Over the past few years, diseases like tuberculosis have made a comeback, seemingly with more force behind them than ever before. Infection rates are slowly rising, and while they may not be much of a problem now, they could become virtually unstoppable once they hit the general public. This all comes down to the fact that the medications human civilization has used to fight the infections, antibiotics, might no longer work. As more and more microbes are exposed to these drugs, the higher the chances of even just one of them developing a resistance and spreading that resistance to other microbes. The looming possibility that this antibiotic resistance might spread further is a major concern, but recent findings show that there may be another cause for concern: human genetics. As if antibiotic resistance ? and how easily it can spread from one strain of bacteria to another ? wasn't enough.

A strain of tuberculosis meningitis bacteria that originated in Beijing, China could kill people who carry a specific genetic defect in their bodies. The strain in question is known to have antibiotic resistance towards the more common antimicrobial agents, but reports indicate that more unconventional agents can help patients recover. The condition is generally fatal in one out of every three cases, even if the patient has access to top-notch medical care facilities and services. The gene in question, known as TLR2, is by itself not considered a major risk factor for infection and death by the Beijing strain. However, research indicates that there is a mutation for this gene that, when combined with an infection of the Beijing tuberculosis strain, can result in a near-guaranteed fatality. The bacterium is worldwide, but the strain in question is usually found only in Asia and in several former Soviet countries.

TLR2 has been linked to the immune system by a number of studies in the past, though the actual role it plays has never been fully discerned. It appears to be important for recognizing and initiating defensive immune responses to tuberculosis bacteria, judging by what is known and the results whenever a mutated TLR2 gene is encountered. The research team took samples from over 187 patients who suffered the tuberculosis meningitis strain, while a larger sample of 236 was taken from those who were infected by the more common pulmonary strain of the disease. The patient samples were analyzed to check if they carried the mutated TLR2 variation. The results showed that the link was strong for both variants, but was significantly stronger with those who had come into contact with the Beijing strain of the bacteria.

An estimated one-third of the global population is infected with one strain of tuberculosis or another, and the infection rate is estimated to be one infection for every second. It is notable that only one in every ten infected individuals will display any symptoms, and this is usually because their immune systems have already been compromised or are naturally weak. Untreated, the condition can kill an estimated 2 million people annually. In recent years, the infection rate has been stable, but the number of deaths has increased ? largely due to the slow increase of resistant strains finding their way to the general population.