Demonstration of homologous recombination events in the evolution of bovine viral diarrhoea virus by in silico investigations

Complete genome sequences of bovine viral diarrhoea virus types 1 and 2 (BVDV-1 and 2) deposited in the GenBank were submitted to bioinformatic analysis using a recombination-detecting software. The results indicate that recombination events are not rare in the case of BVDV, which frequently causes immunotolerance and, consequently, persistent infection in calves. The lack of specific immunity provides an ideal possibility for multiple infections by antigenically related but genetically different BVDV strains, and hence recombinations may occur. Among the 62 BVDV-1 genomes five recombinants and their possible parent strains, while among the 50 BVDV-2 genomes one simple recombinant and its parent strains were identified, which were supported by extremely strong probability values (P values varying between 1.26 × 10–4 and 1.58 × 10–310). Besides the newly identified recombinants, recombination events described previously were confirmed, but in some of these cases former information was completed with new data, or different parent(s) were suggested by the programme (RDP 4.46 BETA) used in this study

Expression of claudin-1, -3, -4, -5 and -7 proteins in low grade colorectal carcinoma of canines

The aim of the present study was to characterise the expression pattern of claudin-1, -3, -4, -5 and -7 tight junction proteins in canine normal colorectum and in the low-grade, tubulopapillary colorectal carcinoma in canines. Methods and results: The biopsy samples included 10 canine normal colorectal tissues and 20 canine low grade colorectal carcinomas (CLGCCs). The canine normal colorectal mucosa was negative for claudin-1. Claudin-1 was detected as a non-diffuse intense membrane labelling of neoplastic epithelial cells in low grade colorectal cancer in canines. Fifty five per cent of all tumours showed a weak cytoplasmic pattern of staining for claudin-1 protein. The normal colorectal mucosa showed diffuse punctate positivity for claudin-3. Claudin-3 was detected as an intense lateral membrane labelling of tumour cells in CLGCCs. Claudin-4 expression in surface and crypt epithelial cells of the intact colorectal mucosa in canines was punctate. Claudin-4 molecule was detected as a lateral membrane labelling of neoplastic cells in CLGCCs. The epithelium of the CLGCCs and the low grade colorectal carcinoma were negative for claudin-5. The surface and crypt epithlial cells of the canine normal colorectal mucosa showed a diffuse lateral membranous pattern of staining for claudin-7. Claudin-7 molecule was detected as an intense membrane labelling of neoplastic cells in CLGCCs. Seventy per cent of all tumours showed weak cytoplasmic positivity for claudin-7. Conclusion: Consequently, we hypothesize that claudin-1 plays a role in the progression of CLGCCs. Further functional studies are needed to clarify the biological role of the mislocalization of the claudin-1 molecule from cell membrane to the cytoplasm in CLGCCs. Lower claudin-4 expression suggests that reduced expression of claudin-4 molecule may lead to cellular disorientation, detachment and invasion of CLGCCs. Further functional studies are needed to clarify the biological role of overexpression and mislocalisation of claudin-7 in CLGCCs

Arterivírusok vizsgálata, különös tekintettel a hazai izolátumok genetikai tulajdonságaira = Investigation of arteriviruses with special regard to the genomic characteristics of local isolates

