Purpose: Heteroresistant Mycobacterium tuberculosis (MTB) is defined as a group of drug-susceptible and resistant bacteria in a single clinical specimen from tuberculosis (TB) patients. Heteroresistance of MTB is considered a preliminary stage to full resistance. The present study aimed to determine the heteroresistance in Mycobacterium tuberculosis in Tabuk province, in the north of the Kingdom of Saudi Arabia.
Method: GenoType MTBDRplus assay was used to determine mutations associated with isoniazid and rifampicin resistance.
Results: A total number of 46 confirmed M. tuberculosis positive sputum samples were scanned for heteroresistance. The present study revealed 3 (6.5%) heteroresistant mutations to either rpoB gene alone, 2 (4.4%) to rpoB and 1 (2.2%) to inhA genes.
Conclusion: The detection of heteroresistant mutations could guide the initiation of an appropriate regimen of treatment.
Keywords: Heteroresistance, Mycobacterium tuberculosis, drug resistance, rpoB mutation, inhA mutation, Tuberculosis (TB).