Researchers at East Carolina University are interested in identifying the genes that enable Lyme disease causing bacteria to move from host to host. Their findings could eventually lead to the development of an antimicrobial medication for the disease.
It’s summer and if working in your yard or enjoying the outdoors, there’s a chance you’ll encounter a tick. These tiny, blood sucking arachnids are a vector for a number of diseases, but the most common is Lyme disease. There’s currently no cure and the disease can often be misdiagnosed. But there's research underway at East Carolina University in Greenville may change the way doctors treat patients with Lyme disease.
While rarely fatal, the illness can be highly debilitating causing flu-like symptoms and a characteristic “bullseye” skin rash. Entomologist with the State Division of Public Health Dr. Alexis Barbarin said symptoms can occur within two to 30 days of a tick bite.
“In the very early stages, they’ll have headaches, fatigue, myalgia or muscle soreness, arthralgia or arthritis and joint soreness.”
If left untreated, the infection can cause neurological disorders and cardiac abnormalities. Lyme disease was discovered in Lyme, Connecticut in the late 70’s and has since been moving farther south.
“But we are seeing an increase in Lyme disease numbers in North Carolina. So last year, we had 293 confirmed and probable cases of Lyme disease and that was in 2017, which is higher than the five-year average of cases.”
The majority of cases in North Carolina are in the western part of the state near the Virginia and Tennessee border. In eastern North Carolina, Pasquotank, Washington and Dare counties have the highest incidence of Lyme disease. Barbarin reasures not all ticks carry Lyme disease.
“The primary vector in our area or in our region of the U.S. is Ixodes scapularis, which is also called the deer tick or the black legged tick.”
When a person is bitten by an infected tick, it takes about 24 hours for the Lyme disease causing bacteria to be transmitted. But survival isn’t an easy task for the bacteria. They’ve had to adapt to protect themselves against the human immune system by altering gene expression and using mobility. Now, there’s a team of researchers at East Carolina University who want to identify the specific genes that relate to the bacteria’s movement in order to stop them.
“We injected the Lyme disease causing bacteria in mouse’s skin. And I show you how they move.”
Associate Professor in the Department of Microbiology and Immunology at the Brody School of Medicine Dr. MD Motaleb showed me a video recorded under a microscope of tiny, spiral-shaped bacteria.
"And here is the bacteria that is swimming in live mouse's skin."
The bacteria use whip-like appendages called flagella to move, he explained.
“They move like eels or snakes.”
The laboratory is also stocked with hundreds of tiny ticks the size of poppy seeds.
“We have the deer ticks in the lab that we can infect them - intentionally infect them with the mutated bacteria and then use those infected tick to see the transmission to mouse.”
The team is testing dozens of genetic mutations in bacteria to determine if they can inhibit transmission of Lyme disease.
"And we believe that there are many of them that still needs to be discovered, but we know how to find them."
Motaleb received a four-year $1.7 million grant from the National Institutes of Health for the project. If researchers are successful, their findings could one day lead to the development of an antimicrobial medication for Lyme disease.
“If they cannot transmit from one host to another, you don’t have to worry about Lyme disease anymore.”
Until then, the way doctors diagnose and manage Lyme disease will remain a debated issue. According to the Centers for Disease Control, Lyme disease is diagnosed based on symptoms, physical findings and the possibility of exposure to infected ticks. Lab tests which identify antibodies to the bacteria taken a couple of weeks after an infection can often be unreliable. Professor of Medicine at Brody School of Medicine Dr. Paul Cook.
“Unfortunately, the testing for Lyme disease is not very good. So what we commonly get are positive test results in a patient who really doesn’t have Lyme disease.”
Cook said physicians must consider how the patient got the tick bite, if they were in an endemic area or not, and what symptoms they’re experiencing. He cautions no one indication – even the bullseye rash – is enough to diagnose a patient with Lyme disease.
“There’s a similar rash that is seen in the south called Southern Tick Associated Rash Illness, or STARI, which causes a virtually identical rash. If we see that identical rash in North Carolina, it’s actually much more likely to be STARI than it is to be Lyme disease.”
Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. July and August are the peak times for contracting the illness. The best way to prevent Lyme disease is to stay out of wooded areas and use insect repellants. It’s always a good idea to check yourself for ticks after you spend time outdoors.
