Phylogenetic diversity among geographically dispersed Chlamydiales endosymbionts recovered from clinical and environmental isolates of Acanthamoeba spp.

摘要: The recently proposed reorganization of the order Chlamydiales and description new taxa are broadening our perception this once narrowly defined taxon. We have recovered four strains gram-negative cocci endosymbiotic in Acanthamoeba spp., representing 5% sp. isolates examined, which displayed developmental life cycles typical members Chlamydiales. One these endosymbiont was found stably infecting an amoebic isolate from a case keratitis North America, with three others acanthamoebae environmental sources America (two isolates) Europe (one isolate). Analyses nearly full-length 16S rRNA gene sequences by neighbor joining, parsimony, distance matrix methods revealed their clustering other but lineage separate those genera Chlamydia, Chlamydophila, Simkania, Waddlia (sequence similarities, <88%) including described species Parachlamydia 91.2 to 93.1%). With sequence similarities each 91.4 99.4%, intra-amoebal endosymbionts may represent distinct and, perhaps, within family Parachlamydiaceae. Fluorescently labeled oligonucleotide probes targeted signature regions were able readily differentiate two groups corresponded phylogenetic lineages. These results reveal significant diversity occurring among nontraditional host supports existence large reservoir related species. Considering that all known be pathogenic, further investigation parachlamydiae as disease-producing agents is warranted.