Genomic monitoring unveils a high prevalence of severe acute respiratory syndrome coronavirus 2 Omicron variant in vaccine breakthrough cases in Bahia, Brazil

SUMMARY OBJECTIVE: Genome sequencing has been proved to be an excellent tool to monitor the molecular epidemiology of the disease caused by severe acute respiratory syndrome coronavirus 2, i.e., coronavirus disease 2019. Some reports of infected, vaccinated individuals have aroused great interest because they are primarily being infected with circulating variants of concern. To investigate the cases of infected, vaccinated individuals in Salvador, Bahia, Brazil, we performed genomic monitoring to estimate the magnitude of the different variants of concern in these cases. METHODS: Nasopharyngeal swabs from infected (symptomatic and asymptomatic), vaccinated or unvaccinated individuals (n=29), and quantitative reverse transcription polymerase chain reaction cycle threshold value (Ct values) of ≤30 were subjected to viral sequencing using nanopore technology. RESULTS: Our analysis revealed that the Omicron variant was found in 99% of cases and the Delta variant was found in only one case. Infected, fully vaccinated patients have a favorable clinical prognosis; however, within the community, they become viral carriers with the aggravating factor of viral dissemination of variants of concern not neutralized by the currently available vaccines. CONCLUSION: It is important to acknowledge the limitations of these vaccines and to develop new vaccines to emergent variants of concern, as is the case of influenza vaccine; going through new doses of the same coronavirus vaccines is "more of the same."

The prognostic role of variations in tumour markers (CEA, CA15.3) in patients with metastatic breast cancer treated with CDK4/6 inhibitors.

Tumour markers have no established role in the monitoring of the course of metastatic breast cancer during antineoplastic therapy, yet cancer antigen 15.3 (CA15.3) and carcinoembryonic antigen (CEA) are commonly used in clinical practice to aid in the early detection of progression of disease (PD). In our multicentre, prospective, real-life study, we enrolled 142 consecutive patients with advanced breast cancer receiving endocrine therapy in combination with a CDK4/6 inhibitor from January 2017 to October 2020; 75 patients had PD at the time of database closure. We measured serum marker concentrations at regular 4-month intervals together with radiological tumour response assessments and in cases of clinical suspicion of PD. Appropriate descriptive and inferential statistical methods were used to analyse serum marker level trends amongst prespecified subgroups and at specific time points (baseline, best radiologically documented tumour response and first detection of PD) in the subpopulation of patients with PD at the time of database closure. Notably, the median time from treatment initiation to best tumour response was 4.4 months. We evaluated the presence of an association between baseline CA15.3 and CEA levels and prespecified clinical characteristics but found no clinically meaningful correlation. We assessed marker level variations at the time of best radiologically documented disease response and PD: in the subgroup of patients who responded to treatment before progressing, we detected a statistically significant correlation with tumour marker variation between the time of best response and progression; this finding was not confirmed in the subgroup of patients that did not benefit from treatment. In conclusion, serum tumour marker flares can be useful in the early diagnosis of PD but should not be used as the sole factor prompting a change in treatment strategy without radiological confirmation.

Development of monoclonal antibodies against prM of Dengue virus 4 / Desenvolvimento de anticorpos monoclonais para prM de Dengue vírus 4

Introduction: dengue is a most common mosquito-borne viral disease in the Americas and tropical countries. Objective: in this work, mice were hyperimmunized with DENV 4 antigen to produce monoclonal antibodies (mAbs). Methodology: DENV 4 (GenBank KC806069) was inoculated in C6/36 cell monolayers cultivated in Leibovitz's 15 medium supplemented with 5% fetal bovine serum and incubated at 28 oC. The virus stock was submitted to concentration and ultracentrifugation and stored at -80 oC until use (VC DENV 4). Balb/c mice were injected intraperitoneally with 50µg of DENV-4 and successive intraperitoneal injections of 25 µg of VCDENV 4 with Freund's incomplete adjuvant were performed. The spleen cells were fused to SP2/0 myeloma cells with PEG 1540 and distributed in 96-well microplates with Iscove's modified medium with Hipoxantina­Aminopterina­Timidina. Hybridoma screening by indirect ELISA showed positive results for six mAbs, and their characterization was performed by Western blotting and Indirect Immunofluorescence (IFI) techniques. Results: the six mAbs showed strong recognition of prM (24/29 kDa), and minor reaction to E protein (66 kDa), E/E protein dimer (105 kDa), and NS1 (49 kDa) protein in two mAbs. The use of mAbs anti-prM as a diagnostic tool using IFI has been demonstrated to detect DENV-4 antigen in infected cells or tissues. Conclusion: DENV 4 generate mAbs with strong reactivity to prM with potential use to confirm the presence of DENV 4 antigen in tissues or infected cells.

