Scientists discover new chlamydia cousin deep under Arctic Ocean

Scientists have discovered a new kind of chlamydia-related bacteria deep under the Arctic Ocean — but they say it’s not a cause for concern. 

‘You don’t have to worry about swimming in the ocean,’ researcher says

A sediment coring device is deployed in the Norwegian-Greenland sea from R/V G.O. Sars during a 2015 expedition by the Centre of Geobiology at the University of Bergen. Samples collected during the expedition helped researchers identify a chlamydia-related bacteria. (Centre of Excellence in Geobiology, University )

Scientists have discovered a new kind of chlamydia-related bacteria deep under the Arctic Ocean — but they say it's not a cause for concern. 

"You don't have to worry about swimming in the ocean," said Jennah Dharamshi, a PhD student at Uppsala University in Sweden.

Dharamshi, who is from Markham, Ont., is the lead author of a new study published in Current Biology. It details how researchers from Sweden, Norway and the Netherlands discovered several groups of chlamydiae (members of a bacterial phylum) in ocean floor sediment.

One of them is a distant relative of the kind of bacteria that causes the sexually transmitted infection chlamydia.  

Dharamshi said studying chlamydia-related bacteria could help scientists understand how it came to infect humans and other animals and what characteristics make the microbes dangerous to humans.

"The common ancestor of these chlamydiae and the STD probably existed millions of years ago," she said. 

Jennah Dharamshi, who is from Markham, Ont., is a PhD student at Uppsala University in Sweden and the lead author of a new study on the discovery of chlamydia-related bacteria deep in the Arctic Ocean. (Submitted by Jennah Dharamshi )

Dharamshi said they were surprised by how much chlamydiae they found in the sediment samples.

"They're considered rare members of the microbial community."

Chlamydiae made up to 43 per cent of the bacteria found, and there were 163 different species. One of the groups of chlamydiae has been classified as a new order of bacteria.

Dharamshi said the discovery indicates chlamydiae are having a greater impact on the environment than previously thought. 

 "There's so much more microbial diversity out there that's still to be explored and so much that we don't yet know."

Study co-author Steffen L Jørgensen is surrounded by sediment cores in the core repository facility at the Institute of Earth Science at the University of Bergen. (Eivind Senneseth)

The bacteria were found in ocean floor sediment taken from near Loki's Castle — a field of five active "black smoker" hydrothermal vents located about 2.35 kilometres under the ocean on the Arctic Mid-Ocean Ridge between Norway and Iceland.

"The hope is by going to these more extreme, different environments, we might be able to discover more and new different things that can help inform us about evolution," Dharamshi said.

Researchers were also surprised to find the chlamydiae up to nine metres below the ocean floor. That's because all studied members of this bacterial group rely on a host to survive — from humans to amoebae — but there are none in the oxygen-free environment of the ocean. 

Dharamshi said they're now studying the metabolism of one of the most abundantly found groups of chlamydiae to try and understand how it survives there.


Emily Blake is a reporter for CBC News, based in Yellowknife. She has worked on and off as a journalist for the past 10 years and her work has appeared in a number of Canadian print, radio and online publications. She covers a range of topics including health, gender, justice and climate change. You can reach her at or follow her on Twitter @BlakeEmily.


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