The virus SARS-CoV-2, which has caused the recent COVID-19 pandemic, may be present in the stools of COVID-19 patients. Therefore, we aimed to detect SARS-CoV-2 in wastewater for surveillance of SARS-CoV-2 in the population. Samples of untreated wastewater were collected from 33 wastewater treatment plants (WWTPs) of different sizes within the Czech Republic. SARS-CoV-2 RNA was concentrated from wastewater and viral RNA was determined using real-time reverse transcription polymerase chain reaction (RT-qPCR). SARS-CoV-2 RNA was detected in 11.6% of samples and more than 27.3% of WWTPs; in some of them, SARS-CoV-2 was detected repeatedly. Our preliminary results indicate that an epidemiology approach that focuses on the determination of SARS-CoV-2 in wastewater could be suitable for SARS-CoV-2 surveillance in the population.

Antibiotic resistance has become a global threat in which the anthropogenically influenced aquatic environment represents not only a reservoir for the spread of antibiotic resistant bacteria (ARB) among humans and animals but also an environment where resistance genes are introduced into natural microbial ecosystems. Wastewater is one of the sources of antibiotic resistance. The aim of this research was the evaluation of wastewater impact on the spread of antibiotic resistance in the water environment. In this study, qPCR was used to detect antibiotic resistance genes (ARGs)—blaCTX-M-15, blaCTX-M-32, ampC, blaTEM, sul1, tetM and mcr-1 and an integron detection primer (intl1). Detection of antibiotic resistant Escherichia coli was used as a complement to the observed qPCR results. Our results show that the process of wastewater treatment significantly reduces the abundances of ARGs and ARB. Nevertheless, treated wastewater affects the ARGs and ARB number in the receiving river.

We studied the differences in a microbial community structure with respect to the water pollution level and seasonal changes. The determination of phylogenetic groups of Bacteria and Archaea was done using fluorescent in situ hybridization (FISH). The total number of microorganisms was determined by direct counting of DAPI (4′,6-diamidino-2-phenylindole) stained samples using a fluorescence microscope. Our results showed that the microbial community structure was significantly dependent on the level of water pollution, both in absolute microbial counts and in relative abundance of phylogenetic groups. For surface water with anthropogenic pollution, the microbial community with significant proportion of Betaproteobacteria and Cytophaga-Flavobacterium was characteristic. Gammaproteobacteria were significant in municipal waste water. In microbial communities with low numbers of microorganisms (e.g. non-polluted water and some industrial waste water) represented the significant component groups Alphaproteobacteria and Archaea. The impact of seasonal changes on the microbial distribution was not significant.

• The only long-term WBE in Czechia was performed during all COVID-19 waves. • Trends in SARS-CoV-2 RNA concentration reflect COVID-19 burden in the population. • SARS-CoV-2 RNA concentration correlate well with clinical data. • Poor relationship between wastewater parameter levels and viral load was observed. • WBE showed predictive potential for public health surveillance.

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, the scientific journal of the Mendel University in Brno, Czech Republic