Introdução: a dengue é uma doença viral transmitida por mosquitos comumente das Américas e países tropicais. Objetivo: neste trabalho, camundongos foram hiperimunizados com antígeno DENV 4 para produzir anticorpos monoclonais (mAbs). Metodologia: DENV 4 (GenBank KC806069) foi inoculado em monocamadas de células C6 / 36 cultivadas em meio Leibovitz 15 suplementado com 5% de soro fetal bovino e incubadas a 28oC. O estoque viral foi submetido à concentração, ultracentrifugação e armazenado a -80 oC (VC DENV 4). Camundongos Balb / c foram injetados intraperitonealmente com 50 µg de VC DENV-4 e injeções intraperitoneais sucessivas de 25 µg de antigeno com adjuvante incompleto de Freund. As células do baço foram misturadas a células SP2/0 com PEG 1540 e distribuídas em microplacas de 96 poços com meio Iscove Modificado em presença de Hipoxantina ­ Aminopterina ­ Timidina. A triagem de hibridomas por ELISA indireto apresentou resultados positivos para seis mAbs, e sua caracterização foi realizada por técnicas de Western blotting e Imunofluorescência Indireta (IFI). Resultados: os seis mAbs mostraram forte reconhecimento de prM (24/29 kDa) e reação menor à proteína E (66 kDa), dímero de proteína E / E (105 kDa) e proteína NS1 (49 kDa) em dois mAbs. O uso de mAbs anti-prM como uma ferramenta de diagnóstico utilizando IFI demonstrou eficacia em detectar o antígeno DENV-4 em células ou tecidos infectados. Conclusão: o mAbs produzidos para DENV 4 demonstraram uma forte reatividade contra prM, e poderiam ser uma ferramenta de uso potencial no diagnóstico de DENV 4 .

Leptomeningeal carcinomatosis and breast cancer: a systematic review of current evidence on diagnosis, treatment and prognosis.

Leptomeningeal carcinomatosis (LC) is a rare but challenging manifestation of advanced breast cancer with a severe impact on morbidity and mortality. We performed a systematic review of the evidence published over the last two decades, focusing on recent advances in the diagnostic and therapeutic options of LC. Lobular histology and a triple-negative intrinsic subtype are well-known risk factors for LC. Clinical manifestations are diverse and often aspecific. There is no gold standard for LC diagnosis: MRI and cerebrospinal fluid cytology are the most frequently used modalities despite the low accuracy. Current standard of care involves a multimodal strategy including systemic and intrathecal chemotherapy in combination with brain radiotherapy. Intrathecal chemotherapy has been widely used through the years despite the lack of data from randomized controlled trials and conflicting evidence on patient outcomes. No specific chemotherapeutic agent has shown superiority over others for both intrathecal and systemic treatment. Although endocrine therapy was heuristically considered unable to exert significant control on central nervous system metastatic disease, retrospective data suggest a favourable toxicity profile and even a possible positive impact on survival. In recent years, encouraging data on the use of targeted agents has emerged but further research in this field is required. Palliative treatment in the form of whole brain or stereotactic radiotherapy is associated with improvement in clinical manifestations and quality of life, with no proven impact on survival. The most investigated prognostic factors include performance status, non-triple-negative disease and multimodal treatment. Validation of prognostic scores is necessary to aid clinicians in the identification of patient subgroups that are most likely to benefit from an intensive therapeutic approach.

SARS-CoV-2 infection in pregnant women and newborns in two maternity hospitals in Salvador-Bahia, Brazil

ABSTRACT The outbreak of the new coronavirus (SARS-CoV-2) causing the coronavirus disease (COVID-19) has spread globally. As of June 18, 2020, a high maternal mortality rate due to SARS-CoV-2 infections was identified in Brazil, representing most of the world cases at that time. An observational, cross-sectional study was performed with pregnant women admitted in two maternity hospitals located in Salvador/Bahia and their newborns, from May 24th up to July 17th of 2020. Among 329 pregnant women enrolled at hospital admission, a high prevalence (n=28; 8.5%) of pregnant women with COVID-19 was observed, as well as a high proportion of asymptomatic cases (n=19; 67.9%). Two newborns had detectable SARS-CoV-2 but evolved without abnormalities. This data highlight the importance of identifying pregnant women with COVID-19 for proper isolation measures to prevent in-hospital transmission.

