SARS-CoV-2 Rapid Antigen Test Based on a New Anti-Nucleocapsid Protein Monoclonal Antibody: Development and Real-Time Validation.

SARS-CoV-2 diagnostic tests have become an important tool for pandemic control. Among the alternatives for COVID-19 diagnosis, antigen rapid diagnostic tests (Ag-RDT) are very convenient and widely used. However, as SARS-CoV-2 variants may continuously emerge, the replacement of tests and reagents may be required to maintain the sensitivity of Ag-RDTs. Here, we describe the development and validation of an Ag-RDT during an outbreak of the Omicron variant, including the characterization of a new monoclonal antibody (anti-DTC-N 1B3 mAb) that recognizes the Nucleocapsid protein (N). The anti-DTC-N 1B3 mAb recognized the sequence TFPPTEPKKDKKK located at the C-terminus of the N protein of main SARS-CoV-2 variants of concern. Accordingly, the Ag-RDT prototypes using the anti-DTC-N 1B3 mAB detected all the SARS-CoV-2 variants-Wuhan, Alpha, Gamma, Delta, P2 and Omicron. The performance of the best prototype (sensitivity of 95.2% for samples with Ct ≤ 25; specificity of 98.3% and overall accuracy of 85.0%) met the WHO recommendations. Moreover, results from a patients' follow-up study indicated that, if performed within the first three days after onset of symptoms, the Ag-RDT displayed 100% sensitivity. Thus, the new mAb and the Ag-RDT developed herein may constitute alternative tools for COVID-19 point-of-care diagnosis and epidemiological surveillance.

SARS-CoV-2 rapid antigen test based on a new anti-nucleocapsid protein monoclonal antibody: development and real-time validation

SARS-CoV-2 diagnostic tests have become an important tool for pandemic control. Among the alternatives for COVID-19 diagnosis, antigen rapid diagnostic tests (Ag-RDT) are very convenient and widely used. However, as SARS-CoV-2 variants may continuously emerge, the replacement of tests and reagents may be required to maintain the sensitivity of Ag-RDTs. Here, we describe the development and validation of an Ag-RDT during an outbreak of the Omicron variant, including the characterization of a new monoclonal antibody (anti-DTC-N 1B3 mAb) that recognizes the Nucleocapsid protein (N). The anti-DTC-N 1B3 mAb recognized the sequence TFPPTEPKKDKKK located at the C-terminus of the N protein of main SARS-CoV-2 variants of concern. Accordingly, the Ag-RDT prototypes using the anti-DTC-N 1B3 mAB detected all the SARS-CoV-2 variants—Wuhan, Alpha, Gamma, Delta, P2 and Omicron. The performance of the best prototype (sensitivity of 95.2% for samples with Ct ≤ 25; specificity of 98.3% and overall accuracy of 85.0%) met the WHO recommendations. Moreover, results from a patients’ follow-up study indicated that, if performed within the first three days after onset of symptoms, the Ag-RDT displayed 100% sensitivity. Thus, the new mAb and the Ag-RDT developed herein may constitute alternative tools for COVID-19 point-of-care diagnosis and epidemiological surveillance.

A novel GPIHBP1 mutation related to familial chylomicronemia syndrome: A series of cases.

BACKGROUND AND AIMS: GPIHBP1 is an accessory protein of lipoprotein lipase (LPL) essential for its functioning. Mutations in the GPIHBP1 gene cause a deficit in the action of LPL, leading to severe hypertriglyceridemia and increased risk for acute pancreatitis. METHODS: We describe twelve patients (nine women) with a novel homozygous mutation in intron 2 of the GPIHBP1 gene. RESULTS: All patients were from the Northeastern region of Brazil and presented the same homozygous variant located in a highly conserved 3' splicing acceptor site of the GPIHBP1 gene. This new variant was named c.182-1G > T, according to HGVS recommendations. We verified this new GPIHBP1 variant's effect by using the Human Splicing Finder (HSF) tool. This mutation changes the GPIHBP1 pre-mRNA processing and possibly causes the skipping of the exon 3 of the GPIHBP1 gene, affecting almost 50% of the cysteine-rich Lys6 GPIHBP1 domain. Patients presented with severe hypertriglyceridemia (2351 mg/dl [885-20600]) and low HDL (18 mg/dl [5-41). Four patients (33%) had a previous history of acute pancreatitis. CONCLUSIONS: We describe a novel GPIHBP1 pathogenic intronic mutation of patients from the Northeast region of Brazil, suggesting the occurrence of a founder effect.

