ABSTRACT
Considering the increasing significance of diseases due to NTM all over the world, we investigated the burden of such diseases in our region. The aim of this study was to assess NTM prevalence from different clinical samples during a period of 8 years in Massih Daneshvari Hospital, in Iran. This descriptive study was performed on 8322 samples obtained from pulmonary TB patients in Mycobacteriology Research Center from 2004 -2012. Using Tb1 and Tb2 primers, a 190 bp fragment of IS6110 gene was amplified in order to identify Mycobacterium species. Specimens with negative IS6110 PCR results were analyzed with PCR-RFLP using hsp65 gene, for NTM investigation. Out of 8322 samples, we identified 124 [1.5%] strains of NTM. The mean age of the patients was 57 +/- 18/9 years [age range: 7 - 88 years]. 55/6% of the patients were male. The most common species detected in our study were Mycobacterium simiae [44.3%], Mycobacterium chelonae [16.9%] and Mycobacterium kansasii [12.9%]. We found a high prevalence rate of Mycobacterium simiae among our patients. Treatment protocols for NTM are different from the protocols for Mycobacterium tuberculosis complex, so early diagnosis of these species will be of great importance
ABSTRACT
A large number of factors are involved in the development of TB, but the most important one belongs to the host genetic factors. One of the genetic factors is cytokine gene polymorphisms. The results of recent studies indicate that IL-12 and IFN-gamma play a central role in regulating the type and level of immune response in mycobacterial infections. Mutations in these genes may be associated with susceptibility to pulmonary TB. The aim of this study was to investigate the frequencies of IFN- gamma [2109], IFN-gamma R1 [-611] and IL-12B [-1188] genes polymorphisms and their relationships with susceptibility to pulmonary TB in Iranian population. This was a case-control study. Thirty TB patients with positive smears hospitalized in TB departments of Masih Daneshvari Hospital and 30 healthy controls with no history of TB were selected for this study. Genotypes of IFN- gamma [2109], IFN-gamma R1 [-611] and IL-12B [-1188] genes were determined by using PCR-RFLP method. The PCR-products were analyzed by use of restriction enzymes. The data were analyzed by means of SPSS and Hardy - Weinberg equilibrium. Considering IFN-gamma R1 [-611] and IL-12B [-1188] genes there was a significant difference between the control and study groups [P < 0.05], but in regard to IFN- gamma [2109], this difference was not detected between the two groups. Mutation in the regions of -611 of IFN-gamma R1 and -1188 of IL-12B genes may increase the host susceptibility to mycobacterium tuberculosis and genotyping of these regions can be used for screening of the high risk individuals