There are a trillion lifeforms out there on Planet Earth, and most of them are invisible – at least to the human eye. Microbes really are the dominant organisms of our world, and every single week, it appears that yet another new species has been discovered in the most unlikely of places.
This week is no exception, and the latest addition to the bacterial kingdom has been found in plain sight: Inside your mouth, specifically within your saliva. Far from just being a new, run-of-the-mill little microbial critter, this is a type of parasitic bacterium, one that can only exist if it infects other bacteria around it.
This parasitic bacteria only has 700 genes – an incredibly low number by any standard – and cannot forge its own amino acids. In order to survive, it steals them from its host cell, according to the team’s presentation at the annual meeting of the American Society for Microbiology in Boston, which took place earlier this month.
“They’re ultra-small bacteria, and live on the surface of other bacteria,” Jeff McLean, an associate professor of periodontics at the University of Washington’s School of Dentistry, and the research group’s lead, told the audience, reported New Scientist.
This newly discovered hunter is somewhat similar to the only other known strain of bacteria (Bdellovibrio) that can infect other bacterial cells; however, this new variant – designated as TM7 – is unique in that it’s a free-living cell that appears to actively hunt down its potential hosts.
Although the new parasitic bacterial species has existed in human saliva for some time now, it had been difficult to detect as, according to New Scientist, it's been incredibly hard to culture and grow in a laboratory setting. Now, of course, we know why: It needed a host to survive.
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