Seroepidemiological studies of herpesvirus-associated diseases of marine turtles: Fibropapillomatosis and lung-eye-trachea disease

We have developed immunological tests that can identify marine turtles in Florida (green and loggerhead) that have been exposed to the LETV herpesvirus. The seroepidemiological data collected provides critical evidence about the relationship between infection with the FP-associated herpesvirus and the LETV herpesvirus. The data supports the hypothesis that LETV and FPHV infections are independent infections of marine turtles. The data shows that wild green turtles in Florida are exposed to the LETD-associated herpesvirus, which is the first description ofLETV infection in free-ranging marine turtles. To our knowledge, the antigenic proteins identified in this study are not only the first proteins from a reptilian herpesvirus to be cloned and expressed, but they represent the first reptilian herpesvirus proteins to be identified as immunogenic in their host species. (16 page document

Complete genome sequence and taxonomic position of anguillid herpesvirus 1

Eel herpesvirus or anguillid herpesvirus 1 (AngHV1) frequently causes disease in freshwater eels. The complete genome sequence of AngHV1 and its taxonomic position within the family Alloherpesviridae were determined. Shotgun sequencing revealed a 249 kbp genome including an 11 kbp terminal direct repeat that contains 7 of the 136 predicted protein-coding open reading frames. Twelve of these genes are conserved among other members of the family Alloherpesviridae and another 28 genes have clear homologues in cyprinid herpesvirus 3. Phylogenetic analyses based on amino acid sequences of five conserved genes, including the ATPase subunit of the terminase, confirm the position of AngHV1 within the family Alloherpesviridae, where it is most closely related to the cyprinid herpesviruses. Our analyses support a recent proposal to subdivide the family Alloherpesviridae into two sister clades, one containing AngHV1 and the cyprinid herpesviruses and the other containing Ictalurid herpesvirus 1 and the ranid herpesviruses

Frequency of shedding of respiratory pathogens in horses recently imported to the United States.

BackgroundImported horses that have undergone recent long distance transport might represent a serious risk for spreading infectious respiratory pathogens into populations of horses.ObjectiveTo investigate the frequency of shedding of respiratory pathogens in recently imported horses.AnimalsAll imported horses with signed owner consent (n = 167) entering a USDA quarantine for contagious equine metritis from October 2014 to June 2016 were enrolled in the study.MethodsProspective observational study. Enrolled horses had a physical examination performed and nasal secretions collected at the time of entry and subsequently if any horse developed signs of respiratory disease during quarantine. Samples were assayed for equine influenza virus (EIV), equine herpesvirus type-1, -2, -4, and -5 (EHV-1, -2, -4, -5), equine rhinitis virus A (ERAV), and B (ERBV) and Streptococcus equi subspecies equi (S. equi) using quantitative PCR (qPCR).ResultsEquine herpesviruses were detected by qPCR in 52% of the study horses including EHV-2 (28.7%), EHV-5 (40.7%), EHV-1 (1.2%), and EHV-4 (3.0%). Clinical signs were not correlated with being qPCR-positive for EHV-4, EHV-2, or EHV-5. None of the samples were qPCR-positive for EIV, ERAV, ERBV, and S. equi. The qPCR assay failed quality control for RNA viruses in 25% (46/167) of samples.Conclusions and clinical importanceClinical signs of respiratory disease were poorly correlated with qPCR positive status for EHV-2, -4, and -5. The importance of γ-herpesviruses (EHV-2 and 5) in respiratory disease is poorly understood. Equine herpesvirus type-1 or 4 (EHV-1 or EHV-4) were detected in 4.2% of horses, which could have serious consequences if shedding animals entered a population of susceptible horses. Biosecurity measures are important when introducing recently imported horses into resident US populations of horses

Potential Application of the CRISPR/Cas9 System against Herpesvirus Infections.

The CRISPR/Cas9 system has been applied in the genome editing and disruption of latent infections for herpesviruses such as the herpes simplex virus, Epstein⁻Barr virus, cytomegalovirus, and Kaposi's sarcoma-associated herpesvirus. CRISPR/Cas9-directed mutagenesis can introduce similar types of mutations to the viral genome as can bacterial artificial chromosome recombination engineering, which maintains and reconstitutes the viral genome successfully. The cleavage mediated by CRISPR/Cas9 enables the manipulation of disease-associated viral strains with unprecedented efficiency and precision. Additionally, current therapies for herpesvirus productive and latent infections are limited in efficacy and cannot eradicate viruses. CRISPR/Cas9 is potentially adapted for antiviral treatment by specifically targeting viral genomes during latent infections. This review, which focuses on recently published progress, suggests that the CRISPR/Cas9 system is not only a useful tool for basic virology research, but also a promising strategy for the control and prevention of herpesvirus latent infections

