Detection of Protozoan Parasites in Wastewater by Molecular Methods in Corum Province

Abstract

Aim: Monitoring of pathogens in untreated wastewater has gained importance today. By investigating the pathogens in untreated wastewater with molecular methods and identifying their genotypes and subtypes, the characteristic features of transmission in the community and molecular surveillance of strains can be determined. In our country, protozoan parasites were frequently investigated in feces and surface water samples by simple conventional methods. Although there are many studies on the prevalence of these protozoa, data on their molecular epidemiology are limited. The aim of the study was to determine the prevalence and genotypessubtypes of Cryptosporidium, Giardia, Blastocystis, Entamoeba and Toxoplasma species in wastewater samples collected from Corum, Turkey. Methods: Untreated wastewater samples were collected from Çorum Municipality Waste Water Treatment Plant once a week for 32 weeks, between October 2019 and May 2020. Genomic DNAs were extracted to determine genotypic characteristics and the presence of parasites in wastewater samples was investigated by conventional and nested-PCR methods. The results obtained were confirmed by sequence analysis. Results: Blastocystis sp., Giardia intestinalis Assemblages A and Cryptosporidium parvum were detected 24 (75%), 9 (28,125%) and 2 (6.25%) respectively in 32 samples while Entamoeba and Toxoplasma species were not detected. Mixed subtypes were detected all of positive samples for Blastocystis sp. and all of the samples (24) were positive for ST1. ST3 (23) and ST2 (20) were the other prevalant subtypes. Neither ST5 and ST7 were detected. The incidence of parasites increased in April and May. Conclusion: There are only a few study indicating the presence of protozoons in wastewater samples by molecular methods in Turkey. C. parvum was detected at a lower rate than expected in our study. Although G. intestinalis Assemblages B is common worldwide, only G. intestinalis Assemblage A was detected but it is compatible with the data of our country. This is the first study on the investigation and subtype identification of Blastocystis sp., Entamoeba and Toxoplasma in wastewater samples in Turkey. As a result, our study revealed the dominant types of these protozoa in our province. Further molecular studies are needed in this regard.