How Fertilizer Helps Bacteria Spread Antibiotic Resistance

A new study found that strains of drug-resistant bacteria can spread their antibiotic resistance to bacteria in soils.

Now recognized as a major global public health problem, antibiotic resistance saw its first manifestations with the emergence of bacterial strains resistant to many antibiotics in the late 1990s and early 2000s.

While the pharmaceutical industry is engaged in a race to develop increasingly potent antibiotics, the findings of a new study on soil bacteria may provide clues to fighting antibiotic resistant infections outside of the pharmacy.

How Animals are Pushing Towards Antibiotic Apocalypse?

Livestock are fed huge amounts of antibiotics to speed up growth and fight diseases.

It very well could be that the overuse of antibiotics in humans and animals is the main cause of rising antibiotic resistance.

As 2017 is coming to a close, we may have already hit a tipping point in superbugs’ antibiotic resistance, as farm animals are expected to be consuming more antibiotics than humans–who already consume too much.

And as animal antibiotics intake rises, given the size and scale of the meat industry, so will “superbugs” resistant to the most common and prevalent medications. As a result, our vulnerability to a slew of common bacterial infections will also rise.

With this troubling milestone reached, we’re getting closer to what experts have been calling antibiotic apocalypse.

Each year an estimated 700,000 people die worldwide of drug resistance in different bacterial diseases.

That figure is projected to soar up to 10 million deaths per year by 2050 if no new treatments or measures to curb antimicrobial resistance were available.

Bacteria can Pass on Drug Resistance Through Soil

Unfortunately, each new antibiotic that appears is followed by the emergence of new strains of bacteria that are resistant to it.

Bacteria not only adapt to survive antibiotics but they also share their resistance with their bacterial counterparts.

Antibiotic resistance can spread rapidly within the bacterial community, thanks to plasmids, DNA molecules that are separate from actual DNA. Plasmids contain the “antibiotic resistance genes”, which are easily shared among bacteria.

Siddhartha Thakur, an associate professor of population health and pathobiology at the College of Veterinary Medicine, have been studying antibiotic resistance and its spreading methods.

In his latest research, Thakur found that antibiotic resistance can be spread to soil bacteria through manure applied as fertilizer.

Thakur came to his conclusions after he studied soil samples from a swine farm and tested them for antibiotic resistant strains of salmonella before the manure was spread.

Three weeks after the manure application, drug-resistant salmonella was still present. Thakur also found that a particular plasmid associated with this strain of salmonella has showed up in other salmonella serotypes that were all resistant to antibiotics at this time.

“This tells us that this particular plasmid is shuttling across different serotypes,” said Thakur. “It could explain why we find antibiotic resistant salmonella strains even on farms that don’t use antibiotics. It seems that once antibiotic resistance takes hold, it doesn’t go away. These bacteria are simply better equipped to survive and so they prosper.”

The findings of the study were published in the journal Applied and Environmental Microbiology.

Do you know anyone who has been affected by antibiotic resistance?