Molecular characterization of Bovine leukemia virus (BLV) isolates from Brazil using the env gene sequences revealed a high conservation of this gene. In most cases the substitutions corresponded to silent transitions. In addition, cystein residues, potential glycosylation sites, neutralization domains and other critical residues involved with the envelope structural domains and viral infectivity were conserved. Most of the substitutions found in the aminoacid sequences of the gp51 protein were localized in the G and H epitopes. Using the SIFT software, it was predicted that they should not alter the protein functions. Phylogenetic analyses showed that partial or complete env gene sequences grouped in three or four phylogenetic clusters, respectively. The sequences from the Brazilian isolates had similar mutation rates as compared to samples from other countries, and belonged to at least two phylogenetic clusters.

Bovine leukemia virus (BLV) is a retrovirus that causes lymphoma in cattle worldwide and has also been associated with breast cancer in humans. The mechanism of BLV infection in humans and its implication as a primary cause of cancer in women are not known yet. BLV infection in humans may be caused by the consumption of milk and milk-products or meat from infected animals. Breast cancer incidence rates in Brazil are high, corresponding to 29.5% a year of cancer cases among women. In 2020, an estimated 66,280 new cases of breast cancer are expected, whereas in 2018 breast cancer has led to 17,572 deaths, the highest incidence and lethality among cancers in women in this country that year. BLV infection occurrence ranges from 60 to 95% in dairy herds. In addition, there are some regions, such as the Minas Gerais State, southeastern Brazil, where the population traditionally consume unpasteurized dairy products. Taken together, this study aimed to verify if there is a higher association between breast cancer and the presence of BLV genome in breast tissue samples within this population that consumes raw milk from animals with high rates of BLV infection. A molecular study of two BLV genes was carried out in 88 breast parenchyma samples, between tumors and controls. The amplified fragment was subjected to BLV proviral sequencing and its identity was confirmed using GenBank. BLV proviral genes were amplified from tumor breast parenchyma samples and healthy tissue control samples from women, revealing a 95.9% (47/49) and 59% (23/39) positivity, respectively. Our results show the highest correlation of BLV and human breast cancer found in the world to date within the population of Minas Gerais, Brazil.

Abstract Blood samples and swabs from ocular conjunctiva and mouth were obtained from 64 cats. Of 64 serum samples, 19 were positive for Leishmania antibodies by ELISA (29.80%). Eight cats were positive by PCR (12.5%) in swab samples from mouth and/or ocular mucosa. Poor kappa agreement between serological and molecular results (k = 0.16) was obtained. From five positive PCR samples one was L. braziliensis and four were L. infantum. Phylogenetic analysis performed with the five isolates of Leishmania, showed that samples of L. infantum isolated from the cats were phylogenetically close to those isolated from domestic dogs in Brazil, while the L. braziliensis is very similar to the one described in humans in Venezuela. The study demonstrated that, despite high seropositivity for Leishmania in cats living in the study region, poor agreement between serological and molecular results indicate that positive serology is not indicative of Leishmania infection in cats. Parasite DNA can be detected in ocular conjunctiva and oral swabs from cats, indicating that such samples could be used for diagnosis. Results of phylogenetic analyzes show that L. infantum circulating in Brazil is capable of infecting different hosts, demonstrating the parasite's ability to overcome the interspecies barrier.

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Problem statement:The objective of the present study was to evaluate occurrence of the Feline Immunodeficiency Virus (FIV) and the Feline Leukemia Virus (FeLV) infection in asymptomatic domestic cats in the metropolitan region of Belo Horizonte, Minas Gerais, using the Polymerase Chain Reaction (PCR) for FIV detection and SNAP Combo Plus for FeLV and FIV detection. Approach: Blood samples were collected from the jugular vein of 78 healthy cats, mixed breeds and ages and both sexes. Specific primers were designed for PCR to amplify a 244 bp fragment of FIV gag gene. Results: Five animals (6.41%) were positive by PCR and three animals (3.85%) were positive by SNAP Combo Plus for FIV and 14 animals were positive for FeLV (17.95%). Conclusion: These results suggest that there is a significant occurrence of asymptomatic infected animals which may serve as potential transmitters of FIV and FeLV.

BackgroundThe allergic test of mallein is one of the most frequently used tests, together with the Complement Fixation Test (CFT), for the diagnosis of glanders in endemic areas. Mallein, a purified protein derivative (PPD), is produced similarly to PPD tuberculin and the end product is a primarily proteic antigen, which is only poorly purified. The immuno-allergic activity of mallein is believed to be due to a high molecular weight group of proteins present in the antigen. To improve the quality of the antigen, in terms of sensitivity and specificity, a new method of mallein production was developed, in which purification was accomplished by ultrafiltration in a Tangential Flow Filtration system (TFF).ResultsThe TFF methodology efficiently separated the high and low molecular weight protein groups of mallein. The five TFF-purified malleins, produced from Burkholderia mallei strains isolated from clinical cases of glanders in Brazil, proved to be more potent than standard mallein in the induction of an allergic reaction in sensitized animals. Regarding specificity, two of the purified malleins were equivalent to the standard and three were less specific.ConclusionSome of the TFF-purified malleins showed considerable potential to be used as an auxiliary test in the diagnosis of glanders.

Suid herpesvirus 1 (SuHV-1) is the causative agent of Aujeszky's disease. The infectious agent has only one serotype, but it was classified by restriction enzyme analysis of the whole genome into four genotypes, named I to IV. The aim of this study was to standardize a rapid method for genotyping SuHV-1 without virus isolation, using a multiplex-PCR followed by enzymatic restriction analysis. The complete genome of the virus was analyzed in silico to determine the restriction sites for the enzyme BamHI. Primers were designed to flank sites with emphasis on certain points of differentiation of genotypes. The standard PCRs were able to detect the SuHV-1 and also to differentiate genotypes from brain tissue of infected pigs. The BamHI-PCR is a rapid, practical, and sensitive way to genotype SuHV-1.

Diagnosis and genotyping of pseudorabies virus by nested-PCR and restriction enzyme analysis RESUMO A pseudoraiva (PR) é uma enfermidade viral responsável por consideráveis perdas econômicas na indústria de suínos. O vírus da pseudoraiva (PrV ABSTRACT Pseudorabies is a disease caused by Suid herpesvirus 1 (PrV) and is responsible for considerable economic losses in the swine industry. The PrV has only one serotype, but based on RFLP (restriction fragment length polymorphism) the virus was divided into four genotypes named I, II, III, IV. The classical methods for