Abstract

The Beijing strain of Mycobacterium tuberculosis bear high transmission potential and there is a significant correlation between Beijing strain and multidrug resistance. Phospholipase of M. tuberculosis plays an important role in its pathogenesis through breaking up phospholipids and production of diacylglycerol (DAG) as an important signaling molecule in infected macrophages as well as a precursor for synthesis of triacylglycerol that acts as an energy store for utilization during long-term dormancy of M.tuberculosis. DNA extraction was performed by using CTAB (cetyltrimethylammonium bromide) method from positive culture specimens of tuberculosis patients (Van Soolingen et al., 1991). Spoligotyping was done for differentiation of Beijing strains from non-Beijing strains. Finally Phospholipase C region was detected by polymerase chain reaction (PCR). The current study showed that, 19 (9.5%) of 200 strains were Beijing strain and 181 (90.5%) were non-Beijing strains, corresponding to spoligotyping. Based on PCR assays for plcA, plcB, plcC genes, of Beijing strains, 16(84.2%) strains were positive forplcA, and 17 (89.4%) strains were positive for plcB and 17(89.4%) strains were positive for plcC genes (Goudarzi et al., 2010). In non-Beijing strains 17 strains (9.4 %), 18 (9.9%), 18 (9.9%) were positive for plcA, plcB, plcC, respectively. Considering the majority of Beijing strains possess phospholipase C genes, it is possible that plc serves a role in pathogenesis and thereby severity of tuberculosis diseases. However, confirmative studies will be needed to verify the exact role of phospholipase C in the pathogenecity ofM. tuberculosis.

Key words: Tuberculosis, phospholipase c, spoligotyping, polymerase chain reaction.