Orf virus infection in sheep or goats

Synergistic Effect of Maternal Micronutrient Supplementation on ORFV DNA Vaccine Immune Response in a Pregnant Model

Contagious ecthyma is a contagious zoonotic disease caused by the Orf virus that can infect farm animals and humans, but no vaccine is available for pregnant mothers. Excessive oxidative stress during pregnancy can suppress the vaccine immune response in pregnant mothers; hence, maternal micronutrient supplementation could effectively improve the immune response, health, and oxidative status during pregnancy. In this study, we employed an 8-week-old pregnant rat model to receive a single intramuscular dose of 200 µg of ORF DNA vaccine with or without vitamin E and selenium supplementation to evaluate their effect on immune responses (specific IgG and IgG isotypes), oxidative stress, liver enzymes, and blood glucose levels in maternal-neonatal serum and milk secretions. Additionally, antioxidant-related gene expressions were analyzed in the maternal placenta and pups' liver. The results showed that supplementation of vitamin E and selenium with ORF DNA vaccination increased the production of specific antibody and IgG isotypes (IgG1 and IgG2a) and reduced the oxidative stress in neonatal-maternal serum and milk compared to both the control group and those vaccinated without supplementation (p < 0.05). Notably, the ORF DNA vaccine did not cause oxidative stress and hepatic damage. However, combined supplementation of vitamin E and selenium with DNA vaccination significantly decreased serum malondialdehyde (MDA) levels and improved the antioxidant-related enzyme activities of glutathione peroxidase (GPX), superoxide dismutase 1 (SOD1), and selenoprotein P (SELP) in the maternal placenta and liver of pups (p < 0.05). In conclusion, maternal supplementation of vitamin E and selenium enhanced the immune responses of the ORF DNA vaccine by mitigating oxidative stress in pregnant rats and could thus be a promising strategy for better health outcomes for both mothers and neonates.

Molecular detection and phylogenetic analysis of Orf viruses from goats in Jiangxi province, China

Orf is a zoonosis caused by the Orf virus (ORFV), which is endemic in goats, sheep, and wild ruminants worldwide. Orf infection is prevalent in China, with outbreaks reported in several provinces. Currently, there is limited information available regarding the characterization of ORFV strains in Jiangxi province. This study investigated an acute outbreak of Orf that occurred in 2021 in a goat herd in the Jiangxi province of China. Clinical signs in this case included lesions on the lips, nose, and inside the mouth. The presence of ORFV was confirmed from tissue samples by polymerase chain reaction (PCR). The nucleotide sequences of the B2L and F1L genes were fully sequenced and used to construct phylogenetic trees. The results of this investigation identified the ORFV JXxy2021 as the cause of the outbreak. The phylogenetic analysis revealed that the ORFV strain JXxy2021 had the highest similarity to the ORFV strains GO and FJ-SL from the neighboring province of Fujian. This suggests that JXxy2021 was likely transmitted from Fujian province. The results have provided valuable information on the genetic characteristics of JXxy2021 and the endemic situations of Orf in China.

Use of a local anaesthetic and antiseptic wound formulation for the treatment of lambs naturally infected with Orf virus

Contagious ecthyma (CE) is a worldwide highly contagious zoonotic viral skin disease of sheep and goats. Treatment for Orf virus (ORFV) infection usually involves topical and oral antibiotics. An anaesthetic and antiseptic topical gel (Multisolfen® or Tri-Solfen®; MS®, Medical Ethics, Australia) has been documented as an efficacious therapy for lesions from mucosal and epithelial viral infections in ruminants. The present study tested a new treatment protocol of MS® for CE therapy on-farm in 150 lambs naturally infected with ORFV. Lambs were divided into three cohorts of 50 lambs each (C, D and E). Cohort C was treated with MS® 3 times with an interval of 3 days between treatments, cohort D was treated daily with hypochlorous acid, whilst cohort E served as untreated controls. The lambs were examined clinically every two days, weight measured weekly, with whole blood and sterile swabs from ORFV lesions collected for haematological analysis and specific ORFV PCR. Cohort C presented fewer lambs displaying ORFV-associated lesions than other cohorts at different times of the experiment. Further, lesions treated with MS® were milder compared with other cohorts. However, following cessation of therapy, most of the lambs again developed ORFV-associated lesions. No differences between cohorts were observed in weight, haematological and PCR results. These findings suggest that topical treatment with MS® is effective for CE in field conditions, especially in the first stages of the clinical course, although treatment with MS® may need to be extended a minimum of 4 weeks.

Detection and Phylogenetic Analysis of Orf Virus and Muskox Rhadinovirus 1 from Muskoxen (Ovibos moschatus) in the Canadian Arctic

Orf virus (genus Parapoxvirus) has been associated with gross skin lesions on muskoxen (Ovibos moschatus) from Victoria Island, Nunavut, Canada, where muskox populations are experiencing population declines. Orf virus causes painful proliferative and necrotizing dermatitis upon viral replication and shedding, which may lead to animal morbidity or mortality through secondary infections and starvation. Herpesvirus, known to cause gross lesions on skin and mucosa during active viral replication, has also been documented in muskoxen but to date has not been associated with clinical disease. Our objective was to characterize the variation of orf virus and herpesvirus in wild muskoxen of the Canadian Arctic. Tissue samples including gross skin lesions from the nose, lips, and/or legs were opportunistically collected from muskoxen on Victoria Island, Nunavut and Northwest Territories, and mainland Nunavut, Canada, from 2015 to 2017. Sampled muskoxen varied in age, sex, location, hunt type, and body condition. Tissues from 60 muskoxen were tested for genetic evidence of orf virus and herpesvirus infection using PCR targeting key viral genes. Tissues from 38 muskoxen, including 15 with gross lesions, were also examined for histological evidence of orf virus and herpesvirus infection. Eleven muskoxen (10 from Victoria Island and one from mainland Nunavut) with gross lesions had microscopic lesions consistent with orf virus infection. Muskox rhadinovirus 1, a gammaherpesvirus endemic to muskoxen, was detected in 33 (55%) muskoxen including 17 with gross lesions. In all tissues examined, there was no histological evidence of herpesvirus-specific disease. Sequencing and characterization of amplified PCR products using phylogenetic analysis indicated that a strain of orf virus, which appears to be unique, is likely to be endemic in muskoxen from Victoria Island and mainland Nunavut. Many of the muskoxen are also subclinically infected with a known muskox-endemic strain of herpesvirus.

Metagenomic profiling of viral and microbial communities from the pox lesions of lumpy skin disease virus and sheeppox virus-infected hosts

Introduction

It has been recognized that capripoxvirus infections have a strong cutaneous tropism with the manifestation of skin lesions in the form of nodules and scabs in the respective hosts, followed by necrosis and sloughing off. Considering that the skin microbiota is a complex community of commensal bacteria, fungi and viruses that are influenced by infections leading to pathological states, there is no evidence on how the skin microbiome is affected during capripoxvirus pathogenesis.

Methods

In this study, shotgun metagenomic sequencing was used to investigate the microbiome in pox lesions from hosts infected with lumpy skin disease virus and sheep pox virus.

Results

The analysis revealed a high degree of variability in bacterial community structures across affected skin samples, indicating the importance of specific commensal microorganisms colonizing individual hosts. The most common and abundant bacteria found in scab samples were Fusobacterium necrophorum, Streptococcus dysgalactiae, Helcococcus ovis and Trueperella pyogenes, irrespective of host. Bacterial reads belonging to the genera Moraxella, Mannheimia, Corynebacterium, Staphylococcus and Micrococcus were identified.

Discussion

This study is the first to investigate capripox virus-associated changes in the skin microbiome using whole-genome metagenomic profiling. The findings will provide a basis for further investigation into capripoxvirus pathogenesis. In addition, this study highlights the challenge of selecting an optimal bioinformatics approach for the analysis of metagenomic data in clinical and veterinary practice. For example, direct classification of reads using a kmer-based algorithm resulted in a significant number of systematic false positives, which may be attributed to the peculiarities of the algorithm and database selection. On the contrary, the process of de novo assembly requires a large number of target reads from the symbiotic microbial community. In this work, the obtained sequencing data were processed by three different approaches, including direct classification of reads based on k-mers, mapping of reads to a marker gene database, and de novo assembly and binning of metagenomic contigs. The advantages and disadvantages of these techniques and their practicality in veterinary settings are discussed in relation to the results obtained.

