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We estimated the diagnostic sensitivity (DSe) and specificity (DSp) of an immunohistochemistry (IHC) protocol compared to the direct fluorescent antibody test (DFAT), which is the gold standard test for rabies diagnosis. We obtained brain samples from 199 domestic and wild animal cases (100 DFAT-negative, 99 DFAT-positive), by convenience sampling from 2 government-accredited rabies virus (RABV) testing laboratories in South Africa, between February 2015 and August 2017. Tissues that had been stored at 4–8°C for several days to weeks at the 2 accredited laboratories were formalin-fixed and paraffin-embedded. Nighty-eight cases tested IHC-positive using a polyclonal anti-RABV nucleoprotein antibody and a polymer detection system. The overall DSe and DSp for the RABV IHC test were 98% (95% CI: 93–100%) and 99% (95% CI: 95–100%), respectively. Domestic dogs accounted for 41 of 98 RABV IHC–positive cases, with the remainder in 4 domestic cats, 25 livestock, and 28 wildlife. Herpestidae species, including 7 meerkats and 9 other mongoose species, were the most frequently infected wild carnivores, followed by 11 jackals. Three cases in domestic dogs had discordant test results; 2 cases were IHC–/DFAT+ and 1 case was IHC+/DFAT–. Considering the implications of a false-negative rabies diagnosis, participating in regular inter-laboratory comparisons is vital, and a secondary or confirmatory method, such as IHC, should be performed on all submitted specimens, particularly negative cases with human contact history. [ABSTRACT FROM AUTHOR]

The value of next-generation sequencing (NGS)-based applications for testing purposes in human medicine is widely recognized. Although NGS-based metagenomic screening may be of interest in veterinary medicine, in particular for intensively farmed livestock species such as pigs, there is a lack of protocols tailored to veterinary requirements, likely because of the high diversity of species and samples. Therefore, we developed an NGS-based protocol for use in veterinary virology and present here different applications in porcine medicine. To develop the protocol, each step of sample preparation was optimized using porcine samples spiked with various RNA and DNA viruses. The resulting protocol was tested with clinical samples previously confirmed to be positive for specific viruses by a diagnostic laboratory. Additionally, we validated the protocol in an NGS viral metagenomics ring trial and tested the protocol on viral multiplex reference material (NIBSC, U.K.). We applied our ViroScreen protocol successfully for 1) virus identification, 2) virus characterization, and 3) herd screening. We identified torque teno sus virus and atypical porcine pestivirus in a neurologic case, determined the full-length genome sequence of swine influenza A virus in field samples, and screened pigs using pen floor fecal samples and chewing rope liquid. [ABSTRACT FROM AUTHOR]

We examined the pathogenesis of the attenuated foot-and-mouth disease virus (FMDV) O/JPN/2000 in pigs. The virus used in this study was passaged three times in primary bovine kidney (BK) cells and once in baby hamster kidney-21 (BHK-21) cells after isolation. A plaque assay demonstrated that this virus exhibited the small plaque (SP) phenotype. There was no clinical or histological evidence of vesicular lesions in pigs intraorally inoculated with 106 50% tissue culture infectious dose (TCID50)/ml of the SP virus (SPV) of FMDV O/JPN/2000. Although fever was detected from 2 or 3 days post inoculation (dpi), there was no other prominent clinical sign up to 6 dpi. Virus shedding from saliva and nasal swab samples was not observed in any pigs inoculated with the SPV of FMDV O/JPN/2000. In the foot, mild lamellar degeneration of prickle cells in the upper layer of the stratum spinosum was histologically observed without development into vesicular or necrotic lesions. Immunohistochemical virus antigen- and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL)-positive reactions observed in the foot at 1 dpi seemed to disappear after 3 and 6 dpi. Our findings suggest that the SPV of FMDV O/JPN/2000 had low pathogenicity against pigs by intraoral inoculation. [ABSTRACT FROM AUTHOR]

AIMS: To develop an indirect ELISA based on recombinant nucleocapsid (rN) protein of wobbly possum disease (WPD) virus for investigation of the presence of WPD virus in Australian brushtail possums (Trichosurus vulpecula) in New Zealand. METHODS: Pre- and post-infection sera (n=15 and 16, respectively) obtained from a previous experimental challenge study were used for ELISA development. Sera were characterised as positive or negative for antibody to WPD virus based on western-blot using WPD virus rN protein as antigen. An additional 215 archival serum samples, collected between 2000-2016 from five different regions of New Zealand, were also tested using the ELISA. Bayesian modelling of corrected optical density at 450 nm (OD450) results from the ELISA was used to obtain estimates of receiver operating characteristic (ROC) curves to establish cut-off values for the ELISA, and to estimate the prevalence of antibody to WPD virus. RESULTS: Western blot analysis showed 5/14 (36%) pre-infection sera and 11/11 (100%) post-infection sera from experimentally infected possums were positive for antibodies to WPD virus. Bayesian estimates of the ROC curves established cut-off values of OD450≥0.41 for samples positive, and OD450<0.28 for samples negative for antibody to WPD virus, for sera diluted 1:100 for the ELISA. Based on the model, the estimated proportion of samples with antibodies to WPD virus was 0.30 (95% probability interval=0.196-0.418). Of the 230 archival serum samples tested using the ELISA, 48 (20.9%) were positive for antibody to WPD virus, 155 (67.4%) were negative and 27 (11.7%) equivocal, using the established cut-off values. The proportion of samples positive for WPD virus antibody differed between geographical regions (p<0.001). CONCLUSION: The results suggested that WPD virus or a related virus has circulated among possums in New Zealand with differences in the proportion of antibody-positive samples from different geographical regions. Antibodies to WPD virus did not seem to protect possums from disease following experimental infection, as one third of possums from the previous challenge study showed evidence of pre-existing antibody at the time of challenge. These results provide further support for existence of different pathotypes of WPD virus, but the exact determinants of protection against WPD and epidemiology of infection in various regions of New Zealand remain to be established. CLINICAL RELEVANCE: Availability of the indirect ELISA for detection of WPD virus antibody will facilitate prospective epidemiological investigation of WPD virus circulation in wild possum populations in New Zealand. [ABSTRACT FROM AUTHOR]

