Analysis of EsxH Gene Mutations and Homology Modeling in Mycobacterium tuberculosis from Clinical Isolates in South Sulawesi

Abstract

Introduction: Tuberculosis (TB) is a significant global public health issue, with Indonesia ranking second worldwide for the highest incidence.Despite the widespread use of the Bacillus Calmette-Gurin (BCG) vaccine, its efficacy remains limited, particularly in preventing the reactivation of latent TB infections in adults.Moreover, Mycobacterium tuberculosis (Mtb), the causative agent of TB, exhibits considerable genetic diversity, which can influence the virulence, transmissibility, and resistance to treatment.The EsxH gene, part of the ESX-3 secretion system, plays a crucial role in the virulence and immune evasion mechanisms of Mtb.Methods and Materials: A total of 40 Mtb-positive isolates from South Sulawesi, Indonesia, were used.Samples were analyzed using molecular detection techniques in accordance with the standard procedures.The EsxH gene was amplified using specific primers via polymerase chain reaction (PCR), purified, and Sanger sequencing.Nucleotide variations were identified using Unipro UGENE, and phylogenetic analysis was conducted to explore the evolutionary relationship as well as the uniqueness of mutations.Additionally, the structural impact of the identified mutations was analyzed using the SWISS-MODEL server by comparing the three-dimensional (3D) models of the EsxH protein with and without mutations to assess any significant structural changes.Results: The study identified unique mutations in the EsxH gene of Mtb isolates from South Sulawesi, specifically at nucleotide positions 28 G>A and 29 C>T, leading to amino acid changes at position 10 (alanine to threonine and alanine to valine).Phylogenetic analysis indicated that these mutations were distinct from the region, while 3D homology modeling showed no significant structural changes.Conclusion: This study contributes to the understanding of M. tuberculosis genetic diversity in South Sulawesi by identifying region-specific mutations in the EsxH gene.While these mutations did not result in major structural alterations to the EsxH protein, further bioinformatic and in vitro studies are needed to explore their functional implications.These findings underscore the importance of continued surveillance and research to improve TB control strategies, as well as to inform the development of more effective vaccines and treatments.

Access to Document

Other files and links

• Link to publication in Scopus
• Open Access Version Available

Fingerprint