The Global Evolutionary History of Orf Virus in Sheep and Goats Revealed by Whole Genomes Data

Orf virus (ORFV) belongs to the genus Parapoxvirus (Poxviridae family). It is the causative agent of contagious ecthyma (CE) that is an economically detrimental disease affecting small ruminants globally. Contagious ecthyma outbreaks are usually reported in intensive breeding of sheep and goats but they have also been reported in wildlife species. Notably, ORFV can infect humans, leading to a zoonotic disease. This study aims to elucidate the global evolutionary history of ORFV genomes in sheep and goats, including the first genomes from Central America in the analyses. In comparison to the last study on ORFV whole genomes, the database now includes 11 more sheep and goat genomes, representing an increase of 42%. The analysis of such a broader database made it possible to obtain a fine molecular dating of the coalescent time for ORFV S and G genomes, further highlighting the genetic structuring between sheep and goat genomes and corroborating their emergence in the latter half of 20th century.

An evaluation of the ecological niche of Orf virus (Poxviridae): Challenges of distinguishing broad niches from no niches

Contagious ecthyma is a skin disease, caused by Orf virus, creating great economic threats to livestock farming worldwide. Zoonotic potential of this disease has gained recent attention owing to the re-emergence of disease in several parts of the world. Increased public health concern emphasizes the need for a predictive understanding of the geographic distributional potential of Orf virus. Here, we mapped the current distribution using occurrence records, and estimated the ecological niche in both geographical and environmental spaces. Twenty modeling experiments, resulting from two- and three-partition models, were performed to choose the candidate models that best represent the geographic distributional potential of Orf virus. For all of our models, it was possible to reject the null hypothesis of predictive performance no better than random expectations. However, statistical significance must be accompanied by sufficiently good predictive performance if a model is to be useful. In our case, omission of known distribution of the virus was noticed in all Maxent models, indicating inferior quality of our models. This conclusion was further confirmed by the independent final evaluation, using occurrence records sourced from the Centre for Agriculture and Bioscience International. Minimum volume ellipsoid (MVE) models indicated the broad range of environmental conditions under which Orf virus infections are found. The excluded climatic conditions from MVEs could not be considered as unsuitable owing to the broad distribution of Orf virus. These results suggest two possibilities: that the niche models fail to identify niche limits that constrain the virus, or that the virus has no detectable niche, as it can be found throughout the geographic distributions of its hosts. This potential limitation of component-based pathogen-only ENMs is discussed in detail.

Orf, a Human Parapoxvirus Infection

Despite being common worldwide, parapoxvirus infections are regarded as neglected zoonoses because their incidence is either unknown or grossly overestimated. In ruminants all throughout the world, parapoxvirus produces oral lesions and infectious pustular dermatitis. The pathogen is typically spread directly via items contaminated with parapoxvirus and indirectly via a near contact with dermatological lesions that contain the virus on affected animals. Animals infected with the parapoxvirus typically exhibit no clinical symptoms, and the mode of parapoxvirus transmission is occasionally unclear. For accurate etiological diagnosis and appropriate therapy of patients affected by zoonotic infections, the significance of adopting a "One Health" approach and cross-sector collaboration between human and veterinary medicine should be emphasized. The causative pathogen of ecthyma contagiosum in general people is the orf virus, which mostly infects various animals, either pets or wildlife species. The illness primarily affects minute wild ruminants, sheep, cattle, deer, and goats, and it can spread to people through contact with infected animals or contaminated meats anywhere in the world. Taxonomically speaking, the virus belongs to the parapoxvirus genus. Thus pathogen can be detected from crusts for a very long period (several months to several years), and the virus is found to be resistant to inactivation with a hot or dry atmosphere. In immunocompetent individuals, the lesions often go away on their own with a period as long 2 months. Nevertheless, it necessitates the applying of diverse strategies, such as antiviral, immunological modulator, or modest surgical excisions in immunosuppressed patients. The interaction of the virus with various host populations aids in the development of a defense mechanism against the immune system. The parapoxvirus illness in humans is covered in this chapter. The orf illness, a significant known human parapoxvirus infection, is given specific attention.

Athena: Speciality Certificate Examination case for infectious disease

This patient’s case highlights the clinical features and potential complications of an infection.

Use of a Local Anaesthetic/Antiseptic Formulation for the Treatment of Lambs Experimentally Infected with Orf Virus

Contagious ecthyma is a highly transmissible eruptive viral disease of the skin and mucosa of sheep and goats distributed worldwide. The treatment of orf lesions is usually based on the use of antiseptics and antibiotics for the management of presumptive secondary infections, increasing risks of antimicrobial resistance. The wound dressing formulation Tri-Solfen® (TS) containing two local anaesthetics (lignocaine and bupivacaine), adrenaline and an antiseptic (cetrimide) in a gel formulation has been demonstrated to reduce suffering and enhance recovery in cattle and buffalo with oral and skin lesions due to foot-and-mouth disease virus infection and reduced the orf viral load in lambs. In the present study, experimental infection with the orf virus was conducted in 50 newborn lambs and 25 animals were treated after the presence of the first lesions with TS and repeated three days later. Daily clinical examination, haematological, serological, biomolecular and post-mortem analyses were conducted during 34 days after treatment. Results indicated that treatment had no effect on weight gain and clinical progression of the lesions. It was determined that seroconversion after experimental infection occurs 34 days after infection and suggested that the deep basal epithelial location of the orf lesions may have prevented the therapy from having altered the clinical course.

ORFV entry into host cells via clathrin-mediated endocytosis and macropinocytosis

Orf virus (ORFV), also known as infectious pustular virus, leads to an acute contagious zoonotic infectious disease. ORFV can directly contact and infect epithelial cells of skin and mucosa, causing damage to tissue cells. So far, the pathway of ORFV entry into cells is unclear. Therefore, finding the internalization pathway of ORFV will help to elucidate the cellular and molecular mechanisms of ORFV infection and invasion, which in turn will provide a certain reference for the prevention and treatment of ORFV. In the present study, chemical inhibitors were used to analyze the mechanism of ORFV entry into target cells. The results showed that the inhibitor of clathrin-mediated endocytosis could inhibit ORFV entry into cells. However, the inhibitor of caveolae-mediated endocytosis cannot inhibit ORFV entry into cells. In addition, inhibition of macropinocytosis pathway also significantly reduced ORFV internalization. Furthermore, the inhibitors of acidification and dynamin also prevented ORFV entry. However, results demonstrated that inhibitors inhibited ORFV entry but did not inhibit ORFV binding. Notably, extracellular trypsin promoted ORFV entry into cells directly, even when the endocytic pathway was inhibited. In conclusion, ORFV enters into its target cells by clathrin-mediated endocytosis and macropinocytosis, while caveolae-dependent endocytosis has little effects on this process. In addition, the entry into target cells by ORFV required an acid environment and the effect of dynamin. Meanwhile, we emphasize that broad-spectrum antiviral inhibitors and extracellular enzyme inhibitors are likely to be effective strategies for the prevention and treatment of ORFV infection.

Viability of Veterinary-Relevant Viruses in Decomposing Tissues over a 90-Day Period Using an In-Vitro System

Depopulation is frequently employed during outbreaks of high-impact animal diseases. Security breaches in sites managing mortality may jeopardize pathogen control efforts as infected carcasses can serve as an infection source. This study evaluated the viability and nucleic acid detection of veterinary-relevant viruses or their surrogates in decomposing tissues. The used viruses were: Senecavirus A1 (SVA), feline calicivirus (FCV), bovine viral diarrhea virus (BVDV), porcine epidemic diarrhea virus (PEDV), bovine alphaherpesvirus 1 (BoHV-1), and swinepox virus (SwPV). Viruses were spiked in three decomposing tissues (swine bone marrow and spleen, and bovine bone marrow) and maintained for 90 days. Samples were kept under two temperature conditions resembling the average soil temperature in central Oklahoma, US, during the winter and summer (5.5 °C and 29.4 °C). At 5.5 °C, SVA and FCV remained viable over the 90 days of the study, followed by BVDV (75 days), BoHV-1 and SwPV (60 days), and PEDV (10 days). At 29.4 °C, SVA remained viable for 45 days, followed by BVDV and BoHV-1 (14 days). SwPV was viable for 10 days, whereas FCV and PEDV were viable for 5 days. Overall, viral nucleic acid detection was not significantly altered during the study. These findings support decision-making and risk management in sites overseeing animal mortality.