Recently, a novel atypical porcine pestivirus (APPV) in pig was reported. In this study, two APPV strains, APPV-China/GZO1/2016 (GZO1) and APPV-China/GD-SD/2016 (GD-SD), were identified in two newborn piglet herds with congenital tremor from China. The open reading frame of the two strains shared an 83.5% nucleotide identity. Phylogenetically, the APPV strains were placed into two groups: GZ01 belonged to group I and GD-SD belonged to group II. A high viral load was detected in the cerebellum (quantification cycles < 26). Further studies should be carried out to thoroughly elucidate the development of congenital tremors caused by APPV. [ABSTRACT FROM AUTHOR]

Cache Valley virus, an orthobunyavirus, is an important cause of ovine neonatal malformations. Information on the seroprevalence of this virus in Saskatchewan livestock populations is lacking. The objectives of this study were to determine the seroprevalence of Cache Valley virus and closely related viruses in sheep, cattle, goats, horses, and mule deer in Saskatchewan by performing a plaque-reduction neutralization test using Cache Valley virus. In total, sera from 130 sheep from 50 flocks were tested. Seroprevalence in sheep was 64.6% (84/130) and 94.0% (47/50) of flocks had 1 or more seropositive sheep. Antibodies to Cache Valley virus or closely related viruses were also detected in serum samples collected from cattle, goats, horses, and mule deer with seroprevalences of 20.0% (5/25), 33.3% (8/24), 69.0% (40/58), and 50.8% (33/65), respectively. These results suggest widespread exposure to Cache Valley virus or closely related viruses in domestic animals and mule deer in Saskatchewan. [ABSTRACT FROM AUTHOR]

We describe molecular testing for felid alphaherpesvirus 1 (FHV-1), carnivore protoparvovirus 1 (CPPV-1), feline calicivirus (FCV), alphacoronavirus 1 (feline coronavirus [FCoV]), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), and canine distemper virus (CDV) in whole blood samples of 109 free-ranging and 68 captive neotropical felids from Brazil. Samples from 2 jaguars (Panthera onca) and 1 oncilla (Leopardus tigrinus) were positive for FHV-1; 2 jaguars, 1 puma (Puma concolor), and 1 jaguarundi (Herpairulus yagouaroundi) tested positive for CPPV-1; and 1 puma was positive for FIV. Based on comparison of 103 nucleotides of the UL24-UL25 gene, the FHV-1 sequences were 99–100% similar to the FHV-1 strain of domestic cats. Nucleotide sequences of CPPV-1 were closely related to sequences detected in other wild carnivores, comparing 294 nucleotides of the VP1 gene. The FIV nucleotide sequence detected in the free-ranging puma, based on comparison of 444 nucleotides of the pol gene, grouped with other lentiviruses described in pumas, and had 82.4% identity with a free-ranging puma from Yellowstone Park and 79.5% with a captive puma from Brazil. Our data document the circulation of FHV-1, CPPV-1, and FIV in neotropical felids in Brazil. [ABSTRACT FROM AUTHOR]

We evaluated duration of PCR-positive results following administration of modified-live viral (MLV) vaccines to beef calves. Twenty beef calves were randomly assigned to either group 1 and vaccinated intranasally with a MLV vaccine containing bovine alphaherpesvirus 1 (BoHV-1), bovine respiratory syncytial virus (BRSV), and bovine parainfluenza virus 3 (BPIV-3), or to group 2 and vaccinated subcutaneously with a MLV vaccine containing bovine viral diarrhea virus 1 and 2 (BVDV-1, -2), BoHV-1, BRSV, and BPIV-3. Deep nasopharyngeal swabs (NPS) and transtracheal washes (TTW) were collected from all calves, and whole blood was collected from group 2 calves and tested by PCR. In group 1, the proportions of calves that tested PCR-positive to BVDV, BoHV-1, BRSV, and BPIV-3 on any sample at any time were 0%, 100%, 100%, and 10%, respectively. In group 1 calves, 100% of calves became PCR-positive for BoHV-1 by day 3 post-vaccination and 100% of calves became PCR-positive for BRSV by day 7 post-vaccination. In group 2, the proportions of calves that tested positive to BVDV, BoHV-1, BRSV, and BPIV-3 on any sample at any time were 50%, 40%, 10%, and 0%, respectively. All threshold cycle (Ct) values were >30 in group 2 calves, irrespective of virus; however, Ct values <25 were observed in group 1 calves from PCR-positive results for BoHV-1 and BRSV. All calves were PCR-negative for all viruses after day 28. Following intranasal MLV viral vaccination, PCR results and Ct values for BRSV and BoHV-1 suggest that attempts to differentiate vaccine virus from natural infection is unreliable. [ABSTRACT FROM AUTHOR]

