Using a multiplex polymerase chain reaction for the identification of Beijing strains of Mycobacterium tuberculosis.

The genotype of a Beijing strain of Mycobacterium tuberculosis (MTB) is usually determined by spoligotyping. However, this technique requires special equipment and is time-consuming. In this study, we developed a new multiplex polymerase chain reaction (PCR) to differentiate between Beijing and non-Beijing strains of MTB. A total of 323 MTB isolates were genotyped by both spoligotyping and the novel multiplex PCR. By spoligotyping, 169 (52.3%) isolates were determined to be Beijing strains and the remaining 154 (47.7%) isolates were non-Beijing strains. The multiplex PCR method produced results identical to those of spoligotyping in the identification of Beijing strains of MTB. This method is highly sensitive, specific, and fast. It is also cost-effective and suitable for screening large numbers of samples.