Generales

By: Julián David Ospina Sánchez - Journalist
Understanding the genetics of the bacterium that causes tuberculosis through genomic sequencing and bioinformatics was the objective that a group of researchers from UdeA set themselves in April 2020. They analyzed 866 genomes in Latin American patients, 90 of them from Medellin. Among the findings are two lineages of Mycobacterium tuberculosis in Colombia and Peru. They constitute key contributions to the care of the disease and public health.  
The National Center for Genomic Sequencing of UdeA obtained the first complete genome of Mycobacterium tuberculosis in Latin America in 2012. Photo: UdeA Communications Office / Alejandra Uribe F.

With the leadership of the National Center for Genomic Sequencing (CNSG) and the Cellular Immunology and Immunogenetics Group (GICIG), Universidad de Antioquia advances the studies of the genome of the bacterium that causes tuberculosis in Latin America. "These are not isolated findings because we have been working on the subject of genomics since 2009 and, in 2012, we had already published the first complete genome of Mycrobacterium tuberculosis in the region", specified Juan Fernando Alzate Restrepo, director of the CNSG.

The latest project is under review by scientists at Springer Nature, an American scientific journal that promotes publications of solid research, according to its website. For this project, the union of CNSG and CIGIG, both from Universidad de Antioquia, led to the analysis of 866 genomes of Mycobacterium tuberculosis collected from Mexico to Argentina, 90 of them in Medellín.

For Alzate Restrepo, the importance of the work has to do with the fact that, in the case of bacteria or pathogens, their genome stores information on what makes them infectious, why they persist in organisms, resist treatment and can be transmitted from one person to another. "With the level of detail that genomic sequencing —step-by-step reading of the genome's component genes— and bioinformatics gave us, we were able to identify two new variants or lineages of Mycobacterium tuberculosis, which causes tuberculosis, in Colombia and Peru", noted Professor Alzate, who added that the Colombian lineage was specifically found in people from Medellin and Manizales. 

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The researchers agreed that it is evident that the bacterium brought by the Spanish during colonization is not being fought now. "That is why it is completely relevant to know how these variants are being transmitted to seek solutions and take public health measures", explained Andrés Baena García, a researcher at GICIG, a research group attached to the Faculty of Medicine.

"We want to understand how the treatments would work better according to the lineages of the bacterium to avoid the sequelae left by tuberculosis in the lungs," said Baena García, who noted that when patients arrive for clinical care, samples are taken and, thanks to the new findings, cases could be classified from lesser to greater severity.

For patients who do not have a severe infection, the studies are also important, as antibiotic treatment could be reduced and not last six months, as is usual. This would also be a relief for the health system, added Baena García.

Detailed capture of Mycrobacterium tuberculosis with Universidad de Antioquia equipment. Photo: courtesy of Centro Nacional de Secuenciación Genómica UdeA.

The Importance of Medellín

According to data collected and studied for more than 35 years by the UdeA immunologist Luis Fernando Barrera Robledo, Medellin is the Colombian city with the most cases of tuberculosis: approximately 1,500 annual reports and a particular incidence in the central and northeastern areas.

Although Mycobacterium tuberculosis was discovered in 1882 by Robert Koch, the few scientific and pharmaceutical advances to deal with it have made the infection it causes one of the deadliest in the world, with approximately 1,000 million cases.

For these reasons, the identification of a predominant lineage in the capital of Antioquia will be key to determining new paths for research on tuberculosis and decision-making so that the results obtained are at the service of the health system.

"Having these records in great detail thanks to genomic sequencing and their systematization makes us think that we are reversing the current phenomenon that indicates we had lost the war against microbes", said Alzate Restrepo, who concluded that, besides the contributions to public health, this research links Universidad de Antioquia with the microbiology of the 21st century.

Shared Effort

The results presented today are the product of the work carried out by the Cellular Immunology and Immunogenetics Group, which obtained resources for 300 million pesos from the Ministry of Science, Technology and Innovation for the project "Association of Mycrobacterium tuberculosis Variants with the Severity of the Disease in Medellin and Antioquia". The National Center for Genomic Sequencing of UdeA joined this project with the contribution of analyses from the rest of the country and Latin America.

"We used the data collected in Latin America in the last 10 years. Until now, we had scattered analyses, which we deepened and integrated until we reached the greatest possible detail of the genomes", noted the director of the CNSG. Universidad de Antioquia also invested close to 300 million pesos for this work.

Besides the director of the CNSG and professor Andrés Baena García, the UdeA immunologist Luis Fernando Barrera Robledo, the professor of the Faculty of Engineering Felipe Cabarcas, the surgeon Hanna Henao and the student of the master's degree in basic biomedical sciences Juan Camilo Ocampo actively participated in the work.