Fenilcetonúria associada à alergia à proteína do leite de vaca / Phenylketonuria Associated with Cow Milk Protein Allergy

Introdução: a fenilcetonúria (PKU) é uma doença do metabolismo da fanilalanina cujo tratamento se baseia na introdução precoce de uma fórmula com restrição de fenilalanina. Relato do caso: uma menina, com diagnóstico de PKU a partir da triagem neonatal, com 82 dias de vida, recebeu tratamento dietético com fórmula com restrição de fenilalanina associada à fórmula láctea e desenvolveu alergia à proteína do leite de vaca (APLV) com sintomas cutâneos e gastrointestinais. Conclusão: o manejo dietético da PKU pode precipitar a ocorrência da APLV.

Introduction: Phenylketonuria (PKU) is a disease of the metabolism of phanylalanine whose treatment is based on the early introduction of a phenylalanine-restricted formula. Case report: A girl with 82 days of life with PKU diagnosis from neonatal screening received dietary treatment with a phenylalanine-restricted formula associated with the milk formula. She developed allergy to cow's milk protein (APLV) with cutaneous symptoms and gastrointestinal disorders. Conclusion: Dietary management of PKU may precipitate the occurrence of APLV.

Traditional Plants Used by Remaining Healers from the Region of Grande Dourados, Mato Grosso do Sul, Brazil.

Although the traditional use of medicinal plants is a very widespread practice in Brazil, there are still few studies aimed at native prescribers, known as healers. The aim of this work was to catalog the medicinal species prescribed by remaining healers of the Grande Dourados region, Mato Grosso do Sul, Brazil. Semi-structured interviews were conducted with support of a standardized questionnaire for remaining healers selected using the "snowball" technique. The medicinal species selected were collected, identified, and classified according to the British National Formulary. Remaining healers were identified in seven municipalities in the region of Grande Dourados. Family, divine revelation, and participation of the Catholic Church were the most important sources of knowledge. Seventy-one medicinal species, mainly herbaceous belonging to Asteraceae, Lamiaceae, Amaranthaceae, and Verbenaceae families, were the most prescribed. Most species are used in the treatment of digestive and cardiovascular diseases, in addition to immune and respiratory diseases. Healers from the region of Grande Dourados maintain considerable ethno-knowledge about the medicinal properties of different medicinal species. Sharing this information values their culture and preserves the knowledge for future generations.

Concomitant helminth infection downmodulates the Vaccinia virus-specific immune response and potentiates virus-associated pathology.

The aim of this work was to elucidate the immunopathological mechanisms of how helminths may influence the course of a viral infection, using a murine model. Severe virulence, a relevant increase in the virus titres in the lung and a higher mortality rate were observed in Ascaris and Vaccinia virus (VACV) co-infected mice, compared with VACV mono-infected mice. Immunopathological analysis suggested that the ablation of CD8+ T cells, the marked reduction of circulating CD4+ T cells producing IFN-γ, and the robust pulmonary inflammation were associated with the increase of morbidity/mortality in co-infection and subsequently with the negative impact of concomitant pulmonary ascariasis and respiratory VACV infection for the host. On the other hand, when evaluating the impact of the co-infection on the parasitic burden, co-infected mice presented a marked decrease in the total number of migrating Ascaris lung-stage larvae in comparison with Ascaris mono-infection. Taken together, our major findings suggest that Ascaris and VACV co-infection may potentiate the virus-associated pathology by the downmodulation of the VACV-specific immune response. Moreover, this study provides new evidence of how helminth parasites may influence the course of a coincident viral infection.