Diseases of Iberian ibex (Capra pyrenaica)

Iberian ibex (Capra pyrenaica) is an ecologically and economically relevant medium-sized emblematic mountain ungulate. Diseases participate in the population dynamics of the species as a regulating agent, but can also threaten the conservation and viability of vulnerable population units. Moreover, Iberian ibex can also be a carrier or even a reservoir of pathogens shared with domestic animals and/or humans, being therefore a concern for livestock and public health. The objective of this review is to compile the currently available knowledge on (1) diseases of Iberian ibex, presented according to their relevance on the health and demography of free-ranging populations; (2) diseases subjected to heath surveillance plans; (3) other diseases reported in the species; and (4) diseases with particular relevance in captive Iberian ibex populations. The systematic review of all the information on diseases affecting the species unveils unpublished reports, scientific communications in meetings, and scientific articles, allowing the first comprehensive compilation of Iberian ibex diseases. This review identifies the gaps in knowledge regarding pathogenesis, immune response, diagnostic methods, treatment, and management of diseases in Iberian ibex, providing a base for future research. Moreover, this challenges wildlife and livestock disease and wildlife population managers to assess the priorities and policies currently implemented in Iberian ibex health surveillance and monitoring and disease management.

The orf virus 129 protein can inhibit immune responses by interacting with host complement C1q binding protein in goat turbinate bone cells

OBJECTIVE

Contagious ecthyma is a severe and highly contagious disease caused by an orf virus (ORFV). The virus is responsible for substantial economic losses in the goat industry and threatens humans. We previously determined the role of ORFV129 protein, one of the five ankyrin-repeat proteins coded by the orf genome, in suppressing the transcription of pro-inflammatory cytokines IL-6, IL-1β and IFN-γ. In the present study, we identified 14 cellular proteins (complement C1q binding protein [C1QBP], MCM7, EIF5A, PKM, SLC6A, TSPAN6, ATP6AP2, GPS1, MMADHC, HSPB6, SLC35B1, MTF1, P3H4, and IL15RA) that interact with ORFV129 using a yeast two-hybrid system in goat turbinate bone cells (GFTCs). The interaction between ORFV129 and (C1QBP), an immune-related protein, was confirmed using immunofluorescence co-localization and co-immunoprecipitation assays. C1QBP overexpression inhibited ORFV replication, whereas the knockdown of C1QBP promoted ORFV replication in GFTCs. Furthermore, ORFV or ORFV129 increased C1QBP expression in GFTCs, indicated that ORFV129-C1QBP interaction might contribute to the ORFV-induced host immune process. In addition, our research showed that ORFV increased the expression of ORFV129, cytokine IL-6, IL-1β and IFN-γ. C1QBP overexpression induced IFN-γ production and reduced IL-6 and IL-1β production. Conversely, C1QBP knockdown induced IL-1β production and reduced IFN-γ and IL-1β production. Moreover, augmentation of ORFV129 expression enhanced the inhibition of the secretion of cytokines IL-6, IL-1β, and IFN-γ induced by the altered expression of C1QBP. These findings suggest different downstream pathways might be involved in regulating different cytokines induced by ORFV129 expression in GFTCs.

Host range, severity and trans boundary transmission of Orf virus (ORFV)

Contagious ecthyma in small ruminants is a zoonotic disease caused by Orf virus (ORFV) in the genus Parapoxvirus that can be deadly to its natural hosts. It causes significant losses worldwide, and commonly infects humans. However, the literature about its comparative severity in sheep and goat hosts is misleading; and while contagious ecthyma has been shown to occur in camels and transmit to humans, there is confusion as to whether ORFV is responsible. Camels are important from a 'One Health' perspective as they have been implicated as a reservoir host for the virus causing Middle East Respiratory Syndrome (MERS), which has a case fatality rate of 35% in humans. We compared ORFV gene sequences and mortality data from the West Bank in Palestine, where ORFV has not been reported previously, with data from the region. Surprisingly, we found that infections of camels that had been attributed to ORFV were more closely related to a different member of the genus Parapoxvirus. Two Middle East ORFVs isolated from humans were unrelated and sat alongside sheep and goat derived sequences on two distinct ORFV lineages of a maximum likelihood B2L gene tree. One of the viral lineages bifurcated to produce a monophyletic group of goat-derived ORFVs characterized uniquely by a glycine at amino acid reside 249. We found that serine is the ancestral allele shared between ORFV infections of sheep and also two closely related Parapoxviruses (PCPV and CCEV), indicating that the glycine allele represents a more recent shift in virus host range adaptation to goats. Furthermore, and contrary to some reports that ORFV is more severe in goats than in sheep, we observed median mortality of up to 24.5% in sheep, but none in goats. We also identified trans-boundary spread of ORFV between the West Bank and Israel.

Human Orf with Immune-Mediated Reactions: A Systematic Review

Background: Orf is a highly contagious zoonosis caused by Orf virus (ORFV), which is endemic in sheep and goats worldwide. Human Orf is usually a self-limiting disease, but potential complications, including immune-mediated reactions, may occur. Methods: We included all articles regarding Orf-associated immunological complications published in peer-reviewed medical journals. We conducted a literature search of the United States National Library of Medicine, PubMed, MEDLINE, PubMed Central, PMC, and the Cochrane Controlled Trials. Results: A total of 16 articles and 44 patients were included, prevalently Caucasian (22, 95.7%) and female (22, 57.9%). The prevailing immunological reaction was erythema multiforme (26, 59.1%), followed by bullous pemphigoid (7, 15.9%). In most cases, the diagnosis was made on the basis of clinical and epidemiological history (29, 65.9%), while a biopsy of secondary lesions was performed in 15 patients (34.1%). A total of 12 (27.3%) patients received a local or systemic treatment for primary lesions. Surgical removal of primary lesion was described in two cases (4.5%). Orf-immune-mediated reactions were treated in 22 cases (50.0%), mostly with topical corticosteroids (12, 70.6%). Clinical improvement was reported for all cases. Conclusions: Orf-related immune reactions can have a varied clinical presentation, and it is important for clinicians to be aware of this in order to make a prompt diagnosis. The main highlight of our work is the presentation of complicated Orf from an infectious diseases specialist's point of view. A better understanding of the disease and its complications is essential to achieve the correct management of cases.

Recent advances in diagnostic approaches for orf virus

Orf virus (ORFV), the prototype species of the Parapoxvirus genus, is an important zoonotic virus, causing great economic losses in livestock production. At present, there are no effective drugs for orf treatment. Therefore, it is crucial to develop accurate and rapid diagnostic approaches for ORFV. Over decades, various diagnostic methods have been established, including conventional methods such as virus isolation and electron microscopy; serological methods such as virus neutralization test (VNT), immunohistochemistry (IHC) assay, immunofluorescence assay (IFA), and enzyme-linked immunosorbent assay (ELISA); and molecular methods such as polymerase chain reaction (PCR), real-time PCR, loop-mediated isothermal amplification (LAMP), recombinase polymerase amplification (RPA), and recombinase-aided amplification (RAA) assay. This review provides an overview of currently available diagnostic approaches for ORFV and discusses their advantages and limitations and future perspectives, which would be significantly helpful for ORFV early diagnosis and surveillance to prevent outbreak of orf. KEY POINTS: • Orf virus emerged and reemerged in past years • Rapid and efficient diagnostic approaches are needed and critical for ORFV detection • Novel and sensitive diagnostic methods are required for ORFV detection.

Rapid Onsite Visual Detection of Orf Virus Using a Recombinase-Aided Amplification Assay

Orf is an important zoonotic disease caused by the Orf virus (ORFV) which can cause contagious pustular dermatitis in goats and sheep. Orf is widespread in most sheep-raising countries in the world, causing huge economic losses. Although diagnostic methods for ORFV infection already exist, it is still necessary to develop a time-saving, labor-saving, specific, low-cost and visual diagnostic method for rapid detection of ORFV in the field and application in grassroots laboratories. This study establishes a DNA extraction-free, real-time, visual recombinase-aided amplification (RAA) method for the rapid detection of ORFV. This method is specific to ORFV and does not cross-react with other common DNA viruses. The detection limits of the real-time RAA and visual judgment of the RAA assay at 95% probability were 13 and 21 copies per reaction for ORFV, respectively. Compared with qPCR, the sensitivity and specificity of the real-time RAA assay were 100%, and those of the visual RAA assay were 92.31% and 100.0%, respectively. The DNA extraction-free visual detection method of RAA established in this study can meet the needs of rapid onsite detection and grassroots laboratories and has important reference value and significance for the early diagnosis of diseased animals.

