There's been quite a lot written on this blog over the years about the dangers that antibiotic resistant pathogens can pose to our healthcare. My concern is that we create many of these pathogens ourselves by allowing the overuse of antibiotics (as well as by producing thousands of "anti-microbial" consumer products). These practices have allowed large numbers of bacteria to mutate into new pathogens which are not easily killed off by our usual armada of drugs.
Now, it appears that Vancomycin resistant enterococci (VRE) have been found in sewage sludge, which is a by-product of waste-water treatment frequently used as a fertilizer. Researchers writing in the scientific journal Acta Veterinaria Scandinavica point out the danger of antibiotic resistance genes passing into the human food chain.
Leena Sahlström, from the Finnish Food Safety Authority (the equivalent of our FDA) worked with a team of researchers from the Swedish National Veterinary Institute to study sewage sludge from a wastewater treatment plant in Uppsala, Sweden. She said, “Antimicrobial resistance is a serious threat in veterinary medicine and human healthcare. Resistance genes can spread from animals, through the food-chain, and back to humans. Sewage sludge may act as one link in this chain”.
The researchers collected sludge from the plant every week for four months, for a total of 77 samples. Of these, 79% tested positive for the drug resistant superbugs. Although VRE themselves are not generally considered to be highly pathogenic, the danger is that they may pass on their resistance genes to other bacteria.
Sahlström and her colleagues conclude that there is a need for more efficient hygienic treatment of sewage sludge, in order to avoid this possibility of the pathogens spreading their antimicrobial resistance by being used as fertilizer on our food.