Scientists identify potential key to Lyme disease

February 9, 2009

Researchers at UT Southwestern Medical Center have identified a protein that may help give Lyme disease its bite. The findings suggest that the bacterial protein, which aids in transporting the metal manganese, is essential for the bacterium that causes Lyme disease to become virulent.

"We believe our findings provide a foundation for further defining metal homeostasis in this human pathogen and may lead to new strategies for thwarting Lyme disease," said Dr. Michael Norgard, chairman of microbiology at UT Southwestern and senior author of a study now online and in an upcoming issue of the Proceedings of the National Academy of Sciences.

Lyme disease, discovered in 1977, is the most prevalent tick-borne infection in the U.S. Borrelia burgdorfei, the bacterium that causes Lyme disease, lives in infected mammals and in the midgut of ticks. When an infected tick bites an animal or a human, the bacteria are transmitted to the new host. Infection causes fever, malaise, fatigue, headache, muscle and joint aches, and a characteristic "bull's-eye" rash that surrounds the site of infection.

To establish infection, however, the bacterium also must acquire a number of essential nutrients, including metals like manganese from its mammalian and tick hosts. Until now, no metal transporter responsible for this acquisition had been identified in this bacterium.

In the current study, microbiologists examined whether bacteria genetically engineered to lack this manganese transporter, called BmtA, transmitted Lyme disease to ticks and mice. The bacterium lacking the transporter, Dr. Norgard said, grows a bit more slowly in the test tube but is not dramatically different from the normal version.

"When you try to grow it in a mouse, however, it can't grow," he said. "The fact that the bacterium without this particular manganese transporter can't grow in a mouse raises important questions about what aspects of physiology and metabolism contribute to the pathogenicity of the organism."

Lead author Dr. Zhiming Ouyang, postdoctoral researcher in microbiology at UT Southwestern, said another newly discovered characteristic about the bacterium that causes Lyme disease is that it doesn't seem to require iron to function, something most other pathogens need to survive.

"Out of the thousands of bacteria known, the Lyme disease agent and only one or two other bacterial species do not require iron for growth," Dr. Ouyang said. "That raises the question as to what other metal co-factors the Lyme disease bacterium depends on to carry out the work that iron does for all these other biological systems. Our research suggests that manganese is a really important one."

The next step is to understand the exact mechanism of how manganese functions in the organism.

"I really think that there's also something to the notion that manganese may regulate the expression of other virulence factors," Dr. Norgard said. "It could be that manganese has more of an indirect effect, but more research is needed to determine what must happen for Borrelia burgdorfei to become virulent."

Source: UT Southwestern Medical Center

Explore further: New vaccine strategy identified for explosive emerging diseases

Related Stories

New vaccine strategy identified for explosive emerging diseases

May 31, 2017
A 'designer' manganese-peptide antioxidant of the world's toughest bacterium, combined with radiation, have shown to be successful in the development of a vaccine to counter Venezuelan Equine Encephalitis Virus (VEEV), a ...

Scientists reveal quirky feature of Lyme disease bacteria

March 21, 2013
Scientists have confirmed that the pathogen that causes Lyme Disease—unlike any other known organism—can exist without iron, a metal that all other life needs to make proteins and enzymes. Instead of iron, the bacteria ...

Team discovers how bacteria exploit a chink in the body's armor

January 20, 2017
Scientists have discovered how a unique bacterial enzyme can blunt the body's key weapons in its fight against infection.

How our immune system backfires and allows bacteria like Salmonella to grow

February 6, 2014
Our immune system wages an internal battle every day to protect us against a broad range of infections. However, researchers have found that our immune response can sometimes make us vulnerable to the very bacteria it is ...

Recommended for you

Researchers developing new tool to distinguish between viral, bacterial infections

July 28, 2017
Antibiotics are lifesaving drugs, but overuse is leading to one of the world's most pressing health threats: antibiotic resistance. Researchers at the University of Rochester Medical Center are developing a tool to help physicians ...

Finish your antibiotics course? Maybe not, experts say

July 27, 2017
British disease experts on Thursday suggested doing away with the "incorrect" advice to always finish a course of antibiotics, saying the approach was fuelling the spread of drug resistance.

Co-infection with two common gut pathogens worsens malnutrition in mice

July 27, 2017
Two gut pathogens commonly found in malnourished children combine to worsen malnutrition and impair growth in laboratory mice, according to new research published in PLOS Pathogens.

Phase 3 trial confirms superiority of tocilizumab to steroids for giant cell arteritis

July 26, 2017
A phase 3 clinical trial has confirmed that regular treatment with tocilizumab, an inhibitor of interleukin-6, successfully reduced both symptoms of and the need for high-dose steroid treatment for giant cell arteritis, the ...

A large-scale 'germ trap' solution for hospitals

July 26, 2017
When an infectious airborne illness strikes, some hospitals use negative pressure rooms to isolate and treat patients. These rooms use ventilation controls to keep germ-filled air contained rather than letting it circulate ...

Researchers report new system to study chronic hepatitis B

July 25, 2017
Scientists from Princeton University's Department of Molecular Biology have successfully tested a cell-culture system that will allow researchers to perform laboratory-based studies of long-term hepatitis B virus (HBV) infections. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.