Clinical and laboratory findings of acute Zika virus infection in patients from Salvador during the first Brazilian epidemic

Abstract Several major epidemics of Zika fever, caused by the ZIKA virus (ZIKV), have emerged in Brazil since early 2015, eventually spreading to other countries on the South American continent. The present study describes the clinical manifestations and laboratory findings of patients with confirmed acute ZIKV infection during the first epidemic that occurred in Salvador, Brazil. All included patients were seen at the emergency room of a private tertiary hospital located in Salvador, Brazil from 2015 through 2017. Patients were considered eligible if signs of systemic viral febrile disease were present. All individuals were tested for ZIKV and Chikungunya infection using PCR, while rapid test was used to detect Dengue virus antibodies or, alternatively, the NS1 antigen. A diagnosis of acute ZIKV infection was confirmed in 78/434 (18%) individuals with systemic viral febrile illness. Positivity was mainly observed in blood, followed by saliva and urine. Coinfection with Chikungunya and/or Dengue virus was detected in 5% of the ZIKV-infected patients. The most frequent clinical findings were myalgia, arthralgia and low-grade fever. Laboratory analysis demonstrated normal levels of hematocrit, platelets and liver enzymes. In summary, in acute settings where molecular testing remains unavailable, clinicians face difficulties to confirm the diagnosis of ZIKV infection, as they rely only on clinical examinations and conventional laboratory tests.

Genomic surveillance of the Chikungunya Virus (CHIKV) in Northeast Brazil after the first outbreak in 2014

Abstract INTRODUCTION: We performed an epidemiological surveillance of the Chikungunya (CHIKV) lineages in Bahia after the 2014 East/Central/South African (ECSA) genotype outbreak. METHODS: Reverse-transcription polymerase chain reaction (RT-PCR), viral isolation, and phylogenetic analyses were conducted on serum samples from 605 patients with CHIKV-like symptoms during 2014-2018. RESULTS: Of the 605 samples, 167 were CHIKV-positive. Viral isolation was achieved for 20 samples; their phylogenetic analysis (E2 protein) revealed the presence of ECSA lineage and reinforced the phylogenetic relationship between ECSA and Indian Ocean lineages. CONCLUSIONS: The genomic surveillance of CHIKV showed that only ECSA lineage circulated in Bahia since the 2014 outbreak.

A localized outbreak of Chikungunya virus in Salvador, Bahia, Brazil

A localized Chikungunya virus (CHIKV; East/Central/South African genotype) outbreak (50 cases, 70% laboratory-confirmed; attack rate: 5.3 confirmed cases/100 people) occurred in a Salvador, Brazil neighborhood, between Apr-Jun/2017. Highly clustered cases in space and time, mostly along a single street, highlight an increased risk of CHIKV transmission among pockets of susceptible populations. This finding underscores the need for ongoing local level surveillance for arboviral outbreaks.

Gastroenterite aguda associada a variantes do Norovírus GII. 4 / Acute gastroenteritis associated with norovirus gii. 4 variants

ABSTRACT BACKGROUND: Norovirus (NoV) is an important etiologic agent of acute gastroenteritis and infects individuals of all ages, especially children in Brazil and worldwide. NoV GII.4 was the most prevalent genotype worldwide because of your extensive genetic diversity. In Brazil, especially in the Northeast, few studies have been developed for identify and molecularly characterize NoV. OBJECTIVE: The present study aimed to detect and describe the molecular epidemiology of NoV associated with acute gastroenteritis. METHODS: The viral RNA extracted from stool samples were subjected to Nested RT-PCR and the genotypes were determined by nucleotide sequences analysis. In total, 278 stool samples assisted at Aliança Hospital in the city of Salvador, with acute gastroenteritis were examined, between March 2009 and July 2012. RESULTS: A high NoV rate (54.2%) was identified in children under 5 years of age. We detected the circulation of different NoV GII.4 variants in Salvador, during the study period as Den Haag 2006b, New Orleans 2009 and Sydney 2012. CONCLUSION: These findings reinforce the need to study the molecular epidemiology of NoV infections in acute gastroenteritis.

