RESUMO
BACKGROUND: The presence of lymphoma in buffaloes was first reported in India in the 1960s. The disease is similar to Enzootic Bovine Leucosis (EBL) caused by Bovine leukemia virus (BLV) in cattle; however, according to our results and those of other studies, the etiology of these lymphomas in buffalo do not appear to be associated with BLV. The objectives of this study are to describe four cases of the disease in buffaloes belonging to the same herd in the Amazon region of Brazil and to perform a clinical-anatomopathological, immunohistochemical, and etiological study of the lymphomas. RESULTS: Over a period of ten years, four buffaloes were observed presenting progressive weight loss, swelling of peripheral lymph nodes, and nodules in the subcutaneous tissue. Upon necropsy, whitish-colored tumor masses were observed in the form of nodules in the subcutaneous tissue, along with miliary nodules on the serosal surfaces of abdominal and thoracic organs and tumors in lymph nodes and other organs. Neoplastic lymphocyte proliferation was observed through histopathology. An immunohistochemical study revealed that the neoplasias were formed by proliferation of predominantly B lymphocytes. The presence of BLV genome was not detected in the lymphomas when using the real-time PCR technique, nor was it detected through immunohistochemical staining using monoclonal antibodies against two viral proteins. Bovine herpesvirus 6 was not detected in the tumors. However, Bovine immunodeficiency virus (BIV) was detected in samples of lymphoma and in the lymph nodes and kidneys of one of the animals. CONCLUSIONS: The occurrence of lymphoma in buffaloes is reported for the first time in Brazil and is characterized by B-cell multicentric lymphoma. The etiology of the disease does not appear to be associated with BLV; however, the detection of BIV in samples of lymphoma from one sick animal deserves further study, considering the oncogenic potential of this virus.
Assuntos
Búfalos , Linfoma/veterinária , Animais , Linfócitos B/citologia , Linfócitos B/patologia , Brasil , Proliferação de Células , Feminino , Vírus da Imunodeficiência Bovina/genética , Vírus da Imunodeficiência Bovina/isolamento & purificação , Linfoma/diagnóstico , Linfoma/patologia , Linfoma/virologia , MasculinoRESUMO
Bovine immunodeficiency is a chronic progressive disease caused by a lentivirus that affects cattle and buffaloes. Although the infection has been described in cattle in some countries, including in Brazil, there are only two reports of infection in buffaloes: one in Pakistan and one in Cambodia. The aim of the present study was to survey the occurrence of bovine immunodeficiency virus (BIV) in water buffaloes from the Amazon region, Pará state, Brazil. BIV proviral DNA was surveyed in 607 whole blood samples of water buffaloes from 10 farms located in the state of Pará using semi-nested polymerase chain reaction (PCR) (PCR-SN) to amplify the pol region of the viral genome. Of the 607 samples tested, 27 (4.4 %) were positive for BIV proviral DNA. The amplified fragments were confirmed by sequence analysis after cloning and nucleotide sequencing. The sequence obtained had 99 % similarity to the reference strain (R-29). The present study provides important epidemiological data because BIV was detected for the first time in water buffaloes in Brazil. Further, the results suggest the possibility of the virus being a risk factor for herd health because it may be a potential causal agent of chronic disease and, also may be associated to other infectious diseases.
Assuntos
Búfalos/virologia , Doenças dos Bovinos/diagnóstico , Vírus da Imunodeficiência Bovina/isolamento & purificação , Infecções por Lentivirus/veterinária , Animais , Brasil/epidemiologia , Camboja , Bovinos , Doenças dos Bovinos/epidemiologia , Clonagem Molecular , DNA Viral/isolamento & purificação , Genoma Viral , Vírus da Imunodeficiência Bovina/genética , Infecções por Lentivirus/epidemiologia , Leucócitos/citologia , Paquistão/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Fatores de RiscoRESUMO
Data on the worldwide distribution of bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) is limited. A prevalence study of antibodies to BIV and BLV was conducted in six different cattle herds in Brazil. Out of a total of 238 sera analyzed, 11.7% were found positive for anti-BIV p26 antibodies as determined by Western blot analysis, 2.1% were positive for anti-BLV gp51 antibodies as detected by immunodiffusion test. Peripheral blood mononuclear cells from BIV seropositive cattle were found to have BIV-provirus DNA, as detected by nested polymerase chain reaction. A nucleotide sequence corresponding to a 298 bp fragment of the BIV pol gene was also analyzed. Amino acid sequences of these Brazilian pol gene products showed 98.0 to 100% homology to the American strain BIV R29, 97.0 to 99.0% to Japanese BIV isolates, and divergence ranged from 0 to 4.0% among Brazilian BIV isolates. This evidence of the presence of BIV and BLV infections in Brazil should be considered a health risk to Brazilian cattle populations and a potential causative agent of chronic disease in cattle.
Assuntos
Doenças dos Bovinos/virologia , Vírus da Imunodeficiência Bovina/isolamento & purificação , Infecções por Lentivirus/veterinária , Vírus da Leucemia Bovina/isolamento & purificação , Animais , Anticorpos Antivirais/sangue , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Leucose Enzoótica Bovina/complicações , Leucose Enzoótica Bovina/epidemiologia , Leucose Enzoótica Bovina/virologia , Feminino , Vírus da Imunodeficiência Bovina/genética , Infecções por Lentivirus/complicações , Infecções por Lentivirus/epidemiologia , Infecções por Lentivirus/virologia , Estudos SoroepidemiológicosRESUMO
Serial virus specimens rescued from rabbits, experimentally infected with bovine immunodeficiency (BIV) strain R29, were monitored for changes in quasispecies population, using the single-strand conformation polymorphism (SSCP) analysis. The generation of characteristic SSCP patterns enables the rapid differentiation of BIV variants derived from the conserved part on the env region of the BIV genome, reducing the need for expensive and time-consuming direct sequencing analyses. Our results showed genetic polymorphism among a number of sampled BIV population in experimentally infected rabbits. At least three SSCP patterns (BIV quasispecies) were detected. The SSCP analysis allows for an easy, sensitive, and rapid screening of genetic variants of the virus and the assessment of variation at a number of tissue target sites. These variations may relate to cell-type targets and/or disease progression, and could be significant to our understanding of lentiviral pathogenesis.