Search

Reasons for performing study: To date, no information is available on the true biological elimination half-life (T1/2) of cardiac troponin I (cTnI) in the equine species. Such data are required to better evaluate the optimal time to acquire the cTnI sample following acute myocardial injury. Objective: To determine the T1/2 of equine cTnI. Methods: Four healthy ponies received i.v. injections of recombinant equine cTnI. Plasma cTnI concentrations were measured with a point-of-care cTnI analyser at multiple time points after injection. Standard pharmacokinetic analysis was performed to establish the T1/2 of cTnI. Results: The average T1/2 of cTnI was determined to be 0.47 h using a single rate elimination model. Conclusion: The elimination of recombinant equine cTnI following i.v. administration is very rapid. Establishing the T1/2 of troponin provides critical information in understanding the clinical application of this cardiac biomarker in equine practice. [ABSTRACT FROM AUTHOR]

A serological survey for the detection of antibodies to influenza A(H1N1)pdm09 was carried out in a population of dogs and cats in Germany. A total of 1150 sera collected in 2010 and 2011 were screened using an ELISA targeting anti-nucleoprotein NP antibodies. Those initially screened positive samples were subsequently tested for antibodies to N1 neuraminidase followed by a virus neutralization test using A/Bayern/74/2009 strain. A prevalence of A(H1N1)pdm09-specific antibodies of 0.13% and 1.93% was estimated among dogs and cats, respectively. Evidence of exposure to other influenza A virus subtypes was also observed. [ABSTRACT FROM AUTHOR]

Background Equid herpesvirus 1 ( EHV-1) is a highly prevalent pathogen in horse populations worldwide. Oronasal infection represents the classic route of disease transmission. Venereal shedding of EHV-1 is not regarded relevant in terms of virus spreading, which is in contrast to the close relatives of EHV-1, bovine and suid alphaherpesvirus, for which artificial insemination is a well-documented and accepted means of virus spread. Objectives Documentation of venereal EHV-1 shedding in 3 naturally infected stallions. Animals Three stallions were infected during an acute outbreak by an EHV-1 strain with the G2254/ D752 Pol genotype. Methods In this observational study, 12 semen samples from these 3 stallions were tested for EHV-1 to determine venereal shedding. EHV-1 was diagnosed by conventional PCR and paired serum neutralization tests in 42 horses. Semen samples were separated into sperm and seminal plasma fractions and tested for EHV-1 by conventional and quantitative PCR as well as virus isolation by cell culture. Results Acute EHV-1 infection was diagnosed on the premise. Five semen samples collected from 2 of the 3 stallions tested positive for EHV-1 by (q) PCR. On days 18 and 20 after onset of fever, the last positive samples were retrieved. All samples were positive in seminal plasma, only three in sperm fraction. Virus isolation attempts were unsuccessful. Conclusions and Clinical Importance The data presented here document shedding of EHV-1 in semen of naturally infected stallions for close to 3 weeks, which seems not to be directly associated with spermatozoa. [ABSTRACT FROM AUTHOR]

Background Research in humans has demonstrated that high serum iron (sFe) concentration can predispose to infection, and many infections subsequently result in alterations of host sFe. A decrease in sFe concentration is an early and sensitive indicator of systemic inflammation caused by tissue necrosis, bacterial infections, or endotoxemia in horses. Serum iron parameters in acute equine herpesvirus type 1 ( EHV-1) infection have not been evaluated previously. Objectives To document the sFe response to EHV-1 infection and to determine whether or not significant differences in sFe concentration exist between EHV-1 infected horses that develop neurologic disease and those that do not. Animals A total of 14 horses experimentally infected with EHV-1. Methods Data were collected as an ancillary data set during a blinded experimental EHV-1 infection. Horses were infected with the rAb4 strain of EHV-1. Temperature, neurologic score, packed cell volume ( PCV), and sFe parameters (sFe concentration, % saturation, and total iron-binding capacity) were recorded daily for 2 weeks. Data were evaluated using Wilcoxon signed rank tests and Wilcoxon rank sum tests with Bonferroni corrections. Conclusions and Clinical Relevance Serum iron concentration decreases significantly in a biphasic pattern after EHV-1 infection. There was no significant difference in sFe concentration in horses that developed neurologic disease and those that did not in these experimentally infected animals. Serum iron parameters may be useful in monitoring the clinical course of viral infections such as EHV-1. [ABSTRACT FROM AUTHOR]

Summary This report summarises the findings of the Second Havemeyer EHV-1 Workshop, which was held in Steamboat Springs, Colorado, USA in September 2008. A total of 38 delegates, consisting of veterinary clinicians and scientists from academia and industry participated in a series of sessions that focused on equine herpesvirus myeloencephalopathy (EHM). Each session consisted of a review, followed by short presentations on current research topics. The sessions included EHM epidemiology, in vivo and in vitro models for studying EHM, EHV-1 virulence determinants, real-time PCR diagnostics, antiviral medications and new vaccination technologies. The report summarises the key advances identified during and since the meeting. Citations are restricted to selected reviews and papers published since the workshop. [ABSTRACT FROM AUTHOR]

