1

Speaker(s)：

Yu-Liang Huang

Topic

Comparison of virulence between various porcine epidemic diarrhea virus strains

Abstract

Since 2013, porcine epidemic diarrhea (PED) had been re-emerged in Asia and America. The outbreak of PED was also occurred in Taiwan in late 2013 and led to the death of numerous suckling piglets. In 2014, a total of 46 farms from 86 farms were confirmed as positive for PEDV. The genomic sequence analysis found that there were two novel PEDV strains (n-PEDV and variant n-PEDV) and the gene was different in the N-terminal of S protein. The gene of n-PEDV strain was same as the highly virulent US strain. However, the variant n-PEDV had a 197 aa deletion in the S protein of n-PEDV. Comparison of virulence between n-PEDV and variant n-PEDV exhibited that the n-PEDV could induce the more severe diarrhea and longer days of PEDV shedding from feces than variant n-PEDV in the suckling piglets with 7 days of age. In summary, the n-PEDV was higher virulence than variant n-PEDV.

2

Speaker(s)：

Chien-Chih Wu

Topic

Serological survey of canine brucellosis in Taiwan

Abstract

Avian botulism, also known as limberneck, is a parsalytic, often fatal disease of birds resulting from ingestion of toxin produced by the bacterium Clostridium botulinum. Seven types of botulinum neurotoxin, designated as types A through G, have been identified. Almost all outbreaks in poultry are caused by type C, although types D or E are also involved. Clinically, paralyzed legs were usually the first symptom being observed in avian botulism, and the paralyses were later demonstrated in wings, neck, and eyelids. Death can result from water deprivation, electrolyte imbalance and respiratory failure. There are no characteristic gross lesions in birds dying of botulism. The most reliable test for avian botulism is the mouse protection test, although the PCR technique is also successfully applied in the detection and differentiation of the neurotoxin genes.

During January and June in 2015, our laboratory received five botulism-suspected cases of wild birds. Four of the cases were black-faced spoonbills. The sera of the cases were tested by the mouse inoculation test to detect the toxins; moreover, carcasses or organs of the cases were tested by the PCR to detect the botulism neurotoxin genes and to identify their types. The outbreak during February 27 and March 2 attacked 14 black-faced spoonbills and resulted in seven deaths. According to the clinical signs and the results of the mouse inoculation tests and the PCR tests, the mosaic C/D neurotoxin of botulism was the etiologic agent of this outbreak in the black-faced spoonbills. The fifth case occurred in Gaoping River during March 5 and 12. There were near 1,000 waterfowl affected, including teals, European wigeons, and shovelers. The mosaic C/D neurotoxin of botulism also contributed to this outbreak in Gaoping River. Detecting and typing Clostridium botulinum and their toxins by the mouse inoculation test and the PCR simultaneously could bring about rapid and definitive diagnosis and the treatment of sick birds, and could therefore prevent or minimize further cases.

3

Speaker(s)：

Yu-Ju Lin

Topic

Analysis of Active Surveillance of HPAI Positive Farms from January to August 2015

Abstract

Porcine circovirus type 2 (PCV2) genome contains two major open reading frames(ORFs), ORF1 encoding the viral replication-associated protein and ORF2 encoding the viral capsid protein. This study was to express the ORF2 capsid protein and Indirect ELISA (iELISA) method was developed for detection of antibody to PCV2. Partial ORF2 gene of PCV2 was amplified by RT-PCR. The RT-PCR amplicons were cloned into a TOPO vector using TA cloning kit; correct clones were confirmed by sequencing. The target genes were subcloned into the pET32 and pCold expression vectors. The expression plasmids were transformed into host cell of BL-21(DE3), then IPTG was used to induce the expression of cloned genes. The solubility of recombinant proteins was tested after induction. Results showed that pCold system expressed a soluble protein and pET32 system showed insoluble inclusion bodies. His tag protein purification kit was used to purify recombinant proteins. The ELISA plates were coated with 2 μg/ml of purified recombinant ORF2 protein and iELISA method was used to test serial dilutions of pig sera which were obtained from the experimental CSFV infected pigs. Results revealed that linear curve could be observed in the iELISA assay. Comparison of homemade and commercial PCV2 IgG iELISA kits for detection of anti-PCV2 antibody from 50 field sera, both of iELISA kits showed high level of correlation (r = 0.938). 

4

Speaker(s)：

Shu-Chia Hu；Hsiang-Jung Tsai

Topic

Training course of Fluorescent Antibody Virus Neutralization at the Nancy Laboratory for Rabies and Wildlife in France

Abstract

The training of diagnostic technique for rabies diagnosis was performed at the Nancy Laboratory for Rabies and Wildlife in Nancy, France on July 13^th ~19^th, 2015. Course for the potency test of rabies vaccine (challenge test in mice), virus titration of oral vaccine, fluorescent antibody virus neutralization (FAVN) were scheduled during this visit. The laboratory and the P3 laboratory of Nancy Laboratory for Rabies and Wildlife were also visited. The experiment data of rabies performed in Taiwan was discussed with Dr. Cliquet Florence during this visit.