Orf virus DNA prime-protein boost strategy is superior to adenovirus-based vaccination in mice and sheep

Contagious ecthyma (Orf), an acute and highly contagious zoonosis, is prevalent worldwide. Orf is caused by Orf virus (ORFV), which mainly infects sheep/goats and humans. Therefore, effective and safe vaccination strategies for Orf prevention are needed. Although immunization with single-type Orf vaccines has been tested, heterologous prime-boost strategies still need to be studied. In the present study, ORFV B2L and F1L were selected as immunogens, based on which DNA, subunit and adenovirus vaccine candidates were generated. Of note, heterologous immunization strategies using DNA prime-protein boost and DNA prime-adenovirus boost in mice were performed, with single-type vaccines as controls. We have found that the DNA prime-protein boost strategy induces stronger humoral and cellular immune responses than DNA prime-adenovirus boost strategy in mice, which was confirmed by the changes in specific antibodies, lymphocyte proliferation and cytokine expression. Importantly, this observation was also confirmed when these heterologous immunization strategies were performed in sheep. In summary, by comparing the two immune strategies, we found that DNA prime-protein boost strategy can induce a better immune response, which provides a new attempt for exploring Orf immunization strategy.

Reassessment of Evidence about Coinfection of Chickenpox and Monkeypox (Mpox) in African Children

In west and central Africa, monkeypox occurs mainly in older children, adolescents and young adults. In two large epidemiology studies of monkeypox outbreaks, the investigators observed a sizable number of coinfections of chickenpox (varicella) and monkeypox. Based on a review of the literature, we propose that chickenpox (human herpesvirus-3 infection) is a risk factor for acquisition of monkeypox infection. Our hypothesis states that the chickenpox skin lesion provides an entry site for the monkeypox virus, which is harbored on a fomite in the environment of the patient. The fact that monkeypox can enter via a scratch or abrasion is a known mechanism of spread for three other poxviruses, including mousepox (ectromelia), orf and molluscum contagiosum. There are many similarities in pathogenesis between certain poxviruses and chickenpox, including a viremia with a cellular stress response leading to high levels of the IL-6 cytokine. One very revealing observation in the two epidemiology studies was that the number of pox as well as the severity of disease in children with chickenpox and monkeypox coinfection was not greater than found in children with monkeypox alone. Based on the above observations, we conclude that, when chickenpox precedes monkeypox, priming of the immune system by the earlier chickenpox infection moderates the severity of the secondary infection with monkeypox. This conclusion also has important public health implications about chickenpox surveillance.

ORFV infection enhances CXCL16 secretion and causes oncolysis of lung cancer cells through immunogenic apoptosis

Oncolytic viruses have been emerging as a promising therapeutic option for cancer patients, including lung cancer. Orf virus (ORFV), a DNA parapoxvirus, can infect its natural ungulate hosts and transmit into humans. Moreover, the ORFV has advantages of low toxicity, high targeted, self-amplification and can induce potent Th1-like immunity. This study explored the therapeutic potential of ORFV infection for human lung cancer therapy and investigated the molecular mechanisms. We used a previously described ORFV NA1/11 strain and tested the oncolysis of ORFV NA1/11 in two lines of lung cancer cells in vitro and in vivo. Treatment of both cell lines with ORFV NA1/11 resulted in a decrease in cell viability by inducing cell cycle arrest in G2/M phase, suppressing cyclin B1 expression and increasing their apoptosis in a caspase-dependent manner. The ORFV NA1/11-infected lung cancer cells were highly immunogenic. Evidently, ORFV NA1/11 infection of lung cancer cells induced oncolysis of tumor cells to release danger-associated molecular patterns, and promoted dendritic cell maturation, and CD8 T cell infiltration in the tumors by enhancing CXCL16 secretion. These findings may help to understand the molecular mechanisms of ORFV oncolysis and aid in the development of novel therapies for lung cancer.

Genome-Wide Analysis and Molecular Characterization of Orf Virus Strain UPM/HSN-20 Isolated From Goat in Malaysia

Contagious ecthyma commonly known as Orf is a globally important, highly contagious zoonotic, transboundary disease that affects domestic and wild ruminants. The disease is of great economic significance causing an immense impact on animal health, welfare, productivity, and trade. Detailed analysis of the viral genome is crucial to further elucidate the molecular mechanism of Orf virus (ORFV) pathogenesis. In the present study, a confluent monolayer of lamb testicle cells was infected with the processed scab sample obtained from an infected goat. The presence of the virus was confirmed using polymerase chain reaction and electron microscopy, while its genome was sequenced using next-generation sequencing technology. The genome sequence of Malaysian ORFV strain UPM/HSN-20 was found to contain 132,124 bp with a G + C content of 63.7%. The homology analysis indicates that UPM/HSN-20 has a high level of identity 97.3–99.0% with the other reference ORFV strain. Phylogenetic analysis revealed that ORFV strain UPM/HSN-20 is genetically more closely related to ORFV strain XY and NP from China. The availability of the genome-wide analysis of ORFV UPM/HSN-20 strain from Malaysia will serve as a good platform for further understanding of genetic diversity, ORFV infection, and strategic development for control measures.

A Deeper Insight into Evolutionary Patterns and Phylogenetic History of ORF Virus through the Whole Genome Sequencing of the First Italian Strains

Orf virus (ORFV) is distributed worldwide and is the causative agent of contagious ecthyma that mainly occurs in sheep and goats. This disease was reported for the first time at the end of 18th century in Europe but very little is currently known about the temporal and geographic origins of this virus. In the present study, the use of new Italian whole genomes allowed for better inference on the evolutionary history of ORFV. In accordance with previous studies, two genome types (S and G) were described for infection of sheep and goats, respectively. These two well-differentiated groups of genomes originated for evolutive convergence in the late 1800s in two different areas of the world (Europe for S type and Asia for G type), but it was only in the early 1900s that the effective size of ORFV increased among hosts and the virus spread across the whole European continent. The Italian strains which were sequenced in the present study were isolated on the Mediterranean island of Sardinian and showed to be exclusive to this geographic area. One of them is likely representative of the early European forms of ORFV which infected sheep and became extinct about one century ago. Such an ancient Sardinian strain may have reached the island simple by chance, where it quickly adapted to the new habitat.

Complete genomic sequences and comparative analysis of two Orf virus isolates from Guizhou Province and Jilin Province, China

Orf virus (ORFV, species Orf virus) belongs to the typical species of the Parapoxvirus genus of the family Poxviridae, which infects sheep, goats, and humans with worldwide distribution. Although outbreaks of Orf have been reported sequentially in several Chinese provinces, the epidemiology of Orf and genetic diversity of ORFV strains still needs to be further characterized. To further reveal the genomic organization of the ORFV-GZ18 and ORFV-CL18 isolates, the complete genome sequences of two recently obtained ORFV isolates were sequenced using the next-generation sequencing technology and analyzed, which had been deposited in the GenBank database under accession number MN648218 and MN648219, respectively. The complete genomic sequence of ORFV-CL18 was 138,495 bp in length, including 131 potential open reading frames (ORFs) flanked by inverted terminal repeats (ITRs) of 3481 bp at both ends, which has genomic structure typical Parapoxviruses. The overall genomic organization of the fully sequenced genome of ORFV-GZ18 was consistent with ORFV-CL18 genome, with a complete genome size of 138,446 nucleotides, containing 131 ORFs flanked by ITRs of 3469 bp. Additionally, the overall G + C contents of ORFV-GZ18 and ORFV-CL18 genome sequences were about 63.9% and 63.8%, respectively. The phylogenetic analysis showed that both ORFV-GZ18 and ORFV-CL18 were genetically closely related to ORFV-SY17 derived from sheep. In summary, the complete genomic sequences of ORFV-GZ18 and ORFV-CL18 are reported, with the hope it will be useful to investigate the host range, geographic distribution, and genetic evolution of the virus in Southern West and Northern East China.

