Alexandre Mendes Amude

Molecular Detection of Canine Distemper Virus and the Immunohistochemical Characterization of the Neurologic Lesions in Naturally Occurring Old Dog Encephalitis

The current article describes a spontaneous case of old dog encephalitis (ODE) in a 7–year-old, intact, female Miniature Schnauzer dog from Londrina, Paraná, southern Brazil. Unlike conventional distemper encephalomyelitis, ODE is a poorly understood and extremely rare manifestation of Canine distemper virus (CDV) infection. The dog was presented with progressive clinical manifestations consistent with cerebral dysfunction. Briefly, histopathologic lesions were restricted to the forebrain and included chronic multifocal lymphoplasmacytic encephalitis with extensive perivascular cuffing, astrocytosis, and intranuclear inclusions within astrocytes and giant cells, with both intracytoplasmic and intranuclear inclusions. Immunohistochemistry (IHC) was used to identify the antigens of the nucleoprotein (NP) of CDV and to detect cluster of differentiation (CD)3, CD79a, macrophage (MAC) 387, glial fibrillary acidic protein, and vimentin to characterize the neuroparenchymal lesions. By IHC, CDV NP was demonstrated predominantly within neurons and astrocytes. Cells that formed perivascular cuffs and some astrocyte-like cells reacted intensely to vimentin. Reverse transcription polymerase chain reaction assay from brain sections further confirmed a role for CDV in this disease by the amplification and partial sequence analysis of the NP gene. These findings confirmed simultaneous detection of CDV in ODE by IHC and molecular assays. In addition, results of the current study could contribute to the neuropathologic characterization of this rare manifestation of CDV.

Antemortem Diagnosis of CDV Infection by RT-PCR in Distemper Dogs with Neurological Deficits without the Typical Clinical Presentation

In dogs with neurological disturbances without myoclonus and extraneural signs, the clinical diagnosis of distemper is difficult perform. Considering the great infectious potential of the disease, the possibility of carrying out an antemortem diagnosis of distemper is important, particularly in hospitalized patients with neurological disease. The present study was carried out to evaluate RT-PCR for antemortem CDV detection in hospitalized dogs with neurological disturbances without the typical findings of distemper. We investigated five dogs with canine distemper virus (CDV) encephalomyelitis, in which the clinical diagnosis was not performed owing to the absence of characteristic signs of the disease, such as myoclonus and systemic signs. We observed an apparent high sensitivity of RT-PCR in urine samples for detection of CDV: four out of five urine samples were RT-PCR positive. The results of the present study suggest that urine is a good biological sample for antemortem CDV detection by RT-PCR in dogs with distemper encephalomyelitis in which the clinical diagnosis is likely to be difficult owing to the absence of suggestive distemper signs. The use of two different body fluids (urine and CSF) may increase the RT-PCR sensitivity for antemortem diagnosis of distemper in such cases.

Frequency of BCoV detection by a semi-nested PCR assay in faeces of calves from Brazilian cattle herds.

Bovine coronavirus (BCoV) is one of the main causes of neonatal calf diarrhoea. Several diagnostic assays have been employed to detect the presence of the virus in stool samples from calves. Despite this, the frequency of BCoV infection among Brazilian and even South American cattle herds has yet to be well characterised. This study describes the occurrence of BCoV infection among calves from dairy and beef herds in four Brazilian states. A total of 282 stool samples from 1 to 60-day-old calves were evaluated for the presence of BCoV by a semi-nested (SN) PCR assay. The animals were from herds (n = 23) located in three geographical regions in Brazil (south, southeast, and center-west). The specific BCoV amplicon was detected in 15.6% (44/282) of the faecal specimens examined, of which 95.4% (42/44) were from diarrhoeic and 4.6% (2/44) from asymptomatic calves. The specificity of the SN-PCR amplicons was evaluated by restriction fragment length polymorphism (RFLP) analysis. The results show that the BCoV is widespread, mainly among calves from 16 to 30-days-old (p = 0.0023), and verify the association between BCoV infection and clinical signs of diarrhoea (p = 0.005). These findings emphasise the importance of this virus in enteric infections of Brazilian cattle herds.

Virus isolation and molecular characterization of canine distemper virus by RT-PCR from a mature dog with multifocal encephalomyelit

A case of multifocal distemper encephalomyelitis in a mature dog is described. In the presented case the ante mortem clinical diagnosis of canine distemper virus (CDV) infection could not be ideally performed due to the absence of typical signs of distemper, such as myoclonus and systemic signs accompanying the nervous signs. The definitive diagnosis of distemper encephalomyelitis was only carried out at post mortem through virus isolation in cell culture from fresh central nervous system (CNS) fragments and CDV nucleoprotein gene detection in the CNS by RT-PCR.

