Researchers surveyed 20 municipal wastewater plants in England, and isolated drug-resistant E. faecium from all sites in untreated and treated wastewater plants which use ultraviolet light disinfection.
Drug-resistant bacteria have the ability to resist the effects of medication that could successfully treat the microbe. Resistant microbes are more difficult to treat, requiring alternative medications or higher doses of antimicrobials. A team of researchers chose 20 wastewater plants for survey and found these drug-resistant E. faecium bacteria in large numbers in untreated wastewater from plants that were directly received hospital sewage. E. faecium is a gram-positive, facultative anaerobic organism. These organisms are generally harmless in healthy people, but can be particularly harmful to ill patients with a weakened immune system. The E. faecium can cause a variety of infections, which include infections of the bloodstream, urinary tract infections (UTI), and wound infections associated with catheters or surgery.
Researchers first isolated strains of the bacterium Enterococcus faecium (E. faecium) from all treated and untreated wastewater plants. Comparison of the E. faecium isolates from wastewater and bloodstream isolates of infected patients demonstrated close genetic connection between the two. Further analysis revealed the presence of shared antibiotic, metal, and biocide resistance genes in isolates from bloodstream, hospital sewage, and municipal wastewater.
The study found close genetic connection of drug-resistant E. faecium isolates released into the environment with the ones causing serious human disease. Researchers say that further research is required in order to determine the implications on public health resulting from exposure to healthcare and pathogens related to waste. Terminal ultraviolet light disinfection of wastewater is a possible solution for lowering environmental contamination with drug-resistant bacteria.