Related Experiment Video
Updated: Nov 2, 2025
06:07
Matrix-based DNA Extraction for Targeted Next-Generation Sequencing on Decontaminated Sputum Samples
Published on: June 6, 2025
583
High within-host diversity found from direct genotyping on post-mortem tuberculosis specimens in a high-burden
Cristina Rodríguez-Grande1, Juan Carlos Hurtado2, Sandra Rodríguez-Maus1
1Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
Summary
Directly analyzing post-mortem tissues revealed frequent within-host Mycobacterium tuberculosis (MTB) diversity, including mixed infections. This highlights the importance of examining multiple tissues to fully understand tuberculosis clonal complexity.
Area of Science:
- Microbiology
- Genetics
- Infectious Diseases
Background:
- Tuberculosis remains a global health challenge, particularly in high-burden countries like Mozambique.
- Understanding Mycobacterium tuberculosis (MTB) clonal complexity is crucial for effective disease control.
- Standard diagnostic methods may underestimate within-host diversity.
Purpose of the Study:
- To characterize the clonal complexity of MTB infections.
- To identify factors that maximize the detection of coexisting MTB strains or variants.
- To assess within-patient diversity using direct genotyping from multiple post-mortem tissues.
Main Methods:
- Genotypic analysis using Mycobacterial Interspersed Repetitive-Unit-Variable-Number Tandem-Repeats (MIRU-VNTR).
- Direct analysis of 70 biopsy specimens from 28 post-mortem tuberculosis cases.
- Inclusion of samples from two or more different tissues per case.
Main Results:
- Genotypic data were obtained for 82.1% of cases, enabling within-patient diversity analysis.
- MIRU-VNTR revealed clonal diversity in 35.7% of cases.
- Five cases showed mixed infections with distinct MTB strains, with brain tissue frequently associated with heterogeneity.
Conclusions:
- Direct MTB genotyping from post-mortem tissues frequently reveals within-host diversity, including mixed and polyclonal infections.
- Standard analysis of respiratory specimens alone likely overlooks significant MTB diversity.
- Comprehensive tissue sampling is essential for accurate assessment of MTB clonal complexity.
Related Concept Videos
01:29Modern Molecular Taxonomy
318
Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...
318
01:26Pulmonary Tuberculosis IV
251
Tuberculosis, more commonly referred to as TB, is an infectious disease stemming from Mycobacterium tuberculosis. While it primarily impacts the lungs, TB can also affect other body areas. Given its severity and global impact, timely and accurate diagnosis is crucial for controlling its spread and improving patient outcomes.
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
251
01:20Applications of Molecular Taxonomy
261
Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to...
261
01:29Pulmonary Tuberculosis I
442
Tuberculosis, often called TB, is a contagious illness primarily caused by Mycobacterium tuberculosis. It mainly affects the lung parenchyma but can also impact other body parts.
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
442