Mucosal Disease Virus Research Articles

PATHOMORPHOLOGICAL ASPECTS OF RELEVANT GASTROINTESTINAL DISEASES IN NEWBORN AND GROWING CALVES

The emphasis of this literature overview is placed on the etiology, epidemiology, specific gross and microscopic pathological changes of the commonest gastrointestinal diseases in newborn and growing calves in dairy and beef farms. Neonatal diarrhea in calves is a multifactorial disease accompanied with high morbidity and mortality rates. It incurs considerable economic losses for cattle industry worldwide. The gastroenteritis in calves is most commonly of infectious or parasitic etiology and the most frequently involved enteropathogens are Cryptosporidium parvum, bovine rotaviruses (GRA BRV), bovine coronaviruses (BCoV), mucosal disease virus - bovine viral diarrhoea (BVDV) and Escherichia coli K99 (F5). Affected calves are from 24th hours to 30 days of age, and the appearance of the disease is largely dependent on the immunological status of newborn calves, the amount of ingested colostrum, whether dams are vaccinated or not during the dry period, and the conditions of housing of newborns. The specific gross and microscopic lesions of the gastrointestinal tract and of some parenchymal organs are essential for the diagnostics and differential diagnostics of reviewed diseases.

Genetic diversity of bovine diarrhea and mucosal disease virus

Abstract Bovine viral diarrhea virus (BVDV) is classified as a member of the Pestivirus genus of the Flaviviridae family. BVDV is one of the most important viral pathogens of ruminants worldwide, causing severe economic losses. Infection results in a wide range of clinical manifestations, ranging from mild respiratory disease to fetal death and mucosal disease. The virus particles are small and contain a singlestranded, positive-sense RNA molecule of approximately 12.3 kb with one large open reading frame flanked by two untranslated regions (5’UTR and 3’UTR). The polyprotein is proteolytically cleaved by viral and host proteases resulting in the formation of mature viral proteins. It is well established that BVDV strains show considerable genetic diversity. BVD viruses are classified as two species: BVDV-1 and BVDV-2. Quite recently, a new putative species, BVDV-3, was detected. The viruses exist as one of two biotypes: cytopathic or non- cytopathic, based on their activity in cell cultures. The phylogenetic analysis of the 5’UTR and Npro region has revealed at least 21 distinct subtypes of BVDV-1 and 4 subtypes of BVDV-2. Genetic diversity of BVD viruses has serious clinical implications such as immune evasion, increase of virulence, host range alteration and also affects the efficacy of vaccination programmes and diagnostic methods. 1. Introduction. 2. Characteristics of BVD virus. 3. Genetic diversity. 4. The importance of genetic variation. 5. Conclusion

ATYPICAL BOVINE PESTIVIRUSES (review)

