COVID-19 Pandemic Modulates the Environmental Contamination Level with Enteric Bacteria from WWTPs

The Covid-19 pandemic was a challenge for the whole world and it had major second-ary effects on the health of the population and the environment. The viral infection caused, in many situations, secondary bacterial infections, especially enteric infections by destabilizing the balance of the gastrointestinal microbiota. The large-scale use of antibiotics and biocides both for curative and preventive purposes has determined an increase in bacterial resistance and at the same time the possibility of the multiplica-tion of pathogenic microorganisms and their transfer in natural environments. Wastewater is the main vector of faecal microorganisms that favour their dissemina-tion in natural aquatic ecosystems. The present paper represents a sub-study of the RADAR project with the aim of demonstrating the effect of the Covid-19 pandemic on the microbiological quality of wastewater from sewage treatment plants in Romania and its impact on receiving rivers. In order to highlight different and important areas of Romania, 3 cities from the east, center and west were selected for the evaluation of microbiological quality of influent and effluent sewage in WWTPs between ante-Covid-19 and the peak period of the Covid-19 pandemic, when the Covid-19 pandemic had a direct consequence on WWTPs processes. Our study showed the high-er contamination with fecal bacteria based on higher Covid-19 incidence. The in-creased usage of pharmaceutical compounds, at their turn, increased the number of resistant bacteria reaching the environment via WWTP effluents.