Pathogenesis of Equid Alphaherpesvirus 1 Infection in the Central Nervous System of Mice.

Equid alphaherpesvirus 1 (EHV-1) causes myeloencephalopathy in horses and occasionally in non-equid species. Although mouse models have been developed to understand EHV-1 pathogenesis, few EHV-1 strains have been identified as highly neurovirulent to mice. The aim of this study was to evaluate the pathogenesis of 2 neurovirulent EHV-1 strains in mice, and to characterize the inflammatory cells and expression of chemokines and the apoptosis marker caspase-3 in the brain of infected mice. C57BL/6J mice were inoculated intranasally with EHV-1 strains A4/72 or A9/92 and evaluated on 1, 2, and 3 days post inoculation (DPI). EHV-1-infected mice showed severe neurological signs at 3 DPI. Ultrastructural analysis revealed numerous viral nucleocapsids and fewer enveloped virions within degenerated and necrotic neurons and in the surrounding neuropil. Histologically, at 3 DPI, there was severe diffuse neuronal degeneration and liquefactive necrosis, prominent microgliosis, and perivascular cuffing composed of CD3+ cells (T cells) and Iba-1+ cells (macrophages), mainly in the olfactory bulb and ventral portions of the brain. In these areas, moderate numbers of neuroglial cells expressed CCL5 and CCL2 chemokines. Numerous neurons, including those in less affected areas, were immunolabeled for cleaved caspase-3. In conclusion, neurovirulent EHV-1 strains induced a fulminant necrotizing lymphohistiocytic meningoencephalitis in mice, with microgliosis and expression of chemokines and caspase-3. This model will be useful for understanding the mechanisms underlying the extensive neuropathology induced by these viral infections.

Ocorrência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em ovinos com distúrbios reprodutivos e fatores de risco / Occurrence of antibodies anti-Toxoplasma gondii and anti-Neospora caninum in sheep with history of reproductive disorders and risk factors

Objetivou-se avaliar a ocorrência, sinais clínicos e fatores de risco associados a soropositividade para Toxoplasma gondii e Neospora caninum em ovinos. Foram utilizados 294 animais com histórico de distúrbios reprodutivos de 28 fazendas do estado de São Paulo, Brasil, diagnosticados através da imunofluorescência indireta (1:64 e 1:50). A ocorrência de T. gondii foi de 29,9% (88/294) e de N. caninum 18% (53/294), sendo 3,7% (11/294) dos ovinos soropositivos para ambos. Observou-se com maiores chances à infecção pelo T. gondii: ovinos mestiços (p=0,04), Santa Inês (p=0,006), fornecimento de pastagem (p<0,001) ou associada a concentrado (p<0,001), uso exclusivamente de monta natural (p=0,002, OR=2,28 e IC95%=1,37-3,79) e a presença de aves nas propriedades (p=0,001). Na infecção por N. caninum essa chance aumentou em: fêmeas (p=0,031), propriedades sem aprisco (p<0,001) e sistema de criação semi-intensivo (p<0,001). Em relação ao histórico de problemas reprodutivos, ovelhas infectadas pelo N. caninum e T. gondii apresentaram redução da chance de apresentarem abortamento (p=0,044) e repetição de estro (p=0,025) respectivamente. O T. gondii esteve mais presente sorologicamente que o N. caninum em ovinos com histórico de distúrbios reprodutivos e apesar de suas semelhanças, diferiram epidemiologicamente em aspectos relacionados as características da criação como raça, sexo, sistema de criação, tipo de alimentação e manejo reprodutivo.(AU)