Parapoxviruses (PaPVs) cause widespread infections in ruminants worldwide. All PaPVs are zoonotic and may infect humans after direct or indirect contact with infected animals. Herein we report the development and validation of a highly sensitive real-time PCR assay for rapid detection of PaPVs. The new assay (referred to as the RVSS assay) was specific for PaPVs only and had no cross-reactivity against other pox viruses. Using a recombinant plasmid as positive control, the analytical sensitivity of the assay was determined to be 16 genome copies of PaPV per assay. The amplification efficiency estimate (91–99%), the intra- and interassay variability estimate (standard deviation [SD]: 0.28–1.06 and 0.01–0.14, respectively), and the operator variability estimate (SD: 0.78 between laboratories and 0.28 between operators within a laboratory) were within the acceptable range. The diagnostic specificity was assessed on 100 specimens from healthy normal animals and all but 1 tested negative (99%). The diagnostic sensitivity (DSe) was assessed on 77 clinical specimens (skin/scab) from infected sheep, goats, and cattle, and all tested positive (100%). The assay was multiplexed with beta-actin as an internal positive control, and the multiplex assay exhibited the same DSe as the singleplex assay. Further characterization of the PaPV specimens by species-specific real-time PCR and nucleotide sequencing of the PCR products following conventional PCR showed the presence of Orf virus not only in sheep and goats but also in 1 bovid. The validated RVSS assay demonstrated high specificity, sensitivity, reproducibility, and ruggedness, which are critical for laboratory detection of PaPVs. [ABSTRACT FROM AUTHOR]

Summary Ophidian paramyxovirus (ferlavirus) is a global threat to reptilian sauropsids in herpetological collections, with occasional but fatal effects. This study characterizes the effects of three different genetic strains of ferlavirus on the dynamic changes of histology and morphometry of the lung of corn snakes ( Pantherophis guttatus ). Lungs from 42 corn snakes were either sham-infected or infected experimentally under standardized conditions. From 4 to 49 days after intratracheal inoculation, the lungs were examined qualitatively and quantitatively. Progressive microscopical changes were seen in the lung. Initially, increased numbers of heterophils were observed in the interstitium followed by proliferation and vacuolation of epithelial cells lining faveoli. Electron microscopy revealed loss of type-I pneumocytes, hyperplasia of type-II pneumocytes, and interstitial infiltrates of heterophils and mononuclear cells. With progression of disease the respiratory epithelium was initially overgrown by transformed type-II pneumocytes and later became multilayered. The results of the study suggest that the respiratory capacity of the lungs declines with disease development. The dynamics of disease development and histopathology differed in snakes infected with different ferlavirus genogroups. Animals infected with virus genogroup B developed histopathological changes and morphometric changes more rapidly and of greater intensity than snakes infected with viruses from genogroups A or C. [ABSTRACT FROM AUTHOR]

Canine distemper virus (CDV) is one of the most serious pathogens found in many species of carnivores, including domestic dogs. In this study, hemagglutinin (H) genes were detected in five domestic Vietnamese dogs with diarrhea, and two CDVs were successfully isolated from dogs positive for H genes. The complete genome of one isolate, CDV/dog/HCM/33/140816, was determined. Phylogenetic analysis showed that all Vietnamese CDVs belonged to the Asia-1 genotype. In addition, the H proteins of Vietnamese CDV strains were the most homologous to those of Chinese CDVs (98.4% to 99.3% identity). These results indicated that the Asia-1 genotype of CDV was the predominant genotype circulating among the domestic dog population in Vietnam and that transboundary transmission of CDV has occurred between Vietnam and China. [ABSTRACT FROM AUTHOR]

Orf virus infection has been prevalent continuously in the population of wild Japanese serows (Capricornis crispus), goat-like grazing cloven-hoofed mammal species that live mainly in mountainous areas of Japan. Currently, definitive diagnosis of infection requires time-consuming laboratory work. To diagnose rapidly on-site, we developed a field-friendly procedure for the detection of orf virus from oral cavity lesions. DNA was extracted from goat saliva spiked with orf virus as a proxy for Japanese serows by a commercial kit without the use of electricity, and the quality of the extracted DNA was evaluated by conventional polymerase chain reaction (PCR). Extracted DNA was amenable to DNA amplification, the same as when extracted in a laboratory. Next, to find optimal conditions for DNA amplification by loop-mediated isothermal amplification (LAMP), Bst and Csa DNA polymerases and 3 colorimetric indicators for visual diagnosis, hydroxy naphthol blue (HNB), malachite green and D-QUICK, were compared using a portable cordless incubator. The combination of Bst or Csa DNA polymerase with HNB was found to be easiest for visual diagnosis by the naked eye, and viral DNA was successfully amplified from all orf virus strains used. These results suggest that the procedure established here can work completely on-site and can be useful for definitive diagnosis and differentiation of orf virus infection in Japanese serows in remote mountainous areas. [ABSTRACT FROM AUTHOR]

