碩士 / 國立屏東科技大學 / 水產養殖系所 / 98 / Nocardia seriolae is the causative agent of nocardiosis in cultured fish and causes high mortality in Taiwan and Japan. In this study, N. seriolae was isolated from 14 species of fish in Taiwan and Japan during 1970 to 2009, and Fourty-one N. seriolae strains were identified by 16Sr DNA gene, hsp gene and rpoβ gene analysis. The variations of 16S rDNA, hsp and rpoβ gene of N. seriolae were 0.2% ( 5 Taiwan strains ), 0.2~0.7% ( 6 Taiwan strains, 2 Japanese strains)、0.2~0.7% (6 Taiwan strains, 3 Japanese strains) isolated from ten fish species from 1986 to 2007, respectively. Further study evaluates the in vitro activity of antimicrobial agents against 89 strains of N. seriolae (67 Taiwan strains and 22 Japanese strains). The 50 and 90% MICs values for 89 strains of N. seriolae of the antimicrobial agents used in this study, florfenicol, lincomycin, doxycyclin, oxytetracycline, and kitasamycin were the most active antimicrobial agents against the isolates tested, followed by erythromycin and spiramycin. Furthermore, in an attempt to develop a vaccine against N. seriolae 961113, microfluidizer antigen (MF), and microfluidizer antigen mixed with ISA 763A adjuvant were injected into Asian seabass, Lates calcarifer. Fish were challenged with N. seriolae 961113 and 980401-2 after immunized 4 weeks and 14 week, respectively. RPS values of MF and MF-ISA 763A group challenged by N. seriolae 961113 at 4 weeks after immunization were at 67% and 83%, respectively. However, RPS values of MF and MF-ISA 763A group challenged by 980401-2 strain at 14 week after immunization were at 0% and 67%. A immunostimulatory but not protective in Asian seabass was observed in immunized group challenged by N. seriolae 980401-2 and 961113 strain at 4 weeks and 14 weeks, respectively. These results suggest that cross protective immune responses against N. seriolae are induced in Asian seabass.
| Identifer | oai:union.ndltd.org:TW/098NPUS5086015 |
| Date | January 2010 |
| Creators | Yao-Lin Li, 李曜伶 |
| Contributors | Shih-Chu Chen, Shinn-Pyng Yeh, 陳石柱, 葉信平 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 85 |
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