Comparative Analysis of the Efficacies of the GeneXpert and Solid Culture Media Techniques in the Diagnosis of Mycobacterium Tuberculosis

Tuberculosis is one of the predominant infectious diseases causing significant deaths worldwide. Detection of Mycobacterium tuberculosis bacilli (MTB) using culture media was officially recognized by World Health Organization. However, there is a significant limitation in the authenticity of evaluation for its effectiveness on clinically important attributes. GeneXpert detects the presence of Mycobacterium tuberculosis (M. tuberculosis) based on the detection of nucleic acid and is able to identify the resistance of both isoniazid (INH) and Rifampicin (RIF) drugs. In this technique, DNA amplification is done using the GeneXpert instrument in the suspected sample with a specific reagent cartridge. Although GeneXpert is a rapid technique compared to other diagnostic tools for MTB identification due to false-negative results, the culture media technique is still considered the gold standard in detecting M. tuberculosis. The current study was designed to evaluate the comparative efficacies of GeneXpert and the solid culture media technique in identifying MTB. Sputum samples of ۲۵۰ (n=۲۵۰) suspected tuberculosis (TB) patients were investigated using both diagnostic techniques. The results revealed that out of the ۲۵۰ suspected patients, ۳۰ (۱۲%) samples were positive with the culture media technique, while only ۱۷ (۶.۸%) samples showed positive results with GeneXpert. Culture tests and GeneXpert are not equally efficient in detecting M. tuberculosis. The current study's findings showed that the culture-based detection method for M. tuberculosis is more efficient and reliable than GeneXpert.

Keywords:

M. tuberculosis , GeneXpert , culture media , Acid-fast Bacilli