Genotypic characterization of psittacid herpesvirus isolates from Brazil

Abstract Thirty-six isolates of psittacid herpesvirus (PsHV), obtained from 12 different species of psittacids in Brazil, were genotypically characterized by restriction fragment length polymorphism (RFLP) analysis and PCR amplification. RFLP analysis with the PstI enzyme revealed four distinct restriction patterns (A1, X, W and Y), of which only A1 (corresponding to PsHV-1) had previously been described. To study PCR amplification patterns, six pairs of primers were used. Using this method, six variants were identified, of which, variants 10, 8, and 9 (in this order) were most prevalent, followed by variants 1, 4, and 5. It was not possible to correlate the PCR and RFLP patterns. Twenty-nine of the 36 isolates were shown to contain a 419 bp fragment of the UL16 gene, displaying high similarity to the PsHV-1 sequences available in GenBank. Comparison of the results with the literature data suggests that the 36 Brazilian isolates from this study belong to genotype 1 and serotype 1.

Genotypic characterization of psittacid herpesvirus isolates from Brazil.

Thirty-six isolates of psittacid herpesvirus (PsHV), obtained from 12 different species of psittacids in Brazil, were genotypically characterized by restriction fragment length polymorphism (RFLP) analysis and PCR amplification. RFLP analysis with the PstI enzyme revealed four distinct restriction patterns (A1, X, W and Y), of which only A1 (corresponding to PsHV-1) had previously been described. To study PCR amplification patterns, six pairs of primers were used. Using this method, six variants were identified, of which, variants 10, 8, and 9 (in this order) were most prevalent, followed by variants 1, 4, and 5. It was not possible to correlate the PCR and RFLP patterns. Twenty-nine of the 36 isolates were shown to contain a 419bp fragment of the UL16 gene, displaying high similarity to the PsHV-1 sequences available in GenBank. Comparison of the results with the literature data suggests that the 36 Brazilian isolates from this study belong to genotype 1 and serotype 1.

An intact signal peptide on dengue virus E protein enhances immunogenicity for CD8(+) T cells and antibody when expressed from modified vaccinia Ankara.

Dengue is a global public health concern and this is aggravated by a lack of vaccines or antiviral therapies. Despite the well-known role of CD8(+) T cells in the immunopathogenesis of Dengue virus (DENV), only recent studies have highlighted the importance of this arm of the immune response in protection against the disease. Thus, the majority of DENV vaccine candidates are designed to achieve protective titers of neutralizing antibodies, with less regard for cellular responses. Here, we used a mouse model to investigate CD8(+) T cell and humoral responses to a set of potential DENV vaccines based on recombinant modified vaccinia virus Ankara (rMVA). To enable this study, we identified two CD8(+) T cell epitopes in the DENV-3 E protein in C57BL/6 mice. Using these we found that all the rMVA vaccines elicited DENV-specific CD8(+) T cells that were cytotoxic in vivo and polyfunctional in vitro. Moreover, vaccines expressing the E protein with an intact signal peptide sequence elicited more DENV-specific CD8(+) T cells than those expressing E proteins in the cytoplasm. Significantly, it was these same ER-targeted E protein vaccines that elicited antibody responses. Our results support the further development of rMVA vaccines expressing DENV E proteins and add to the tools available for dengue vaccine development.

Outbreak of human herpesvirus type 1 infection in nonhuman primates (Callithrix penincillata).

Human herpesvirus type 1 (HHV-1) is widely dispersed among the human population. Although infection is often asymptomatic in humans, nonhuman primates develop a severe and often fatal infection. In August 2006, 13 black-tufted marmosets (Callithrix penincillata) from a group of 14 presented with clinical apathy, anorexia, and ataxia. Physical examination revealed conjunctivitis, erosive or ulcerative lesions on the skin, and swollen lymph nodes. Of the 14 animals captured, 10 died. Grossly, ulcers and erosions were observed on the skin of face, nasal planum, lips, and oral mucosa. Histologically, superficial vesicular and erosive stomatitis with associated basophilic intranuclear inclusion bodies in the squamous epithelium were observed. Swabs from oral lesions and tissue samples from necropsied animals were positive for HHV-1 by nested polymerase chain reaction for eight animals.

Identification and isolation of psittacid herpesvirus from psittacids in Brazil.

