1

Speaker(s)：

Yu-Hua Shih

Topic

Development of Duck Viral Hepatitis Vaccine

Abstract

Duck viral hepatitis (DVH) is an acute, highly contagious, viral disease of young ducklings , usually <6 weeks of age, and is characterized by liver lesions and opisthotonos. , In order to control DVH, the AHRI developed a DVH active immunization vaccine and a passive hyperserum to effectively prevent the occurrence of DVH. In 2015, we conducted field trials of our developed duck viral hepatitis vaccine. The results showed that this vaccine is both safe and efficacious, and that the duck egg antibodies reach the national inspection standards (NI＞3.0) after immunization. The value of this egg yolk antibody product was assessed in order to determine the potential for future technology transfer opportunities and additionally, one batch was produced for national inspection. In conclusion, AHRI demonstrated its capabilities in combating the occurrence of duck viral hepatitis in the future.

2

Speaker(s)：

Yu-Hua Shih

Topic

A report on the visit to the China Agricultural University and the Poultry Institute of the Chinese Academy of Agricultural Sciences

Abstract

Duck viral hepatitis (DVH) is an important disease affecting waterfowl, causing significant annual economic losses worldwide. The Animal Health Research Institute (AHRI) plans to apply for the establishment of a World Organization for Animal Health (OIE)’s reference laboratory, specifically focused on DVH. There is currently no OIE reference laboratory for the study of DVH in the world. The Poultry Institute of the Chinese Academy of Agricultural Sciences and the College of Veterinary Medicine of the China Agricultural University are all important institutes actively researching waterfowl diseases. Research fellow Tseng Chun-hsein and assistant researcher Shih Yu-hua were dispatched to visit these institutes in China. Critical insight regarding waterfowl diseases outbreaks was gained and the invaluable exchange of technical knowledge was also achieved. In conclusion, based on the research experience and technical exchange attained at these two poultry disease research institutes, we were able to assess the occurrence of international pandemic situations of DVH as well as foster further international cooperation. We believe initiatives such as these will be invaluable for the application of an OIE reference laboratory and for future vaccine development projects.

3

Speaker(s)：

Nan-Ling Kuan

Topic

Detection of class I integrons in avian pathogenic Escherichia coli and avian Salmonella

Abstract

Ninety-one isolates of avian pathogenic Escherichia coli (APEC) and 65 isolates of avian Salmonella were cultured from bacterial infection cases in poultry during 2013-2015. Based on Modified Kauffmann-White Scheme, 33 isolates of Salmonella Pullorum, six isolates of Salmonella Typhimurium, three isolates of Salmonella Enteritidis, one isolates of Salmonella Haifa, and 22 isolates of Salmonella sp. were included. As an important mechanism of antimicrobial resistance, integrons refer to mobile DNA elements, which may contain one to several resistant gene cassettes. In this study, class I integrons were detected by PCR and gene sequencing. The results revealed that 60.7% 61/91) of APEC and 36.9% (24/65) of avian Salmonella isolates carried class I integrons with various size from 721 bp to 1,900 bp. These class I integrons contained gene cassettes encoding resistance to aminoglycosides (aadA), trimethoprim (dfr) and β-lactamase (BlaPSE1). All the dfr-positive isolates were resistant to trimethoprim/sulfamethoxazole; the aadA-positive isolates were increased in the minimum inhibitory concentration of streptomycin. The results indicated that types of resistant cassette assays reflected the relevant resistances in APEC and Salmonella isolates.

4

Speaker(s)：

Tzu-Ming Huang

Topic

Vibrio parahaemolyticus Infection of Cultured Shrimp in Taiwan

Abstract

The shrimp farming industry is one of the most important aquacultures in Taiwan. Aquatic animals infected or contaminated by foodborne pathogens can cause food poisoning in humans. Recently, shrimp farmers in Taiwan have experienced massive losses of juvenile shrimp and as a result, the diseased shrimp were submitted to a college for diagnosis, followed by referral to Animal Health Research Institute for foodborne pathogen isolation. Vibrio parahaemolyticus strains producing TL toxin (thermolabile hemolysin), and not producing TDH and TRH toxin (thermostable direct hemolysin, and thermostable direct hemolysin-related, respectively) were isolated by enrichment of Vibrio species from diseased giant tiger prawns (Penaeus monodon) and Pacific white shrimp (Penaeus vannamei). Due to varying degrees of necrosis observed in the hepatopancreatic gland, nucleic acid detection for the published virulence factors found in emerging Vibrio parahaemolyticus infections in shrimp was carried out. The isolates obtained from one giant tiger prawn farm and two Pacific white shrimp farms possessed the published virulence factor, Pir-like toxin. The results of the present study revealed that V. parahaemolyticus encoding a previously characterized virulence factor could be isolated from the diseased tiger prawn and white shrimp in Taiwan.