The objective was to evaluate the occurrence, clinical signs and risk factors associated with seropositivity to Toxoplasma gondii and Neospora caninum in sheep. We used 294 sheep with history of reproductive disorders from 28 farms located in the state of São Paulo, southeastern Brazil. Producers were interviewed, and blood samples were collected to perform indirect immunofluorescence tests (1:64 and 1:50 respectively). The frequency of T. gondii infection was found to be 29.9% (88/294), the frequency of N. caninum was 18% (53/294), and 3.7% (11/294) of the sheep were seropositive for both. We observed the following risk factors associated with T. gondii infection: crossbred sheep (p=0.04), Santa Inês breed (p=0.006), pasture supply (p<0.001) or associated with concentrate (p<0.001), exclusive use of natural breeding (p=0.002), and presence of birds on farms (p=0.001). For N. caninum the factors were: female sheep (p=0.031), absence of barns (p<0.001), and semi-intensive system (p<0.001). In relation to the history of reproductive problems, N. caninum and T. gondii infected sheep presented a reduction in the risk of having an abortion (p=0.044) and repeated estrus (p=0.025) respectively. T. gondii was more serologically present than N. caninum in sheep with a history of reproductive disorders and, despite their similarities, differed epidemiologically in aspects related to breeding characteristics such as race, sex, breeding system, type of feeding and reproductive management.(AU)

Pesquisa de anticorpos IgG para Neospora caninum e avaliação dos fatores de risco em ovinos do Estado de Sergipe / Neospora caninum IgG antibody research and evaluation of the risk factors associated to the infection in ovine, State of Sergipe, Brazil

O objetivo desse trabalho foi determinar a ocorrência de anticorpos IgG para Neospora caninum bem como avaliar os fatores de risco associados à infecção em rebanhos ovinos do estado de Sergipe, Brasil. Foram coletadas, nos anos de 2011 e 2012, 1200 amostras de sangue de ovinos oriundos de sessenta propriedades distribuídas em três mesorregiões do estado para pesquisa de anticorpos para N. caninum pela Reação de Imunofluorescência Indireta (RIFI) utilizando-se como ponto de corte de 50 e as amostras diluídas na base 2. Os dados de 34 variáveis estudadas foram obtidos a partir de questionários aplicados aos proprietários e analisados para se determinar a frequências absolutas e relativas e análise dos fatores de risco pelo teste Qui-quadrado de Pearson (p≤0,05). A ocorrência de ovinos soropositivos para N. caninum foi de 39,83% (478/1200). Em relação às mesorregiões a ocorrência de animais e propriedades positivas foi de, respectivamente, 55,88% (380/680) e 88,24% (30/34) na Leste; 21,42% (60/280) e 42,85% (6/14) no Agreste e 15,83% (38/240) e 41,67% (5/12) no Sertão. Os títulos de anticorpos variaram de 50, representando 96,02% (459/478) das amostras soropositivas, a 6400 (1/478). Dentre as variáveis significantes, na analise multivariada, que foram consideradas com fatores de risco para a infecção pelo N. caninum estavam propriedades localizadas na mesorregião Leste (p=0,000, OR=4,64, IC95%=3,36-6,41), presença de fonte de água parada e corrente (p=0,000 OR=2,03, IC95%=1,41-2,92), ausência de quarentena (p=0,000 OR=2,71, IC95%=2,08-3,53), não utilização de esterqueiras (p=0,000 OR=3,14, IC95%=2,45-4,02), criações com finalidade de subsistência (p=0,000 OR=4,99, IC95%=3,15-7,92), de reprodução (p=0,002, OR=1,74, IC95%=1,22-2,49), presença de cães (p=0,000 OR=2,74, IC95%=1,73-433) e circulação de animais silvestres nos rebanhos (p=0,000 OR=3,45, IC95%=2,44-4,87). Os resultados evidenciam a ocorrência de N. caninum em rebanhos ovinos sergipanos, demonstrando o manejo e a localização dos rebanhos no estado como importantes fatores de risco.(AU)

