Antibiotic-resistant genes found in London canals and ponds

According to research conducted by UCL, freshwater sources in central London contain high levels of antibiotic-resistant genes, with the Thames having the largest amount.

The Regent Cbad, Regent's Pond Park and Serpentine contained all the genes, but at levels lower than those of the Thames, containing genes offering resistance to bacteria to antibiotics such as the penicillin, erythromycin and tetracycline.

The genes come from bacteria found in human and animal waste. When humans take antibiotics, much of the drug is excreted in the sewers and then into the freshwater sources. The presence of antibiotics in these water sources creates an environment in which microbes carrying resistance genes can multiply faster and share their resistance with other microbes.

Dr. Lena Ciric (UCL, Civil Engineering, Environment and Geomatics), responsible for the project, said: "This shows that it is necessary to continue research on the effectiveness of different methods of treating the disease. 39 water for the removal of antibiotics, none of the currently used treatments have been designed to incorporate it.

"This is particularly important in the case of water mbades in which we reject our treated wastewater, which still contains antibiotics.It is also important to look at the levels of antibiotics and resistant bacteria in our sources of drinking water. "

There is currently no legislation to eliminate antibiotics or resistant genes from water sources, which implies that antibiotics and resistant genes may be present in small amounts in drinking water although this would require testing.

The Thames is likely to contain higher levels of antibiotics and resistant genes, as a large number of wastewater treatment plants flow upstream and into London.

Antibiotics entering sewers are diluted by rinsing, but even low levels can encourage resistance genes to multiply and spread to more microbes.

The research team has developed a method based on DNA that can provide information on the number of each of the resistant genes per liter of water. They then compared the number of resistance genes in London's different water systems.

The team is currently experimenting with the removal of antibiotics, resistant bacteria and genes from the water collected in the natural water system in London, using slow sand filtration, a form of treatment drinking water.

This technique is used worldwide, including at the Coppermills treatment plant in Thames Water, which supplies drinking water for much of northeastern London. They study different filtration techniques, varying proportions of sand and activated carbon and different flow rates.