RESUMO CONTEXTO: Norovírus (NoV) é o agente etiológico mais importante nas gastroenterites agudas e infecta indivíduos de todas as idades, especialmente crianças no Brasil e no mundo. O NoV GII.4 é o genótipo mais prevalente em todo o mundo devido a sua elevada diversidade genética. No Brasil, principalmente no Nordeste, poucos estudos têm sido desenvolvidos a fim de identificar e caracterizar molecularmente o NoV. OBJETIVO: O presente estudo teve como objetivo detectar e descrever a epidemiologia molecular do NoV associado com gastroenterite aguda. MÉTODOS: RNA viral extraído a de amostras de fezes foi submetido a amplificação por Nested-RT-PCR e o genótipo determinado por analise da sequência de nucleotídeos. Um total de 278 amostras de pacientes atendidos no Hospital Aliança, na cidade de Salvador, com gastroenterite aguda foram examinados, entre março de 2009 a julho de 2012. RESULTADOS: Uma alta taxa de NoV (54,2%) foi identificado em crianças de até 5 anos de idade. Detectou-se a circulação de diferentes variantes de NoV GII.4 em Salvador, durante o período do estudo, tais como Den Haag 2006b, New Orleans 2009 e Sydney 2012. CONCLUSÃO: Estes achados reforçam a necessidade de maiores estudos para esclarecer a epidemiologia molecular das infecções por NoV em casos de gastroenterite aguda.

Characterization of isolates of equine infectious anemia virus in Brazil.

Equine infectious anemia is an important infectious disease that affects equids worldwide. Control of the disease is currently based on detection of anti-p26 EIAV by Agar Gel Immunodiffusion (AGID). In this work, 62 animals were examined by AGID and nested-PCR using primers for the gag gene. Fifty-three samples (85.5%) were positive by nested-PCR, whereas only 33 samples (53%) were positive for AGID. Fifteen amplicons obtained by nested-PCR were sequenced and the aligned results subjected to phylogenetic analysis. The analysis suggests that the Brazilian EIAV form a cluster with WSU5, EIAVUK and Wyoming strains from United States.

Zika virus infection induces mitosis abnormalities and apoptotic cell death of human neural progenitor cells.

Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC). We found that NPC are highly susceptible to ZIKV and the infection results in cell death. ZIKV infection led to a marked reduction in cell proliferation, ultrastructural alterations and induction of autophagy. Induction of apoptosis of Sox2+ cells was demonstrated by activation of caspases 3/7, 8 and 9, and by ultrastructural and flow cytometry analyses. ZIKV-induced death of Sox2+ cells was prevented by incubation with the pan-caspase inhibitor, Z-VAD-FMK. By confocal microscopy analysis we found an increased number of cells with supernumerary centrosomes. Live imaging showed a significant increase in mitosis abnormalities, including multipolar spindle, chromosome laggards, micronuclei and death of progeny after cell division. FISH analysis for chromosomes 12 and 17 showed increased frequency of aneuploidy, such as monosomy, trisomy and polyploidy. Our study reinforces the link between ZIKV and abnormalities in the developing human brain, including microcephaly.

Human bocavirus in acute gastroenteritis in children in Brazil.

Epidemiological surveillance for Human Bocavirus (HBoV) was conducted on 105 fecal specimens from children with acute gastroenteritis in Bahia, Brazil. Among of a total 105 stool samples, 44 samples were positive for HBoV as detected by nested-PCR. Of the 44 positive samples, co-infections with other enteric viruses (Norovirus, Adenovirus, and Rotavirus) were found in 12 pediatric patients. Mixed infections among HBoV with Norovirus were frequently observed in this population. The phylogenetic analysis identified the presence of HBoV-1, and HBoV 2A species. This study shows that HBoV is another viral pathogen in the etiology of acute gastroenteritis in children in Bahia, Brazil.

Monoclonal antibodies against Caprine arthritis-encephalitis virus epitopes in the p28 and p55(gag) viral proteins.

