Processing Magazine

Research finds antibiotic-resistant bacteria in municipal wastewater

May 29, 2014

Municipal sewage systems carrying wastewater from hospitals and private homes release antibiotic-resistant bacteria into the environment, contributing to the emerging drug-resistance problems, new research by a team of academics at the Universite de Franche-Comte in Besancon, France has suggested.

Drug residue in wastewater creates antibiotic resistance in many types of bacteria, including E. coli, and this makes many drugs inefficient and many diseases hard to treat. Moreover, because resistance is spread through water it passes on to crops as well, according to study author Xavier Bertrand, quoted by Reuters. However, he also pointed out that the study cannot determine the extent to which the presence of E. coli in wastewater contributes to the global spread of the bacteria.

The team of researchers based their study on samples from 11 sites in Besancon's wastewater system taken once a week over a period of 10 weeks. Most of the sites contained wastewater from the city, whereas two of the sites contained water from university hospitals. A small proportion of the samples was taken at sites with rainwater, but livestock farming wastewater was not included in the study.

Results showed that every single sample contained E. coli and 96 percent of the samples had antibiotic-resistant strains. After treating water to an extent to make it safe to be released into the environment, the level of antibiotic-resistant E. coli fell by 94 percent, Reuters said.