In 2007-2008, a canine distemper virus (CDV) epidemic occurred among wild animals in Wakayama Prefecture, Japan, and many mammals, including the wild boar and deer, were infected. In this study, CDV prevalence among wild animals was surveyed before and after the epidemic. At first, an enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase-conjugated protein A/G was established to detect CDV antibodies in many mammalian species. This established ELISA was available for testing dogs, raccoons and raccoon dogs as well as virus-neutralization test. Next, a serological survey of wild mammalians was conducted, and it was indicated that many wild mammalians, particularly raccoons, were infected with CDV during the epidemic, but few were infected before and after the epidemic. On the other hand, many raccoon dogs died during the epidemic, but CDV remained prevalent in the remaining population, and a small epidemic occurred in raccoon dogs in 2012-2013. These results indicated that the epidemic of 2007-2008 may have been intensified by transmission to raccoons. [ABSTRACT FROM AUTHOR]

Molecular methods for the detection of Schmallenberg virus (SBV) RNA were rapidly developed after the emergence of this novel orthobunyavirus in Europe. The SBV epizootic wave has declined, but infectious SBV in SBV RNA–positive semen remains a possible risk for the distribution of SBV. However, the abilities of SBV molecular detection methods used at European laboratories have not yet been assessed, to our knowledge. The performances of extraction and real-time reverse transcription polymerase chain reaction (RT-qPCR) methods used at 27 German and 17 other European laboratories for SBV RNA detection in the matrices of whole blood, serum, tissue homogenate, RNA eluates, and bovine semen were evaluated in 2 interlaboratory trials with special emphasis on semen extraction methods. For reliable detection of viral genome in bovine semen samples, highly effective extraction methods are essential to cope with the potential inhibitory effects of semen components on PCR results. All methods used by the 44 laboratories were sufficiently robust to detect SBV RNA with high diagnostic sensitivity (100%) and specificity (95.8%) in all matrices, except semen. The trials demonstrated that the published recommended semen extraction methods (Hoffmann et al. 2013) and a combination of TRIzol LS with an alternative extraction kit have a considerably higher diagnostic sensitivity to detect SBV RNA in semen up to a detection limit of Cq ≤35 compared to other extraction methods used. A thorough validation of extraction methods with standardized semen batches is essential before their use for SBV RNA detection in bovine semen. [ABSTRACT FROM AUTHOR]

The fetal goat tongue cell line ZZ-R 127 and the fetal porcine kidney cell line LFBK-αvβ6 have been reported to have high sensitivity to various Foot-and-mouth disease virus (FMDV) strains. The suitability of ZZ-R 127 cells for FMDV isolation not only from epithelial suspensions but also from other clinical samples has already been confirmed in a previous study. However, to our knowledge, the suitability of LFBK-αvβ6 cells has not been evaluated using clinical samples other than epithelial materials. In addition, both cell lines have never been compared, in terms of use for FMDV isolation, under the same conditions. Therefore, in the current study, the virus isolation rates of both cell lines were compared using clinical samples collected from animals infected experimentally with FMDV. Viruses were successfully isolated from clinical samples other than epithelial suspensions for both cell lines. The virus isolation rates for the 2 cell lines were not significantly different. The Cohen kappa coefficients between the virus isolation results for both cell lines were significantly high. Taken together, these results confirmed the suitability of LFBK-αvβ6 cells for FMDV isolation from clinical samples other than epithelial suspensions. The levels of susceptibility of both cell lines to FMDV isolation were also confirmed to be almost the same. [ABSTRACT FROM AUTHOR]

The article describes the effects of avian hepatitis E virus (HEV) infection among chickens from organic layers. Topics covered include the study was done on 141 chickens from 10 organic layer flocks that have confirmed history of egg production decline from 2012 to 2014, usual findings confirmed signs of the disease on the white foci of the liver and regressed ova, and results confirmed that the avian HEV infection is linked to genotype 2.

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Early detection of infection by the Aleutian mink disease virus (AMDV; Carnivore amdoparvovirus 1) by polymerase chain reaction (PCR) or counterimmunoelectrophoresis (CIEP) has important ramifications in virus eradication programs. A spleen homogenate containing a local isolate of AMDV was injected intraperitoneally into black (n = 44) and sapphire (n = 12) American mink (Neovison vison). Animals were euthanized 10 days postinoculation and anti-AMDV antibodies and AMDV DNA were tested in plasma and 7 organs by CIEP and PCR, respectively. Viral DNA was detected in the plasma, spleen, lymph nodes, bone marrow, and lung samples of all inoculated mink, but was not detected in some small intestine, kidney, and liver samples. In contrast, antibodies were detected in the plasma of 3 sapphire (25.0%) and 19 black (43.2%) mink but not in any of the organs. The sensitivity of the CIEP test on plasma samples was 39.3%, implying that low levels of antibodies during the early stages of virus exposure resulted in failure to detect infection by the CIEP test. We concluded that CIEP is not a reliable test for early detection of AMDV infection in mink and that there were considerable differences among mink of each color type for production of detectable levels of antibodies. PCR tests on samples of saliva, rectal swabs, and feces did not produce consistent and reliable results. [ABSTRACT FROM PUBLISHER]

CASE HISTORY: One 4.5-month-old male Border Collie cross presented with aggression and seizures in October 2006. A 16-month-old, female, spayed Border Collie cross presented with hypersalivation and a dropped jaw and rapidly became stuporous in September 2007. The dogs were littermates and developed acute neurological signs 5 and 27 days, respectively, after vaccination with different modified live vaccines containing canine distemper virus. HISTOPATHOLOGICAL FINDINGS: Sections of brain in both dogs showed evidence of encephalitis mainly centred on the grey matter of brainstem nuclei, where there was extensive and intense parenchymal and perivascular infiltration of histiocytes and lymphocytes. Intra-nuclear and intra-cytoplasmic inclusions typical of distemper were plentiful and there was abundant labelling for canine distemper virus using immunohistochemistry. DIAGNOSIS: Post-vaccinal canine distemper. CLINCIAL RELEVANCE: Post-vaccinal canine distemper has mainly been attributed to virulent vaccine virus, but it may also occur in dogs whose immunologic nature makes them susceptible to disease induced by a modified-live vaccine virus that is safe and protective for most dogs. [ABSTRACT FROM PUBLISHER]

