Newly-Discovered Bacteria Found To Cause Lyme Disease

A new species of bacteria – capable of causing Lyme disease – has been discovered by scientists at the Mayo Clinic in Minnesota. The bacterium was isolated from six patients showing symptoms of the illness, and was found to be very closely related to a bacterial strain that commonly causes Lyme disease, known as Borrelia burgdorferi.

Named Borellia mayonii as a tribute to the founder of the Mayo Clinic, Dr. William Mayo, the bacterial infection causes similar symptoms – including headache, fever, neck pain and rash – as those characteristic of Lyme disease. The new bacteria was discovered using genetic testing at the Centers for Disease Control and Prevention (CDC), and the researchers published their results in the journal, Lancet Infectious Diseases.

Lyme disease is the most common vector-transmitted disease in the US, and is passed to humans from blacklegged (deer) ticks. If left untreated, early symptoms of infection can worsen to arthritis in the joints.

While B. mayonii shares many similarities to B. burgdorferi, there are a few symptom-related differences between the two. Unlike B. burgdorferi, B. mayonii may cause nausea and vomiting and its associated rash is more diffuse compared to the typical “bull’s eye” rash pattern seen in patients infected with B. burgdorferi.

“This discovery adds another important piece of information to the complex picture of tick-borne diseases in the US,” said Dr. Jeannine Peterson, a microbiologist at the CDC. The new species was identified when researchers analyzed 9,000 blood samples taken from residents of Wisconsin, North Dakota and Minnesota with suspected cases of Lyme disease, and found that six sample contained a DNA signature that was distinct from that of B. burgdorferi.

The genetically distinct DNA sequences allowed the scientists to discover the previously unknown bacterial species. According to the researchers, B. mayonii has been isolated from blacklegged ticks in northwestern Wisconsin, therefore north central Minnesota and western Wisconsin are considered to be likely areas of exposure.

Dr. Bobbi Pritt, director of the Clinical Parasitology Laboratory at the Mayo Clinic, said it could be that the bacterial species has just begun to show up in the upper Midwest, however it “is possible that this species has been present for even longer but at such low levels that it escaped detection.” Despite the risk of contracting Lyme disease from the new bacterial strain, the researchers say that the same PCR-based test used to identify B. burgdorferi will also work to diagnose infection with B. mayonii.

In addition, the antibiotics used to treat traditional Lyme disease will also be effective against the new pathogen. “The public should continue to take the recommended precautions against tick bites, as Lyme disease and other tick-borne diseases are well-established in much of the Northeast,” said Pritt.