Cetacean <i>Morbillivirus</i>: Current knowledge and future directions

We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported

Occurrence of canine parvovirus type 2c in the United States

Canine parvovirus (CPV) type 2 (CPV-2) emerged around 1978 as a major pathogen of dogs worldwide. In the mid-1980s, the original CPV-2 had evolved and was completely replaced by 2 variants, CPV-2a and CPV-2b. In 2000, a new variant of CPV (named CPV-2c) was detected in Italy and now cocirculates with types 2a and 2b in that country. The CPV-2c has also been reported from single outbreaks in Vietnam and Spain. This study was conducted to determine if CPV-2c occurs in the United States. Thirty-three fecal samples were collected from dogs in 16 states between April 2006 and April 2007 and were tested for CPV using real-time polymerase chain reaction (PCR). Positive samples were further tested using conventional PCR and minor-groove binding TaqMan PCR assays to determine the viral type and to differentiate vaccine strains from field strains. Twenty-seven samples were positive for CPV, 7 of which were CPV-2c from 5 states: Arizona, California, Georgia, Oklahoma, and Texas. Of the 7 isolates, 4 differed from European CPV-2c isolates by 2 additional single-nucleotide mutations at positions 4076 and 4104, the latter of which produces a ThrAla change at residue 440 located near a major antigenic site. The coast-to-coast geographic distribution of the states in which CPV-2c was detected strongly suggests that this new CPV variant is probably widespread in the United States. The continuous evolution of CPV requires that monoclonal antibody-based and nucleic acid-based diagnostic assays should be periodically checked for sensitivity on prevalent CPV strains

Manutenção in vitro de células IDE8 em dois tipos de soro bovino In vitro maintenance of IDE8 cells using two types of bovine serum

<abstract language="eng">The present study had the objective of defining the culture conditions, optimizing the maintenance and expansion of an IDE-8 cell line in Brazil, with the aim to propose its use as a model for in vitro infection and multiplication of Brazilian strains of rickettsia and other hemoparasites. The supplementation of IDE-8 cells with two distinct fetal bovine sera (a Brazilian and an imported) was evaluated. Culture media were changed weekly and subcultures were carried out every 15 days. The development of cultures and subcultures was evaluated by the percentage of viability and cellular morphology. The results indicate that the imported SFB can be replaced by the Brazilian SFB one, as no significant differences (P<0.05) were seen among culture viabilities

Prevalence and risk factors associated with bovine viral diarrhea virus infection in dairy herds in Jordan

A cross-sectional study was carried out to determine the seroprevalence and to identify risk factors associated with bovine viral diarrhea virus (BVDV) infection in 62 non-vaccinated dairy herds (671 cows) in Jordan between January and June 2007. Information regarding herd management was recorded through a personal interview with farmers. Antibodies against BVDV were detected using an indirect ELISA test. Chi-square analysis and multivariable logistic regression model were used to identify risk factors for BVDV seropositivity. The true prevalence of antibodies against BVDV in individual cows and cattle herds was 31.6% and 80.7%, respectively. The seroprevalence of BVDV in medium and large size herds was significantly higher than that in smaller herds. There was no significant difference in BVD seroprevalence between different age groups. Random-effects logistic regression model revealed two major factors associated with seropositivity to BVDV; exchange of visits between adjacent farm workers and not isolating newly purchased animals before addition to the herd. The seroprevalence of BVDV in cows located in the northern Jordanian governorates was significantly higher than that in other studied governorates. Results of this study indicated that BVDV is highly prevalent in Jordan and BVDV infection could be controlled by livestock-trade control, and applying strict biosecurity measures in the dairy farms.A. Q. Talafha, S. M. Hirche, M. M. Ababneh, A. M. Al-Majali and M. M. Ababne

Ocorrência de animais persistentemente infectados pelo vírus da diarréia viral bovina em rebanhos bovinos nos Estados de Minas Gerais e São Paulo

A pesquisa de animais persistentemente infectados (PI) pelo vírus da diarréia viral bovina (BVDV) foi realizada em 26 rebanhos bovinos, não vacinados contra o BVDV, localizados nos Estados de Minas Gerais e São Paulo, Brasil. Utilizando uma estratégia de amostragem, de cada rebanho foram obtidas cinco amostras de sangue de bezerros, entre 6 e 12 meses de idade, e os soros sanguíneos foram submetidos ao teste de virusneutralização (VN) para o BVDV-1 e o BVDV-2. Os rebanhos que apresentaram pelo menos três das cinco amostras reagentes a um dos genótipos do BVDV, e com títulos de anticorpos superiores a 128, foram selecionados para a pesquisa de animais PI. Em três rebanhos que apresentaram tal condição, foram colhidas amostras pareadas de sangue de todos os bovinos do rebanho, com intervalo de 30 dias entre as colheitas, e o soro sanguíneo foi submetido ao teste de VN para o BVDV-1 e o BVDV-2. Nas amostras não reagentes a pelo menos um dos genótipos do BVDV e naquelas provenientes de bovinos com menos de seis meses de idade, realizou-se a pesquisa do BVDV pela reação em cadeia da polimerase precedida pela transcrição reversa (RT-PCR). Dos rebanhos analisados, foram detectados dois animais PI a partir de amostras obtidas nas colheitas pareadas provenientes de um rebanho localizado no Estado de Minas Gerais

Aspectos clínicos, patológicos, imuno-histoquímicos e virológicos em cinco bezerros persistentemente infectados com o vírus da diarreia viral bovina em uma propriedade do Rio Grande do Sul

O vírus da diarreia viral bovina (BVDV) é responsável por diferentes síndromes que afetam bovinos em todo o mundo, causando grandes perdas econômicas. O presente trabalho analisou as características clínicas, patológicas e imuno-histoquímicas e virais de cinco bovinos persistentemente infectados pelo BVDV de uma mesma propriedade, localizada no Município de Viamão, Rio Grande do Sul. Dentre os sinais clínicos verificados destacaram-se subdesenvolvimento, secreções nasais e oculares, além de catarata congênita unilateral em dois bovinos. As principais lesões observadas durante a necropsia consistiram de aumento dos linfonodos mesentéricos, evidenciação das placas de Peyer e pododermatite e lesões crostosas no plano nasal e na região periocular em um animal. Os achados microscópicos caracterizavam-se, principalmente, por infiltrado mononuclear na lâmina do intestino delgado e rarefação linfoide com infiltrado histiocitário nos centrofoliculares de linfonodos e nas placas de Peyer. Antígenos virais foram detectados por imuno-histoquímica principalmente em queratinócitos da epiderme, no epitélio de folículos pilosos e células mononucleares da derme de orelhas e pele; histiócitos e em linfócitos dos linfonodos; células foliculares da tireoide; no citoplasma de neurônios e, em menor escala, em células da micróglia no córtex cerebral e no hipocampo. O isolamento viral de amostras de sangue e órgãos dos animais confirmou a presença de BVDV não citopático. Também foi possível detectar a presença do genoma viral por RT-PCR no soro dos animais. A análise filogenética do fragmento parcial da região 5' não traduzida do genoma viral permitiu a classificação da amostra viral como BVDV tipo 2b. O presente estudo reforça a necessidade de investigar e caracterizar surtos de BVD e descrever suas diferentes for-mas de apresentação