The aim of this study was to determine the occurrence of antibodies IgG against Neospora caninumand evaluate the risk factors associated with the infection in ovine herds, State of Sergipe, Brazil. Blood samples (n=1200) were collected from sheep raised in 60 sheep run located in the three mesoregions of the State of Sergipe, between 2011 e 2012. Antibodies were investigated by Indirect Immunofluorescence Antibody Test of which cutoff point was 50 and positive samples were diluted in base 2 until the last positive titer. Data from 15 variables was obtained from questionnaires given to farmers. Absolute and relative frequencies were determined and the risk factors were analyzed by Pearson's Qui-Square test (p≤0,05). The occurrences of serum reactive sheep were 39.83% (478/1200). The occurrences of positive sheep and sheep run were 55.88% (380/680) and 88.24% (30/34) in the Eastern region; 21.42% (60/280) e 42.85% (6/14) in dry region and 15.83% (38/240) e 41.67% (5/12) in the backwoods respectively. Antibody titers ranged from 50 (n=459), represented 96.02% (459/478) of seropositive samples to 6400 (1/478). Among the significant variables in the multivariate analysis were considered risk factors for infection with N. caninum were, sheep run located in Eastern region (p=0.000, OR=4.64, CI95%=3.36-6.41); standing and running water sources (p=0.000 OR=2.03, CI95%=1.41-2.92), absence of quarantine (p=0.000, OR=2.71, CI95%=2.08-3.53), absence of dunghill (p=0.000, OR=3.14, CI95%=2.45-4.02), presence of dogs (p=0.000, OR=2.74, CI95%=1.73-433), presence of wild animals (p=0.000, OR=3.45, CI95%=2.44-4.87) and subsistence (p=0.000, OR=4.99, CI95%=3.15-7.92) or reproduction (p=0.002, OR=1.74, CI95%=1.22-2.49) livestock were important risk factors. Our results highlight the occurrence ofN. caninumin the ovine herds from State of Sergipe. Management and location of sheep runs were important risk factors associated to the infection.(AU)

Molecular characterization of Brazilian equid herpesvirus type 1 strains based on neuropathogenicity markers.

Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.

Molecular characterization of Brazilian equid herpesvirus type 1 strains based on neuropathogenicity markers

Partial nucleotide sequences of ORF72 (glycoprotein D, gD), ORF64 (infected cell protein 4, ICP4) and ORF30 (DNA polymerase) genes were compared with corresponding sequences of EHV-1 reference strains to characterize the molecular variability of Brazilian strains. Virus isolation assays were applied to 74 samples including visceral tissue, total blood, cerebrospinal fluid (CSF) and nasal swabs of specimens from a total of 64 animals. Only one CSF sample (Iso07/05 strain) was positive by virus isolation in cell culture. EHV-1 Iso07/05 neurologic strain and two abortion visceral tissues samples (Iso11/06 and Iso33/06) were PCR-positive for ORF33 (glycoprotein B, gB) gene of EHV-1. A sequence analysis of the ORF72, ORF64 and ORF30 genes from three EHV-1 archival strains (A3/97, A4/72, A9/92) and three clinical samples (Iso07/05, Iso11/06 and Iso33/06) suggested that among Brazilian EHV-1 strains, the amplified region of the gD gene sequence is highly conserved. Additionally, the analysis of ICP4 gene showed high nucleotide and amino acid identities when compared with genotype P strains, suggesting that the EHV-1 Brazilian strains belonged to the same group. All the EHV-1 Brazilian strains were classified as non-neuropathogenic variants (N752) based on the ORF30 analysis. These findings indicate a high conservation of the gD-, ICP4- and ORF30-encoding sequences. Different pathotypes of the EHV-1 strain might share identical genes with no specific markers, and tissue tropism is not completely dependent on the gD envelope, immediate-early ICP4 and DNA polymerase proteins.

Occurrence of antibodies against Toxoplasma gondii and its isolation and genotyping in donkeys, mules, and horses in Brazil.

The occurrence of antibodies against Toxoplasma gondii was determined in donkeys, mules, and horses from different regions of Brazil. Serum samples from 304 donkeys (67.11%), 118 horses (26.05%), and 31 mules (6.84%) were analyzed by means of the indirect fluorescent antibody test (cutoff=64). Antibodies against T. gondii were detected in 129 equids (28.47%) (82 donkeys, 32 horses, and 15 mules). Tissue samples from 19 seropositive and 50 seronegative animals were obtained in order to isolate the parasite by means of mouse bioassay, and T. gondii was isolated from a donkey. Through genotypic characterization of the isolate, by means of polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) using 11 genotypic markers, the genotype #163 (TgCkBr220), which has already been described in chickens in Brazil, was identified.