Abstract
Drug-resistant tuberculosis is a major problem worldwide. Based on the knowledge of specific mutations occurring in Mycobacterium tuberculosis genome, drug resistance can be detected earlier. The aim of this study was to determine the prevalence of the most common mutations associated with resistance to Isoniazid (INH), Streptomycin (SM) and Ethambutol (EMB) in Mycobacterium tuberculosis isolates from Morocco in order to select target mutations to develop tests for rapid detection of drug-resistant Mycobacterium tuberculosis Moroccan isolates. A total of 199 M. tuberculosis isolates collected from the National Tuberculosis Reference Laboratory in Morocco were subject to katG, inhA, rrs, rpsL and emb mutation analysis by PCR probe-based assay. The genotypic results were then compared to drug susceptibility testing results for the corresponding drugs. Among 66 phenotypically INH resistant isolates, 80.3% (53/66) were found to be genotypically INH resistant from which 77.3% (51/66) and 3% (2/66) had respective mutations in katG315 and inhp-15 codons. Of the 58 phenotypically SM resistant isolates, genotypic SM resistance was confirmed in 17.2% (10/58) cases. Nucleotide mutations at codons 43 and 88 of rpsL gene and at codon 512 of rrs gene were found respectively in 12.1% (7/58); 1.7% (1/58) and 3.4% (2/58) of the phenotypically SM resistant Mycobacterium tuberculosis isolates. Finally, mutations at codon 306 of embB gene were identified in 42.3% (11/26) of Mycobacterium tuberculosis isolates phenotypically EMB resistant. This study showed that a large proportion of Mycobacterium tuberculosis resistant isolates from Morocco carry a large number of mutations in different codons (especially katG315, embB306 and rpsL43) of the corresponding genes associated with drug resistance. Thus, molecular analysis based on the identification of such mutations is useful but not fully sufficient to predict all drug resistance cases. Based on these results, rapid drug resistance genotyping can be used as an adjunct to the traditional culture based methods in reference laboratories.
Highlights
Mycobacterium tuberculosis is the causative agent of tuberculosis (TB)
Tuberculosis isolates to INH, SM and EMB determined by the proportional method revealed that 33% (66/199) of the isolates are INH resistant (INHR), from which 92.4% (61/66) are multidrug resistant (MDR), whereas 29.1% (58/199) and 13.1% (26/199) M. tuberculosis isolates are respectively resistant to SM (SMR) and EMB (EMBR) (Table 3)
Is the rise in frequency of M. tuberculosis strains resistant to many drugs [24] and the slowness to get phenotypic drug susceptibility testing (DST) results
Summary
Mycobacterium tuberculosis is the causative agent of tuberculosis (TB). The disease has affected humans for at least several millennia [1]. 3 million people globally die of TB and 8 million new individuals become infected It constitutes a major public health problem, especially in developing countries where almost 98% of all TB deaths occur and where surveillance for resistance of. Conclusion: This study showed that a large proportion of Mycobacterium tuberculosis resistant isolates from Morocco carry a large number of mutations in different codons (especially katG315, embB306 and rpsL43) of the corresponding genes associated with drug resistance. Molecular analysis based on the identification of such mutations is useful but not fully sufficient to predict all drug resistance cases Based on these results, rapid drug resistance genotyping can be used as an adjunct to the traditional culture based methods in reference laboratories
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
