Antibiotic resistance in European wastewater treatment plants mirrors the pattern of clinical antibiotic resistance prevalence

Integrated antibiotic resistance (AR) surveillance is one of the objectives of the World Health Organization global
action plan on antimicrobial resistance. Urban wastewater treatment plants (UWTPs) are among the most important
receptors and sources of environmental AR. On the basis of the consistent observation of an increasing northto-
south clinical AR prevalence in Europe, this study compared the influent and final effluent of 12 UWTPs located
in seven countries (Portugal, Spain, Ireland, Cyprus, Germany, Finland, and Norway). Using highly parallel quantitative
polymerase chain reaction, we analyzed 229 resistance genes and 25 mobile genetic elements. This first
trans-Europe surveillance showed that UWTP AR profiles mirror the AR gradient observed in clinics. Antibiotic use,
environmental temperature, and UWTP size were important factors related with resistance persistence and
spread in the environment. These results highlight the need to implement regular surveillance and control measures,
which may need to be appropriate for the geographic regions.