Abstract Increasingly frequent outbreaks of atypical viral infections, detection of new viruses, modified isolates and quasispecies with a confirmed or potential emergence have become a worrying feature of the last decades characterized by extremely close international dealings. For the cattle industry, they pose real and serious threat because of a tendency to spread widely and quickly due to globalization and the use of standardized zootechnical and veterinary protocols. The Flaviviridae family comprises several genera of which the genus Pestivirus, including four viruses, i.e. the cattle viral diarrhea — mucosal disease (VD-MD) virus types 1 and 2, swine fever virus and sheep border disease virus, are important to farm animals (http://ictvonline.org/virusTaxonomy.asp). The charac-teristics of a new group of viruses genus Pestivirus of the Flaviviridae family, allocated in the period from 2000 to 2014 from the buffalo and cattle, as well as fetal calf serum used for cell cultures and vaccines production harvested in Australia, Canada, Mexico, Brazil and the United States and pack-aged in Europe (H. Schirrmeier et al., 2004; A. Cortez et al., 2006; E. Bianchi et al., 2011; B. Rod-rigues et al., 2011; H. Xia et al., 2011; H. Xia et al., 2012; S. Peletto et al., 2012) are submitted in the review. The virus has been isolated in Thailand, Bangladesh and China (L. Liu et al., 2009; L. Mao et al., 2012; N. Haider et al., 2014). Messages on the isolation of the agent in other European coun-tries, North America, Russia, India and Australia are absent (F.V. Bauermann et al., 2013). The widespread use of contaminated biological products can facilitate the penetration of the virus in dif-ferent regions of continent causing their potential emergence for cattle. Strains of viruses presented cytopathogenic and non-cytopathogenic biotypes not officially classified and have a variety titles in literature: a third type of viral diarrhea-mucosal disease in cattle (BVDV), an atypical pestivirus (HoBi-like), the fifth type of Pestivirus genus (N. Decaro et al., 2012). Based on phylogenetic analy-sis were identified two genetic groups: Brazilian and Thai, which differ from the prototype member of the genus - the BVD virus but having a great similarity in the manifestation of clinical signs, the ability to infect the foetus of cattle and buffalo (F.V. Bauermann et al., 2013). In cattle a spontaneous or experimental infection caused by HoBi-like virus is very similar to the cattle VD-MD and manifests as diarrhea, abortion, respiratory syndrome, persistent infection (F.V. Bauermann et al., 2013). The situation is aggravated by the fact that they like the BVDV are able to induce persis-tent infection and forms permanent epizootic foci (M.N. Weber et al., 2014). The discovery of this group of viruses requires a critical assessment of the diagnostic tools and vaccines against the BVDV. To date, the there are no tests for the detection of ruminants’ pestiviruses or their antibodies, particularly due to high variability of this virus group. That is why their laboratory diagnosis should not rely on the use of a single test. The best approach would be serological diagnosis of the herd followed by the identification of persistently infected animals, the virus isolation and molecular analysis (F.V. Bauermann et al., 2013). Given the lack of HoBi-like infection diagnostics, these vi-ruses can remain unnoticed and, presumably, compromising the effectiveness of control or eradica-tion programs of BVDV realized in certain European countries and the United States (K. Stahl et al., 2004; J.F. Ridpath, 2010). Keywords: pestiviruses, viral diarrhea-mucosal disease, atypical viruses, sequencing, genetic subgroups, fetal serum, buffalo, molecular diagnostics, control programs.

Development of TaqMan-based qPCR method for detection of caprine arthritis–encephalitis virus (CAEV) infection

A specific and sensitive two-step TaqMan real-time PCR has been developed for rapid diagnosis of caprine arthritis-encephalitis virus (CAEV) infection by using a set of specific primers and a TaqMan probe targeting a highly conserved region within the gene encoding the viral capsid protein (CA). The assay successfully detected CAEV proviral DNA in total DNA extracts originating from cell culture, whole blood samples and isolated PBMCs, with a lower detection limit of 102 copies and a linear dynamic range of 105 to 1010 copies/ml. There was no cross-reaction with other animal viruses (e.g., goat pox virus, bovine leukemia virus, bovine mucosal disease virus, swine influenza virus and Nipah virus). When applied in parallel with serological AGID and conventional PCR for detection of CAEV in field samples, this assay exhibited a higher sensitivity than these traditional methods, and 7.8 % of the 308 specimens collected in the Shanxi and Tianjin regions of China from 1993 to 2011 were found to be positive. Thus, the TaqMan qPCR assay provides a fast, specific and sensitive means for detecting CAEV proviral DNA in goat specimens and should be useful for large-scale detection in eradication programs and epidemiological studies.

Detection of the bovine viral diarrhoea / mucosal disease (BVD/MD) virus in tissues from aborted ruminant foetuses using immunohistochemistry

Various tissues from aborted ruminant foetuses were collected, fixed in formalin and embedded in paraffin wax. Sections were made and exposed to a primary monoclonal antibody against the bovine viral diarrhoea/mucosal disease (BVD/MD) virus, and subsequently to a goat anti-mouse secondary antibody conjugated to horse radish peroxidase (HRP). Diaminobenzidine (DAB) was the substrate and it released a brown pigment in the tissues on reacting with the HRP in an immunohistochemistry (IHC) procedure. Of 27 aborted foetuses, an immunoperoxidase staining reaction was observed in 1 ovine and 5 bovine foetuses. The IHC procedure located BVD/MD viral antigen in a wide variety of foetal tissues including cerebral cortical neurons, the pseudostratified columnar epithelial cells lining the bronchi, alveolar lining cells and alveolar macrophages, hepatocytes, renal tubular lining cells and the Purkinje fibres in the myocardium.

