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Background Tuberculosis is a serious infectious disease affecting millions of people. In spite of efforts to reduce the disease, increasing antibiotic resistance has contributed to persist in the top 10 causes of death worldwide. In fact, the increased cases of multi (MDR) and extreme drug resistance (XDR) worldwide remains the main challenge for tuberculosis control. Whole genome sequencing is a powerful tool for predicting drug resistance-related variants, studying lineages, tracking transmission, and defining outbreaks. This study presents the identification and characterization of resistant clinical isolates of Mycobacterium tuberculosis including a phylogenetic and molecular resistance profile study by sequencing the complete genome of 24 strains from different provinces of Ecuador. Results Genomic sequencing was used to identify the variants causing resistance. A total of 15/21 isolates were identified as MDR, 4/21 as pre-XDR and 2/21 as XDR, with three isolates discarded due to low quality; the main sub-lineage was LAM (61.9%) and Haarlem (19%) but clades X, T and S were identified. Of the six pre-XDR and XDR strains, it is noteworthy that five come from females; four come from the LAM sub-lineage and two correspond to the X-class sub-lineage. A core genome of 3,750 genes, distributed in 295 subsystems, was determined. Among these, 64 proteins related to virulence and implicated in the pathogenicity of M. tuberculosis and 66 possible pharmacological targets stand out. Most variants result in nonsynonymous amino acid changes and the most frequent genotypes were identified as conferring resistance to rifampicin, isoniazid, ethambutol, para-aminosalicylic acid and streptomycin. However, an increase in the resistance to fluoroquinolones was detected. Conclusion This work shows for the first time the variability of circulating resistant strains between men and women in Ecuador, highlighting the usefulness of genomic sequencing for the identification of emerging resistance. In this regard, we found an increase in fluoroquinolone resistance. Further sampling effort is needed to determine the total variability and associations with the metadata obtained to generate better health policies.

Tuberculosis (TB) is among the most deadly diseases that affect worldwide, its impact is mainly due to the continuous emergence of resistant isolates during treatment due to the laborious process of resistance diagnosis, non-adherence to treatment and circulation of previously resistant isolates ofMycobacterium tuberculosis. The aim in this study was evaluate the performance and functionalities of web-based tools: Mykrobe, TB-profiler, PhyReSse, KvarQ, and SAM-TB for detecting resistance in isolate ofMycobacterium tuberculosisin comparison with conventional drug susceptibility tests. We used 88M. tuberculosisisolates which were drug susceptibility tested and subsequently fully sequenced and web-based tools analysed. Statistical analysis was performed to determine the correlation between genomic and phenotypic analysis. Our data show that the main sub-lineage was LAM (44.3%) followed by X-type (23.0%) within isolates evaluated. Mykrobe has a higher correlation with DST (98% of agreement and 0.941Cohen's Kappa) for global resistance detection, but SAM-TB, PhyReSse and Mykrobe had a better correlation with DST for first-line drug analysis individually. We have identified that 50% of mutations characterised by all web-based tools were canonical inrpoB, katG,embB, pncA, gyrAandrrsregions. Our findings suggest that SAM-TB, PhyReSse and Mykrobe were the web-based tools more efficient to determine canonical resistance-related mutations, however more analysis should be performed to improve second-line detection. The improvement of surveillance programs for the TB isolates applying WGS tools against first line drugs, MDR-TB and XDR-TB are priorities to discern the molecular epidemiology of this disease in the country.

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