs of leptospirosis and renal colonisation.

Summary Background Population-based data on COVID-19 are essential for guiding policies. There are few such studies, particularly from low or middle-income countries. Brazil is currently a hotspot for COVID-19 globally. We aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody prevalence by city and according to sex, age, ethnicity group, and socioeconomic status, and compare seroprevalence estimates with official statistics on deaths and cases. Methods In this repeated cross-sectional study, we did two seroprevalence surveys in 133 sentinel cities in all Brazilian states. We randomly selected households and randomly selected one individual from all household members. We excluded children younger than 1 year. Presence of antibodies against SARS-CoV-2 was assessed using a lateral flow point-of-care test, the WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech, Guangzhou, China), using two drops of blood from finger prick samples. This lateral-flow assay detects IgG and IgM isotypes that are specific to the SARS-CoV-2 receptor binding domain of the spike protein. Participants also answered short questionnaires on sociodemographic information (sex, age, education, ethnicity, household size, and household assets) and compliance with physical distancing measures. Findings We included 25 025 participants in the first survey (May 14–21) and 31 165 in the second (June 4–7). For the 83 (62%) cities with sample sizes of more than 200 participants in both surveys, the pooled seroprevalence increased from 1·9% (95% CI 1·7–2·1) to 3·1% (2·8–3·4). City-level prevalence ranged from 0% to 25·4% in both surveys. 11 (69%) of 16 cities with prevalence above 2·0% in the first survey were located in a stretch along a 2000 km of the Amazon river in the northern region. In the second survey, we found 34 cities with prevalence above 2·0%, which included the same 11 Amazon cities plus 14 from the northeast region, where prevalence was increasing rapidly. Prevalence levels were lower in the south and centre-west, and intermediate in the southeast, where the highest level was found in Rio de Janeiro (7·5% [4·2–12·2]). In the second survey, prevalence was similar in men and women, but an increased prevalence was observed in participants aged 20–59 years and those living in crowded conditions (4·4% [3·5–5·6] for those living with households with six or more people). Prevalence among Indigenous people was 6·4% (4·1–9·4) compared with 1·4% (1·2–1·7) among White people. Prevalence in the poorest socioeconomic quintile was 3·7% (3·2–4·3) compared with 1·7% (1·4–2·2) in the wealthiest quintile. Interpretation Antibody prevalence was highly heterogeneous by country region, with rapid initial escalation in Brazil's north and northeast. Prevalence is strongly associated with Indigenous ancestry and low socioeconomic status. These population subgroups are unlikely to be protected if the policy response to the pandemic by the national government continues to downplay scientific evidence. Funding Brazilian Ministry of Health, Instituto Serrapilheira, Brazilian Collective Health Association, and the JBS Fazer o Bem Faz Bem.

Population based data on COVID-19 are essential for guiding public policies. We report on the first of a series of planned seroprevalence surveys relying upon on household probabilistic samples of 133 large sentinel cities in Brazil, including 25,025 participants from all 26 states and the Federal District. Seroprevalence of antibodies to SARS-CoV-2, assessed using a lateral flow rapid test, varied markedly across the country’s cities and regions, from below 1% in most cities in the South and Center-West regions to up to 25% in the city of Breves in the Amazon (North) region. Eleven of the 15 cities with the highest seroprevalence were located in the North, including the six cities with highest prevalence which were located along a 2,000 km stretch of the Amazon river. Overall seroprevalence for the 90 cities with sample size of 200 or greater was 1.4% (95% CI 1.3–1.6). Extrapolating this figure to the population of these cities, which represent 25% of the country’s population, led to an estimate of 760,000 cases, as compared to the 104,782 cases reported in official statistics. Seroprevalence did not vary significantly between infancy and age 79 years, but fell by approximately two-thirds after age 80 years. Prevalence was highest among indigenous people (3.7%) and lowest among whites (0.6%), a difference which was maintained when analyses were restricted to the North region, where most indigenous people live. Our results suggest that pandemic is highly heterogenous, with rapid escalation in Brazil’s North and Northeast, and slow progression in the South and Center-West regions.

BackgroundWhile the recommended laboratory diagnosis of COVID-19 is a molecular based assay, population-based studies to determine the prevalence of COVID-19 usually use serological assays.ObjectiveTo evaluate the sensitivity and specificity of a rapid diagnostic test for COVID-19 compared to quantitative reverse transcription polymerase chain reaction (qRT-PCR).MethodsWe evaluated the sensitivity using a panel of finger prick blood samples from participants >18 years of age that had been tested for COVID-19 by qRT-PCR. For assessing specificity, we used serum samples from the 1982 Pelotas (Brazil) Birth Cohort participants collected in 2012 with no exposure to SARS-CoV-2.ResultsThe sensitivity of the test was 77.1% (95% CI 66.6 - 85.6), based upon 83 subjects who had tested positive for qRT-PCR at least 10 days before the rapid diagnostic test (RDT). Based upon 100 sera samples, specificity was 98.0% (95% CI 92.9 - 99.8). There was substantial agreement (Kappa score 0.76) between the qRT-PCR results and the RDT.InterpretationThe validation results are well in line with previous assessments of the test, and confirm that it is sufficiently precise for epidemiological studies aimed at monitoring levels and trends of the COVID-19 pandemic.

COVID-19, the disease produced by the virus SARS-CoV-2, has spread quickly throughout the world, leading the World Health Organization to first classify it as an international health emergency and, subsequently, declaring it pandemic. The number of confirmed cases, as April 11, surpassed 1,700,000, but this figure does not reflect the prevalence of COVID-19 in the population as, in many countries, tests are almost exclusively performed in people with symptoms, particularly severe cases. To properly assess the magnitude of the problem and to contribute to the design of evidence-based policies for fighting COVID-19, one must accurately estimate the population prevalence of infection. Our study is aimed at estimating the prevalence of infected individuals in the state of Rio Grande do Sul, Brazil, to document how fast the infection spreads, and to estimate the proportion of infected persons who present or presented symptoms, as well as the proportion of asymptomatic infections. Four repeated serological surveys will be conducted in probability samples of nine sentinel cities every two weeks. Tests will be performed in 4,500 participants in each survey, totaling18,000 interviews. Interviews and tests will be conducted at the participants' household. A rapid test for the detection of antibodies will be used; the test was validated prior to the beginning of the fieldwork.A COVID-19 é uma doença produzida pelo vírus SARS-CoV-2. Esse vírus se espalhou rapidamente pelo mundo, o que levou a Organização Mundial da Saúde a classificar a COVID-19 como uma emergência de saúde internacional e, posteriormente, a declará-la uma pandemia. O número de casos confirmados, no dia 11 de abril de 2020, já passa de 1.700.000, porém esses dados não refletem a real prevalência de COVID-19 na população, visto que, em muitos países, os testes são quase que exclusivamente realizados em pessoas com sintomas, especialmente os mais graves. Para definir políticas de enfrentamento, é essencial dispor de dados sobre a prevalência real de infecção na população. Este estudo tem por objetivos avaliar a proporção de indivíduos já infectados pelo SARS-CoV-2 no Rio Grande do Sul, Brasil, analisar a velocidade de expansão da infecção e estimar o percentual de infectados com e sem sintomas. Serão realizados quatro inquéritos sorológicos repetidos a cada 15 dias, com amostragem probabilística de nove cidades sentinela, em todas as sub-regiões do Estado. As entrevistas e testes ocorrerão no âmbito domiciliar. Serão utilizados testes rápidos para detecção de anticorpos, validados previamente ao início da coleta de dados.

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.