ARCHAEA
When they were identified in the late 1970s based upon ribosomal sequences,
Archaea were viewed as a group of archaic bacteria (Woese and Fox, 1977). Indeed, because of their capacity of methanogenesis, archaea were supposed to live in ancient organisms and received the name of“archaea.”This name is misleading as it speculates that these organisms resemble ancient cells and live in specific and “archaic like” environment. They have long been considered as extremophile bacteria that can be found in the most extreme environments (temperature,salinity,and pH). This explains the fact that archaea have not been extensively studied in clinicalmicrobiologyandtheirplaceamonglivingorganismslong went unrecognized.