• Korean Journal of Veterinary Service
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• v.37 no.1
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• pp.59-65
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• 2014

Equine herpesvirus myeloencephalopathy, out of symptoms by equine herpesvirus type 1 (EHV-1) infection, can cause devastating losses on individual farms. Although myeloencephalopathy syndromes of horses in Korea have been recognized for a couple of years in horse populations, there is little study regarding the occurrence of EHV-1 infections. The present study was performed to detect the viral infection of horses with neurological syndrome using real-time PCR. Fifteen horses (27.3%) out of 55 horses with neurological deficiency were positive for EHV-1 viral antigen. Among these 7 horses, 4 horses were detected genotype of A2254/N752 and 3 horses G2254/D752 strain, respectively.

• Korean Journal of Veterinary Service
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• v.25 no.4
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• pp.333-346
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• 2002

We previously reported that the equine herpesvirus type 1(EHV-1) immediate-early protein(IE protein) physically interacts with the general transcription factor human TFIIB(Jang et al, J Virol 75：10219-10230, 2001). The interaction between the IE protein and TFIIB is necessary for the IE protein to efficiently transactivate the early TK and late IR5 EHV-1 promoters. A panel of deletion and truncation mutants of the TFIIB gene was constructed and employed in protein-binding assays to map the IE protein-binding domain within TFIIB. Evidence is presented that the first direct repeat of TFIIB interacts specifically with the EHV-1 IE protein.

• Journal of Life Science
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• v.21 no.8
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• pp.1156-1162
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• 2011

Equine coital exanthema caused by equine herpesvirus type 3 (EHV-3) is a venereal disease which seriously drops horse reproduction rates. Here, we isolated EHV-3 from infected horses and investigated their biological characteristics. Initial cytopathic effects such as rounding of cells were detected 48 hours post infection of the virus into RK-13 cells. The infected cells were going to detach from the surface of culture flasks 72 hours post infection. The type of isolated viruses from swabbed samples was EHV-3 by PCR analysis. Glycoprotein G (gG) of isolated EHV-3 has a 99.25 percent similarity rate to that of EHV-3 334/74 control strain. The isolated EHV-3 was named Georo strain. Georo strain consisted of four major proteins including 145 kD, 60 kD, 45 kD and 40 kD, as shown by SDS-PAGE analysis. We hope the newly isolated Georo strain of EHV-3 can be used for studying various aspects of Korean equine coital exanthema.

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.83-88
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• 2001

It is impotent to identify the causative agents of abortion in equine for minimizing the loss of breeding costs in equine Industry. Recently, the abortion has often occurred in equine herds and thus the purpose of the study was aimed at the identification of equine herpesvirus-1, one of the frequent pathogens to abortion, using polymerase chain reaction. Six fetuses to be aborted at nine to ten months in pregnancy reared in six herds were used in the study. Two primers in the PCR were made from glycoprotein B gene of EHV-1. The primers specific for EHV-1 amplified 1880 bp of PCR products from DNA extracts from thorax fluids, livers, lungs, and spleens of four in six aborted fetuses. Consequently, PCR could be applied to diagnose the abortion of EHV-1 and also confirmed to play a major role of the viral pathogen associated with equine abortion in Jeju island.

• Korean Journal of Veterinary Service
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• v.43 no.2
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• pp.59-65
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• 2020

The aim of the study was to investigate the seroprevalence of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4), equine influenza virus (EIV), and Streptococcus (S.) equi subspecies equi in the horse population of Jeju. Serum samples were taken from 71 horses, regularly vaccinated with EHV-1 and strangles twice (April and November) a year. In April 2014, seropositive rates of EHV-1 and strangles were 24.5% and 84.5%, while in November, were 26.8% and 62.0%, respectively. A total of 1,144 serum samples, including Jeju native horses, Halla horses, and Thoroughbred horses were collected from slaughter house for 4 years (2014 to 2017) and it is unclear the animals were vaccinated or not. The seropositive rates in Jeju was 21.9% (250/l,144) for EHV-1, 96.4% (1,103/1,144) for EHV-4, 14.6% (129/882) for EIV, and 79.3% (879/1,108) for strangles. The seropositive rate was the highest in Thoroughbred, but lowest in Hala horse.

• Korean Journal of Veterinary Research
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• v.52 no.1
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• pp.61-64
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• 2012

This study evaluated the epizootiological characteristics of equine coital exanthema (ECE) in South Korea. A PCR test was used to determine the equine herpesvirus 3 (EHV-3) release period, excretion by suckling foals, morbidity rate, effect on fertility, and onset of breeding partner after treatment. The morbidity rate of ECE based on clinical symptoms was 8.3% (2/24) for stallions and 10.8% (45/416) for mares, and 29 of 45 (64.4%) animals were positive on the PCR test. Ten (22%) broodmares had symptoms before breeding, while 26 (58%) had symptoms after breeding. Nine (20%) mares had uncertain coverage periods and occurrence times. Suckling foals had no clinical findings and EHV-3 was not detected in their nostrils, although it was detected on teasers. No lesions were observed in the clitoral fossa on broodmares, although EHV-3 was detected by PCR. The period of EHV-3 emission was 22~23, 18~19, 6, and 58 days in stallions, broodmares, teasers, and mares with a mixed E. coli-like infection, respectively. ECE had no negative effects on the breeding capability of stallions and no symptoms were observed in broodmares after recovering from ECE.