Ibaraki virus (IBAV) is a member of the epizootic hemorrhagic disease virus (EHDV) serogroup, which belongs to the Orbivirus genus of the Reoviridae family. Although EHDV, including IBAV, represents an ongoing threat to livestock in the world, molecular mechanisms of EHDV replication and pathogenesis have been unclear. The reverse genetics (RG) system is one of the strong tools to understand molecular mechanisms of virus replication. Here, we developed a RG system for IBAV to identify the nonessential region of a minor structural protein, VP6, by generating VP6-truncated IBAV. Moreover, several tags were inserted into the truncated region to produce VP6-tagged IBAV. We demonstrated that all VP6-tagged IBAV could replicate in BHK cells in the absence of any helper VP6 protein. Further, tagged-VP6 proteins were first assembled into puncta in cells infected with VP6-tagged IBAV. Our data suggests that, in order to initiate primary replication, IBAV VP6 is likely to accumulate in some parts of infected cells to assemble efficiently into the primary replication complex (subcore). [ABSTRACT FROM AUTHOR]

A vaccine for equine coronavirus (ECoV) is so far unavailable. Bovine coronavirus (BCoV) is antigenically related to ECoV; it is therefore possible that BCoV vaccine will induce antibodies against ECoV in horses. This study investigated antibody response to ECoV in horses inoculated with BCoV vaccine. Virus neutralization tests showed that antibody titers against ECoV increased in all six horses tested at 14 days post inoculation, although the antibody titers were lower against ECoV than against BCoV. This study showed that BCoV vaccine provides horses with antibodies against ECoV to some extent. It is unclear whether antibodies provided by BCoV vaccine are effective against ECoV, and therefore ECoV challenge studies are needed to evaluate efficacy of the vaccine in the future. [ABSTRACT FROM AUTHOR]

Total of 185 blood samples collected from 11 layer farms (aged between 19 and 108 weeks) in Namakkal, Tamil Nadu were tested for the presence of antibodies against avian metapneumovirus by using a commercial enzyme-linked immunosorbent assay kit (IDEXX APV Ab test, Liebefeld-Bern, Switzerland) to determine antibodies against A, B and C subtypes of avian metapneumovirus and demonstrated 99.46 per cent seropositivity against aMPV antibodies. [ABSTRACT FROM AUTHOR]

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Schmallenberg virus causes stillbirths in animal populations like cattle, goats, sheep, bison and Alpaca. The first case was reported in Germany in November 2011 in a town called Schmallenberg. Consequently, many more cases were reported all over Europe, in The Netherlands, Belgium, the United Kingdom and France. Here, we elaborate on the recently identified Schmallenberg virus and its pathological outbreak in animals. [ABSTRACT FROM AUTHOR]

Rabbit hemorrhagic disease (RHD) is contagious and highly lethal. Commercial vaccines against RHD are produced from the livers of experimentally infected rabbits. Although several groups have reported that recombinant subunit vaccines against rabbit hemorrhagic disease virus (RHDV) are promising, application of the vaccines has been restricted due to high production costs or low yield. In the present study, we performed codon optimization of the capsid gene to increase the number of preference codons and eliminate rare codons in Spodoptera frugiperda 9 (Sf9) cells. The capsid gene was then subcloned into the pFastBac plasmid, and the recombinant baculoviruses were identified with a plaque assay. As expected, expression of the optimized capsid protein was markedly increased in the Sf9 cells, and the recombinant capsid proteins self-assembled into virus-like particles (VLPs) that were released into the cell supernatant. Rabbits inoculated with the supernatant and the purified VLPs were protected against RHDV challenge. A rapid, specific antibody response against RHDV was detected by an ELISA in all of the experimental groups. In conclusion, this strategy of producing a recombinant subunit vaccine antigen can be used to develop a low-cost, insect cell-derived recombinant subunit vaccine against RHDV. [ABSTRACT FROM AUTHOR]

Between 2008 and 2012, commercial Swiss layer and layer breeder flocks experiencing problems in laying performance were sampled and tested for infection with Duck adenovirus A (DAdV-A; previously known as Egg drop syndrome 1976 virus). Organ samples from birds sent for necropsy as well as blood samples from living animals originating from the same flocks were analyzed. To detect virus-specific DNA, a newly developed quantitative real-time polymerase chain reaction method was applied, and the presence of antibodies against DAdV-A was tested using a commercially available enzyme-linked immunosorbent assay. In 5 out of 7 investigated flocks, viral DNA was detected in tissues. In addition, antibodies against DAdV-A were detected in all of the flocks. [ABSTRACT FROM PUBLISHER]