Diagnosis of malignant catarrhal fever by PCR using formalin-fixed, paraffin-embedded tissues.

A previously described polymerase chain reaction (PCR) assay (amplification of a 238-bp fragment of ovine herpesvirus 2 [OHV-2] genomic DNA) for diagnosis of sheep-associated malignant catarrhal fever (MCF) was adapted for use on formalin-fixed, paraffin-embedded tissues. Variables affecting its use were examined. Archived tissues from cattle, white-tailed deer (Odocoileus virginianus), and bison (Bison bison) diagnosed with MCF by clinical signs or histologic lesions were obtained from 2 veterinary diagnostic laboratories. Tissues from healthy animals and from animals diagnosed with other common bovine viral diseases were examined as controls. A total of 86 blocks from 37 suspect MCF cases were examined. Forty-one blocks from healthy animals and animals with unrelated viral diseases were examined as controls. The assay was specific for sheep-associated MCF and did not yield false-positive signals from healthy animals or from cases of infectious bovine rhinotracheitis, bovine virus diarrhea, mucosal disease, or parainfluenza-3 virus infection. A wide variety of tissues were suitable substrates, including spleen, lymph node, intestine, brain, lung, and kidney. Extracted DNA provided a more suitable target than did unextracted tissue lysate. The highest levels of viral DNA were present in lymphoid organs and intestine, but the data indicate that in acute clinical cases, most organs contain sufficient viral DNA to serve as a suitable diagnostic specimen. Fixation of 0.5-cm3 blocks of tissue in 10% neutral buffered formalin was deleterious to the target DNA, and PCR signals progressively diminished after fixation for >45 days. Detection of genomic DNA of OHV-2 by PCR was successful for archived tissues that were 15 years old.

A neuropathological survey of brains submitted under the Bovine Spongiform Encephalopathy Orders in Scotland

Bovine spongiform encephalopathy was not confirmed histologically in 225 of 829 bovine brains submitted for diagnosis. Several previously described disorders of the central nervous system were observed in these brains as well as disorders not previously recognised in Britain, including bilateral vacuolation of the substantia nigra, hippocampal sclerosis with brainstem neuronal chromatolysis and necrosis, focal symmetrical encephalomalacia and meningio-angiomatosis. Severe cerebellar dysplasia consistent with pre-natal bovine viral diarrhoea--mucosal disease virus infection or mineralisation of the blood vessels of the basal ganglia were interpreted respectively as congenital changes or changes due to ageing and were considered to be of no clinical significance.

Diabetes Mellitus in Cattle Infected With Bovine Viral Diarrhea Mucosal Disease Virus

Diabetes in cattle has various etiologies1. In humans, virus-induced insulin dependent diabetes mellitus (IDDM) has been reported. It has also been reported that cattle infected with foot-and-mouth disease contracted diabetes mellitus2. Craighead and coworkers observed experimental diabetes in mice after inoculation of encephalomyocarditis virus3. Other viruses suspected of inducing diabetes are coxsackie, mumps, rubella and cytomegalo virus4.
 Bovine viral diarrhea mucosal disease (BVD-MD) is a frequently fatal infectious disease of cattle. There is no concrete evidence to date that BVD-MD virus induces diabetes. In this report, the clinicopathological characteristics of diabetes mellitus in cattle were described, and the relationship between BVD-MD and diabetes mellitus was discussed.

Diabetes mellitus in cattle infected with bovine viral diarrhea mucosal disease virus.

Four Japanese black cattle and four Holstein-Friesian cows were diagnosed with diabetes mellitus. Based on intravenous glucose tolerance tests, all these animals were believed to be insulin-dependent diabetics. Moreover, bovine viral diarrhea-mucosal disease (BVD-MD) virus was isolated and mucosal lesions and diarrhea were recognized in all cases. There was no genetic relation among the affected cattle. The breeding places of these cattle were different to each other. Therefore, it is suggested that BVD-MD virus induced the diabetes mellitus.

