Tuberculosis Diagnosis and Detection of Drug Resistance: A Comprehensive Updated Review

Abstract

Tuberculosis (TB) is a significant public health challenge, especially in developing nations. Developing a TB eradication strategy is hampered by the global health concern of drug-resistant (DR) TB. Effective patient treatment, preventing TB transfer and avoiding the upsurge of DR strains depend primarily on the timely and accurate identification of DR TB. Due to inadequate sensitivity, the necessity of trained laboratory personnel, the sluggish growth pattern of Mycobacterium bacilli in culture, and the small number of bacilli that are usually found in extrapulmonary TB samples, TB diagnosis is still tricky in clinical practice. Although mycobacterial culture is the gold standard to identify TB and determine drug resistance, it takes 2 to 8 weeks to develop. Despite their high cost, nucleic acid amplification tests (NAATs) and whole-genome sequencing (WGS) are the commonly employed molecular-based methods for diagnosing and identifying TB. The WHO suggested the GeneXpert MTB/RIF to identify TB and detect resistance to rifampicin. In comparison, numerous molecular techniques were developed, including allele-specific PCR (MAS-PCR), solid-phase hybridization, real-time PCR (RT-PCR) and droplet digital PCR-based technique (DDPCR). This manuscript is intended to overview the current approaches for the phenotypic and genotypic diagnosis of TB disease and identifying resistance to antitubercular drugs depending on recently published articles, WHO and CDC reports, and commercially available diagnostic tools.