The genome of the Caprine Arthritis-Encephalitis Virus (CAEV) encodes the polycistronic precursor protein p55(gag). Proteolytic cleavage of p55(gag) generates the viral core proteins. Some studies suggest that the CAEV p55(gag) protein contains epitopes or antigenic determinants for these core proteins. This work reinforces this hypothesis and demonstrates that monoclonal antibodies (MAbs) that are directed against the capsid protein (p28) of CAEV are also reactive against the precursor p55(gag) protein and the intermediate cleavage products, p44, p36 and p22. The major activity of the MAbs was directed against p28. The MAbF12 binding site in p28 was found to be a linear epitope with a structure that is stable after SDS treatment and remains unaltered after ß-mercaptoethanol (ß-ME) treatment. The MAbF12 binding site in the p55(gag), p36 and p22 proteins was found to be a linear epitope with cross-linked sulphide bonds. In conclusion, these findings suggest that the p28 epitope is presented differently from the epitope in the polycistronic precursor protein p55(gag). The highly immunogenic p28 contains a linear epitope that is detergent-stable and is not altered by ß-ME treatment, whereas the p55(gag) epitope contains a linear epitope susceptible to denaturing agents.

Primeiro relato do vírus Orf em rebanhos caprinos do semiárido brasileiro / First report on the Orf virus infection in goat herds from Brazilian semiarid region

O Ectima contagioso, popularmente conhecido como Boqueira, é uma doença causada pelo vírus Orf, que induz lesões pustulares agudas na pele de ovinos e caprinos. No presente trabalho, é relatada pela primeira vez a identificação e confirmação laboratorial do vírus Orf em rebanhos caprinos da Bahia. A Agência Estadual de Defesa Agropecuária da Bahia (ADAB) relatou a ocorrência de focos de uma doença epitelial nos caprinos das raças Canindé e Alpina Britânica nas localidades de Barreira e Pedra Alta, no município de Araci. Foram coletadas as amostras das lesões de crostas labiais do rebanho da localidade de Barreira e das crostas dos tetos do rebanho de Pedra Alta. Os materiais coletados foram submetidos à extração de DNA e posterior reação em cadeia da polimerase (PCR), para amplificação dos genes do vírus Orf: ORFV011 (B2L, 1022 pares de bases [pb]) e ORFV 059 (F1L, 1062 pb). Todas as amostras foram positivas na reação de PCR, confirmando-se a presença do vírus Orf nas lesões observadas nos rebanhos caprinos das comunidades de Barreira e Pedra Alta.

Asymptomatic oral human papillomavirus (HPV) infection in women with a histopathologic diagnosis of genital HPV.

The oral route of human papillomavirus (HPV) transmission is not fully understood. It has been suggested that genital infection can act as a reservoir for oral HPV infection. We investigated the presence of oral HPV DNA and anti-HPV IgA in the buccal cavity of patients with a histopathologic diagnosis of cervical HPV infection. One hundred women underwent oral clinical examinations to detect HPV-DNA by polymerase chain reaction and salivary anti-HPV IgA by indirect immunofluorescence. Information on the personal habits of all the women was collected in personal interviews. Our results showed that 99% of the patients had no clinical manifestations of oral HPV. However, HPV DNA was detected in 81% of oral mucosa samples, and anti-HPV IgA was detected in the saliva of 44% of the patients. Consumption of alcoholic beverages was significantly associated with detection of oral HPV DNA and salivary anti-HPV IgA. Other behavioral risk factors associated with oral HPV and anti-HPV IgA are also discussed. In conclusion, patients with genital HPV infection are at risk for subclinical oral HPV infection. Thus, a molecular assay might be necessary to diagnose such infections.

Produção de antígeno viral para o sorodiagnóstico da artrite-encefalite caprina utilizando um teste imunoenzimático (ELISA) / Viral antigen production for the sorodiagnóstico of the goat artrite-encefalite using one has tested imunoenzimático

O vírus da Artrite-encefalite caprina (CAEV) é um Lentivírus de pequenos ruminantes, que causa uma doença crônica e progressiva, caracterizada por encefalomielite, mastite, pneumonia e artrite. O diagnóstico é baseado na detecção de anticorpos contra o vírus através da Imunodifusão em Gel de Agarose (IDGA), técnica sorológica de referência para CAEV, porém de baixa sensibilidade. O objetivo deste trabalho foi produzir um antígeno a partir da cultura de células de membrana sinovial caprina (MSC) infectadas com a CAEV, para ser utilizado em um teste diagnóstico (ELISA indireto). O antígeno foi obtido de culturas de células de MSC infectadas e posterior tratamento com SDS 0,1%. Amostras de soros caprinos (n=343) foram utilizadas para detectar a presença de anticorpos para CAEV pelo teste ELISA indireto e a técnica IDGA. Nessas amostras, o teste ELISA detectou 72 (21%) amostras positivas. Entretanto, o teste IDGA detectou 30 (8%) amostras positivas. O ELISA indireto também detectou precocemente uma soroconversão em 5 animais de um total de 13 controlados periodicamente durante 2 anos. A sensibilidade e a especificidade do teste ELISA com relação a IDGA foi de 73,3% e 84% respectivamente. Esse ELISA com o antígeno viral assim produzido mostrou-se efetivo, de baixo custo e sensível para o diagnóstico sorológico de anticorpos para CAEV.