Bovine virus diarrhoea virus : speculation and observations on current concepts

This final chapter highlights the advances and some of the unanswered questions concerning bovine virus diarrhoea virus (BVDV) presented in this Review by specialists from around the world. Persistently viraemic cattle play an essential role in the dissemination of BVDV but it is suggested that acute infections with the virus are also important. The role of latency is considered but, as yet, there is no evidence that it plays a part in pathogenesis. It is well established that BVDV, Border disease virus and hog cholera virus infect sheep and pigs. There is also some indication that pestiviruses may be involved in other infections of ruminants, such as syndrome X and hyena disease. They also infect other ruminants, such as deer, and human infections have been reported. It is now known that the pathogenesis of mucosal disease is due to the combined action of the two BVDV biotypes. However, the cause of death remains an enigma. It is suggested that, due to the importance of this syndrome, it may be an appropriate time to reconsider the use of "mucosal disease virus" to replace the ungainly name "BVDV".

An Outbreak of Mucosal Disease in a Dairy Herd

An outbreak of mucosal disease (MD) was studied in a dairy herd, comprising 12 cows, 9 heifers and 18 calves. During a period of 1 month, six 5 to 8 month-old calves showed typical signs of MD. They all died or were killed in extremis after 2-8 days with progressively worsening clinical signs. Post mortem lesions were examined in one calf. Non-cytopathogenic MD virus was isolated from serum or tissues from 3 clinically affected calves and from 1 healthy heifer. All cows and heifers except for the viremic one possessed neutralizing antibodies against bovine pestivirus. According to the current MD-pathogenesis concept, the affected calves were probably infected transplacentally during the first half of foetal life with pestivirus from the persistently infected heifer in the herd.

黒毛和種肥育牛に見られた牛ライノウイルス感染症

There was an outbreak of an acute respiratory disease in cattle in Nagasaki Prefecture in March, 1987. The 45 cattle, all from different places in Nagasaki Prefecture from outsideof the prefecture, involved in the outbreak showed fever, coughing, nasal discharge, labored breathing and diarrhea five days after they were introduced and five of them died.Pasteurella haemolytica was isolated from six nasal swab specimens in seven ill cattle (85.7%). Mycoplasma SP. was isolated from two of seven specimens (28.6%). Two cytopathogenic virus strains were isolated in MDBK cell cultures from nasal swabs of cattle with markedleukopenia.The isolants were readily inactivated by acid and heating at 50°C for 30 minutes, but they resisted chloroform. The type of their nucleic acid was determined to be RNA. Immunoelectron microscopy using convalescent serum revealed picornavirus-like particles in cultured material.The isolants were neutralized with antiserum against the Sd-1 strain of bovine rhinovirus type 1.A significant rise in antibody titer was shown against the isolants in convalescent serum of the ill cattle, but not against bovine respiratory syncytiai virus, bovine adenovirus type 7, or bovine entero virus. A small rise in antibody titer against bovine herpesvirus type 1, parainfluenza virus type 3 and bovine viral diarrhea mucosal disease virus, was shown. It is considered, however, that such a sero-conversion may be due to vaccination of combined vaccine against these viral agents.Serologic survey against the isolated virus in sera collected from 195 cattle in 1987 in Nagasaki Prefecture revealed that 73. 5% of those over one year old were antibody positive, while 29. 9% of those from four to 10 months old particulaly have a tendency to show a low positive rate.

北海道の石狩地区における牛ウイルス性下痢・粘膜病 (BVD・MD)

北海道の石狩地区における牛ウイルス性下痢・粘膜病 (BVD・MD)

Abortion, stillbirth and illthrift in cattle associated with mucosal disease virus.

Abortion, stillbirth and illthrift in cattle associated with mucosal disease virus.

Effect of bovine virus diarrhoea—mucosal disease virus infection on salmonella infection in calves

The possibility that bovine virus diarrhoea virus (BVDV) infection could aggravate concurrent salmonella infections was investigated in two series of experiments with Salmonella dublin and S typhimurium. In both series of experiments the clinical signs tended to be more severe in dual infections than in those with salmonella alone. Faecal excretion of S dublin was similar in both single and dual infected calves. A protracted bacteraemia occurred only in two dual infected calves, one of which died from suppurative meningitis. In the case of S typhimurium, body temperatures, passage of abnormal faeces and isolation rates of salmonella from faeces were significantly increased. The results suggest that BVDV infection may indeed exacerbate the effects of salmonella infection and the aetiological relationship of the two agents should be considered during outbreaks of bovine salmonellosis.

