Chlamydia-related bacteria discovered deep below the Arctic Ocean


Chlamydia and related bacteria, collectively called Chlamydiae, and all studied members of this group depend on interactions with other organisms to survive.

Chlamydiae specifically interact with organisms such as animals, plants and fungi, and including microscopic organisms like amoeba, algae and plankton.

Chlamydiae spend a large part of their lives inside the cells of their hosts, humans, but also of koala bears.

Most knowledge about Chlamydiae is based on studies of pathogenic lineages in the lab. But do Chlamydiae also exist in other environments? The new research shows that Chlamydiae can be found in the most unexpected of places.

An international group of researchers report the discovery of numerous new species of Chlamydiae growing in deep Arctic Ocean sediments, in absence of any obvious host organisms.

Unexpectedly, the research team came across highly abundant and diverse relatives of Chlamydia.

“Finding Chlamydiae in this environment was completely unexpected, and of course begged the question what on earth were they doing there?”

says Jennah Dharamshi from Uppsala University and lead author of the study

 The team discovered that one of these new groups of Chlamydiae is closely related to Chlamydia that cause disease in humans and other animals.

“inding that Chlamydia have marine sediment relatives, has given new insights into how chlamydial pathogens evolved, some of these new groups of Chlamydiae are exceptionally abundant in these ocean sediments.

Unfortunately, the researchers have as of yet been unable to grow these Chlamydiae or take images of them. “Even if these Chlamydiae are not associated with a host organism, we expect that they require compounds from other microbes living in the marine sediments.

Additionally, the environment they live in is extreme, without oxygen and under high pressure, this makes growing them a challenge,” explains Thijs Ettema.

Nevertheless, the discovery of Chlamydiae in this unexpected environment challenges the current understanding of the biology of this ancient group of bacteria, and hints that additional Chlamydiae are awaiting to be discovered.

The Yucatan Times