Bovine viral diarrhea virus-infected MDBK monolayer as antigen in enzyme-linked immunosorbent assay (ELISA) for the measurement of antibodies in bovine sera.

A specific ELISA for the detection of IgG antibodies against bovine viral diarrhea virus (BVDV) has been developed and was compared with the seroneutralization (SN) titers for a total of 60 bovine serum samples. A BVDV-infected Madin-Darby Bovine Kidney (MDBK) cell monolayer served as test antigen. The following results were obtained: a coefficient of correlation (r) of 0.63 (P less than 0.01) between BVDV-ELISA and SN titer in BVDV-seroconverted animals and 0.71 for all sera, including that from BVDV vaccinated animals; a sensitivity of 92%, a specificity of 91%, a concordance of 92%; and a demonstration of a parallel increase in BVDV-ELISA and SN titers in animals with seroconversion. The BVDV-ELISA permits a more complete evaluation of the humoral immune response to BVDV.

Importance of primer selection in the application of PCR technology to the diagnosis of bovine leukemia virus.

The polymerase chain reaction (PCR) was used to detect bovine leukemia virus in bovine blood samples. When applied to leucocytes extracted from the blood samples, the standard method of DNA extraction gave good correlation with agar gel immunodiffusion, but a method in which 5 microliters of blood was the starting material was unreliable. Selection of the primers was important, and differences in results were observed when the PCR method was applied to blood samples from different geographic areas. The sensitivity varied from 50% to 90%, depending on the primer set applied to the gag gene of proviral nucleic acid. This variation was based on geographic origin of the cattle, suggesting an influence of viral strain. In some areas, more than 1 primer may needed to optimize results.

A generalized inclusion body disease in the budgerigar (Melopsittacus undulatus) caused by a papovavirus-like agent.

High mortality rates have been reported in budgerigars between one and 15 days of age in 19 aviaries in the Province of Quebec. The most consistent signs of disease were abdominal distention, lack of down feathers on the back and abdomen, lack of filoplumes on the head and neck, and retarded growth of the tail and contour feathers in birds that either survived or died later. Internal gross lesions were hydropericardium, enlarged heart and liver with multiple pinpoint white spots or large, yellow foci, pale or congested kidneys, congested lungs, and ascites. Histologic examination revealed large, slightly basophilic inclusion bodies in the enlarged nuclei of many different cells. These inclusion bodies were composed of viral particles. Multiple foci of coagulation necrosis were scattered in the myocardium and liver parenchyma, and granulovacuolar degeneration was common in renal tubular epithelial cells. Ballooning degeneration was multifocal in the epidermis and very extensive in the epithelial cells of developing feather follicles, and this led to their partial or complete destruction. Viral particles 50 to 55 nm in diameter were observed in negatively stained preparations from different organs of affected birds. These particles had the size and morphology of a papovavirus. In experimentally infected 25-day-old budgerigars, histologic examinations revealed the presence of intranuclear inclusions in hepatocytes, epithelial cells of the kidney tubules, and reticular cells of the spleen, despite the absence of clinical signs. We feel that this disease is caused by a papovavirus-like agent that can replicate in many tissues of the body, causing widespread lesions responsible for the high mortality rate of very young budgerigars and for the absence and/or incomplete development of feathers.

Coronaviruses associated with outbreaks of transmissible enteritis of turkeys in Quebec: hemagglutination properties and cell cultivation.

