#Science researchers in the United States have declared the new discovery of a parasitic bacteria in human saliva unprecedented in that it lives off of other bacteria.

Bacterial parasite is completely dependent on bacterial host

Each bacterium of the newly discovered microbe lives off another species of bacteria called Actinomyces odontolyticus. Both exist inside human saliva. The extremely small bacteria, with only 700 genes, had evaded detection despite decades of research because it is a parasitic microbe that can only live on its host. It is extremely difficult to isolate it for study in the laboratory. In contrast, A. odontolyticus has a total of 2200 genes.


The discovery of the parasitic bacteria correlates with scientists’ speculation that a high percentage of microbial organisms in our saliva had yet to be identified. The discovery has yet to be peer-reviewed by other scientists but has been met with interest by researchers in the field. The parasitic bacteria were discovered when Jeff Mclean and his team of researchers at the University of Washington School of Dentistry encountered a strange RNA fragment during human saliva testing and examined it for careful testing. Although encountered in previous lab tests by other scientists, the new study was the first successful attempt at locating the origin of the RNA fragment.

First bacteria unable to produce its own genetic material

The parasitic microbe is incapable of producing its own amino acids to propagate and must live off the host.


Eventually, A. odontolyticus is killed by the parasite after creating holes in the host’s membrane and depleting its host of nutrients. The discovery is significant because it would be the first strain of bacteria other than Bdellovibrio to infect other bacteria. However, Bdellovibrio can survive on its own without depending completely on a host. Nevertheless, scientists have previously surmised that host-parasite relationships between microbes are common in nature based on gene data that they have encountered during laboratory research.

New strain has potential to uncover causes behind human diseases

The researchers at the University of Washington have postulated that a link exists between various human diseases and the newly discovered parasite due to the high concentrations of the parasite’s genetic material in people with gum disease. It seems that in the beginning, A.odontolyticus affected by the bacteria are able to evade disease-fighting white blood cells. As a result, the human body becomes less effective at fighting off infection. Possible conditions exacerbated by the parasite include gum disease, resistance to bacteria and cystic fibrosis. Understanding the biological mechanisms of the parasitic bacteria can potentially have implications in the study of these diseases and in the study of resistance to antibiotics. #Health