Title: Archaea and Their Potential Role in Human Disease | Infection and Immunity
Headings: Archaea and Their Potential Role in Human Disease
Archaea and Their Potential Role in Human Disease
POTENTIAL PATHOGENICITY OF ARCHAEA
POTENTIAL ASSOCIATIONS OF ARCHAEA WITH HUMAN DISEASE
CONCLUSION AND FUTURE STUDIES
ACKNOWLEDGMENTS
REFERENCES
KEYWORDS

Content: It is possible such structures may be involved in host-microbe adherence or microbe-microbe interactions within a potential host. Once an archaeal pathogen reaches its specific host niche, it should be able to compete successfully with other endogenous flora for survival and persistence, in a manner similar to that of the known bacterial pathogens. Clues to the nature of archaeal interactions within the endogenous flora may be gleaned from recent studies of methanogen survival in arthropods. Methanogens have been identified in the hindguts of many terrestrial arthropods, including millipedes, cockroaches, termites, and scarab beetles ( 20 ). Three types of symbiosis have been described for such arthropods as follows: colonization of the hindgut lumen by free methanogens, association of methanogens with chitinous structures in the hindgut (chitinous bristles in the cockroach hindgut are covered with a mucous layer containing a complex biofilm), and the internalization of methanogens within intestinal anaerobic protists. Such protists include amoebomastigotes, flagellates, trichomonads, and ciliates ( 21 ). For example, methanogens resembling Methanobrevibacter species have been demonstrated in the cytoplasm of the ciliate Nyctotherus ovalis within the cockroach hindgut by electron microscopy ( 17 ). Sequence-based methods have also been used to identify methanogens in the termite hindgut ( 41 ). Methanogen-protozoa symbioses may be a common feature of many anaerobic ecosystems.