Genotyping analysis of 220 clinical isolates of Mycobacterium tuberculosis from Beijing area

To understand the class and characteristics of genotypes of Mycobacterium tuberculosis(M.tuberculosis)to provide the scientific basis for the prevention and treatment of tuberculosis,220 clinical isolates of M.tuberculosis from Beijing area were collected and their genotypes were investigated with spacer oligonucleotide typing(Spoligotyping)and multiple loci VNTRs(variable number tandem repeats)analysis(MLVA).Meanwhile,the results were analyzed by BioNumerics(version 5.0)software and statistical Fisher analysis.It was found that two genetic groups,i.e.Beijing family and non-Beijing family,could be demonstrated in these 220 strains of clinical isolates as detected by Spoligotyping,all-together displaying 20 genotypings,in which 202 strains were belonged to the Beijing family(91.82%).In the Beijing family,192 strains were typical Beijing family(9⒌05%)and 10 strains were atypical Beijing family(4.95%).In 98 strains of Beijing family and in 6 strain of non-Beijing family,22 and one strains were drug-resistant,respectively(22.55% and 16.67%),however,there was no significant difference as determined by Fisher analysis(P=0 5835,P0 05).With MLVA,5 genetic groups were typed in 220 clinical isolates,displaying 59 genotypes,in which the chief genotypes were Beijing family(9⒈37%),China-2(⒉73%)and China-3(⒋55%).From this survey,it is evident that marked gene polymorphism exists in M.tuberculosis isolated from Beijing area,in which the Beijing family is the main and prevalent strain in Beijing area,but it has no significant correlation with drug resistance.