# Mycobacterium tuberculosis cultured in MGIT media for whole-genome sequencing application: a systematic literature review and meta-analysis

## TL;DR

This study reviews and analyzes methods for using early positive cultures of Mycobacterium tuberculosis in whole-genome sequencing to improve drug resistance diagnosis and transmission tracking.

## Contribution

The study proposes a standardized workflow and terminology for WGS using MGIT cultures, based on a meta-analysis of sequencing quality factors.

## Key findings

- 96.1% of analyzed sequencing data passed quality control thresholds.
- Sequencing cycle count significantly impacts sequencing quality.
- A standardized workflow and reporting checklist are recommended for MGIT-based WGS.

## Abstract

Whole-genome sequencing (WGS) holds promise for accurate and comprehensive diagnosis of drug resistance in Mycobacterium tuberculosis and identification of transmission events. ‘Early positive cultures’ (EPC) are increasingly used when WGS is implemented to guide clinical care to reduce the turnaround time. We performed a systematic literature review to compare methods used for EPC-based WGS and performed an individual sample data meta-analysis to identify variables associated with bioinformatic quality measures. Of 423 studies identified, 15 met eligibility criteria. We analysed 1,065 FASTQ files from 11 studies using Illumina sequencing; 96.1% passed all quality control thresholds. Median genome coverage was 65× (IQR, 63–82), with a pooled mapping percentage of 91.2%. The meta-analysis showed that the number of sequencing cycles was significantly associated with improved sequencing quality, while other laboratory variables had no consistent effect. Based on these findings, we suggest replacing the term EPC with ‘clinical primary culture’ and propose a standardized workflow and reporting checklist for WGS on primary Mycobacteria Growth Indicator Tube (MGIT) cultures.