Examination of uterine biopsies from infertile cows for the presence of viruses and mycoplasmas

Uterine biopsies from 45 infertile cows were examined for the presence of mycoplasmas, bovine viral diarhoea--mucosal disease virus, bovine syncytial virus and other viruses. No viruses were detected. Ureaplasmas were isolated from four cows, two clinically normal and two with nodular vulvovaginitis.

BOVINE HERPESVIRUS 1 ‐ INFECTION OF THE UPPER ALIMENTARY TRACT OF CATTLE AND ITS ASSOCIATION WITH A SEVERE MORTALITY

SUMMARY A severe cattle mortality in which 132 out of 340 animals died on a property in southern Queensland was investigated. Clinical signs shown by affected animals included fever, inappetance, depression, lethargy, salivation, diarrhoea, ataxia, and ulceration of the oral cavity. The most common lesions seen at autopsy of 6 affected animals were ulceration of the tongue, gums, dental pad and buccal mucosa, linear ulceration of the caudal third of the oesophagus, mild catarrhal enteritis and necrosis of lymph nodes draining areas of ulceration.Bovine herpesvirus type 1 (BHV 1) was isolated from 3 out of 5 animals from which virus isolation was attempted. BHV 1 was recovered from oesophageal ulcers, retropharyngeal lymph nodes, blood clot, and swabs from ulcers in the oral cavity but not from spleen, liver or mesenteric lymph node. Serum neutralising (SN) antibody to BHV 1 was detected in 4 out of 12 affected animals in the second of paired serum samples but not in the first. Mucosal Disease (MD) virus was not recovered from any of 17 animals from which isolation was attempted but moderate MD SN titres, without a rise on paired sera, were detected in affected animals.Fever, depression, inappetance, ulceration of the upper alimentary tract, and adrenal necrosis were produced in 2 susceptible animals following inoculation with third passage cell culture fluid containing BHV 1. A serological response to BHV 1, but not to MD virus was detected in one of the cattle infected experimentally.

Isolation of Viruses from Cultures of Bovine Endometrial Cells

Endometrial cells from the uteri of pregnant and nonpregnant cattle were cultured. The presence of one or both of two viruses, noncytopathic mucosal disease virus and bovine syncytial virus, was demonstrated in seven of 19 endometria investigated. It was necessary to subculture the cells an average of four times to detect the viral infections. Difficulties were encountered in producing endometrial cell cultures from cows at term or near the end of term and also from older animals. The infections detected may be significant because both of the viruses isolated are capable of infecting the bovine fetus in utero and mucosal disease virus has been associated with bovine fetal diseases.

The distribution of antibodies to Border disease virus among sheep in England and Wales

Within a sample of the sheep population of England and Wales, 10.8 per cent of 3506 individuals had immunodiffusion test antibody to bovine viral diarrhoea mucosal disease virus antigen. There were marked differences between various geographical regions in the proportion of sheep with antibody, and Border disease may be more common in some areas than disease records indicate.

Serological studies of mucosal disease virus in England and Wales

A survey of the cattle population in England and Wales showed that about 62 per cent of animals had neutralising (SN) antibody to BVD-MD virus in their serum. Fewer seropositive individuals were detected by immunodiffusion (53 per cent), and complement fixation (CF) tests (34 per cent). The prevalence of antibody was not affected by herd size, but some variation was found between various regions of the country, and the proportion of animals seropositive rose markedly with age. The immunodiffusion test was a specific but relatively insensitive method of detecting antibody compared with the SN test. The data suggest that the CF test may detect a different, short-lived antibody. For diagnostic serology, the SN test was superior to the other methods. No antibody to the virus was detected in human or equine sera but about 7.3 per cent of sheep sampled had serum antibody to the virus in the immunodiffusion test.