Molecular evidence for concurrent infection of goats by orf virus and bovine herpesvirus 1

Orf is a disease of small ruminant animals, including goats and sheep, that is caused by a parapoxvirus. Although the mortality rate is low, economic losses may occur due to the clinical signs. Bovine herpesvirus 1 (BoHV-1) infection is known to cause respiratory and reproductive disorders mainly in cattle; however, it has been found to circulate among goats and sheep as well. In contrast to orf virus (ORFV), BoHV-1 does not induce clinical disease in goats. In this study, we aimed to detect the presence of ORFV by molecular methods and to uncover eventual simultaneous herpesvirus infections masked by orf disease signs. To this end, 82 goats, housed near to a cattle herd, were tested. By polymerase chain reaction (PCR), three goats (3.7%) were found to harbour both viruses, while an additional goat was positive for ORFV only. The PCR products were sequenced and phylogenetic analyses were performed. This study revealed that ORFV and BoHV-1 may be present simultaneously in an animal causing a concurrent infection. These data should be taken into consideration when looking for secondary pathogens in diseased goats, and the prevention methods should be developed accordingly.

Orf Virus Detection in the Saliva and Milk of Dairy Goats

Orf is a zoonotic and highly contagious disease caused by Orf virus (ORFV) infection. Orf outbreaks in sheep and goats usually lead to high culling rate and mortality in newborn kids and lambs, posing a great threat to the development of goat and sheep industry. Human Orf occurs via direct contact with infected animals or fomites. While this disease is traditionally thought to spread through direct contact, whether other transmission routes exist remains unclear. Herein, we report the detection of ORFV in the saliva and milk of dairy goats without clinical Orf symptoms. Further analyses showed that these ORFV are infectious, as they can induce characteristic cytopathic changes in primary mammary and lip cells. Importantly, these ORFV can induce typical Orf lesions after inoculation in ORFV-free dairy goats. This is the first study showing that live, infectious ORFV can be isolated from the saliva and milk of asymptomatic goats, highlighting novel potential transmission routes of ORFV. These findings provide a novel idea for the prevention and control of Orf spread.

A new enzyme-linked immunosorbent assay for serological diagnosis of seal parapoxvirus infection in marine mammals

Introduction

Seal parapoxvirus (SPPV) infection has been reported among pinnipeds in aquaria in Japan; however, its seroprevalence is unknown. Therefore, an enzyme-linked immunosorbent assay (ELISA) was developed for serological diagnosis of SPPV infection.

Material and Methods

The gene encoding the major envelope protein of SPPV was cloned into the eukaryotic expression vector pAcGFP1-N1, which encodes the green fluorescence protein (GFP), thereby producing a fusion protein (Env-GFP). Parental and cloned vector DNA was independently transfected into cultured seal cells for the expression of GFP and Env-GFP. The wells of an ELISA plate were coated with either GFP- or Env-GFP-transfected cell lysates. The light absorbance of each serum sample was adjusted by subtracting the absorbance of GFP-coated wells from that of Env-GFP-coated wells. Sera from two spotted seals (Phoca largha), six beluga whales (Delphinapterus leucas), three Pacific white-sided dolphins (Lagenorhynchus obliquidens), and ten bottlenose dolphins (Tursiops truncatus) from an aquarium in Japan were examined using the ELISA.

Results

Positive reactions were not observed, except in one preserved sample collected ten years ago from a naturally SPPV-infected spotted seal.

Conclusion

The established ELISA could be useful in screening marine mammal sera for anti-SPPV antibodies.

Protective Efficacy of an Orf Virus-Vector Encoding the Hemagglutinin and the Nucleoprotein of Influenza A Virus in Swine

Swine influenza is a highly contagious respiratory disease of pigs caused by influenza A viruses (IAV-S). IAV-S causes significant economic losses to the swine industry and poses challenges to public health given its zoonotic potential. Thus effective IAV-S vaccines are needed and highly desirable and would benefit both animal and human health. Here, we developed two recombinant orf viruses, expressing the hemagglutinin (HA) gene (OV-HA) or the HA and the nucleoprotein (NP) genes of IAV-S (OV-HA-NP). The immunogenicity and protective efficacy of these two recombinant viruses were evaluated in pigs. Both OV-HA and OV-HA-NP recombinants elicited robust virus neutralizing antibody response in pigs, with higher levels of neutralizing antibodies (NA) being detected in OV-HA-NP-immunized animals pre-challenge infection. Although both recombinant viruses elicited IAV-S-specific T-cell responses, the frequency of IAV-S-specific proliferating CD8+ T cells upon re-stimulation was higher in OV-HA-NP-immunized animals than in the OV-HA group. Importantly, IgG1/IgG2 isotype ELISAs revealed that immunization with OV-HA induced Th2-biased immune responses, whereas immunization with OV-HA-NP virus resulted in a Th1-biased immune response. While pigs immunized with either OV-HA or OV-HA-NP were protected when compared to non-immunized controls, immunization with OV-HA-NP resulted in incremental protection against challenge infection as evidenced by a reduced secondary antibody response (NA and HI antibodies) following IAV-S challenge and reduced virus shedding in nasal secretions (lower viral RNA loads and frequency of animals shedding viral RNA and infectious virus), when compared to animals in the OV-HA group. Interestingly, broader cross neutralization activity was also observed in serum of OV-HA-NP-immunized animals against a panel of contemporary IAV-S isolates representing the major genetic clades circulating in swine. This study demonstrates the potential of ORFV-based vector for control of swine influenza virus in swine.

Immunomodulatory Strategies for Parapoxvirus: Current Status and Future Approaches for the Development of Vaccines against Orf Virus Infection

Orf virus (ORFV), the prototype species of the parapoxvirus genus, is the causative agent of contagious ecthyma, an extremely devastating skin disease of sheep, goats, and humans that causes enormous economic losses in livestock production. ORFV is known for its ability to repeatedly infect both previously infected and vaccinated sheep due to several immunomodulatory genes encoded by the virus that temporarily suppress host immunity. Therefore, the development of novel, safe and effective vaccines against ORFV infection is an important priority. Although, the commercially licensed live-attenuated vaccines have provided partial protection against ORFV infections, the attenuated viruses have been associated with major safety concerns. In addition to safety issues, the persistent reinfection of vaccinated animals warrants the need to investigate several factors that may affect vaccine efficacy. Perhaps, the reason for the failure of the vaccine is due to the long-term adaptation of the virus in tissue culture. In recent years, the development of vaccines against ORFV infection has achieved great success due to technological advances in recombinant DNA technologies, which have opened a pathway for the development of vaccine candidates that elicit robust immunity. In this review, we present current knowledge on immune responses elicited by ORFV, with particular attention to the effects of the viral immunomodulators on the host immune system. We also discuss the implications of strain variation for the development of rational vaccines. Finally, the review will also aim to demonstrate future strategies for the development of safe and efficient vaccines against ORFV infections.

Study on the Role of the Common House Fly, Musca domestica, in the Spread of ORF Virus (Poxviridae) DNA under Laboratory Conditions

ORF virus (Poxviridae) is the causative agent of contagious ecthyma (soremouth), a disease primarily affecting sheep and goats worldwide, but also humans exposed to disease-ridden animals. Pathogens are shed with scabs, and infection mainly occurs by direct contact. Although the disease is relatively benign and self-limiting, the morbidity rate is high in livestock with subsequent significant financial and economic impact. The aim of the study was to experimentally investigate the potential for the housefly, Musca domestica, to act as a mechanical vector of the virus. Homogenate of crusted scabs from ORFV-positive sheep (Italy, Apulia) were used to infect laboratory-reared flies. Flies walking on viral mixture and flies inoculated on their wings were individually placed in Falcon tubes and the ORFV DNA was searched by PCR on tube walls; flies were fed on the same homogenized crusts and their crop and spots (vomit and feces) molecularly examined for ORF DNA at 2, 4, and 6 h. All of the flies (100%) used in the experiments were able to pick up and transmit the viral genome to contact surfaces; 60% were found ORF virus (DNA)-positive in both spots and crop. These results suggest that M. domestica could play a role as potential mechanical vector and/or reservoir in the epidemiology of the ORF virus infection. Thus, house fly management should be considered in the measures to control the disease in ovine-caprine farms.