Background: Early identification of inhalation-transmitted equine herpesvirus type 1 (EHV-1) infections has been facilitated by the availability of a number of real-time quantitative PCR (qPCR) tests. A direct comparison between nasal swab qPCR and traditional virus isolation (VI) requires a method for normalizing the qPCR samples and controlling for PCR inhibitors present in some clinical samples. Objectives: To quantify EHV-1 shedding in viral swabs using an internal control and to compare fast qPCR to VI for the detection of EHV-1 in nasal swabs from horses. Animals: Fifteen horses experimentally infected with EHV-1. Methods: Experimental study: Nasal swab samples were collected daily after experimental infection for up to 21 days. VI was performed by conventional methods. The DNA was prepared for qPCR with the addition of a known quantity DNA of Marek's disease virus as an internal control. qPCR was performed. Results: The qPCR method detected virus up to day 21 after challenge, whereas VI detected virus only to day 5. The median Kaplan-Meier estimates for EHV-1 detection were 12 days for qPCR and 2 days for VI ( P < .0001). When compared with VI, the sensitivity and specificity of qPCR were 97 (95% CI: 86–100) and 27% (95% CI: 20–35). Conclusions and Clinical Importance: We conclude that fast qPCR of nasal swab samples should be chosen for diagnosis and monitoring of herpesvirus-induced disease in horses. Recommended reference ranges of CT values are provided as well as justification of a minimum 10-day quarantine period. [ABSTRACT FROM AUTHOR]

An enzyme-linked immunosorbent assay (ELISA) for the detection of Marek's disease virus (MDV)-specific antibodies was developed. Chicken embryo cells (CEC) or chicken kidney cells (CKC) were infected with MDV vaccine strain CVI988/Rispens, and infected-cell lysates were prepared at day 5 post-infection by freeze-thawing. Uninfected-cell lysates served as negative controls. Sera were used at a 1 : 100 dilution and were added in parallel to wells containing the infected and uninfected cell lysates. The optical densities at 492 nm (OD492 nm) were measured after detection of bound chicken antibodies with anti-chicken IgG peroxidase conjugate and colour reactions using o-phenylenediamine (OPD) as a substrate. The best results concerning the signal-to-noise ratio were obtained by using CKC cells rather than CEC for antigen preparation. The OD492 nm of plasma or serum samples with infected CKC was <0.02 when samples of unvaccinated and unchallenged maternal antibody-negative white leghorn chickens were tested. Sera and plasma samples of positive control birds exhibited OD492 nm of <0.01 when tested with uninfected CKC. The assay was used to monitor a trial that compared experimental BAC DNA vaccines and a commercial vaccine. Sustained seroconversion and antibody titers that were constantly rising until day 84 after vaccination (71 days after challenge) was observed only when chickens did not develop Marek's disease. In contrast, chickens developing the disease mounted marginal and short-lived antibody titers only. We conclude that the developed ELISA may be a valuable tool for the evaluation of the efficacy of MDV vaccination under experimental but possibly also under field conditions. [ABSTRACT FROM AUTHOR]

Examines the cloning of genome of equine herpesvirus type 1 (EHV-1) strain RacL 11 as bacterial artificial chromosomes in Escherichia coli. Insertion of mini F plasmid sequences into viral genomes; Isolation of recombinant viruses; Expression of green fluorescent protein.

The nucleotide sequence of the UL10 (glycoprotein M) and the UL11 homologs of Marek’s Disease Virus 1 strain GA was determined. The UL10 open reading frame encodes a type III membrane protein of 424 amino acids that contains eight hydrophobic domains and two consensus N-linked glycosylation sites. The UL11 homologous gene encodes an 84 amino acid polypeptide, and contains a highly conserved myristylation site at its aminoterminus. By analysis of infected-cell RNA with strand-specific RNA probes, transcription of both UL10 and UL11 in infected cells was demonstrated. Coupled in vitro transcription-translation confirmed that the UL10 product is a 47 kD N-glycosylated viral protein that aggregated upon boiling, whereas the UL11 protein exhibited a size of 12 kD after in vitro translation. [ABSTRACT FROM AUTHOR]

The equine herpesvirus type-1 modified live-vaccine strain RacH (256th passage on porcine embryonic kidney cells) was investigated by restriction-enzyme analysis and compared to representative plaque isolates of the 12th passage (RacL11, RacL22) and 185th passage (RacM24, RacM36). The restriction patterns of all Rac plaque isolates differed compared with reference strain Ab4. The left UL terminus was shortened by 0.1 kbp and a missing BamHI site led to the fusion of the f and t fragments. In some Rac derivatives, losses of restriction sites without deletions were observed: 1. One BamHI site located in the ribosyl reductase gene was missing in RacH, RacM24, RacM36, and RacL22; and 2. An SaiI site mapping to the gp14 (gB) gene was absent in RacM24, RacM36 and RacH. An identical deletion of 0.85 kbp in size was found in both copies of the inverted repeat (IR) regions of RacH. The deletion was present only in the terminal IR of the medium-passage derivative RacM36. By contrast, in the genomes of the apathogenic RacM24, as well as the pathogenic plaque isolates RacL11 and RacL22, no deletions in the IRs were detectable. Nucleotide-sequence and Northern-blot analyses revealed that the deletions led to the elimination of one or both copies of the gene 67 (IR6) open-reading frame in RacM36 and RacH and affected the gene 68 (EUS1) in RacH. [ABSTRACT FROM AUTHOR]