Summary: The aim of this study was to compare the virulence of type 1 and type 2 porcine reproductive and respiratory syndrome virus (PRRSV) as assessed by the level of viral replication, viral distribution and apoptosis in stillborn fetuses and live-born piglets from infected pregnant gilts. Type 1 or type 2 PRRSV was given intranasally to pregnant gilts at 3 weeks before the expected date of parturition. Regardless of virus genotype, PRRSV-infected gilts farrowed between 102 and 109 days of gestation, while control uninfected gilts carried the pregnancy to term and farrowed at 114–115 days of gestation. There were no significant differences in the mean number of virus-infected cells per unit area of tissue when type 1 and type 2 virus infections were compared between stillborn fetuses and live-born piglets. Stillborn fetuses from the type 1 PRRSV-infected pregnant gilts had a significantly higher mean number of apoptotic cells per unit area of thymus (P = 0.013) than those from type 2 PRRSV-infected pregnant gilts. Significant differences in virulence were not observed between types 1 and 2 PRRSV in terms of female reproductive failure, although thymic apoptosis differed in stillborn fetuses from type 1 and type 2 PRRSV-infected pregnant gilts. [ABSTRACT FROM AUTHOR]

Summary: Schmallenberg virus (SBV) is an orthobunyavirus of the family Bunyaviridae that is associated with stillbirth and malformations in ruminants. The infection has been identified in many European countries since August 2011. The present study investigated retrospectively the occurrence of SBV infection in ruminants using immunohistochemistry and in-situ hybridization in brain tissues archived between 1961 and 2010 (112 cattle, 57 sheep, 16 goats and 27 wild ruminants). Eighty-five animals with inflammatory brain lesions and 47 animals with malformations were included. Due to the lack of SBV protein and RNA detection, SBV appears to have been introduced recently into Northern parts of Europe from tropical or subtropical regions. [ABSTRACT FROM AUTHOR]

Feline leukemia virus (FeLV) causes a range of neoplastic and degenerative diseases in cats. To obtain a more sensitive and convenient diagnosis of the disease, we prepared monoclonal antibodies specific for the FeLV p27 to develop a rapid diagnostic test with enhanced sensitivity and specificity. Among these antibodies, we identified two clones (hybridomas 8F8B5 and 8G7D1) that specifically bound to FeLV and were very suitable for a diagnostic kit. The affinity constants for 8F8B5 and 8G7D1 were 0.35 x 109 and 0.86 x 109, respectively. To investigate the diagnostic abilities of the rapid kit using these antibodies, we performed several clinical studies. Assessment of analytical sensitivity revealed that the detection threshold of the rapid diagnostic test was 2 ng/mL for recombinant p27 and 12.5 x 104 IU/mL for FeLV. When evaluating 252 cat sera samples, the kit was found to have a kappa value of 0.88 compared to polymerase chain reaction (PCR), indicating a significant correlation between data from the rapid diagnostic test and PCR. Sensitivity and specificity of the kit were 95.2% (20/21) and 98.5% (257/261), respectively. Our results demonstrated that the rapid diagnostic test would be a suitable diagnostic tool for the rapid detection of FeLV infection in cats. [ABSTRACT FROM AUTHOR]

The availability of the fetal goat tongue cell line ZZ-R 127 for the isolation of Foot-and-mouth disease virus (FMDV) has not been evaluated using clinical samples other than epithelial suspensions. Therefore, in the current study, the availability of ZZ-R 127 cells for the isolation of FMDV was evaluated using clinical samples (e.g., sera, nasal swabs, saliva, feces, and oropharyngeal fluids) collected from animals experimentally infected with an FMDV isolate. Virus isolation rates for the ZZ-R 127 cells were statistically higher than those for the porcine kidney cell line (IB-RS-2) in experimental infections using cattle, goats, and pigs (P < 0.01). Virus titers in the ZZ-R 127 cells were also statistically higher than those in the IB-RS-2 cells. The availability of ZZ-R 127 cells for the isolation of FMDV not only from epithelial suspensions but also from other clinical samples was confirmed in the current study. [ABSTRACT FROM PUBLISHER]

The article offers information on a study that improves a previously designed loop-mediated isothermal amplification (LAMP) method with an additional pair of loop primers, which accelerates the reaction. LAMP was used for the detection of Marek's disease virus virulent field strains. The study describes two other LAMP procedures for the specific detection of FC126 strain of turkey herpesvirus and nonpathogenic SB-1 strain. It compared and confirmed the developed LAMP procedures with polymerase chain reaction.

The article offers information on a study that developed a multiplex qpolymerase chain reaction for Marek's disease virus (MDV) and chicken anemia virus (CAV). The study aims to provide a new diagnostic standard that would simultaneously evaluate the presence at the infection level of the clinical samples. It is driven by the importance of both viruses for poultry health and productivity. The importance of the real-time multiplex PCR in terms of the diagnosis and detection of low copies of each virus, MDV and CAV in single- and in multiple-virus infections, is noted.

