Deep under the Arctic Ocean seafloor lurks several newfound species of chlamydia bacteria. The species, cousins to the one that causes the sexually transmitted infection (STI), seem to survive despite a lack of oxygen and obvious hosts to prey upon, new research suggests.

Chlamydia is the most commonly reported STI in the U.S., with an estimated 2.86 million infections occurring each year, according to the Centers for Disease Control and Prevention. The specific bacterium that triggers the disease, Chlamydia trachomatis, belongs to a large group of related microbes collectively known as Chlamydiae, many of which depend on host organisms to survive.

But now, scientists have unearthed a slew of Chlamydiae bacteria living about 2 miles (3 kilometers) beneath the surface of the Arctic Ocean, growing several feet below the seafloor sediment. Although subjected to intense pressure and largely deprived of oxygen, the microbes grow in abundance and even seem to dominate certain patches of the seafloor.

"Finding Chlamydiae in this environment was completely unexpected, and of course begged the question what on earth were they doing there?" lead author Jennah Dharamshi, a graduate student studying microbial diversity and evolution at Uppsala University in Sweden, said in a statement. . . [livescience.com]