Antibiotic Resistance To Be Fought With New Drugs Found In Dirt
Antibiotic drugs have been used for the last 70 years to treat patients who have infectious diseases. Since the 1940s, they have greatly reduced illness and death. However, excessive antibiotic use is so prevalent that infectious organisms have adapted, making the drugs less effective.
Consequently, each year in the United States, at least 2 million people become infected with bacteria that are resistant to antibiotics. At least 23,000 people die each year as a direct result of these infections.
Antibiotic: Soil Is Healthy
It’s logical to consider soil and dirt as lifeless. But, in fact, soil is full of healthy microbial life. Indeed, many dirt-dwelling microorganisms may yield new powerful antibiotics that can destroy current resistant infections.
Recently, NIH-funded researchers discovered a new class of antibiotics, called malacidins (Latin for, “killing the bad”). They analyzed the DNA bacteria from more than 2,000 soil samples, from all across the United States. These compounds successfully killed several types of multidrug-resistant bacteria in laboratory tests. Most impressive was the ability of malacadins to wipe out the lethal highly drug resistant MRSA bacteria skin infections in rats. Often referred to as a “super bug,” MRSA threatens the lives of tens of thousands of Americans each year.
Antibiotic: New Powerful Malacidin Antibiotic Drugs
In the study reported in Nature Microbiology, researchers led by Sean Brady at The Rockefeller University, New York took a different approach. They scoured DNA extracted from trillions of soil-dwelling bacteria, most of them collected by citizen scientists living all around the country and mailed to Brady and colleagues in plastic baggies.
The researchers found novel clusters of genes that structurally resemble current look like calcium-dependent antibiotics. Calcium based antibiotics attack bacteria only in places where calcium is present to carry out basic cellular functions.
Antibiotic: Results Show Malacidins Effectively Fight Bacteria
The researchers found that Malacidin based compounds killed many multidrug-resistant pathogens, including several different strains of the deadly MRSA. They were also successful in treating a Staph-infected skin wound on rats, without causing any apparent toxicity or damage to the animals’ own cells.
Malacidins attack an essential part of the bacterial cell wall in a unique way compared to current calcium-dependent antibiotics. Their mechanism is unique, as it is difficult for other bacteria to circumvent. The researchers found that after 20 days of exposure to sublethal levels of malicidins, none of the tested lab bacteria showed signs of resistance.
Malacidins are just the start. Researchers believe the soil contains an untapped reservoir of antibiotics. Sophisticated tools will find them. This is great news, as a solution to the growing problem of antibiotic resistance may just be right in our own backyards.