Molecular characterization of group A rotavirus isolates obtained from hospitalized children in Salvador, Bahia, Brazil

Rotavirus is a major cause of infectious diarrhea in infants and young children. The objective of this study was to characterize the genotypes of Human Rotavirus found in children hospitalized with acute diarrhea in the Pediatric Hospital Prof. Hosannah de Oliveira of the UFBA in Salvador, Bahia, Brazil, during the years of 1999, 2000 and 2002. Fecal samples were analyzed (n=358) by methods EIARA and SDS-PAGE for detection of Rotavirus. Positive samples of one or two of these methods (n=168) were submitted to RT-PCR and Multiplex-Nested PCR to determine genotypes G and P. A hundred sixty-eight (46.9 percent) samples were positive and 190 (53.1 percent) negative. Only 17 (4.7 percent) samples had divergent results. The distribution of genotypes G during the first year, showed that the genotype G9 was present in 96,8 percent of the analyzed samples, in the second year, it was responsible for 96 percent and in the third year, 88,1 percent. The characterization of genotypes P demonstrated that the genotype P1A[8] was the most outstanding in all years. In this study we discuss the benefit to control the genotypes of Rotavirus through the molecular characterization for the development of potential vaccines.

Isolamento e identificação do vírus da Artrite encefalite caprina, a partir do co-cultivo de células mononucleares do sangue com células de membrana sinovial de cabra / Isolation and identification of the caprine arthritis-encephalitis virus from the co-cultivation of peripheral blood mononuclear cells with goat membrane sinovial cells

O vírus da Artrite encefalite caprina é o agente causal de uma doença progressiva e debilitante em caprinos, em que as células da linhagem monócito/macrófago são as principais hospedeiras do vírus in vivo. Essas células estão presentes no colostro, no leite ou no sangue. Estudos demonstram que a replicação viral é dependente do nível de maturação ou diferenciação da célula monocítica, influenciando na sensibilidade de detecção do vírus. Neste estudo, utilizamos o cocultivo de monócitos/macrófagos com células de membrana sinovial de cabras, para o isolamento do vírus circulante no campo; a técnica de double nested PCR (dn PCR) dos co-cultivos e sangue, viabilizou a confirmação do isolamento viral, e a detecção direta do vírus no sangue. Através dessa técnica, detectou-se a presença do DNA proviral em animais soronegativos por Imunodifusão em Gel de Agarose (IDGA); esses achados confirmam que o tempo entre o inicio da infecção e o aparecimento de anticorpos no sangue é variável, facilitando a permanência de animais falsos-negativos no rebanho. Nas amostras processadas, tivemos uma divergência de resultados entre amostras sorologicamente positivas, entretanto, negativas por dn PCR, quando se utilizou a amplificação direta do sangue. Quanto ao cultivo de monócitos/ macrófagos in vitro e posterior co-cultivo com células de MSC obteve-se êxito pelo isolamento do vírus em quatro animais, havendo sido um deles soronegativo. O presente estudo demonstra o primeiro isolamento do vírus nos rebanhos do estado da Bahia, além da implementação da técnica de dn PCR, em co-cultivo de células.

Pesquisa do vírus da diarréia viral bovina em bovinos jovens / Investigation of bovine viral diarrhea virus in young bovines

Nesta pesquisa analisamos a presença do vírus da Diarréia viral bovina em bovinos jovens através de um estudo sorológico e isolamento viral. A técnica de seroneutralização detectou de um total de 220 bovinos, 123 (56 por cento) animais sorologicamente positivos. A distribuição dos títulos de anticorpos soroneutralizantes(TSN), mostrou que 82 por cento das amostras apresentaram TSN de até 512, enquanto que 18 por cento apresentaram TSN maiores que 512. O isolamento viral a partir da fração leucocitaria desses bovinos, confirmou a presença do vírus em quatro bovinos aparentemente saudáveis e de um bezerro com sintomatologia respiratória. Os cinco isolados virais não apresentaram efeito citopático nos cultivos celulares.