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Seminar 841  

 

Seminar:  841  

1

Speaker(s)

Chyi-Sing, Hwang

Topic

A Serological Surveys of Herpes B Virus in Macaque

Abstract

Specific pathogen-free (SPF) experimental animals are now commonly requested for research purposes. Common definition of SPF in nonhuman primates (NHPs) is free of Mycobacterium tuberculosis (M.tb.), simian immunodeficiency virus (SIV), simian type D retrovirus (SRV), herpes B virus/Cercopithecine herpesvirus 1 (CHV-1), and simian T cell lymphotropic/leukemia virus (STLV). Besides, herpes B virus is a zoonotic pathogen causing the central nervous system disease in human.

To understand the prevalence of herpes B virus infection in macaques in Taiwan, we had used commercial kits to detect antibodies of herpes B virus. We found that 37.39% in total 132 sera samples showed positive results. Among them, samples obtained from wildlife rescue center and the zoo tested 37.17% and 41.93% positive respectively. These results could be used as a reference for public health related field.

2

Speaker(s)

Cheng-chu Hsieh

Topic

Research on Recombinant Probiotics Expressing Classical Swine Fever Virus

Abstract

Classical swine fever virus (CSFV), a member of the genus Pestivirus of the family Flaviviridae, is a small, enveloped, single - stranded RNA virus. Classical swine fever (CSF) is a highly contagious viral disease of pigs and cause significant economic losses in pork industry. The disease may run an acute, subacute, chronic onset or inapparent course, depending on a variety of virus and host factors. The severity of this disease varies with the strain of the virus, the age of the pig, and the immune status of the herd. Therefore, to develop a more efficacious vaccine against CSF is of great importance. The term "probiotic" originally referred to live microorganisms, when administered in adequate amounts, confer a health benefit on the host. Their conception of probiotics involved the notion that substances secreted by one microorganism stimulated the growth of another microorganism. They influence several components of the immune response including humoral, cellular or innate immunity. The recombinant probiotics delivering heterologous antigens to the immune system has been investigated, suggesting the potential use of probiotics as safe oral vaccines. In this study, the CSFV - specific cytotoxic T lymphocyte epitope E290 peptide has been expressed in the genetically engineered Lactobacillus strain. Animal trials and antibody detection test will be done in the future.

3

Speaker(s)

Yen-Lin Lee

Topic

Animal Trials for Bovine Ephemeral Fever Vaccine

Abstract

Bovine ephemeral fever (BEF) is an arthropod-borne viral disease caused by Rhabdovirus. There have been outbreaks every 3-6 years in Taiwan. For the purpose of improving the BEF vaccination program, we have been developing a live vaccine with YHL virus strain isolated from Japan, and several animal trials have been conducted to confirm the safety and efficacy of this live vaccine. In the reversion to virulence test, five serial passage of the virus have been performed in calves, and no systemic infection or any adverse effect has been observed. In addition, the calves could develop a rapid serum neutralizing (SN) antibody response against BEF virus after receiving YHL live vaccine plus subsequent inactivated vaccine booster. The antibody titers reached to 1:256. However, whether this BEF vaccine could provide enough protection against wild type virus attack still remains unknown because attempts to establish the cattle challenge model have been failed in the past few years. Not any clinical signs, viremia or leucopenia appeared during the experimental period in all testing calves either inoculated intravenously the grinding fluids of Culicoides and mosquitoes containing BEF viruses or directly inoculated the blood collected from sick cattle. The efficacy of the live vaccine could only be evaluated by the SN antibody titers. As to adjuvant improvement of BEF inactivated vaccine, two selected adjuvants were mixed with inactivated BEF virus respectively and inoculated to calves. The results indicated that the SN titers induced by these two adjuvants were higher and lasted longer compared with the AHRI commercial aluminum gel vaccine. In conclusion, more adjuvants will be tested in the future to improve both safety and efficacy of the BEF vaccine.

4

Speaker(s)

Jen-Chieh Chang, Wei-Cheng Hsu

Topic

Establishment of Rabies virus Neutralisation Test and the Visit report to the Rabies Laboratory of Chinese Center for Disease Control and Prevention

Abstract

For a better understanding on rabies epidemiology of wildlife populations and vaccination efficacy, the rapid fluorescent focus inhibition test (RFFIT) for determining rabies virus neutralising antibody was introduced into AHRI from US Center for Disease Control and Prevention (CDC). Based on the CDC protocol and OIE Terrestrial Manual, we performed the RFFIT on Lab-tek chamber slides by using rabies CVS-11 strain, mouse neuroblastoma (MNA) cell line, and either WHO or OIE standard sera. We have cryopreserved the CVS-11 seed virus, stock virus and MNA cells. The sera collected from dogs were used in the preliminary RFFIT. The RFFIT technique could be applied to the serology and epidemiology of wildlife rabies surveillance in the future.

Two staffs of AHRI were dispatched to go to the Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, China CDC for studying the diagnosis, surveillance techniques and research of rabies in June 2014. After passing the qualification of biosafety training, we started the practical experiment, including the real-time reverse transcription polymerase chain reaction (rRT-PCR), virus neutralisation test RFFIT and FAVN, immune-chromatographic test for rabies antigen, FFD50 and FFU, CVS production, etc. The visit can enhance the diagnostic techniques and researches in our rabies laboratory, such as the application of RFFIT detection, real-time RT-PCR and wildlife surveillance project. The research achievements of bat lyssavirus surveillance, the design of animal experiment and molecular epidemiology in China could be the references of wildlife animals’ rabies research and the prevention and control strategy making in Taiwan in the future.