[Research on the relationship between variable number of tandem repeats sequences and serogrouping of Neisseria meningitis].

ABSTRACT

OBJECTIVE: To research the relationship between variable number of tandem repeats sequences (VNTRs) in genome and serogrouping of Neisseria meningitides (N. meningitidis). METHODS: 118 meningococcal strains which were isolated from invasive patients and carriers in China were serogrouped by antiseria agglutination testing. 38 strains were serogroup A. 80 were serogroup C. And then four variable number of tandem repeats sequences (VNTRs) loci in the DNA of 118 meningococcal strains were amplified by PCR. A dendrogram was constructed on the basis of DNA length of PCR productions by the Unweighted Pair Group Method with Arithmetic Averages (UPGMA). The two pair primers-specific were designed based on the nucleotide variant afterward the VNTR01 locus (T01-A and T01-AC, T01-C and T01-AC) to amplify 118 meningococcal strains. RESULTS: 118 strains were classified into five VNTR groups. 98.3% (116/118) strains were identical between serogrouping and VNTRs genotyping. 97.3% (36/37) strains of serogroup A were categorized into group I of VNTRs genotyping. 98.7% (75/76) strains of serogroup C were categorized into group II of VNTRs genotyping. According to the presence or absence of PCR products using two pair primers-specific, 118 strains were classified into two groups which correspond to serogroup A and C. The sensitivity of primers-specific T01-A and T01-AC was 89.5% (34/38). The specificity of primers-specific T01-A and T01-AC was 100% (38/38). The sensitivity of primers-specific T01-C and T01-AC was 100% (80/80). The specificity of primers-specific T01-C and T01-AC was 95.2% (80/84). CONCLUSION: VNTRs genotyping has high relation to serogrouping A and C. The nucleotide sequence variations in the galactosyl-transferase gene related to the serogrouping A and C.