Az elmúlt négy évben vizsgáltuk a két állategészségügyi szempontból fontos arterivírus, a sertések szaporodásbiológiai zavarokkal és légzőszervi tünetekkel járó tünetegyüttesét előidéző vírus (PRRSV) és a lovak fertőző arteritisét előidéző vírus (EAV) hazai elterjedtségét és megállapítottuk, hogy mindkét vírus hazai előfordulása elmarad a nyugat-európai országokban megfigyelttől. Mindkét vírusfertőzés diagnosztikájában kidolgoztuk és széleskörűen alkalmaztuk az RT-PCR alapú diagnosztikai módszert. Az amplifikációs termékek nukleotid-sorrendjének meghatározása után vizsgáltuk a két vírus filogenetikai viszonyait magyarországi és a környező országokból származó pozitív minták felhasználásával, továbbá összehasonlítottuk ezeket a nemzetközi génbankban elhelyezett szekvenciákkal is. A PriProET és Taqman technikára valamint valós idejű RT-PCR eljárásra alapozott módszerekkel a vírusfertőzések in vitro és in vivo zajló kinetikájáról tudtunk adatokat gyűjteni. Eredményeinket nyolc referált szakfolyóiratben megjelent vagy közlésre elfogadott közleményben és két PhD értekezésben közöltük illetve foglaltuk össze. | In the four years of the study period the occurrence of the two arteriviruses of veterinary significance, the porcine reproduction and respiratory syndrome virus (PRRSV) and the equine arteritis virus has been investigated, and it was demonstrated, that the presence of both viruses is lower then in the Western European countries. An RT-PCR based diagnostic method has been developed and routinely applied in the diagnosis of both viral infections. After sequencing the amplicons the phylogenetic relationship of the viruses was investigated using positive samples collected in Hungary and in the neighbouring countries, and these were compared to sequences deposited in the GenBank. Data were collected on the in vitro and in vivo kinetics of the virus multiplication using methods based on PriProET and Taqman technique and real time RT-PCR methods. The results were published and summarised in eight articles published in peer reviewed periodicals and in two PhD theses

Claudin-7 protein differentiates canine cholangiocarcinoma from hepatocellular carcinoma

The aim of the present study was to characterise the expression pattern of claudin-7 tight junction protein in canine normal liver, hyperplastic and primary neoplastic lesions of the canine liver and whether this tight junction protein can help differentiate canine cholangiocarcinomas from canine hepatocellular carcinomas. Methods and results: Necropsy samples included 15 canine normal liver tissue samples, 10 hepatocellular nodular hyperplasias, 6 hepatocellular adenomas, 15 well-differentiated and 6 poorly differentiated hepatocellular carcinomas, 6 cholangiocellular hyperplasias, 10 cholangiocellular adenomas, 15 well-differentiated and 6 poorly differentiated cholangiocarcinomas, 6 normal extrahepatic bile ducts, 8 normal gall bladder tissue samples, and 5 cystic mucinous hyperplasias of the gall bladder. In all canine normal liver tissue samples the hepatocytes were negative for claudin-7 and the normal biliary epithelial cells showed intense basolateral membrane claudin-7 positivity. In all cholangiocellular hyperplasia samples and in all cholangiocellular adenoma samples the benign cholangiocytes showed intense basolateral membrane positivity for claudin-7. In all samples of the well-differentiated and poorly differentiated cholangiocarcinomas, the malignant neoplastic biliary epithelial cells showed intense basolateral membrane positivity for claudin-7. Neither the hyperplastic nodules of the liver cells nor the hepatocellular adenomas reacted with claudin-7. The well-differentiated and poorly differentiated hepatocellular cancers were negative for claudin-7. The epithelial cells of canine normal extrahepatic bile ducts, gall bladder and cystic mucinous hyperplasias of the gall bladder showed intense basolateral membrane positivity for claudin-7. Differences in the intensity of claudin-7 reaction were not apparent among different types of proliferative lesions of cholangiocytes or degrees of cellular differentiation of neoplastic biliary epithelial cells. Conclusion: Consequently, we hypothesize that claudin-7 is an excellent immunohistochemical marker of the cholangiocellular differentiation in canines and can be used to detect benign and malignant proliferative lesions of the canine biliary tract. It can also help to differentiate canine cholangiocarcinomas from hepatocellular carcinomas

Seroprevalence of bovine viral diarrhoea virus in Hungary — situation before launching an eradication campaign