Coronaviruses were observed by electron microscopy in the intestinal contents of turkeys in Quebec flocks where repeated outbreaks of enteritis occurred. Three isolates could be serially propagated in turkey embryos inoculated by the amniotic route with clarified intestinal contents. Purification and concentration of viral particles contained in intestinal contents of infected embryos were achieved by precipitation with polyethylene glycol and ultracentrifugation on sucrose density gradients. Three particle types were demonstrated: intact virions with a density of 1.18 to 1.20 g/ml and incomplete particles with densities of 1.14 and 1.24 g/ml. Hemagglutination of rabbit and guinea pig erythrocytes was demonstrated with the intact viral particles; the hemagglutinin was not dependent on incubation temperature. All the isolates were antigenically related, as shown by hemagglutination-inhibition. The turkey coronaviruses did not cross-react with antisera against coronaviruses of avian infectious bronchitis, porcine transmissible enteritis, bovine neonatal calf diarrhea, or mouse hepatitis. One of the Quebec isolates was shown to induce syncytia formation on its third passage in primary chicken-embryo kidney cell cultures. Electron-microscopic examination of infected cell-culture fluids revealed characteristics coronavirus particles identical to those found in intestinal contents of infected turkeys.

Early detection of bovine leukemia virus in cattle by use of the polymerase chain reaction.

A study was performed to determine whether experimentally induced bovine leukemia virus (BLV) infection in cattle could be detected earlier by use of polymerase chain reaction (PCR) amplification of genomic DNA extracted from leukocytes than by use of conventional agar-gel immunodiffusion (AGID). The PCR primers were designed to amplify a 375-base-pair region of the proviral gag gene. Five cows were identified that were BLV-negative on the basis of AGID and PCR results. At day 0, these cows were inoculated IM with blood pooled from 3 naturally infected cows. Blood samples were taken on days 0, 1, and 7, and every 2 weeks thereafter until 3 months after inoculation. Three of the cows were BLV-positive by AGID test results 3 weeks after inoculation, and the remaining 2 seroconverted at 5 weeks. In contrast, all 5 cows were BLV-positive by PCR results 7 days after inoculation and remained positive for the duration of the study. Five cows that were BLV-positive by AGID test and PCR results on day 0 and from which samples were obtained at the same times as those from the other 5 cows, remained BLV-positive by results of both tests during the course of the study. Results indicate that under experimental conditions, BLV infection in cattle can be detected as much as 2 to 4 weeks earlier by use of PCR than by use of the AGID test.

Seroepidemiologic study of Neospora caninum in dairy herds.

OBJECTIVE: To identify risk factors associated with Neospora caninum infection in dairy herds in Québec and to estimate seroprevalence in case and control herds. DESIGN: Herd-based case-control and seroprevalence study. ANIMALS: 3,059 cows from 24 case and 22 control dairy herds in Québec. PROCEDURE: Blood samples were obtained from each cow, and sera were tested, using an ELISA, for antibodies to N caninum. Owners of herds answered questionnaires requesting information on demographics and herd management practices. Seroprevalence was compared between case and control herds, using the Mann-Whitney test. Risk factors were compared between case and control herds, using logistic regression. RESULTS: All case herds and 73% of control herds had at least one seropositive cow. Median seroprevalence was significantly greater among case herds (22.5%) than among control herds (7.5%). Dogs were found most often and in greatest numbers on farms housing case herds compared with control herds during the past 3 years. CLINICAL IMPLICATIONS: Although the exact role that dogs have in transmission of N caninum in dairy herds needs to be elucidated, dogs should have limited access to barns and cattle.

Papovavirus induced feather abnormalities and skin lesions in the budgerigar: clinical and pathological findings.

Feather abnormalities and skin lesions caused by a papovavirus infection in budgerigars are described. Diseased one to 15 day old birds displayed a lack of nestling down feathers and filoplumes on the head and neck. Survivors older than 15 days exhibited retarded growth and temporary absence of feathers variable from bird to bird. Several birds between 15 and 25 days of age had flight feathers with total absence or marked sparseness of the vanes. After 25 days, feathers began to grow, although the tail and/or some flight feathers of some of the birds remained underdeveloped or absent for several weeks. Several of these affected birds were unable to fly and are called "runners"Microscopic lesions in the feather follicles of the affected birds less than 15 days of age, were characterized by focal, multifocal or diffuse ballooning degeneration in the lateral and axial plate cells of the barb ridges with the presence of large basophilic or amphophilic intranuclear inclusions in the same cells. Focal areas of ballooning degeneration with intranuclear inclusions were also found in the epidermis. Clinical observations made on these birds are compared with those reported in the literature for French molt.

