The phylum Elusimicrobia previously known as 'Termite Group 1' has been shown to be widespread in different ecosystems like marine environment, sewage sludge, contaminated sites and soils. The high abundance of 'Elusimicrobia' representatives is only evidenced for the lineage of symbionts found in termites.
The first organism to be cultured was Elusimicrobium minutum, however other two species has being partially described and placed in a separate class, known as Endomicrobia.
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)  and National Center for Biotechnology Information (NCBI) and the phylogeny is based on 16S rRNA-based LTP release 106 by The All-Species Living Tree Project 
Notes: ♥ Strains not lodged at National Center for Biotechnology Information (NCBI) and or listed in the List of Prokaryotic names with Standing in Nomenclature (LPSN)