Blog | Friday, May 29, 2009

Superbug threat lurks in sewer

The threat of antibiotic resistance is attributed mainly to the overprescribing and overuse of antibiotics, but a new study explores a new, often-overlooked, danger: sewage sludge.

The study, by the Swedish National Veterinary Institute and the Finnish Food Safety Authority and published in the journal Acta Veterinaria Scandinavica, analyzes vancomycin-resistant enterococci (VRE) found in sewage sludge from a waste-water treatment plan. Researchers performed the unenviable task of collecting sludge from the plant weekly for four months and found that 79% of the 77 samples tested positive for drug-resistant superbugs. The danger, the researchers noted, is that VRE may pass on resistant genes to other bacteria.

Since sewage sludge is often used as fertilizer, its use threatens to spread antimicrobial resistance throughout the animal and human food chains, researchers warned. More efficient hygienic treatment of sewage sludge, they concluded, must become another weapon in the public health arsenal against superbugs.