Detection of bovine coronavirus and type A rotavirus in neonatal calf diarrhea and winter dysentery of cattle in Quebec: evaluation of three diagnostic methods.

The use of direct electron microscopy, enzyme-linked immunosorbent assay, and protein A-gold immunoelectron microscopy for the identification of bovine coronavirus and type A rotavirus were examined. Two hundred and forty-nine samples from diarrheic calves and winter dysenteric cattle from seven geographic areas in Quebec were examined for the presence of viruses by direct electron microscopy of negatively stained preparations. In addition, all the samples were analyzed by enzyme-linked immunosorbent assay, and a random selection of 47 samples were also analyzed by protein A-gold immunoelectron microscopy. Thirty-nine percent of samples examined by direct electron microscopy contained viral particles; bovine coronavirus and type A rotavirus were the most common viruses involved. Overall agreement between any two of the methods used compared favorably with results obtained by others using similar methods. The presence of coronavirus and rotavirus in fecal samples obtained from neonatal calves and the presence of coronavirus in samples from winter dysenteric adult cattle suggested their etiological roles in the respective diseases. Furthermore, results from protein A-gold immunoelectron microscopy of coronavirus-like particles implied that a different coronavirus or some other viruses might be involved in these diseases. Finally, the efficiency of direct electron microscopy, enzyme-linked immunosorbent assay and protein A-gold immunoelectron microscopy as diagnostic tools is discussed.

[Isolation of infectious bovine rhinotracheitis virus from the tarsal joint of a bull (author's transl)]. / Isolement du virus de la rhino-trachéite infectieuse bovine à partir du liquide synovial du tarse d'un taureau.

Isolation of infectious bovine rhinotracheitis virus from the tarsal joint of a bullInfectious bovine rhinotracheitis virus was isolated from the right tarsal joint of a bull who was showing signs of a systemic viral infection. The clinical signs manifested by 16 bulls of this herd are described, the laboratory methods used are listed and the results are analysed and discussed.

[The debate within the CSN on the organization of mental health.]. / Le débat au sein de la CSN sur l'organisation de la santé mentale.

The authors attempt in this article, to account for the political stakes in mental health which are in process of elaboration, among the C.S.N., and the discussions they generate in this national union. They describe firstly the implication of the unions in Quebec during recent years. Secondly, they outline the main events that led to actual government interventions in certain institutions. Then they establish the following facts: the extent of mental sickness, the desinstitutionalisation, the finality of psychiatric hospitals and the alternative resources. Lastly, they disclose the C.S.N.'s point of view on various questions: prevention, social réintégration, work, desinstitutionalisation and psychiatric hospitals' reform.

Types of avian infectious bronchitis strains isolated in Quebec.

Between 1976 and 1980, 24 isolates of infectious bronchitis virus were obtained from Quebec flocks. The serological classification of these isolates was demonstrated by cross neutralization tests using antisera to 13 different reference virus strains. Of the 24 isolates, ten were identified as Connecticut, six Holland and one SE-17 types. Seven strains did not react with any of the specific antisera.

Serology of bovine parainfluenza virus type 3: comparison of the enzyme linked immunosorbent assay and hemagglutination inhibition.

An enzyme linked immunosorbent assay (ELISA) for the detection of antibody to bovine parainfluenza virus type 3 has been compared with the hemagglutination inhibition test on 130 field sera, and seven other paired sera showing a significant raise of titers. The ELISA was found to be four to 64 times more sensitive than the hemagglutination inhibition test and the two tests demonstrated a good correlation.

Interspecific differences between the DNA restriction profiles of canine adenoviruses.

Identification of canine adenovirus-1 ( CAV -1) and canine adenovirus-2 ( CAV -2) strains was done by electrophoresis of restriction endonuclease-fragmented viral DNA. Results obtained with this sensitive and reproducible technique clearly show that CAV -2 is not a variant of CAV -1 but a distinct virus.