Molecular characterization of waterborne protozoa in surface water and sediment in Brazil: a taxonomic survey of ciliated protozoa and their correlation with Giardia duodenalis and Cryptosporidium spp.

Abstract

The detection of Giardia duodenalis and Cryptosporidium spp. was performed, along with the identi cation of the ciliated protozoa biodiversity, to evaluate the correlation between these protozoa in freshwater quality monitoring. Water and sediment samples from two sites in the Atibaia River (Campinas, São Paulo, Brazil) were collected monthly for two years (n = 96). Pathogenic protozoa in water and sediment were detected by using immunomagnetic separation, followed by visualization by immuno uorescence assay (IFA). All positive aliquots in IFA were subjected to DNA extraction and subsequently nested PCR. Qualitative (in vivo observation and silver impregnation) and quantitative (in vivo enumeration) analyses were performed for the ciliated protozoa. Giardia cysts were detected in 62.5% of the surface water samples and Cryptosporidium spp. in 25.0%. In the sediment, cysts were detected in 35.4% samples and oocysts in 16.6%. A total of 57 samples positive for Giardia cysts were subjected to sequencing, 40 of which were harboring G. duodenalis (24 were characterized as sub assemblage AII). For ciliated protozoa, 73 taxa belonging to 53 genera were identi ed over the period of the study. These results revealed a high degree of contamination by waterborne protozoa in the main water source which supplies drinking water for more than one million people in Campinas (São Paulo), highlighting the need for continuous monitoring of this catchment site. In addition, the present study provides important data regarding the sources of the water body degradation, i.e., fecal contamination of human origin, in addition to the survey of the ciliated protozoa.

Dairy wastewater treatment employing microencapsulated Pseudomonas aeruginosa on low acyl gellan gum

“…In Brazil, the membrane filtration technique is the most used alternative for the research analysis of Giardia spp. cysts in various water matrices (Rosado-García et al, 2017), being detected in raw and treated water from rivers (Scherer et al, 2022;Bonatti et al, 2023), treated sewage (Miglioli et al, 2017), marine and estuarine waters (Leal et al, 2018), and swimming pools (Pineda et al, 2020). However, this technique also presents limitations when used in highturbidity water samples (Coelho et al, 2017).…”

Water for Human Consumption in Rural Areas Worldwide: A Systematic Review of the Presence of <i>Cryptosporidium</i> spp. and <i>Giardia</i> spp.

“…The risk of contamination is significantly higher in surface waters when compared to underground waters, because of the spilling of treated and untreated domestic sewage (Bonatti et al, 2023;Cheng et al, 2009;Toledo; Martins; Freire, 2017) and the superficial water outflow containing bovine faeces (Escobar et al, 2022;Imre et al, 2017).…”