Five cases of off virus infection in Korean black goats were diagnosed in our laboratory between 2010 and 2011. One orf virus (ORF/2011) was isolated from an ovine testis cell line (OA3.Ts) for use as a vaccine candidate. Sequences of the major envelope protein and off virus interferon resistance genes were determined and compared with published reference sequences. Phylogenetic analyses revealed that orf viruses from Korean black goats were most closely related to an isolate (ORF/09/Korea) from dairy goats in Korea. This result indicates that the orf viruses might have been introduced from dairy goats into the Korean black goat population. [ABSTRACT FROM AUTHOR]

The pathogenicity induced by co-challenge with the rB strain of very virulent Infectious bursal disease virus (vvIBDV) and IBDV pathotypes endemic in the United States was evaluated in specific pathogen–free chickens. Four- and 6-week-old birds were simultaneously challenged with a 105 50% egg infectious dose (EID50) of rB mixed with a 105 EID50 of one of the following viruses: standard classic (STC), subclinical variant (Del-E), subclinical variant (T1), or avirulent serotype 2 (OH). Each challenge group consisted of 5 chickens. The severity of disease was assessed by comparing the 5-day mortality rates, bursal lesions (mean bursal lesion scores), and mean bursal-to-body weight ratios in each of the challenged groups. A mortality of 100% (10/10 and 5/5) was observed in birds inoculated with only the vvIBDV (rB) strain at 4 weeks and 6 weeks of age, respectively. Although the sample sizes were low, a significant reduction in mortality and severity of disease, based on mean bursal lesion scores, was observed in groups co-challenged with rB and the less virulent pathotypes Del-E, T1, or OH at 4 weeks of age. Co-challenge with rB and the antigenically similar STC strain did not result in a significant decrease in mortality compared to challenge with the pathogenic rB strain at 4 weeks of age, but a significant reduction in the mean bursa lesion score was observed. At 6 weeks of age, a significant decrease in mortality and mean bursa lesion score was observed in the rB groups co-challenged with STC, Del-E, or T1 but not OH. [ABSTRACT FROM PUBLISHER]

The article discusses a study that investigated the subclinical infection rate of psittacine beak and feather disease (PBFD) in live psittacine birds imported from some countries and bred in Japan from April 2003 to March 2004. An overview of PBFD is presented. It also discusses the process of randomly selecting beak and feather disease virus (BFDV) samples for sequencing, and the details relating to the nucleotide sequences of the selected BFDV samples.

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The prevalence of various viral infections was examined in primary accession cases of feline lower urinary tract disease (FLUTD) and healthy control cats in Norway. Urine samples from 102 cats with clinical signs of FLUTD and 73 healthy control cats were tested for the presence of feline calicivirus (FCV), feline coronavirus (FCoV) and feline herpesvirus-1 (FHV-1) by polymerase chain reaction. All urinary samples were negative for FCV and FCoV. One (1%) of the FLUTD cats was found to be positive for FHV-1. The results did not indicate an association between the viral infections examined and signs of FLUTD in the study sample. [ABSTRACT FROM AUTHOR]

The article deals with a study about the glycoprotein (GP) of lymphocytic choriomeningitis virus (LCMV). Topics discussed include LCMV infection in animals, the tropism of LCMV-GP-pseudotypes, and whether infection of LCMV-GP-pseudotypes was affected by the expression of four cell surface molecules namely Axl and Tyro3 and DC-SIGN and LSECtin, that are known receptors of Lassa virus.

The outer membrane proteins (OMPs) of Brucella (B.) abortus have been extensively studied, but their immunogenicity and protective ability against B. abortus infection are still unclear. In the present study, B. abortus Omp28, a group 3 antigen, was amplified by PCR and cloned into a maltose fusion protein expression system. Recombinant Omp28 (rOmp28) was expressed in Escherichia coli and was then purified. Immunogenicity of rOmp28 was confirmed by Western blot analysis with Brucella-positive mouse serum. Furthermore, humoral- or cell-mediated immune responses measured by the production of IgG1 or IgG2a in rOmp28-immunized mice and the ability of rOmp28 immunization to protect against B. abortus infection were evaluated in a mouse model. In the immunogenicity analysis, the mean titers of IgG1 and IgG2a produced by rOmp28-immunized mice were 20-fold higher than those of PBS-treated mice throughout the entire experimental period. Furthermore, spleen proliferation and bacterial burden in the spleen of rOmp28-immunized mice were approximately 1.5-fold lower than those of PBS-treated mice when challenged with virulent B. abortus. These findings suggest that rOmp28 from B. abortus is a good candidate for manufacturing an effective subunit vaccine against B. abortus infection in animals. [ABSTRACT FROM AUTHOR]

This study measured the clinical prevalence of peste des petits ruminants (PPR) among sheep and goats in India between 2003 and 2009 by analyzing clinical samples from suspected cases of PPR that were submitted to the Rinderpest and Allied Disease Laboratory, Division of Virology, IVRI, Mukteswar for PPR diagnosis. PPR outbreaks were confirmed by detecting PPR virus (PPRV)-specific antigen in the clinical samples. Clinical samples (blood, nasal swabs, spleen, lymph node, kidney, liver, intestine, and pooled tissue materials) were taken from a total of 592 sheep and 912 goats in different states of India and screened for the presence of PPRV antigen using a monoclonal antibody-based sandwich ELISA kit. A total of 20, 38, and 11 laboratory-confirmed PPR outbreaks occurred among sheep, goat, and combined sheep and goat populations, respectively. Our findings provide evidence of widespread PPR endemicity in India. The underlying reasons could be variations in husbandry practices in different geographical regions, agro-climatic conditions, and livestock migration. Furthermore, decrease in the number of PPR outbreaks over time might be due to the effectiveness of current live PPR vaccines and timely vaccination of target species. Vaccination against PPR has been practiced in India since 2002 to control this disease. [ABSTRACT FROM AUTHOR]