Pathogenic, Molecular, and Immunological Properties of a Virus Associated with Sea Turtle Fibropapillomatosis. Phase II : Viral Pathogenesis and Development of Diagnostic Assays

Research conducted under this RWO from July 1, 1997 through June 30, 2000 has provided important new information about the pathogenesis, virology, and immunology of marine turtle fibropapillomatosis. In particular, we have provided strong evidence for the association of a herpesvirus with fibropapillomatosis of the green turtle,Chelonia mydas, and the loggerhead turtle, Caretta caretta, in Florida. In addition we have provided new evidence for the absence of papillomaviruses from sea turtle fibropapillomas. Although unsuccessful, important new attempts were made to cultivate the FP-associated herpesvirus in vitro in collaboration with the National Wildlife Health Center. During this period of time, we completed publication of the first comprehensive description of the comparative pathology and pathogenesis of experimentally induced and spontaneous fibropapillomas of green turtles (Chelonia mydas). We initiated innovative studies on the persistence of a Chelonian herpesviruses in the marine environment demonstrating for the first time that the environmental survivability of Chelonian herpesviruses makes them real threats to marine turtle health. Finally, we explored development of a serological assay for FP using synthetic herpesvirus peptides and developed methodologies for detection of antibodies to LETV [Iung-eye-trachea virus] a disease-associated herpesvirus of the green turtle, Chelonia mydas.. This last initiative is ongoing and will further our efforts to develop specific immunological assays for the FP-associated herpesvirus and FP. (17 page document

Statistical properties of thermodynamically predicted RNA secondary structures in viral genomes

By performing a comprehensive study on 1832 segments of 1212 complete genomes of viruses, we show that in viral genomes the hairpin structures of thermodynamically predicted RNA secondary structures are more abundant than expected under a simple random null hypothesis. The detected hairpin structures of RNA secondary structures are present both in coding and in noncoding regions for the four groups of viruses categorized as dsDNA, dsRNA, ssDNA and ssRNA. For all groups hairpin structures of RNA secondary structures are detected more frequently than expected for a random null hypothesis in noncoding rather than in coding regions. However, potential RNA secondary structures are also present in coding regions of dsDNA group. In fact we detect evolutionary conserved RNA secondary structures in conserved coding and noncoding regions of a large set of complete genomes of dsDNA herpesviruses.Comment: 9 pages, 2 figure

Speculations on the clinical significance of asymptomatic viral infections

A detailed understanding of asymptomatic chronic viral infections is critical to analyse their pathogenesis, assess the severity and burden of disease and, where required, optimize public health control measures. Recent studies on herpesviruses showed that the hostevirus interactions are modulated by coinfections, emphasizing the relevance of co-infections in determining the clinical expression (from asymptomatic to symptomatic infections) and the severity of herpesvirus-associated diseases (either neoplastic or infectious diseases). To demonstrate causality between viruses (virome) and diseases, Koch's postulates should be adapted adding new knowledge on hostemicrobe relationship and microbial interactions. In the present review we aim to provide an update on asymptomatic chronic infections and criteria for causality and on the virological, immunological and hostevirus interactions in asymptomatic chronic infections in human hosts, focusing on herpetic infections

Further strategies for evaluating the etiological role of a tumor-associated herpesvirus in marine turtle fibropapillomatosis

In 1992, an interdisciplinary research team headquartered at the University of Florida began studies in key targeted areas of fibropapillomatosis (FP) etiology and pathogenesis. At that time, little was known about FP outside of field studies documenting its prevalence in different areas of the world and studies of tumor histopathology. Our primary objective was to develop a broad-based scientific understanding of FP by applying principles of tumor biology, immunology, pathology, virology, molecular biology, and epidemiology to FP in the green turtle, Chelonia mydas. Long-term goals included the development of assays for FP and study of any role of environmental co-factors in the disease. This report is a continuation of that effort and the results reported here bring us closer to understanding the role of a tumor-associated herpesvirus in marine turtle fibropapillomatosis. This research has demonstrated that marine turtle herpesviruses can persist for extended periods of time as infectious agents in the marine environment and that wild green turtles in Florida are exposed to the LETD-associated herpesvirus. This is the first description of LETV infection in free-ranging. marine turtles. In addition, data is presented that supports the hypothesis that LETV and FPHV infections are independent. These data reveal new levels of complexity that must be addressed before reliable serodiagnostic assays for herpesvirus infections of chelonians can be developed for widespread application. The results reported here also raise new concerns about the potential impact of infections by new herpesviruses on populations of wild marine turtles, an area which has previously been unexplored by turtle biologists. (8 page document

The seroprevalence and salivary shedding of herpesviruses in Behcet's syndrome and recurrent aphthous stomatitis

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