AHRI report No.31

Serological investigation of Erysipelothrix rhusiopathiae isolates and vaccine improvement to control erysipelas of swine

1. Department of Biological Products Research, Taiwan Animal Health Research Institute.  
2 Chia-Yi Hsien Livestock Disease Control Center Tay-pao

Erysipelothrix rhusiopathiae (E. rhusiopathiae) was isolated in 14 strains 
from 14 swine with clinical erysiplas in a field swine farm. With the agar gel precipitation (AGP) test, all isolates were identified to be serovar la. Serovars of 12 E. rhusiopathiae strains supplied by manufacturers of animal biological products were identified to be 7 la and 5 lalb. According to the AGP test, the seed strains of E. rhusiopathiae used for attenuated live vaccine production by manufacturers of animal biological products in Taiwan were identified to be serovars la and 2a2b. The growth curve of E. rhusiopathiae was investigated with shaking culture, static conditions and fermentation methods. The results indicate that the maximum level of growth at 37 "C was reached 16 h after seed inoculation. The concentrations of the bacterial cells reached 1.5- 2.3 X 10¹⁰ CFU/mL and then decreased gradually. Although there were no significant differences among the three methods of culture for bacterial growth, the concentration of bacterial cells 2.3 X 10¹⁰ CFU/mL from fermentation culture exceeded those from the other two methods. Trial production of both attenuated vaccine and inactivated poly-valent bacterin produced growth agglutination antibody titers in the range 1 : 16- 1 : 128 in swine. [*Chen C, Chan IP, Lu CC, Lai JS, Ko HJ, Lu TC, Huang JT, CHang YL and 
Yen CM. Sero1ogica1 Investigation of Ery sipelothrix rl1usiopathiae isolates and vaccine improvement to contro] erysipelas of swine. 

Erysipetothrix rhusiopathiae, Serotype, Vaccine