Reports of influenza A virus infections in dogs has received considerable attention from veterinarians, virologists, and epidemiologists. Interaction between influenza viral hemagglutinin and cell oligosaccharides containing sialic acid residues results in infection. Sialic acids have an α-2,3-linkage to the penultimate galactose in the avian influenza virus receptor and an α-2,6-linkage in the human receptor. To date, there are no detailed data on the tissue distribution or histological features of either type of sialic acid-linked influenza virus receptors in beagle dogs, which are common laboratory animals and pets. We conducted the current study to visualize the in situ tissue distribution of both sialic acid-linked influenza virus receptors in various organs of beagle dogs using Maackia amurensis lectin II and Sambucus nigra agglutinin. Both α-2,3- and α-2,6-sialic acid-linked receptors were detected in the endothelial cells of the respiratory tract and other organs. Endothelial cells of most gastrointestinal organs were negative for α-2,3-sialic acid-linked receptors in the dogs. Our results suggested that these canine organs may be affected by influenza virus infection. The findings from our study will also help evaluate the occurrence and development of influenza virus infections in dogs. [ABSTRACT FROM AUTHOR]

Abstract: Feather loss in psittacine birds is an extremely common and extremely frustrating clinical presentation. Causes include medical and non-medical causes of feather loss both with and without overt feather destructive behavior. Underlying causes are myriad and include inappropriate husbandry and housing; parasitic, viral and bacterial infections; metabolic and allergic diseases; and behavioral disorders. Prior to a diagnosis of a behavioral disorder, medical causes of feather loss must be excluded through a complete medical work-up including a comprehensive history, physical exam, and diagnostic testing as indicated by the history, signalment and clinical signs. This article focuses on some of the more common medical and non-medical causes of feather loss and feather destructive behavior as well as approaches to diagnosis and treatment. [Copyright &y& Elsevier]

Most studies that investigate the prevalence of infections with feline leukemia virus (FeLV) are based on the detection of p27 antigen in blood, but they do not detect proviral DNA to identify the prevalence of regressive FeLV infections. The aim of the present study was to assess the prevalence and status of FeLV infection in cats in Southern Germany. P27 antigen enzyme-linked immunosorbent assay (ELISA), anti-p45 antibody ELISA, DNA polymerase chain reaction (PCR) of blood and RNA PCR of saliva were performed. Nine out of 495 cats were progressively (persistently) infected (1.8%) and six were regressively (latently) infected (1.2%). Cats with regressive infections are defined as cats that have been able to overcome antigenemia but provirus can be detected by PCR. Twenty-two unvaccinated cats likely had abortive infections (regressor cats), testing FeLV antigen- and provirus-negative but anti-p45 antibody-positive. Most of the FeLV-vaccinated cats did not have anti-FeLV antibodies. Both progressive, as well as regressive infections seem to be rare in Germany today. [ABSTRACT FROM PUBLISHER]

The article presents a study which examines the case of fatal Canid herpesvirus 1 (CaHV-1) infection in a 9-year-old spayed female Bichon Frise dog. It observes the intranuclear inclusion bodies in the adrenal gland of the CaHV-1-infected puppies. It confirms the CaHV-1 infection by doing immunohistochemistry, in situ hybridization, and polymerase chain reaction to the liver samples. Results have showed that CaHV-1 should be included in the diagnosis of hepatic necrosis in adult dogs.

The article presents research on blue eye disease, a viral swine disease that is endemic in Mexico and caused by a porcine rubulavirus (PoRV). Atypical outbreaks of the disease were detected in 1990 and 2003 that produced neurological signs and reproductive problems in pigs. This study analyzed the hemagglutinin-neuraminidase protein and found the PoRV strains were genetically and antigenetically different.

Infectious bovine keratoconjunctivitis (IBK) is an acute disease caused by Moraxella bovis (Mb). Several factors may predispose animals to an IBK outbreak; one commonly observed is infection with bovine herpes virus type 1 (BHV-1). The aim of this study was to investigate the dynamics of BHV-1 virus infection and its relation with clinical cases of IBK in weaned calves from a beef herd with a high prevalence of lesions caused by Mb. Sampling was carried out in six stages and included conjunctival swabs for isolating Mb as well as blood samples for identifying antibodies specific for BHV-1. A score for IBK lesions after observing each eye was determined. The findings of this study showed a high prevalence of BHV-1 virus infection (100% of animals were infected at the end of the trial); 67% of animals were culture-positive for Mb, but low rates of clinical IBK (19% of calves affected) were detected at the end of the trial. These results suggest that infection with BHV-1 did not predispose these animals to IBK, and that Mb infection produced clinical and subclinical disease in the absence of BHV-1 co-infection. [ABSTRACT FROM AUTHOR]

The article discusses a study which examined a three-month-old white-tailed deer that died from Deerpox virus infection. The white-tailed deer was brought to the Mississippi Veterinary Research and Diagnostic Laboratory for postmortem examination. Findings of the examination showed that extensive lesions can develop in white-tailed deer with Deerpox virus.

Viral traffic occurs readily between wild and domesticated stocks of finfish because aquatic environments have greater connectivity than their terrestrial counterparts and because the global expansion and dynamic nature of intensive aquaculture provide multiple pathways of transmission and unique drivers of virus adaptation. Supported by examples from the literature, we provide reasons why viruses move from wild fish reservoirs to infect domestic fish in aquaculture more readily than ‘domestic’ viruses move across the interface to infect wild stocks. We also hypothesize that ‘wild’ viruses moving across the interface to domestic populations of finfish are more frequently associated with disease outbreaks and host switches compared to domestic viruses that cross the interface to infect wild fish. [Copyright &y& Elsevier]