A study published in Nature Communications describes how a team led by the London School of Hygiene and Tropical Medicine in the UK has devised a genetic barcode to help doctors and researchers easily identify different types of tuberculosis.
Lead author Dr. Taane Clark, Reader in the School’s Genetic Epidemiology and Statistical Genomics, says:
“There is increasing interest in new technologies that can assist those treating tuberculosis patients. This new barcode can be easily implemented and used to determine the strain-type that is a surrogate for virulence.”
“New technology is making it easier to track mutations but genomes are very complicated and we hope this simple barcode will help people with their research,” explains co-author and tuberculosis (TB) expert Dr. Ruth McNerney, a Senior Lecturer in Pathogen Biology and Diagnostics at the School.
TB is a worldwide, deadly respiratory disease caused by various strains of Mycobacterium tuberculosis. Although it usually involves the lungs, it can affect any part of the body. It takes about 6 months to treat the disease with antibiotics.
According to the World Health Organization (WHO), TB is second only to HIV/AIDS as the greatest killer worldwide due to a single pathogen. The disease causes illness in over 8 million people every year and kills over 1 million. Most of the deaths occur in low- and middle-income countries.
In healthy people infected with TB, the immune system keeps it at bay. People who are not aware they are infected can carry the pathogen around the world.
Over the last 70,000 years, TB bacteria have been evolving alongside humans, diversifying into families of strains that affect different people in different ways, and spreading from person to person through the air.
To pinpoint the origins and map how TB moves around the globe, Dr. Clark and colleagues examined over 90,000 genetic mutations across a global collection of 1,600 M. tuberculosis genomes.
Of the 90,000 or so mutations, around 7,000 of them are strain-specific, but the team discovered you only need 62 of them to code the entire known global family of circulating TB bacteria strains.
The authors say the barcode is the first to cover all main lineages, and “classifies a greater number of sublineages than current alternatives.”
Dr. Clark says they are making their findings “available to the doctors and scientists working with tuberculosis so that they can more easily know what strains they are dealing with.”
In July 2014, Medical News Today reported how WHO plan to eradicate TB in 33 countries.