Publications by authors named "Afif Elghraoui"

Article Synopsis
  • Five new or repurposed drugs for multi-drug resistant tuberculosis were approved recently, but resistance to these drugs developed quickly, potentially due to existing resistance in the bacteria prior to treatment.
  • A study analyzed 409 clinical bacterial samples to find new and existing genetic variants associated with drug resistance, discovering 5 known and 67 novel resistance variants in 13 genes.
  • The results showed that 21% of the samples had preexisting mutations that could lead to drug resistance, mainly due to mutations affecting drug activation and efflux mechanisms, raising concerns about how these mutations arose and their implications for future treatments.
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Background: Rifampicin (RIF) is a key first-line drug used to treat tuberculosis, a primarily pulmonary disease caused by . RIF resistance is caused by mutations in , at the cost of slower growth and reduced transcription efficiency. Antibiotic resistance to RIF is prevalent despite this fitness cost.

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Motivation: The phylogenetic signal of structural variation informs a more comprehensive understanding of evolution. As (near-)complete genome assembly becomes more commonplace, the next methodological challenge for inferring genome rearrangement trees is the identification of syntenic blocks of orthologous sequences. In this article, we studied 94 reference quality genomes of primarily Mycobacterium tuberculosis (Mtb) isolates as a benchmark to evaluate these methods.

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Accurate and timely functional genome annotation is essential for translating basic pathogen research into clinically impactful advances. Here, through literature curation and structure-function inference, we systematically update the functional genome annotation of Mycobacterium tuberculosis virulent type strain H37Rv. First, we systematically curated annotations for 589 genes from 662 publications, including 282 gene products absent from leading databases.

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Background: The genetic basis of virulence in Mycobacterium tuberculosis has been investigated through genome comparisons of virulent (H37Rv) and attenuated (H37Ra) sister strains. Such analysis, however, relies heavily on the accuracy of the sequences. While the H37Rv reference genome has had several corrections to date, that of H37Ra is unmodified since its original publication.

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We report the discovery and confirmation of 23 novel mutations with previously undocumented role in isoniazid (INH) drug resistance, in catalase-peroxidase (katG) gene of Mycobacterium tuberculosis (Mtb) isolates. With these mutations, a synonymous mutation in fabG1 (g609a), and two canonical mutations, we were able to explain 98% of the phenotypic resistance observed in 366 clinical Mtb isolates collected from four high tuberculosis (TB)-burden countries: India, Moldova, Philippines, and South Africa. We conducted overlapping targeted and whole-genome sequencing for variant discovery in all clinical isolates with a variety of INH-resistant phenotypes.

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