1.Council for Agricultural Planning and Development, Executive Yuan.
2. Department of Veterinary Medicine, National Chung Shing University.
3. Taiwan Provincial Livestock Research Institute, Mio-Li Research Station.
4.Chia-Yi Hsien Livestock Disease Control Center.
Ching Chen, C. C. Lu, T. C. Lin! H, K. Shieh; N. J. Li, I. P. Chan, T, G. Chang, S.T. Lin, D. W. Horng J. S. Liang and W. C. Chang4
Escherichia coli strains with pili and enterotoxins producible ability were used for vaccine production. The newly developed vaccine was used to immunize 56
experimental sows, 2 sows observed at the laboratory and 54 sows on two farms.
Solid immunity but no side reaction was observed.
The anti-K88, K99 and 987 P antibody titers arose from <1 or low levels to 32-2, 048 x in serum or colostral whey of immunized sows determined by slide agglutination test, while anti-heat labile cnterotoxin antibody titers were 4 x in serum and > 32x in colostral whey by immunodiffusion tess test.
For piglets that sucked the colostrum of immunized sows, the anti-K88, K99 and 987 P antibody titers in serum were almost same as those of their mother sows. The average anti-heat labile enterotoxin antibody titers of piglets borne from the sow No. 1 and 2 kept at the laboratory were 3.6x and 6x respectively. In the field application, the average serum titers of piglets were 6.4x and 7.lx in farm A and B, respectively. Solid protection from challenge exposure with 10 ml of 5 x 1010 CFU/ml of enterotoxins and pili mixed cell suspension by stomach tube administration in piglets were demonstrated.
On the other hand, potency test in mice immunized by intraperitoneal inoculation was also conducted. The survival rate for vaccinaled group was 100%( 20/20 ) while control group was 0% ( 0/10) after the IP challenge with 0.1 ml cell suspension of enterotoxins and pili, 8-9x 108 CFU/ml.