Jilin Province Pig Pathogenic Streptococcus Isolation And Identification

Pig streptococcosis is a wide spread infectious disease which has occurred everywhere in the world and it also is one of the main infectious disease that puzzling pig farms in our country these years. Because of the great varity of streptothrix serum type and the complex structure of antigen, it presents different clinical symptom, such as septicemia, meningoencephalitis, endocarditis, pneumonia's, porodenia arthritis etc. It often occurs combinating with other disease. There is arising tendency of infection rate and death rate in recent year. Extensive attention is paid by clinicians and scientific researchers. It has occurred everywhere in our country, and the rate is in an rising trend especially in assembling pig farms. Now it is one of the most known bacterium disease. The first report of it aboard was in 1945, and 1949 in our country. It spreaded fast in 1960's, and in 1970's it has been reported in most area in our country. It is defined the second class animal epidemic disease by law. Based on the investigation in recent years, piglets in JiLin province are mainly occurred in spring and autumn. The infection rate is about 2% to 5%,and the death rate is about 40%.Now we are not very clear with occurrence regulation and the original characteristic of pig streptococcosis disease . Its' infection and spread can not be effectively controlled simply by medicines. So we study it from pathogen.Between 2001 and 2002,we did epidemilogy survey, clinical diagnosis and pathological anatomy to acute, thermal and sepsis infectious disease in big pig farms in Chanchun, JiLin, Yanji and Gongzhuling. Based on the preliminary diagnosis of pig septic streptococcosis, pathogen separation was done, and 20 Pig Pathogenicity streptothrix were separated. Assortment identification was done through the combination of medium character, biochemistry character and serum reaction, its morphotype, chromosome, medium character and biochemistry character were in coincidence with pig streptococcosis. The result of fluidity test in biochemistry experiment showed that there were five strains belong to C group streptothrix, nine strains belong to D group streptothrix, three strains belong to E group streptothrix, one belong to A group and two strains can not be confined. In this experiment, there were fifteen strains streptothrix had different action in mice pathogenicity. This invistigation showed that Jilinlocal pig streptococcosis serum type are not confined in C group streptothrix.The development of pig streptothrix polyvalent inactivated vaccine is the pressing obligation to control this disease. Based on Jilin local pig streptothrix popular strains, we have chosen the representative F6 strain to be proceeded completely characteristic authenticates, which can provide consult data for research of manufacture of polyvalent inactivated vaccine.At present, there are reports of pig streptothrix in America, England, France, Russia, Japan, India, Denmark, Canada etc. The streptothrix which separated from septic and cerebritis pig body mainly belong to type II of R group pig streptothrix and type I of S group pig streptothrix, only small amount of C group, D group and L group streptothrix cause endocarditis and septicema, which has some difference in according to our serum type.