Comparative genomics of Mycobacterium africanum Lineage 5 and Lineage 6 from Ghana suggests distinct ecological niches

Isaac Darko Otchere, Mireia Coscolla, Leonor Sanchez-Buso, Adwoa Asante-Poku, Daniela Brites, Chloe Loiseau, Conor Meehan, Stephen Osei-Wusu, Audrey Forson, Clement Laryea, Abdallah Iddrisu Yahayah, Akosua Baddoo, Gloria Akosua Ansa, Samuel Yaw Aboagye, Prince Asare, Sonia Borrell, Florian Gehre, Patrick Beckert, Thomas A. Kohl, Sanoussi N'diraChristian Beisel, Martin Antonio, Stefan Niemann, Bouke C. de Jong, Julian Parkhill, Simon R. Harris, Sebastien Gagneux, Dorothy Yeboah-Manu

Research output: Contribution to journalA1: Web of Science-article

Abstract

Mycobacterium africanum (Maf) causes a substantial proportion of human tuberculosis in some countries of West Africa, but little is known on this pathogen. We compared the genomes of 253 Maf clinical isolates from Ghana, including N = 175 Lineage 5 (L5) and N = 78 Lineage 6 (L6). We found that the genomic diversity of L6 was higher than in L5 despite the smaller sample size. Regulatory proteins appeared to evolve neutrally in L5 but under purifying selection in L6. Even though over 90% of the human T cell epitopes were conserved in both lineages, L6 showed a higher ratio of non-synonymous to synonymous single nucleotide variation in these epitopes overall compared to L5. Of the 10% human T cell epitopes that were variable, most carried mutations that were lineage-specific. Our findings indicate that Maf L5 and L6 differ in some of their population genomic characteristics, possibly reflecting different selection pressures linked to distinct ecological niches.

Original languageEnglish
Article number11269
JournalScientific Reports
Volume8
Number of pages11
ISSN2045-2322
DOIs
Publication statusPublished - 2018

Keywords

  • TUBERCULOSIS COMPLEX STRAINS
  • BOVIS
  • POLYMORPHISMS
  • HYPOTHESIS
  • EVOLUTION
  • VIRULENCE
  • PROTEINS
  • ANTIGENS
  • CAMEROON
  • ESAT-6

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