Simultaneous detection and typing of Mycobacterium tuberculosis complex bacteria

atively high death rate. About 30 percent of the world's population is latently infected with Mycobacterium tuberculosis. The annual incidence of all forms of TB is currently about 1.7 million globally, and is increasing. TB causes more health problems than any other disease caused by a single infectious agent. The increasing global TB burden is much more serious than in previous decades. This is probably due to multiple factors including changing demographic situations, deterioration of TB control programmes, co-infection with Human Immunodeficiency Virus (HIV), medical practitioners who have insufficient knowledge of the disease, limited health provisions especially for those living in poor socioeconomic conditions, increasing immigration from countries endemic for the disease, and the emergence and spread of multi-drug resistant (MDR)-TB. The increase of drugresistance, and especially MDR-TB, presents a serious threat to tuberculosis control. Consequently, MDR-TB has led to the development of more rapid and efficient methods of diagnosis and identification of resistance phenotypes as well as new epidemiological markers. The standardised and most frequently used molecular fingerprinting technique for detecting M. tuberculosis complex isolates is IS6110 Restriction Fragment Length Polymorphism (RFLP). Spoligotyping was developed as a PCR-based macroarray technique for the simultaneous detection and differentiation of M. tuberculosis complex strains. Spoligotyping has one disadvantage, namely it is less discriminatory than IS6110 RFLP when strains contain many IS6110 copies, but it has four major advantages compared with other amplification methods for strain differentiation and genotyping. Firstly, detection and genotyping can be performed directly on bacterial DNA from clinical samples without the need for culturing. Secondly, the different subspecies of the M. tuberculosis complex can be distinguished (M. tuberculosis, M. bovis, M. bovis BCG, M. bovis subsp. caprae comb. nov., M. africanum, M. microti and M. canettii). Thirdly, genotyping can be performed much more quickly than with RFLP techniques, and fourthly it is a more sensitive method for strains with one or two IS6110 S poligotyping & TB