New Hope for Antibiotic Resistance in Humans and Pets
In August of last year I posted about the growing threat of antibiotic resistant bacteria to worldwide health. This topic is so important that it is increasingly seen as the biggest problem for human and veterinary doctors in the not too distant future.
One of the contributors to bacterial resistance has been that there has not been a new class of antibiotics introduced in over 30 years. Research, government regulations, and economic forces have all played a role in this lack of scientific investigation. That may all have changed now that a new class of bacteria was discovered in the back yard of a microbiologist.
Bacteria, Fungus, and Antibiotics
Most of us are unaware that the miracle we call antibiotics are produced by bacteria and fungus. These microbes have been producing antibiotics for billions of years to protect themselves from other bacteria and fungi. But we were not aware of these life-saving properties of microscopic bugs until Alexander Fleming showed that a common mold inhibited the growth of Staphylococcus in a petri dish in 1928. Fleming had discovered penicillin. It would not be until the late 1940s that penicillin could be mass produced and used to treat wounded American soldiers during World War II and the Korean War.
Think about this. Doctors and veterinarians had no antibiotics to treat disease until the early 1950s. Antibiotics have only been a part of medical and veterinary therapy for 60 years. Antibiotics were introduced only 29 years before I started practicing veterinary medicine. I can’t imagine being a veterinarian during the times of James Herriot and treating animals without the benefit of antibiotics. After the amazing discovery of penicillin, the medical power of bacteria and fungi was released. In this short period of time we now have 20 different classes of antibiotics from different bacteria and fungi.
What is a class of antibiotics? A class of antibiotics has a specific molecular structure and is from a particular group of bacteria or fungus that targets a specific group of disease-causing bacteria. New classes of antibiotics have given us medical practitioners multiple weapons to fight disease. With the 30 year drought in new antibiotic discovery and the overuse of antibiotics during that time, disease causing bacteria have become resistant to this vast arsenal of drugs. Diseases once again have the better poker hand.
The New Bacteria and New Antibiotics
Bacteria and other microbes are finicky and refuse to grow in laboratories. That is why microbiologists have found antibiotics from only 1% of wild microbial species. The other 99% won’t bend to our laboratory will. But some scientists have found a work-around. By collecting soil samples from the backyard of a colleague, scientists used a technology to individually identify bacteria and then return them to the soil to multiply in their own habitat rather than in the lab. They were able to produce large colonies of a soil bacterium called Eleftheria terrae that uses the secret weapon teixobactin to protect itself from other bacteria.
It turns out that teixobactin is a triple threat against disease causing bacteria. It destroys many types of drug-resistant bacteria, it is safe to use in any mammal, and bacteria cannot easily develop resistance to it.
Teixobactin kills other bacteria by destroying their cell wall. Many present day antibiotics kill bacteria by the same method of cell wall destruction. But the way teixobactin does it makes it difficult for bacteria to develop resistance and avoid destruction like they do with other antibiotics.
The scientists chose the toughest treatment test for teixobactin. They infected mice with a fatal dose of MRSA (flesh eating Staphylococcus that is resistant to virtually every antibiotic). The mice were injected with teixobactin one hour after the MRSA infection. Every mouse survived.
The exciting part of this discovery is not just the finding of teixobactin, but the new technology that allows the cultivation of bacteria in their own habitat. Scientists will be able to work with a far greater percentage of Earth’s microbes; this will open possibilities far beyond teixobactin. Man may once again control disease-causing bacteria for the long term — with help from our own backyards.
Dr. Ken Tudor