According to Professor Hazel Barton, bacteria found in caves may hold the key to developing new antibiotics that can target drug-resistant bacteria.
Antibiotics are more complicated in structure than anti-viral or even anti-cancer drugs. The reason is that antibiotics' chemical structure resembles that of a spider web, using chemical keys to fit inside the molecular locks of bacteria and destroy the cells from the inside. Because of the complexity of their structure, function, and design, scientists most often turn to nature to design and make them. In fact, of the myriad of antibiotics on the market today, a whopping 99 percent of them come from microorganisms, particularly bacteria and fungi in soil.
Unfortunately, those soil-dwelling organisms are starting to run out, forcing researchers to examine microbes from more extreme and exotic environments.
Hazel Barton has turned to cave bacteria precisely because of their extreme, isolated environments. There, bacteria have needed to adapt over millions of years to threats such as perpetual famine, no sunlight and a lack of micronutrients to eat. In fact, the laboratory environment for many of these bacteria is too rich. One microbe she described was able to survive by eating the plasticizers that come out of the plastic of lab dishes.
Importantly to the study and development of new antibiotics, Barton and her colleagues tested the organisms for antibiotic compounds. In a single sample, the microbes produced 38 antibiotic compounds. To compare, less than 100 antibiotics have ever been identified in nature. This single sample produced a third as many.
Barton believes the explanation for the microbes' prowess lies in caves' isolation. With a limited amount of resources, microbes are forced into deadly competition. Many kill one another to be in a better position. Barton tested the organisms and found that they were resistant to each antibiotic to which they were exposed, even though they had certainly never come into contact with manmade antibiotics before. One was resistant to 14 antibiotics, and researchers were able to identify one mechanism of antibiotic resistance that they never had seen before.
Barton believes that this resistance to antibiotics means that we will never win against bacteria as long as we misuse antibiotics. Hopefully, the discovery of new species of microbes, such as the ones described, will lead us to new drugs.