Optimization of methods for sanitary-microbiological and sanitary-parasitological control of wastewater
Authors: Zagaynova Angelika V. , Aslanova Mariya M. , Kurbatova Irina V. , Rakova Vera M. , Fedez Zlata E. , Pay Galina V. , Gritsyuk Olga V. , Pankova Marina N. , Novozhilov Konstantin A. , Abramov Ivan A. , Ivanova Polina A. , Nedachin Aleksandr E. , Avtonomova Anastasiya V. , Starodubova Nataliya Y. , Savostikova Olga N. 
Published: June 2022

Introduction. The main reason for the problems of surface reservoirs in many regions of Russia is the non-compliance with sanitary protection zones and the discharge of insufficiently treated wastewater into reservoirs. SanPiN 1.2.3685-21 introduced a list of the new controlled sanitary-microbiological and parasitological safety indicators for disinfected wastewater and surface water bodies. For some indicators, there are no methods of determination in the current methodological documents. In this work, studies were carried out using various methods, including accelerated ones, which make it possible to determine the normalized indicators in wastewater and surface waters. Goals and objectives - optimization of methods for the study of surface and wastewater in the implementation of sanitary-microbiological and sanitary-parasitological control. Materials and methods. Bacteriological, parasitological indicators, as well as coliphages were determined in samples of surface and wastewater. To detect and identify generalized coliform bacteria, E. coli, enterococci, P. aeruginosa and legionella, in addition to membrane filtration and direct seeding methods, test systems (IDEXX) were used: Colilert-18 and Colilert-24, Pseudolert, Enterolert, Legionelert. Obligate anaerobes of C. perfringens were cultured in an anaerobic box (Anaerobic Station A55, Don Whitley Scientific) in an atmosphere of a three-component gas mixture. Species identification of microorganisms was carried out by time-of-flight mass spectrometry (MALDI TOF MS) using a Microflex mass spectrometer with MALDI BioTyper software (Bruker, Germany). Isolation of RNA/DNA of viruses and bacteria was carried out using a set of reagents “AmpliSens. RIBOT-prep.” Results. As a result of the conducted studies, P. aeruginosa; E. coli, R. ornithinolytica, A. hydrophila, A. caviae, A. molluscorum; E. hirae, E. faecium, E.faecalis; C. perfringens; S. lutetiensis, S. suis were isolated and identified from wastewater at all stages of treatment, high fungal contamination was found, and also Group F adenovirus DNA (both in wastewater and surface water samples) and additionally rotovirus and norovirus RNA, Campylobacter DNA. SarsCov-2 virus RNA was not detected in any sample. Lamblia spp., Blastocystis spp. and Cryptosporidium parvum were identified; opportunistic Entamoeba spp.; helminth eggs - Toxocara spp., Hymenolepis diminuta, Hymenolepis nana, Asagis lumbricoides, egg oncospheres Tenia spp.; Nematodes spp. larvae. Limitations. Since clinically significant strains of bacteria, fungi, and parasitic protozoa were found in the studied water samples, it is important to expand knowledge about water sources as reservoirs and spreaders of these pathogens. Conclusion. Monitoring is now urgently needed to quantify pathogens circulating in surface water and wastewater.