Characteristics of Mycobacterium tuberculosis genotype and the relationship between Beijing genotype and drug-resistant phenotypes in Tianjin / 中华流行病学杂志

ABSTRACT

Objective To explore the distribution and characteristics on genotype of Mycobacterium tuberculosis and the relationship between Beijing genotype and drug-resistant phenotypes in Tianjin city. Methods 656 clinical strains were collected from Tianjin Center for Tuberculosis Control and ten other Tuberculosis Institute in Tianjin from January 2008 to June 2009.Information regarding administration, clinical as well as laboratory findings of patients were collected.Proportion method was adopted to detect the susceptibility on four anti-tuberculosis drugs, namely streptomycin (SM), isoniazid (INH), rifampicin (RFP) and ehambutol (EMB). Both Beijing and non-Beijing genotypes were differentiated by multiplex PCR. The relationship between Beijing genotype and drug-resistant phenotypes was analyzed. Results In this study, the overall resistance rate of MTB was 26.98%, with multidrug-resistant rate was 6.25%. Among 656 MTB strains, 600isolates (91.46% ) belonged to Beijing genotype. There was significant difference between Beijing and non-Beijing genotype (x2=4.26, P=0.039) among the Tianjin household registered population.Concerning the drug resistance, there was no significant difference between the two groups.Conclusion Beijing genotype strains were the predominant one in Tianjin. The proportion of people infected with the Beijing genotype strains in Tianjin household registration of patients was significantly higher than the proportion of patients in the floating population in the same region.Results from the statistical analysis did not reveal any statistically significant association between Beijing genotype and drug resistance.