Designing BH3-Mimetic Peptide Inhibitors for the Viral Bcl-2 Homologues A179L and BHRF1: Importance of Long-Range Electrostatic Interactions

Viruses have evolved strategies to prevent apoptosis of infected cells at early stages of infection. The viral proteins (vBcl-2s) from specific viral genes adopt a helical fold that is structurally similar to that of mammalian antiapoptotic Bcl-2 proteins and exhibit little sequence similarity. Hence, vBcl-2 homologues are attractive targets to prevent viral infection. However, very few studies have focused on developing inhibitors for vBcl-2 homologues. In this study, we have considered two vBcl-2 homologues, A179L from African swine fever virus and BHRF1 from Epstein-Barr virus. We generated two sets of 8000 randomized BH3-like sequences from eight wild-type proapoptotic BH3 peptides. During this process, the four conserved hydrophobic residues and an Asp residue were retained at their respective positions, and all other positions were substituted randomly without any bias. We constructed 8000 structures each for A179L and BHRF1 in complex with BH3-like sequences. Histograms of interaction energies calculated between the peptide and the protein resulted in negatively skewed distributions. The BH3-like peptides with high helical propensities selected from the negative tail of the respective interaction energy distributions exhibited more favorable interactions with A179L and BHRF1, and they are rich in basic residues. Molecular dynamics studies and electrostatic potential maps further revealed that both acidic and basic residues favorably interact with A179L, while only basic residues have the most favorable interactions with BHRF1. As in mammalian homologues, the role of long-range interactions and nonhotspot residues has to be taken into account while designing specific BH3-mimetic inhibitors for vBcl-2 homologues.

Corynebacterium freneyi Bacterial Septicemia Secondary to Contagious Ecthyma in a Wild Muskox (Ovibos moschatus)

A wild muskox (Ovibos moschatus) with dermatitis typical of contagious ecthyma had secondary bacterial septicemia with Corynebacterium freneyi that included laminitis, hepatitis, and suppurative encephalitis. This case supports the association between orf virus infection and fatal secondary infections, which may have contributed to population declines on Victoria Island, Canada.

Effect of a Topical Formulation on Infective Viral Load in Lambs Naturally Infected with Orf Virus

Introduction

Orf is a highly contagious eruptive viral disease of the skin and mucosa of sheep and goats. Although vaccination with live or attenuated orf virus is the preferred option for disease control, the vaccine is unavailable in many countries. Treatment of orf lesions involves standard hygiene and in numerous cases, management of presumptive secondary infections with antibiotics, increasing risks of antimicrobial resistance (AMR). The wound dressing formulation Tri-Solfen^® containing two local anaesthetics (lignocaine and bupivacaine), adrenaline and an antiseptic (cetrimide) in a gel formulation was developed for pain relief in sheep undergoing surgical husbandry procedures in Australia. Recently, TS therapy was found to reduce suffering and enhance recovery in cattle and buffalo with oral and skin lesions due to foot-and-mouth disease (FMD) virus infection. It was noted that TS has a low pH and is potentially viricidal, potentially aiding disease control.

Methods

One-month-old lambs (n=14), naturally infected with orf, were recruited from a farm during a natural outbreak of the disease. The animals were selected at the early stages of the infection and randomly divided into two cohorts: Group A (n=11) treated with the topical wound gel formulation (TS); and Group B (n=3) an untreated control group. Swabs were obtained before treatment (T0) and on days one (T1), 3 (T2) and 5 (T3) post-treatment, then submitted to direct DNA extraction with real-time PCR quantification, plus incubation with primary tissue cultures from ovine skin fibroblasts (OSF) and T-immortalized goat embryonic fibroblasts (TIGEF).

Results

Although no significant differences were found in the clinical progression of the lesions and PCR quantification (p=0.722) between these small cohorts, there was a significant difference (p<0.05) in reduction in infective viral load between the groups when assessed in OSF cell cultures between T0 and T3.

Conclusion

These preliminary findings suggest that treatment of early stage lesions with this TS may reduce the infective viral load present in orf lesions.

Molecular Insights into the Genetic Variability of ORF Virus in a Mediterranean Region (Sardinia, Italy)

Orf virus (ORFV) represents the causative agent of contagious ecthyma, clinically characterized by mild papular and pustular to severe proliferative lesions, mainly occurring in sheep and goats. In order to provide hints on the evolutionary history of this virus, we carried out a study aimed to assess the genetic variation of ORFV in Sardinia that hosts a large affected small ruminant population. We also found a high worldwide mutational viral evolutionary rate, which resulted, in turn, higher than the rate we detected for the strains isolated in Sardinia. In addition, a well-supported genetic divergence was found between the viral strains isolated from sheep and those from goats, but no relevant connection was evidenced between the severity of lesions produced by ORFV and specific polymorphic patterns in the two species of hosts. Such a finding suggests that ORFV infection-related lesions are not necessarily linked to the expression of one of the three genes here analyzed and could rather be the effect of the expression of other genes or rather represents a multifactorial character.

Comparative analysis of B2L genes in vaccine and wild strains of orf virus in China

Orf is highly contagious zoonoses which is caused by the orf virus (ORFV). In order to determine the characteristics of B2L genes between vaccine strain and wild strain of ORFV in China. In this study we choose the weak vaccine of ORFV produced in biological products (Shandong Taifeng, China) and the wild strain (FJ-PN) isolated and identified in our laboratory to amplify, clone and sequence the B2L genes, and the changes in nucleotide, amino acid and secondary and tertiary protein structure of the B2L proteins were compared and analyzed by bioinformatics software. Comparison results showed that the nucleotide sequence similarity and amino acid sequence similarity of the B2L genes of vaccine strain and wild strain were 98.6% and 98.7% respectively. There was no significant difference between the primary, secondary and tertiary structures of the B2L proteins. The results of this study provide ideas for the study on the function and molecular biological characteristics of related proteins after the ORFV is weakened.

Research Relevant Background Lesions and Conditions: Ferrets, Dogs, Swine, Sheep, and Goats

Animal models provide a valuable tool and resource for biomedical researchers as they investigate biological processes, disease pathogenesis, novel therapies, and toxicologic studies. Interpretation of animal model data requires knowledge not only of the processes/diseases being studied but also awareness of spontaneous conditions and background lesions in the model that can influence or even confound the study results. Species, breed/stock, sex, age, anatomy, physiology, diseases (noninfectious and infectious), and neoplastic processes are model features that can impact the results as well as study interpretation. Here, we review these features in several common laboratory animal species, including ferret, dog (beagle), pig, sheep, and goats.

Management of Reproductive Diseases in Male Small Ruminants

Reproductive tract diseases can be a significant cause of subfertility or infertility in male small ruminants. Affected males can usually be identified early by performing routine serologic screening and yearly breeding soundness examinations. Early diagnosis will either maximize treatment success or expedite culling decisions. Once clinical signs of diseases develop, prognosis for breeding ability declines. Veterinary practitioners should used ancillary diagnostic techniques, such as ultrasound examination and laboratory testing to acquire a diagnosis and determine prognosis of reproductive lesions. Some diseases (eg, brucellosis) should be ruled out immediately to cull affected animals and minimize transmission within the herd.

"FastCheckFLI PPR-like"-A Molecular Tool for the Fast Genome Detection of PPRV and Differential Diagnostic Pathogens

To assist the global eradication of peste des petits ruminants virus (PPRV), a molecular test for the rapid and reliable detection of PPRV was developed which additionally enables the detection of pathogens relevant for differential diagnostics. For this purpose, the necessary time frame of a magnetic bead-based nucleic acid extraction protocol was markedly shortened to 7 min and 13 s. The optimized extraction was run on a BioSprint 15 platform. Furthermore, a high-speed multi-well RT-qPCR for the genome detection of PPRV and additional important pathogens such as Foot-and-mouth disease virus, Parapoxvirus ovis, Goatpox virus, and Mycoplasma capricolum subsp. capripneumoniae was established and combined with suitable internal control assays. The here-described qPCR is based on a lyophilized master mix and takes only around 30 to 40 min. Several qPCR cyclers were evaluated regarding their suitability for fast-cycling approaches and for their diagnostic performance in a high-speed RT-qPCR. The final evaluation was conducted on the BioRad CFX96 and also on a portable Liberty16 qPCR cycler. The new molecular test designated as "FastCheck^FLI PPR-like", which is based on rapid nucleic acid extraction and high-speed RT-qPCR, delivered reliable results in less than one hour, allowing its use also in a pen-side scenario.