Psittacid herpesvirus (PsHV) was isolated from 41 birds kept in captivity in Belo Horizonte, Minas Gerais/Brazil using chicken embryo fibroblasts (CEF) cell cultures. For this study, leukocytes or cloacal swabs of live birds were used. Also, portions of liver, spleen or kidney from birds collected at necropsy were utilized for these tests. PCR tests confirmed the presence of PsHV in 100% of samples. Thirty-three of the PCR products were sequenced and the results disclosed a 99% and 100% identity when compared with other sequences PsHV-1 (AY372243.1 and AF261756.1), previously deposited in GenBank. In addition, histopathology was performed and 19 of the 29 birds contained random multifocal lymphoplasmacytic hepatitis with necrotic foci, suggestive of viral infection. Three samples were examined by electron microscopy to visualize the viral particles obtained from cell culture. The viral structures measured 269 nm in average, had envelopes with an icosahedral capsid and tegument, consistent with herpesvirus. Thus, a total of 41 isolates were obtained from PsHV cell cultivation in CEF, confirming the circulation of the virus between parrots kept in captivity in Belo Horizonte, and affirming the importance of further studies in this area.

Evaluation of the proliferative activity of methanol extracts from six medicinal plants in murine spleen cells

A number of natural compounds have been used as immunomodulatory agents, enabling the function of the immune system to be modified by stimulating or suppressing it. There has been increasing interest in the study of therapeutic action of plant extracts regarding their immunomodulatory activity. The aim of this study was to identify and evaluate the action of extracts of the medicinal plants Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis and Vernonia scorpioides on the development of spleen cells from mice, using the in vitro cellular proliferation assay. The cells, obtained by mechanical rupture of mice spleen (5x10(4) cells/mL), were incubated with methanol extracts (10, 50, 100 and 200 µg/mL) and phytohemagglutinin (PHA, 5 µg/mL). The basal control for proliferation consisted of cells alone, while the positive control consisted of cells and PHA. The cell culture was kept at 37 ºC in 5 percent CO2 for 72 hours, and cell proliferation was revealed by the blue tetrazolium reduction assay (MTT). The results were expressed as percentage of growth and were analyzed using the Kruskal-Wallis and Mann-Whitney tests. The C. brasiliense, I. pes-caprae and M. elaeagnoides extracts showed dose-dependent induction of cell proliferation, with a significant increase in cell proliferation (p<0.03) and percentage growth of 88.2 percent, 73.1 percent and 52.7 percent, respectively, suggesting T lymphocyte stimulation. By contrast, M. robusta, R. imperialis and V. scorpioides extracts showed significance only with a negative percentage of growth, suggesting inhibition of cell proliferation (p<0.04). Further biomonitoring studies will enable the fractions and isolated substances responsible for the immunomodulatory activities to be identified.

Várias substâncias de origem natural têm sido utilizadas como agentes imunomoduladores, permitindo modificar a função do sistema imune e propiciando o estudo de atividades terapêuticas de extratos de plantas. Este trabalho objetivou identificar a atividade imunomodulatória dos extratos de seis plantas medicinais da flora brasileira, Calophyllum brasiliense, Ipomoea pes-caprae, Matayba elaeagnoides, Maytenus robusta, Rubus imperialis e Vernonia scorpioides, sobre a proliferação de células esplênicas de camundongos. As células esplênicas murinas obtidas por ruptura mecânica do baço (5x14³ células/mL) foram incubadas com os extratos metanólicos das plantas (10, 50, 100, 200 µg/mL) e fito-hemaglutinina (PHA, 5 µg/mL). O controle basal de proliferação foi constituído de células apenas e o controle positivo formado por células e PHA. O cultivo celular foi mantido a 37 ºC, 5 por cento de CO2, 72 horas, com quantificação da proliferação celular pelo ensaio de redução do azul de tetrazólio. Os resultados expressos em percentagem de crescimento foram analisados pelos testes de Kruskal-Wallis e Mann-Whitney. Os extratos de C. brasiliense, I. pes-caprae e M. elaeagnoides mostraram indução dose-dependente da proliferação celular (p<0,03), com percentagem de crescimento de, respectivamente, 88,2 por cento, 73,1 por cento e 52,7 por cento, sugerindo estímulo de linfócitos T. Contrariamente, os extratos de M. robusta, R. imperialis e V. scorpioides apresentaram significância apenas com percentagem de crescimento negativa, indicando inibição da proliferação celular (p<0,04). A continuidade no estudo biomonitorado permitirá a identificação das frações e substâncias isoladas responsáveis pelas atividades imunomoduladoras.

Survey of feline leukemia virus and feline coronaviruses in captive neotropical wild felids from Southern Brazil.

