Behind the rheumatic fever generator

2002/03/27 Elhuyar Zientzia

• Mikrobiologia

Rheumatic fever is a very contagious type of fever. Every year, 400,000 people worldwide are contaminated and people who become ill suffer from heart damage from the disease for a lifetime.

This disease is caused by the M18 strain of Streptococcus bacteria. Although penicillin is normally used to treat diseases caused by Streptococcus bacteria, this special strain is resistant to treatment.

In addition, the detection of the disease is very complicated, since the symptoms are very similar to those produced by other strains of Streptococcus and because the identification tests do not distinguish the different strains.

Due to all these difficulties, the clarification project of the genetic code of the M18 strain was launched. The first results have now been published and the researchers have come to a rather surprising conclusion. Apparently, when compared to other strains of Strepetococcus, 10% of the bacteria genes of the M18 strain are foreign. By analyzing the origin of these foreign genes, they discover that they are genes of phages. Phages are viruses that attack bacteria. Therefore, it can be said that the bacteria of the M18 strain are also ‘sick’. The cause of these foreign genes is that the M18 strain is resistant to penicillin and causes human disease.