Genotypes and drug susceptibility of Mycobacterium tuberculosis Isolates in Shihezi, Xinjiang Province, China
1 Department of Pathogenic Biology and Immunology, School of Medicine, Shi Hezi University, Shihezi, People’s Republic of China
2 The First Hospital of Shi Hezi University, Shihezi, People’s Republic of China
3 National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Beijing, People’s Republic of China
BMC Research Notes 2012, 5:309 doi:10.1186/1756-0500-5-309Published: 19 June 2012
Tuberculosis (TB) remains a major global health problem. To investigate the genotypes of Mycobacterium tuberculosis (MTB) and the distribution of Beijing family strains, molecular epidemiology technologies have been used widely.
From June 2010 to June 2011, 55 M. tuberculosis isolates from patients with pulmonary TB were studied by Beijing family-specific PCR (detection of the deletion of region of difference 105 [RD105]), and mycobacterial interspersed repetitive units variable number tandem repeat (MIRU-VNTR) analysis. Twenty-four MIRU-VNTR loci defined the genotypes and clustering characteristics of the local strains. All strains were subjected to a drug susceptibility test (DST) by the proportion method on Lowenstein-Jensen (LJ) culture media.
Fifty-five clinical isolates of MTB were collected. Beijing family strains represented 85.5% of the isolates studied. Using 24 loci MIRU-VNTR typing categorized the strains into eight gene groups, 46 genotypes, and seven clusters. 83.6% (46/55) of the isolates belonged to the largest gene group. Thirty-six isolates (65.5%) were susceptible, nineteen (34.5%) were resistant to at least one drug, seven (12.8%) were Multidrug-Resistant Tuberculosis (MDR TB), and two (3.6%) were extremely drug-resistant tuberculosis (XDR-TB).
The results showed there were obvious polymorphisms of VNTRs of MTB clinical strains. Beijing family strains of MTB were predominant in the Shihezi region of Xinjiang province. There was no correlation between the drug-resistance and Beijing family strains of MTB. It is necessary to strengthen the monitoring, treatment, and management of drug-resistance TB in Shihezi region, Xinjiang.