A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refúgio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase-PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil.

Naturally occurring feline leukemia virus subgroup A and B infections in urban domestic cats.

A nested-PCR (n-PCR) was used to detect feline leukemia virus (FeLV) proviral DNA in blood samples from 464 sick and 608 healthy domestic cats (Felis catus) selected by convenience, and a significantly high prevalence of FeLV infection was observed. n-PCR results revealed the presence of FeLV proviral DNA in 47.2 % of sick cats and 47.4 % of healthy cats. Phylogenetic analysis revealed that FeLV samples from healthy or sick cats were grouped into separate clades. We determined FeLV subgroups by an n-PCR based on the envelope (env) gene. The partial env gene of FeLV Minas Gerais (MG) samples were compared to various exogenous FeLV isolates and endogenous (enFeLV) provirus from the same region. FeLV-B MG samples were more similar to endogenous sequences and to natural FeLV-B isolates than to either FeLV-A or FeLV-C. The results revealed the circulation of FeLV-B in large populations of urban domestic cats in Brazil.

Prevalência de infecções do trato urinário e bacteriuria em gestantes da clínica ginecológica do ambulatório materno infantil de Tubarão – SC no ano de 2005 / Prevalence of urinary infection and asymptomatic bacteriuria in pregnant in a clinics in south Brazil

Introdução: A prevalência de bacteriúria assintomática é de 10 % na gravidez. A Escherichia coli corresponde a 80-90% das infecções. A cultura de urina deveser usada como um procedimento de rotina na primeira visita pré-natal. O tratamento da bacteriúria assintomáticaprevine complicações na gestação como pielonefrite aguda. Objetivos: Determinar a prevalência de infecção dotrato urinário em gestantes da clínica ginecológica do Ambulatório Materno Infantil de Tubarão-SC no período de 2005. Métodos: Foi realizado um estudo observacional, descritivo sobre registros secundários de todas as gestantes(17 - 40 anos) do Ambulatório Materno Infantil de Tubarão no período 01/01/2005 a 31/12/2005. Resultados: Das 192 gestantes, 70 (36,46%) pacientes foram incluídas com alterações clínicas e/ou laboratoriais de infecção do trato urinário. A solicitação de urocultura foi realizada em 28 (40%) pacientes. Destas, 11 (39,29%) apresentaram urocultura positiva, sendo a Escherichia coli mais prevalente em 45,45%. Prevalência de tratamento medicamentoso nas gestantes queapresentaram alterações clínicas e/ou laboratoriais foi de 45,71%. Conclusões: Urocultura continua sendo o melhor método diagnóstico para infecção do trato urinário. Solicitá-la precocemente na primeira visita pré-natal para diagnosticar e tratar os casos de bacteriúria assintomática torna-se imprescindível para prevenir uma futuracomplicação.

Introduction: The prevalence of asymptomatic bacteriuria is 10% during pregnancy. The Escherichia coli bacterium is responsible for 80-90% of the infections. The urine culture should be used as a routine procedure in the first pre-natal visit. The treatment of asymptomatic bacterium prevents complications during pregnancy such as acute pyelonephritis. Objectives: To determinate the prevalence of urinarytract infection in pregnant women at the Ambulatório Materno Infantil – Tubarão– SC during the period of 2005. Methodology: A descriptive Observational study was realized using secondary records of all pregnant woman (17-40 years old) of the Ambulatório Materno Infantil ofTubarão in the period from January 1st 2005 through December 31st 2005. The information was typed in a file created by the “Epi-data Program” and analyzed in the “Epi-Info Program”. The averages were compared by Kruskal-Wallis test, the proportions by qui-square testor Fisher exact test, when correspondent. Results: Of the 192 pregnant woman, 70 (36,46%)patients were included with clinical and/or laboratorial alterations of urinary tract infection. The uroculture request was realized in 28 (40%) patients. Among them, 11 (39,29%) presented positive uroculture, Escherichia coli being the most prevalent bacteria (45,45%). Theprevalence of the women that presented clinical and/or laboratorial alterations that were treated was 45,71%.Conclusions: Uroculture continues to be the best diagnostics methods for infection of urinary tract. Its earlyrequest in the fist pre-natal visit to diagnose and treat the asymptomatic bacteriuria becomes indispensable inpreventing future complications.