Bovine viral diarrhoea (BVD) is a viral disease appearing in various forms and causing high economic losses in the cattle stocks of Hungary. The aim of the present study was to determine the prevalence of bovine viral diarrhoea virus (BVDV) in Hungary through a monitoring survey carried out on samples collected in cattle-keeping units throughout the country. Since no such survey had been carried out in Hungary during the last thirty years, our study may serve as a basis for later monitoring investigations aimed at following the progress of an expected eradication campaign of BVD. The tests were carried out using an ELISA method, on a total of 1200 blood samples submitted from 54 cattle herds. The herds had not been vaccinated against BVDV before the sampling. Out of the 1200 samples, 521 proved to be positive (43.4%), 40 gave doubtful result (3.3%) and 639 were negative (53.3%). In some stocks the samples were collected from cows having completed several lactation periods, and therefore the seronegativity indicates the BVDV-free status of the given stock. Moreover, among the positive herds we found a few where the seropositivity rate was rather low (< 5%). According to the results of the survey, a rather high portion (about one third) of the cattle-keeping units of Hungary can be regarded as BVDV free, which ratio is much higher than had been expected on the basis of surveys carried out on a lower number of samples and in smaller regions of the country. Hence, the chances of an eradication campaign launched in the near future, or carried out parallel to the IBR eradication programme, are better than previously expected

Immunohistochemical characterization of type II pneumocyte proliferation after PRRSV (Type I) challenge

The study aimed to histologically and immunohistochemically characterize lung lesions after a challenge with a recently isolated PRRSV field strain in growing pigs 10 and 21 days post infection (DPI). In the first phase of the study lung lesions were evaluated microscopically on routine haematoxylin and eosin stained slides. The evaluation was performed as a blinded analysis and the lesions were scored based on the following criteria: (1) pneumocyte hypertrophy and hyperplasia, (2) septal mononuclear infiltration, (3) intraalveolar necrotic debris, (4) intraalveolar inflammatory cell accumulation and (5) perivascular inflammatory cell accumulation. For further characterization of the lung lesions, immunohistochemical stainings were performed using anti-cytokeratin, anti-Ki67, anti-TTF-1 (Thyroid Transcription Factor-1), anti-myeloid receptor (MAC387), and anti-PRRSV antibodies to identify alveolar epithelial cells, proliferating cells, type II pneumocytes, macrophages, and PRRSV antigen, respectively. The evaluation of the immunohistochemical stainings revealed that humanized anti TTF-1 antibodies can successfully identify type II pneumocytes in porcine lung tissue. Marked proliferation of these cells was confirmed by a significant (p<0.05) increase of TTF-1 positive cells in acute cases compared to the lungs of control pigs. Cytokeratin labeling marked the type I, and type II pneumocytes as well as bronchial epithelial cells, however this staining was not suitable for cell counting purposes. When the routine histological scores were compared to the number of immunohistochemically positive cells, Ki67 cell counts were found to show positive correlation (p<0.05) with the overall severity of the lesions

Detection of a putative novel adenovirus by PCR amplification, sequencing and phylogenetic characterisation of two gene fragments from formalin-fixed paraffin-embedded tissues of a cat diagnosed with disseminated adenovirus disease

Adenoviral nucleic acid was detected by polymerase chain reaction (PCR) in formalin-fixed paraffin-embedded tissue samples of a cat that had suffered from disseminated adenovirus infection. The identity of the amplified products from the hexon and DNA-dependent DNA polymerase genes was confirmed by DNA sequencing. The sequences were clearly distinguishable from corresponding hexon and polymerase sequences of other mastadenoviruses, including human adenoviruses. These results suggest the possible existence of a distinct feline adenovirus

Identification of reference markers for characterizing honey bee (Apis mellifera) hemocyte classes

Cell mediated immunity of the honey bee (Apis mellifera) involves the activity of several hemocyte populations, currently defined by morphological features and lectin binding characteristics. The objective of the present study was to identify molecular markers capable of characterizing subsets of honey bee hemocytes. We developed and employed monoclonal antibodies with restricted reactions to functionally distinct hemocyte subpopulations. Melanizing cells, known as oenocytoids, were defined by an antibody to prophenoloxidase, aggregating cells were identified by the expression of Hemolectin, and phagocytic cells were identified by a marker expressed on granulocytes. We anticipate that this combination of antibodies not only allows for the detection of functionally distinct hemocyte subtypes, but will help to further the exploration of hematopoietic compartments, as well as reveal details of the honey bee cellular immune defense against parasites and microbes