• Journal of Microbiology
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• v.40 no.1
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• pp.11-19
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• 2002

Mice immunized with equine herpesvirus type-1(EHV-1) L-particles skewed a significant increase (p<7.75) in serum antibody titers. Upon a booster dose four weeks lateral antibody titers increased significantly. Interestingly, immunization via intravenous or intramuscular route induced significantly higher (p<0.75) antibody titers. However, mice iummunized with UV-treated L-particles, visions or immunization via intranasal route induced lower antibody titers. Upon challenge inoculation with wildtype EHV-1, our data showed there was a poor correlation between antibody titers and protection against virus replication. Therefore, the role of cell-mediated immunity Inwards protection was investigated. As predicted, the strongest cell-mediated immunity, as measured by delayed-hypersensitivity test, was detected in mice immunized with live virus particles. The magnitude of cell-mediated immune response correlated with the efficacy of L-particles as immunizing agent. The highest efficacy, as indicated in mice immunized via intranasal routed was highly correlated with cell-mediated immunity. A similar phenomenon was also demonstrated in mice immunized intranasally with UV-treated L-particles. However, the degree of protection was reduced when mice immunized intravenously or intramuscularly with UV-treated L-particles. In conclusion, protection conferred in these animals was highly implicated by immune cells and the least by antibodies. The route of immunization and the nature of the antigen also contributed to the efficacy of L-particles as immunizing agent. In contrast to that of herpes simplex virus type 1, our data showed EHV-1 non-infectious L-particles are highly suitable for immunization of the host against EHV-1 disease.

• Korean Journal of Veterinary Service
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• v.27 no.4
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• pp.355-369
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• 2004

The equine herpesvirus type 1 (EHV-1) immediate-early (IE) protein is a potent transactivator responsible for the activation of both early and late genes during the course of infection and is comprised of discrete functional domains that mediate its many functions. Interaction between trans activators such as the IE protein and various components of the RNA polymerase II transcription initiation machinery has been demonstrated to be critical for transactivation. In the present report, it is addressed the hypothesis that the IE protein interacts with various components of transcription machinery to mediate transactivation of target viral genes. In these studies, it is demonstrated that in vitro transcribed and translated IE protein interacts with TFIIB-agarose conjugate but not with TFIID-agarose conjugate. Additional immunoprecipitation studies using nuclear extracts derived from EHV-1 infected RK-13 cells confirmed that the IE protein interacts strongly with TFIIB, but fails to interact with TFIID. IR2, a truncated form of the IE protein lacking the potent transactivation domain and involved in the down-regulation of the IE gene, also interacted with TFIIB but not with TFIID. Studies were also performed to ascertain if particular TBP-associated factors (TAFs) could mediate IE or IR2 binding to TFIID. In vitro transcribed and translated TAF250 added to nuclear extracts generated from EHV-1 infected cells also failed to mediate an interaction between the IE protein or the IR2 protein and TFIID. This study demonstrated that the IE protein mediates transactivation of target viral genes by a mechanism that involves TFIIB. This is in contrast to mechanisms that have been proposed for both the herpes simplex virus ICP4 and VP16 protein which have been proposed to transactivate viral genes through interactions involving both TFIIB and TFIID. This study also intimates that IR2 mediate its repressive effects during the course of EHV-1 infection by a mechanism that involves sequestration of various transcription factors.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.105-113
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• 2014

Equine herpesvirus type 1 (EHV-1) is an economically important pathogen of horses and exerts its major impact by inducing abortion storms and sporadic abortions in pregnant mares, early neonatal death in foals, and respiratory disease in young horses. Although equine herpesvirus type 4 (EHV-4) rarely causes clinical manifestations of disease in organs other than the respiratory track, isolated cases of myeloencephalopathy and sporadic abortions have been reported in EHV-4 infections. Here, we report an abortion storm in Thoroughbred breeding farms in Jeju island, South Korea. It occurred for 16 days from first abortion to last one. There were no clinical signs prior to abortion and stillbirth in broodmares. Two PCR-primers were made on glycoprotein B gene of EHV-1 and EHV-4 to amplify specific common regions of the viruses. We could detect the virus specific genes in aborted samples by PCR, and concluded that the cause of abortion storm was EHV infection. This report describes the first abortion storm case caused by EHV in Thoroughbred breeding farms in South Korea.

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.187-190
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• 2011

The Thoroughbred horse was an approximately 4-years-old castrated male with highly emaciation, nasal epistaxis and subsequently died. Gross necropsy revealed epistaxis and hyperemia on the lung, multiple hemorrhage in muscle, and liver was focally attached to the peritoneum with fibrin. According to polymerase chain reaction (PCR), Equine herpes virus type 1 and 4 (EHV type 1, 4) was detected in the lung and trachea. In bacterial culture from kidney, liver, spleen, muscle and blood, Streptococcus equi subsp. zooepidemicus was isolated. Based on the gross lesion and PCR, this horse was diagnosed as EHV type 1, 4 and S. zooepidemicus coinfection.