Researchers at the Karolinska Institutet in Sweden have come closer to understanding why some people become seriously ill with meningococcal disease. In some cases, patients even die from a common bacterium that leaves most people unharmed. In the published study, researchers identified RNA mutations within the bacterium Neisseria meningitidis with ainvasive meningitisassociated. This was the first time that a non-coding RNA in a bacterium was linked to disease progression.
The severity of meningococcal disease
The researchers have also designed and validated a PCR test that can detect these mutations. They found that non-coding RNA mutations within the bacterium N. meningitidis are almost twice as likely to be associated with severe meningococcal disease. This is a rare but serious infection that can cause death, according to the study authors. Neisseria meningitidis is a bacterium commonly found in the noses of 10 to 15 percent of the human population. Generally, these bacteria do not cause meningococcal infection. However, when this happens, people can become ill very quickly and die within hours if they are not treated. The research began back in 2017 after a strain of the bacterium was isolated from a Swedish teenager. The patient succumbed to onebacterial meningitis.
Compared to another strain of the same bacterium isolated from an asymptomatic individual, the researchers discovered a mutation in a regulatory non-coding RNA molecule. This is known as an RNA thermal sensor, or RNAT, and was found within the deceased teenager's tribe. The finding prompted the researchers to search for more than 7,000 RNAT configurations from N. meningitidis from all over Europe. In total, they discovered five new variants of RNATs. These could be associated with meningitis. They occurred more frequently in people who were sick with the bacterium. These variants had the common feature of producing more and larger capsules. The capsules accordingly isolated the bacterium, thereby helping to evade the body's immune system.
The study resultssupport further research into the potential involvement of these and other non-coding RNAs in the development of bacterial diseases. In the future, this PCR test can be coupled with a simple nasal swab in a clinic, enabling rapid identification of these mutations and subsequent treatment.