Dysbiosis of the gut microbiota maybe exacerbate orf pathology by promoting inflammatory immune responses

Orf is a contagious disease caused by the epitheliotropic orf virus (ORFV) that mainly affects goats and sheep. Orf occurs worldwide and can cause great losses to livestock production. Mounting evidence has shown that gut microbiota plays a pivotal role in shaping the immune responses of the host and thus affecting the infection process of a wide range of pathogens. However, it is unclear whether gut microbiota plays a role during orf development. In this study, we exploited asymptomatic ORFV-carrier goats to explore the potential effects of gut microbiota on orf pathogenesis. The results showed that antibiotics-induced gut microbiota disruption significantly aggravated orf, as indicated by the greater disease severity and higher percentage of animals manifesting clinical orf symptoms. Further analysis suggested IL-17-induced excessive neutrophil accumulation in the diseased lips was potentially responsible for the tissue pathology. In addition, skin γδT cells may be an important source of IL-17. In conclusion, our study showed that the gut microbiota of ORFV-carrier goats plays a central role in controlling inflammatory pathology during ORFV infection, partly through suppressing IL-17-mediated local proinflammatory immune responses. This finding can provide help for elucidating the pathogenesis of orf and also suggests an efficient strategy to minimize the inflammatory pathology by maintaining a healthy gut microbiota during orf development.

Whole-Genome Sequence of an Orf Virus Isolate Derived from a Cell Culture Infected with Contagious Ecthyma Vaccine

This is a draft genome of an orf virus (ORFV) vaccine strain assembled via long- and short-read hybrid assembly. ORFV is a zoonotic pathogen that affects sheep and goats. The genome of the virus contained in the vaccine was found to have high similarity (98%) to those of other published strains.

This is a draft genome of an orf virus (ORFV) vaccine strain assembled via long- and short-read hybrid assembly. ORFV is a zoonotic pathogen that affects sheep and goats. The genome of the virus contained in the vaccine was found to have high similarity (98%) to those of other published strains.

Field investigation and phylogenetic characterization of orf virus (ORFV) circulating in small ruminants and Pseudocowpoxvirus (PCPV) in dromedary camels of eastern Sudan

In this study, livestock herders in eastern Sudan were interviewed through structured questionnaire involved 14046 animals in 151 herds (87 camel herds, 51 sheep and 13 goats) from June to September of 2016 in Showak area of Gadarif State to get some epidemiological information on contagious ecthyma (CE) infection. 102 suspected cases of CE were investigated (38 sheep, 22 goats and 42 camels) by a second questionnaire focusing on age and sex of affected animals beside number and localization of the lesions. Representative tissue samples of scab lesion scrapings were collected from a total of 36 suspected sheep, goats and camels for DNA extraction to identify PPV by quantitative real-time PCR and gel-based PCR, then a PCR protocol was used to obtain DNA fragment of B2L gene from six DNAs (2 from each animal species) for sequencing. Phylogenetic tree based on nucleotide sequences was constructed and all data were analyzed statistically. Obtained result has shown morbidity rate of 23.8% and a case fatality rate of 4.7 % in overall investigated animals resulting in a significant economic loss. Within individual herd, the morbidity rate varied from 5.6 to 42.8%, while the case fatality rate ranged between 0 and 33.3%. Camels accounted for the highest case fatality rate with 6.5% compared to sheep and goats which their rates were 2.8% and 1.3%, respectively. 93% of the affected animals were young less than one-year-old. The prevalence of CE was high in the rainy season compared to winter and summer. Out of 36 scab materials collected from sheep, goats, and camels, 24 gave positive specific amplification in real-time PCR and 21 in the gel-based PCR. DNA sequencing confirmed the PCR results. All sequences had a high G + C content of 62.6-63.9%. A BLAST search also revealed that the studied sheep PPV (SPPV) isolates shared 99.08% nucleotide sequence intragroup identity, 96.88-97.27% identity with the goat PPV (GPPV) isolates and together they belong to the Orf virus (ORFV) species, while the camel PPV (CPPV) isolates are close to the Pseudocowpoxvirus (PCPV) species of the PPV genus and share 92.51-93.62 % identity with the GPPV isolates. In conclusion the present study demonstrated that the gross lesion produced by PPV in sheep, goats and camels is generally similar, yet the PPVs circulating in eastern Sudan in camels (PCPV) are genetically distinct from those affecting sheep and goats (ORFV). Contagious ecthyma in eastern Sudan causes significant morbidities and mortalities and control measures, guided by the results of this investigation ought to be implemented.

Proteomic analyses reveal that Orf virus induces the activation and maturation of mouse bone marrow-derived dendritic cells

Orf virus (ORFV) is known for its immunostimulatory capacities and has been utilized as an efficient viral vector vaccine in non-permissive host species. Murine bone marrow-derived dendritic cells (BMDCs) are able to react with ORFV. In this study, we aimed to identify pivotal differentially expressed proteins involved in the process of DCs' differentiation in response to ORFV. Our findings showed that ORFV activates the maturation and differentiation of DCs. We further identified and validated seven differentially expressed proteins following ORFV stimulation. With functions in biological processes such as stimulus response, DCs maturation, antigen presentation and Th1 cell activation. Western blot analyses validated the respective changes in protein expression. The huge number of differentially expressed proteins identified in this study will be valuable for elucidating the mechanisms underlying ORFV-induced immunomodulation of murine BMDCs.

Integrated Analysis of Differentially Expressed miRNAs and mRNAs in Goat Skin Fibroblast Cells in Response to Orf Virus Infection Reveals That cfa-let-7a Regulates Thrombospondin 1 Expression

Orf is a zoonotic disease that has caused huge economic losses globally. Systematical analysis of dysregulated cellular micro RNAs (miRNAs) in response to Orf virus (ORFV) infection has not been reported. In the current study, miRNA sequencing and RNA sequencing (RNA-seq) were performed in goat skin fibroblast (GSF) cells at 0, 18, and 30 h post infection (h.p.i). We identified 140 and 221 differentially expressed (DE) miRNAs at 18 and 30 h.p.i, respectively. We also identified 729 and 3961 DE genes (DEGs) at 18 and 30 h.p.i, respectively. GO enrichment analysis indicates enrichment of apoptotic regulation, defense response to virus, immune response, and inflammatory response at both time points. DE miRNAs and DEGs with reverse expression were used to construct miRNA-gene networks. Seven DE miRNAs and seven DEGs related to "negative regulation of viral genome replication" were identified. These were validated by RT-qPCR. Cfa-let-7a, a significantly upregulated miRNA, was found to repress Thrombospondin 1 (THBS1) mRNA and protein expression by directly targeting the THBS1 3' untranslated region. THBS1 has been reported to induce apoptosis; therefore, the cfa-let-7a-THBS1 axis may play an important role in cellular apoptosis during ORFV infection. This study provides new insights into ORFV and host cell interaction mechanisms.

Development and applications of a monoclonal antibody against caprine interferon-gamma

Background

Interferon-gamma (IFN-γ) is an important mediator of type I immune response and has antiviral, immunoregulatory and anti-tumor properties, plays a wide range of roles in inflammation and autoimmune diseases. The aim of this study was to obtain monoclonal antibody (mAb) against caprine IFN-γ by immunizing of BALB/c mice with the purified rIFN-γ.

Results

Recombinant caprine IFN-γ was expressed in Escherichia coli strain BL21 (DE3) and monoclonal antibodies against caprine IFN-γ were produced by immunizing of BALB/c mice with rIFN-γ. One hybridoma secreting mAb was screened by enzyme-linked immunosorbent assay (ELISA) which was designated as 2C. MAb secreted by this cell line were analyzed through ELISA, western blot and application of the mAb was evaluated by immunofluorescence analysis using goat lip tissues infected with Orf virus. ELISA analysis revealed that mAb 2C can specifically recognize rIFN-γ protein and culture supernatant of goat peripheral blood mononuclear cells (PBMCs) stimulated by concanavalin A (Con A) but cannot recognize the fusion tag protein of pET-32a. Western blot analysis showed that mAb 2C can specifically react with the purified 34.9 kDa rIFN-γ protein but does not react with the fusion tag protein of pET-32a. Immunofluorescence results demonstrated that mAb 2C can detect IFN-γ secreted in histopathological sites of goats infected with Orf virus.

