A comprehensive update to the Mycobacterium tuberculosis H37Rv reference genome

Area of Science:

• Genomics
• Microbiology
• Bioinformatics

Background:

• The H37Rv strain is the standard reference for Mycobacterium tuberculosis (M. tuberculosis) genome sequencing.
• Existing reference sequences may contain inaccuracies or lack comprehensive genetic information.

Purpose of the Study:

• To introduce Bact-Builder, a novel pipeline for accurate bacterial genome assembly.
• To re-evaluate and update the M. tuberculosis H37Rv reference genome sequence.

Main Methods:

• Development and application of the Bact-Builder pipeline using consensus building.
• De novo assembly of three H37Rv aliquots from a single stock.
• Comparative analysis against the existing H37Rv reference genome and other common strains.

Main Results:

• Two of three H37Rv genome assemblies were 100% identical; the third differed by one nucleotide.
• The new sequence is ~6.4 kb longer than the reference, containing ten novel genetic regions.
• These regions include PE/PPE gene insertions and new esxN/esxJ paralogs, also found in other H37Rv strains.

Conclusions:

• Bact-Builder provides accurate and reproducible de novo bacterial genome assemblies.
• The study provides significant updates to the primary M. tuberculosis H37Rv reference genome sequence.