Neurological and epidemiological aspects of a BoHV-5 meningoencephalitis outbreak

Bovine herpesvirus 5 is a DNA virus that has been associated with meningoencephalitis in young cattle. While its clinical diagnosis is obscured by other major diseases that also produce similar neurological disease in cattle, the use of conventional virological techniques is hampered by the establishment of a lifelong latent infection in the host and the difficulty in differentiating BoHV-1 and BoHV-5. The aim of the current report is to describe the clinical and epidemiological aspects observed in a natural outbreak of BoHV-5 meningoencephalitis in a dairy cattle herd from Brazil. In the outbreak, the affected animals consisted of nine calves, which presented three possible forms of the neurological disease, subjectively classified as peracute, acute, and subacute/chronic. In contrast to conventional herpetic meningoencephalitis, characterized mainly by progressive multifocal brain dysfunctions, BoHV-5 infection resulted in focal non-progressive caudal brainstem dysfunction (pontomedullary syndrome) in an animal presented with subacute/chronic BoHV-5 meningoencephalitis. The evaluation of CNS tissue of affected calves through both histological examination and multiplex-PCR was able to confirm BoHV-5 infection. Additionally, the analysis of CSF samples through PCR allowed ante-mortem BoHV-5 diagnosis during the outbreak, which enabled the implementation of several measures of control for the disease.

First report of feline morbillivirus in South America.

Feline morbillivirus was first identified in healthy and diseased stray cats captured in Hong Kong. Recently, it was demonstrated that the virus circulates within cat populations in Japan, Italy, Germany, and the USA. Importantly, an association between feline morbillivirus infection and chronic kidney disease was suggested by histological analysis of kidney tissue of infected cats. The aim of this study was to verify the presence and examine the genetic diversity of feline morbilliviruses associated with infections of domestic cats in Brazil. Seventeen cats without clinical manifestations of urinary tract diseases from a multi-cat household and 35 random client-owned cats admitted to the Teaching Veterinary Hospital for a variety of reasons were evaluated for paramyxoviral infection and the presence of uropathy. A fragment of the paramyxoviral L gene was amplified from urine samples using a reverse transcription semi-nested PCR assay. For the first time, we detected a feline morbillivirus strain that was genetically related to viral strains previously characterized in Japan in urine samples from cats in South America, in Brazil. This together with the recent description of feline morbillivirus identification within cat populations in the USA, suggests a possible widespread distribution of this viral agent on the American continent. Our data demonstrated feline morbillivirus RNA shedding mostly in the urine of cats without clinical, laboratorial, or ultrasonographic signs of urinary tract diseases. In contrast to previously published findings that associated feline morbillivirus infection with chronic kidney disease, we did not observe a clear relationship between feline morbillivirus RNA shedding in urine and kidney disease in the cats evaluated.

Atypical necrotizing encephalitis associated with systemic canine distemper virus infection in pups.

This report describes the naturally occurring atypical neuropathological manifestation of systemic canine distemper virus (CDV) infection in two 16-day-old Pit Bull pups. CDV-induced changes affected the gray and white matter of the forebrain while sparing the hindbrain. Histologically, there was necrosis with destruction of the nervous parenchyma due to an influx of inflammatory and reactive cells associated with eosinophilic intranuclear inclusion bodies within glial cells. Positive immunoreactivity against CDV antigens was predominantly observed within astrocytes and neurons. RT-PCR was used to amplify CDV-specific amplicons from brain fragments. These findings suggest the participation of CDV in the etiopathogenesis of these lesions.

Canine distemper virus active infection in order Pilosa, family Myrmecophagidae, species Tamandua tetradactyla

Canine distemper virus (CDV) is a highly contagious disease pathogen which causes disease in the domestic dog and species classified in the Canidae, Procyonidae, Mustelidae, Hyaenidae, Ursidae, Viveridae, Felidae, Tayassuidae, and Cercopithecidae families. A combined strategy that involved the direct sequencing of amplicons from genes coding for nucleocapsid, large polymerase, and hemagglutinin proteins of CDV, as well as the pathological findings and the immunohistochemical detection of viral nucleocapsid protein in diverse tissues, confirmed the participation of CDV in the development of a neurological disease in a southern tamandua (Tamandua tetradactyla) from Midwestern Brazil. Phylogenetic analysis based on the hemagglutinin gene sequences revealed that the strain from this study grouped with isolates from the Europe 1/South America 1 lineage. The specific polymorphisms at the SLAM receptor-binding site of the hemagglutinin gene, previously linked to disease emergence in novel hosts, were not detected in this genome. These findings represent the first description of CDV-induced infection in the Tamandua tetradactyla and extend the distribution of this infection to include members of the family Myrmecophagidae, order Pilosa.