Conclusions

A caprine IFN-γ-specific mAb was successfully developed in this study. Further analyses showed that the mAb can be used to detect IFN-γ expression level during contagious ecthyma in goats.

Establishment and characterization of transformed goat primary cells by expression of simian virus 40 large T antigen for orf virus propagations

Due to the limited host range of orf virus (ORFV), primary cells derived from its natural hosts, such as goats and sheep, are recommended for isolation and propagation of wild type ORFV. This situation limits the option for the study of virus-host interaction during ORFV infection since primary cells only support a few numbers of passages. SV40 T antigen is a viral oncoprotein that can abrogate replicative senescence, leading to an extended life span of cells. In this study, the transformation of two goat primary cells, fibroblast (FB) and testis (GT) cells, were achieved by stably expressing SV40 T antigen using the lentiviral technique. The presence of the gene encoding SV40 T antigen was validated by polymerase chain reaction (PCR) and western blot analyses. As evidenced by immunofluorescent microscopy, the two types of cells expressing SV40 T antigen (namely, FBT and GTT) were purified to homogeneity. Moreover, faster growth kinetics and a lower serum dependency were noticed in FBT and GTT, as compared with their counterpart parental cells. FBT and GTT remain permissive and can form plaque of ORFV, despite with different profiles; generally speaking, with SV40 T expression, ORFV forms plaques with smaller size and distinct margin. Most importantly, the prolonged life span of goat FBT and GTT serves as an ideal cell culture resource for ORFV isolation from the field, studies of ORFV pathogenesis and efficient vaccine development.

Identification of strain diversity and phylogenetic analysis based on two major essential proteins of Orf viruses isolated from several clinical cases reported in Malaysia

There is a little information on the characterization of Orf virus strains that are endemic in Malaysia. The relationship between the severity of disease and the molecular genetic profile of Orf virus strains has not been fully elucidated. This study documented the first confirmed report of contagious ecthyma causing by Orf virus in goats from a selected state of eastern peninsular Malaysia. The disease causes significant debilitation due to the inability of affected animals to suckle which brings a great economic loss to the farmers. A total of 504 animals were examined individually to recognize the affected animals with Orf lesion. Skin scrapping was used to collect the scab material from the infected animals. The presence of Orf virus was confirmed by combination of methods including virus isolation on vero cells, identification by Transmission Electron Microscopy (TEM) and molecular technique using PCR and Sanger sequencing. The results showed the successful isolation of four Orf virus strains with a typical cytopathic effects on the cultured vero cells line. The morphology was confirmed to be Orf virus with a distinctive ovoid and criss cross structure. The phylogenetic analysis revealed that these isolated strains were closely related to each other and to other previously isolated Malaysian orf viruses. In addition these Orf virus strains were closely related to Orf viruses from China and India. This study provides more valuable insight in terms of genotype of Orf virus circulating in Malaysia.

Do UK sheep farmers use orf vaccine correctly and could their vaccination strategy affect vaccine efficacy?

Orf, a parapoxvirus, is a zoonosis causing a contagious pustular dermatitis, and has a high morbidity in sheep worldwide. Despite a vaccine being available, orf prevalence in England is estimated to be 2 per cent in ewes and 20 per cent in lambs​​. There is concern that farmers are not complying with the vaccination guidelines and therefore the objective of this study was to investigate if orf vaccine is used correctly on sheep farms in the UK and to identify barriers and motivators of sheep farmers to use the vaccine. The survey was completed by 570 respondents. The results show several areas of concern; only 27 per cent of respondents used the correct site (axilla), 37 per cent of respondents would use orf vaccine up to a week after opening a vial (shelf life is eight hours), 33 per cent of respondents would vaccinate their ewes too close to lambing and 73 per cent of respondents did not separate vaccinated and non-vaccinated animals (both leading to infection risk for non-vaccinated animals). When vaccinating, only 53 per cent of respondents were wearing gloves and 31 per cent washed their hands just before and immediately after vaccination. Results demonstrate that orf vaccination is not carried out correctly on all UK sheep farms, which is likely to affect vaccine efficacy. A concern around vaccine efficacy, the 'hassle' of the scratch administration, the 'risk of making it worse' and the zoonotic risk when vaccinating were the most common barriers for using orf vaccine, highlighting the importance of veterinary advice when prescribing orf vaccine.

An association of Orf virus infection among sheep and goats with herd health programme in Terengganu state, eastern region of the peninsular Malaysia

BACKGROUND

Orf virus causes a scabby skin lesions which decreases productivity in small ruminants. The unknown status of this disease in the eastern region of Peninsular Malaysia warrants a study to determine sero-prevalence of orf with regards to farmers' compliance level towards the Herd Health Program (HHP) programme.

RESULTS

Out of 504 animals, 115 were positive for Orf-virus antibodies. An overall prevalence rate of 22.8% indicated a high prevalence of orf disease in this region. It was observed that 25.1% (92/367) of goats were positive and 16.8% (23/137) of sheep sero-converted for Orf virus antibody. Several factors were measured for their possible association with prevalence of Orf virus infection. The prevalence was higher in LY farm, JC breed, kid and female animals, and in the presence of disease lesion. Chi-square analysis showed a significant association of three risk factors which are species, age and sex of the animals (P < 0.05). Notwithstanding, all other variables showed no significant difference (P > 0.05). Farms surveyed usually practised intensive management system, keeping animals in the shade at all time, due to limited availability of suitable land as a free-range grazing area. An interview with small holder farmers revealed a lack of awareness of the main goals of herd health programme. An overall compliance level of 42.7% was observed for all HHP parameters. Among the 14 main components of HHP modules, animal identification had recorded highest compliance level (84.62%) while milking management recorded the least compliance (- 82.69%). That explained why there was a high sporadic prevalence of Orf infection in this region.

CONCLUSION

Good herd health supervision is a rehearsal target to prevent an outbreak and the spread of diseases thus reduces economic losses among farmers. Therefore, a good herd health programme should be in place, in order to prevent and control disease transmission as well as to improve herd immunity.

Genomic characterization of two Orf virus isolates from Jilin province in China

Orf virus (ORFV), a typical member of the Parapoxvirus genus within the family Poxviridae, which is the causative agent of Orf, a common epitheliotropic viral disease of sheep, goats, wild ruminants, and humans. In the present study, we sequenced the complete genomic sequences of two ORFV strains (ORFV-SY17, isolated from sheep, and ORFV-NA17, isolated from goat) and conducted the comparative analysis of multiple ORFVs. The complete genomic sequence of ORFV-SY17 was at length of 140,413 bp, including 131 potential open reading frames (ORFs) flanked by inverted terminal repeats (ITRs) of 4267 bp at both ends. The ORFV-NA17 strain displayed the similar genome structure with ORFV-SY17. The whole genomic sequence of ORFV-NA17 strain was 139,287 bp in length and contained 132 ORFs flanked by ITRs of 3974 bp. The overall G+C contents of ORFV-SY17 and ORFV-NA17 genome sequences were about 63.8% and 63.7%, respectively. The ITR sequences analysis showed that ORFV-SY17 and ORFV-NA17 contained the terminal BamHI sites and conserved telomere resolution sequences at both ends of their genome. In addition, comparative analysis of ORFs among ORFV-SY17, ORFV-NA17, and other ORFV strains revealed several sequence variations caused by insertions or deletions, especially in ORFs 005 and 116, which were very likely associated with host species. Phylogenetic analysis based on the complete genome sequences revealed that ORFV-SY17 was genetically closely related to NA1/11 and HN3/12 strains derived from sheep, while ORFV-NA17 was closely related to YX strain derived from goat. The multiple alignment of deduced amino acid sequences further revealed the genetic relationship between host species and genetic variations of ORFV strains. Taken together, the availability of genomic sequences of ORFV-SY17 and ORFV-NA17 strains from Jilin Province will aid in our understanding of the genetic diversity and evolution of ORFV strains in this region and can assist in distinguishing between ORFV strains that originate in sheep and goats.