[021] MTSU, TN Tech researchers discover new bacteria in cooling towers, hot tubs

MURFREESBORO — Middle Tennessee State University and Tennessee Technological University student and faculty researchers have discovered two new species of bacteria found in a cooling tower and hot tub in Putnam County, Tennessee.

And the discovery may provide clues to new pathways of disease and treatment, said the lead scientists, whose nearly 20-year research endeavor has been published in Genome Announcements (January 2016) and the International Journal of Systematic Microbiology) in February.

To view video of the researchers discussing their findings, visit

https://youtu.be/f6UH42rrc4I.

Including nearly $1 million in U.S. Environmental Protection Agency grant funding, MTSU and Tennessee Tech researchers and students used a variety of microscopic and genomic techniques to describe these organisms, which have been named “Candidatus Berkiella aquae” and “Candidatus Berkiella cookevillensis.”

MTSU professor Mary Farone named them in honor of the city of Cookeville, where the cooling tower and hot tub were located, and for Dr. Sharon Berk, a Tennessee Tech researcher for 27 years, who is now an MTSU senior scientist writing grant proposals for research for the Office of Research and Sponsored Programs.

“We are hoping that the genetic assessments will lead to how it’s getting into the nucleus and maybe using that to figure out how to take things into a cancer cell that you want to target, that would be the ultimate good thing about it,” said Berk.

“The significance of this work is we’re finding new organisms in cooling towers and in constructed environments like hot tubs and showers, but primarily in cooling towers,” Berk added.

In addition to Cookeville, researchers not only took samples from cooling towers primarily in Sparta, Tennessee, and Murfreesboro, but also from Texas and New Jersey.

Through the years, about 15 Tennessee Tech undergraduate and graduate students and more than a dozen MTSU grad and undergraduate students assisted with the research in on-campus laboratories and locations where bacteria samples were collected.

Although pneumonia is the leading reason for adult hospitalization in the U.S., a cause for pneumonia is detected in less than 40 percent of the cases, Farone said.

“Neither of the new bacteria are currently associated with respiratory disease as far as we know, but their small size, location in the nucleus and failure to grow by conventional laboratory methods may prevent their detection,” Farone said. “However, their unusual movement into and replication to large numbers in the cell nucleus represents a novel bacterial cause of cell death.”

Although other bacteria have been shown to infect the nuclei of certain cells, the new bacteria reproduce to high numbers in the nucleus, killing host cells (including in one case, human cancer cells) in less than five days, Farone said.

“Amoebae are the organisms also responsible for transmission of bacteria that cause Legionnaires’ disease, a pneumonia illness first described in 1976,” Farone said. “Although the bacteria responsible for Legionnaires’ disease do not infect the cell nucleus but divide in cytoplasm of human cells, genomic analysis shows these two newly described intranuclear bacteria share some of the same disease-causing genes with Legionnaires’ disease bacteria.”

Farone, Berk and the other lead researchers’ findings are significant considering recent deadly outbreaks in New York City and Flint, Michigan, that were associated with human-constructed water systems such as cooling towers.

Berk (at Tech and MTSU), Mary and Anthony Farone and Anthony Newsome at MTSU and Tennessee Tech biology associate professor John Gunderson played vital roles in the study.

At MTSU, former grad student Yohannes Mehari and molecular bioscience doctoral candidate Brock Arivett have proven to be invaluable in the research experience.

“Hopefully, this will be important for us to be able to determine the way to transport things into the nucleus for future studies,” Arivett said.

The project began with an ecological study of amoebae and bacteria in natural versus human-constructed environments.

The TTU Center for the Management, Utilization and Protection of Water Resources (the Water Center) and MTSU provided support in addition to many Cookeville and Murfreesboro businesses, which agreed to provide water samples.