OBJECTIVE: To identify S. suis and to evaluate the homogeneity of isolates of S. suis from human and swine. METHODS: Culture, morphology, API biochemical tests and serum coagulate tests were used. All the 7 strains of streptococcus were confirmed to be S. suis serotype 2. Two strains and 1 strain were isolated from blood and cerebrospinal fluid (CSF) of patients, respectively, while the other 4 strains were obtained from the infected swine or their corpses. Seven strains of S. suis serotype 2 and reference strain SS2 were analyzed by randomly amplified polymorphic DNA analysis with six primers and Rep PCR with four primers and thalli fatty acid profile analysis. Cluster and principal compound analysis of results were performed with RAPD, Phylip and Treeview software. RESULTS: By analysis on RAPD patterns, a close relationship among 7 strains of S. suis serotype 2 and reference strain SS2 was discovered. Human-born strains and swine-born strains exhibit similar RAPD patterns. There was a same clonal relationship between strains originated from the blood and CFS of the patients. These results were confirmed by thalli fatty acid profile to have genotypic and phenotypic identity. CONCLUSION: Homogeneity exists among the 7 strains and reference strain SS2.
OBJECTIVE: To identify S. suis and to evaluate the homogeneity of isolates of S. suis from human and swine. METHODS: Culture, morphology, API biochemical tests and serum coagulate tests were used. All the 7 strains of streptococcus were confirmed to be S. suis serotype 2. Two strains and 1 strain were isolated from blood and cerebrospinal fluid (CSF) of patients, respectively, while the other 4 strains were obtained from the infected swine or their corpses. Seven strains of S. suis serotype 2 and reference strain SS2 were analyzed by randomly amplified polymorphic DNA analysis with six primers and Rep PCR with four primers and thalli fatty acid profile analysis. Cluster and principal compound analysis of results were performed with RAPD, Phylip and Treeview software. RESULTS: By analysis on RAPD patterns, a close relationship among 7 strains of S. suis serotype 2 and reference strain SS2 was discovered. Human-born strains and swine-born strains exhibit similar RAPD patterns. There was a same clonal relationship between strains originated from the blood and CFS of the patients. These results were confirmed by thalli fatty acid profile to have genotypic and phenotypic identity. CONCLUSION: Homogeneity exists among the 7 strains and reference strain SS2.