Group Identification Of Pathogeny And Vaccine Production Of Streptococcosis Suis In Sin Yang Region

Streptococcosis suis, the general term of certain disea caused by the infection of streptococcus, is a wide-spread infectious disease among the swine. At present, the disease has been found in more than 20 countries. In china, the disease is prevalent in more than 20 provinces (cities, autonomous regious), including South China, Southwestern, Jiangxi, East of China and other regions. Nowadays, streptococcosis suis, one of the infectious disease that has been haunting the development of swine-keeping for years is on the rise. The research was performed to select certain typical bacterial strain as the vaccine strain to produce polyvalent inactivity vaccine for the local prevention and counterchecking of the disease on the basis of the separation and identification of streptococcosis suis, in the southern part of Xinyang region of Henan Province.1. From 2000 to 2003, 20 strains of streptococcosis suis were identified and separated in southern part of Henan Province. The 20 strains were divided into C-group streptococcus (15/20), D-group streptococcus (3/20) and two unidentified strains (2/20).2. Among the C-group, D-group and the unidentified streptococcus, SC2, SC7, SD14, SX8, which had good immunity and virus-filtering were chosen to produce polyvalent vaccine during the separation and identification. According to many domestic materials and practical experiments. Martin broth containing 0.2% glucose and 2% serum of swine was selected as the vaccine producing nutrient medium. The strain grew well in the nutrient medium. Finally, the polyvalent inactivity vaccine was made.3. The polyvalent inactivity vaccine was safe and effective. The storage test showed that under 4-8 degrees centigrade, it can be kept for about 10 months, while under 18-22 degrees centigrade, almost 6 months.4. This polyvalent inactivity vaccine of streptococcus suis was safe and effective through immunity test. Under the same condition, in experimental group, morbidity was only 0.5% and mortality was only 0.3%; while in control group, morbidity was 16%, mortality was 10%. The chi square test demonstrated that there was a significant difference (P＜0.001). This polyvalent inactivity vaccine can be employed in preventing and counterchecking the streptococcosis suis in the southern part of Henan Province.