Infectious diseases kill roughly 13 million people worldwide, annually, a toll that continues to rise, aided and abetted by resistance genes. Now a study, published in the March 2012Â issue of Antimicrobial Agents and Chemotherapy finds reservoirs of resistance in agricultural soils. These contained more diverse populations of drug-resistant bacteria, with greater levels of resistance, than composted and forest soils. Vegetable garden soil alone harbored multidrug-resistant bacteria, and also had the highest level of resistance to three major antibiotic classes.
"The observations of this study point to the widespread presence of high level antibiotic-resistant bacteria in agricultural soils," says first author Magdalena Popowska, of the University of Warsaw, Poland.
Antibiotics, and resistance genes thereto, occur naturally in soil due to the arms race between microbial species competing for territory. "Almost 50 percent of Actinomycetes isolated from soil are capable of synthesizing antibiotics, which provide a natural antibiotic residue in soils," says Popowska. But the use of antibiotics to promote livestock growth boosts the resistance to a whole new level, as demonstrated by the differences in resistance level in agricultural and forested soils, she says. Manure from antibiotic-fed animals exacerbates the resistance spread, as demonstrated by the high levels in the manure-amended vegetable garden soils.
The spread of resistance and multi-resistant strains of pathogens and opportunistic bacteria that can infect humans and animals is aided and abetted by the fact that they are frequently carried on mobile genetic elements, notably plasmids and transposons, that can be transferred not only among bacteria of the same species, but among different species, says Popowska.
The results of this study "should assist in the development of regulations regarding the use of antibiotics in the broader environment e.g. in plant protection products fish farming, and industry," says Popowska. "We think they will also help optimize methods allowing the combating of emerging bacterial infections, as well as in the development and application of new chemotherapeutic agents."
The use of antibiotics "should be restricted to dangerous bacterial infections, and to strict medical supervision," says Popowska. "This cannot be emphasized strongly enough."
Reference: Popowska M, et al. Influence of soil use on prevalence of tetracycline, streptomycin, and erythromycin resistance and associated resistance genes. Antimicrobial Agents and Chemotherapy 56:1434-1443. 2012.
I Was There: An Infection Preventionist on the COVID-19 Pandemic
April 30th 2025Deep feelings run strong about the COVID-19 pandemic, and some beautiful art has come out of those emotions. Infection Control Today is proud to share this poem by Carmen Duke, MPH, CIC, in response to a recent article by Heather Stoltzfus, MPH, RN, CIC.
From the Derby to the Decontam Room: Leadership Lessons for Sterile Processing
April 27th 2025Elizabeth (Betty) Casey, MSN, RN, CNOR, CRCST, CHL, is the SVP of Operations and Chief Nursing Officer at Surgical Solutions in Overland, Kansas. This SPD leader reframes preparation, unpredictability, and teamwork by comparing surgical services to the Kentucky Derby to reenergize sterile processing professionals and inspire systemic change.
Show, Tell, Teach: Elevating EVS Training Through Cognitive Science and Performance Coaching
April 25th 2025Training EVS workers for hygiene excellence demands more than manuals—it requires active engagement, motor skills coaching, and teach-back techniques to reduce HAIs and improve patient outcomes.
The Rise of Disposable Products in Health Care Cleaning and Linens
April 25th 2025Health care-associated infections are driving a shift toward disposable microfiber cloths, mop pads, and curtains—offering infection prevention, regulatory compliance, and operational efficiency in one-time-use solutions.