Isolation, serotype determination and toxicity test of Streptococcus suis strains caused disease in pigs at Thai Nguyen province

Abstract

The result of isolation, serotype determination and toxicity test of S. suis strains caused the disease in pigs in Thai Nguyen province showed that 52.60% of samples were infected with S. suis. Of which, the rate of samples collecting from the weaning piglets at 2-3 months old and under 1 month old, from that S.suis strains were isolated to be 58.91% and 45.79%, respectively. The isolated S. suis strains belonged to the serotypes: 2, 7, 9, 21 and 29, of which serotype 2 accounted for the highest proportion (58.16%), followed by serotype 9 (16.33%), serotype 7 (7.18%), serotype 21 (1.96%) and serotype 29 (2.61%). The virulence of S. suis strains belonging to serotype 2 and 9 was very strong, killed 100% of the experimental white mice within 12-24 hours.