Diagnosing and treating chlamydia is a difficult task. The disease is sexually transmitted. Experts explain that identifying the exact phenotype of this intracellular parasite is a huge step towards developing a therapy. After years of studying chlamydia’s genetic changes, researchers at the University of Vienna have finally discovered the secret behind pathogenic resistance – recombinations. The problem with the disease is that half of those affected have no symptoms. In this way, they actively spread the microorganisms. Women are particularly vulnerable because chlamydial infection is known to cause infertility, life-threatening ectopic pregnancy, premature birth, cervical cancer, and genital damage. For several years now, researchers have suspected that recombinant factors play a key role in the genetic diversity of this bacterium. Factors that can provide some biological advantages, such as pathogenicity, antigens, proteins, etc. To identify them precisely, the research team looked at four new strains that are genetically related to that of chlamydia and compared them to existing DNA data. They found extensive and persistent shuffling at the base of the genome between different chlamydial families. This is a factor that contributes to the development of the pathogen, as well as its ability to “trick” the host’s immune cells. NEWS_MORE_BOX They also identified genomic “hotspots” that play key roles in adaptation and survival. The hypothesis states that new genes are created by gene duplication, and some of them are present in the genome for a long period of time, while others are lost or deleted from the genome. The scientists explain that one of the most surprising findings is that such evolution has so far been observed among fungi, plants and animals. Data from the study are published in Molecular Biology and Evolution.