A potential new antibiotic has been discovered by scientists scouring soil samples, which may be able to treat drug-resistant diseases and provide a solution to the antibiotic crisis we are already facing.
The rate at which new antibiotics are being developed is not keeping up with the ability of infectious disease to evolve to become resistant to the antibiotics we have. This is reaching crisis point, as we are seeing increasing numbers of drug-resistant strains of diseases, against which current antibiotics have no effect. There haven’t really been any completely new antibiotics discovered for several decades, so it’s no wonder the super bugs are outsmarting us. Apparently, scientists have been suffering from a lack of biodiversity in their efforts.
Meanwhile large numbers of people die each year from drug-resistant infections worldwide. Despite the wide availability of antibiotics, infectious diseases remain a leading cause of death. If we don’t quickly find new treatments, mortality rates due to drug-resistant infections are expected to increase tenfold by 2050. In the United States alone, an estimated 2 million people a year are diagnosed with infections that don’t respond to antibiotics, and 23,000 of them die as a result.
New hope for antibiotic research on ‘super bugs’
A small group of innovative scientists are tackling this problem in a unique way: the search for new antibiotics in our soil environment. The results of their study was published in Nature Microbiology journal in January 2018 and also featured in Time Magazine.
Most antibiotics these days are the result of lab tests and cultures based on already known antibiotic strains, but there are tens of thousands of bacteria in the soil, most of which are unknown to modern medicine. The researchers from Rockerfeller University in New York and New Jersey Medical School consider this a vast untapped potential, which should be exploited if we are to seriously address the crisis that already exists. The use of bacteria to discover new antibiotics had been largely abandoned, because it stopped yielding much new material, but these scientists believe this has been the fault of outdated lab methodology – the ‘culture-dependent’ approach.
In this new study, crude DNA was extracted from 1,985 soil samples from across the United States. Using unique DNA sequencing strategies, they set out to find genes that could result in antibiotic molecules. They were particularly interested in calcium-dependent antibiotics, a family of peptides (chains of amino acids) that require calcium for antibacterial activity. Calcium-dependent antibiotics have been shown to target either cell wall biosynthesis or cell membrane integrity. These gene clusters were cloned, sequenced and analysed, and compared to known antibiotics.
In searching for potential calcium-dependent antiobiotics, the team of researchers discovered malacidins, a distinctive new class of antibiotics that are commonly found in soil but have never been reported in natural culture-based discovery efforts.
The malacidins were shown to be effective against multidrug-resistant infections, and able to treat rats infected with methicillin-resistant Staphylococcus aureus (MRSA). This means that antibiotics derived from malacidins may be effective against multiple diseases that have become resistant to clinically used antibiotics, “including the antibiotic of last resort vancomycin”. Malacidins also did not select for resistance under laboratory conditions.
More research is needed to confirm these can be turned into a clinical drug, which could take several years, but it’s a very promising start.
“Environmental microbes are in a continuous antibiotic arms race”, that could help us overcome the problem of drug-resistance, and it turns out that the family of calcium-dependent antibiotics is much larger than previously thought.
While these new antibiotic discovery methods are still being fully developed, they may aid in the systematic discovery of more natural antibiotics that have been waiting under our noses to be discovered.
What’s causing the antibiotic crisis?
Antibiotic resistance is largely caused by over-prescription and overuse of antibiotics, as well as incorrect use of antibiotics, and the presence of antibiotics in animal-derived food products, due to intensive farming methods. The other problem, as mentioned above, is the stagnation of innovation in developing new antibiotics.
Some ways to be part of the solution are to eat organic meat and animal products; avoid taking antibiotics for a viral infection; avoid antibiotics for anything non-life threatening; eat fermented foods and probiotics to help build your natural resistance.
Searching for antibiotics in our soil is supported by the evidence that regular contact with soil helps strengthen the immune system. For example children growing up on farms, or in regular contact with healthy soil, show greater resistance to infection, because these microbes are introduced to the body naturally, allowing it to develop a natural antibiotic response.
One valid concern is that drug companies will only develop these medicines if they can see a profit in it. If antibiotics can be dug up in your back yard, will they have an incentive to develop them into drugs that potentially can’t be patented? The answer, of course, is that governments need to get involved in this research, so that the profit motive is not a factor in saving people’s lives.
