Antibiotic resistance can occur naturally in soil bacteria.

Scientists have found antibiotic-resistant bacteria in prairie soils that had little or no exposure to human or animal activity.U.S. Department of Agriculture (USDA) scientists have found antibiotic-resistant bacteria in prairie soils that had little or no exposure to human or animal activity. Antibiotics have effectively treated bacterial diseases for years, but some bacteria have developed resistance to the antibiotics that once killed them.Agricultural Research Service (ARS) researchers are investigating agriculture-related antibiotic resistance and developing solutions to address food safety, animal production and protection, and the environment. Part of their efforts involves looking at antibiotic resistance in soils. Antibiotic-resistant bacteria and antibiotic-resistant genes found in soils where manure was deposited by animals can provide valuable information about what is currently present in a sample site, such as a feedlot. However, the concern is that even if bacteria in manure are dead, their genes can persist in soils. The team examined native prairie soils that had little human impact and no animal grazing during the past 20 years. They collected soil samples from the sites and screened them for antibiotic-resistant bacteria. They found that all prairies contained bacteria that were resistant to tetracycline and cefotaxime -- two commonly prescribed antibiotics that treat a wide variety of infections -- and nearly half of the samples contained bacteria resistant to two or more antibiotics.