[Environmental Chlamydiae with medical significance].

The molecular biological analysis of a chlamydia-like bacterium from Acanthamoeba sp., originated from the nasal mucosa of a female subject, led to the description of the new species Parachlamydia acanthamoebae. It provided the basis for establishing its own family Parachlamydiaceae, which was genetically separated from the traditional Chlamydiaceae. In the following years other chlamydia-like bacteria, replicating within different free-living amoeba species, have been observed. Due to their close genetic distance to P. acanthamoebae, they have been classified as Parachlamydiaceae. Thus, the description of the two novel genera, Neochlamydia and Metachlamydia, as well as a new species, Protochlamydia naegleriophila, was accomplished. Their role as potential pathogens was confirmed in a number of cases by antibodies and DNA detection in patient material.