A chemical has been found to be deadly to the bacteria that cause Lyme disease, and harmless to other bacteria and animals. This drug may be able to eradicate the disease in its entirety.
An American research team has tested the chemical hygromycin A in mice with the Lyme disease. The drug was found to kill the bacteria that cause the disease, without harmful side effects for the mice themselves. This is hopeful news, because it could potentially displace Lyme in its entirety.
‘Lyme disease is a good candidate for eradication,’ emphasizes molecular microbiologist Kim Lewis from Northeastern University in Boston. ‘We are ready for the first field studies, which will start next summer.’
Lyme disease is caused by bacteria of the species Borrelia burgdorferi, which are mainly found in wild mice. Ticks that feed on these mice become infected and can subsequently infect other animals, including humans.
The disease is an increasing problem in North America, Europe and Asia. When you are bitten by a tick that carries Lyme disease, you first get a rash. A red ring forms around the place where you were bitten, and you may feel the flu. If you don’t get treated, you could have problems for a long time to come. This way the bacteria can spread to your connective tissue and cause Lyme arthritis here.
The treatment of Lyme disease now consists of a course of broad-spectrum antibiotics, such as doxycycline, which kill a wide range of bacteria. They also kill the bacteria that reside in your gut, you gut microbiome, which can cause a whole host of new disease symptoms, including diarrhea. Such a non-specific course of antibiotics can also lead to the development of antibiotic resistance.
Lewis’s team found during the study that the chemical hygromycin A was quite effective at killing the strain of bacteria that B. burgdorferi belong, called spirochetes. Spirochetes are shaped like a corkscrew and can literally burrow into tissue. “They’re pretty nasty pathogens,” says Lewis. This strain of bacteria also causes diseases such as syphilis, for example.
Hygromycin A is no stranger to the fight against bacteria, Lewis says. In the 1980s, the drug was also investigated as a possible treatment for a disease in pigs, but it was eventually abandoned. The drug may also be used against syphilis, especially because this bacterial infection is less and less responsive to standard treatments.
The hygromycin A treatment used in this study had no harmful side effects for the mice – no matter how high the dose. “It’s incredibly safe, that doesn’t happen often,” said Lewis.
In addition to giving the drug directly, the research team also added it to the food of the infected mice. The drug also proved successful in killing B. burgdorferi-bacteria. In theory, this could mean that placing this food in natural areas could eradicate Lyme disease there.
A similar field study was done ten years ago, but then with food to which doxycycline had been added. The study turned out to be very successful, Lewis says. However, it is not desirable to spread this agent in nature, because many micro-organisms could develop antibiotic resistance in this way.
Lewis’s research suggests that it is very difficult for B. burgdorferibacteria to develop resistance to hygromycin A. The drug is very similar to important nutrients that the bacteria cannot produce themselves. So they have to absorb these nutrients from their environment. They have a specific transporter for this in their cell membrane. Mutations in this transporter therefore also block the supply of these nutrients.
Although there are currently vaccines against Lyme disease developed, it would of course be better to eradicate the disease in its entirety. The company FlightPath is now preparing the papers in the US to get permission to test the drug in humans.