Molecular detection and genotyping of group A rotavirus in two wastewater treatment plants, Iran

In different countries especially developing countries, treatment of urban wastewater might be ineffective removal of pathogens such as group A rotavirus. The objective of this study is to evaluate the efficiency of rotavirus removal in two wastewater treatment plants (WWTPs) in Isfahan, Iran. To meet the study objectives, 96 sewage samples from influent (n = 48) and final effluents (n = 48) were collected by grab sampling. Two different concentration methods included pellet and two-phase used for concentrating sewage samples. The presence of rotavirus antigens in all concentrated sewage samples was screened by enzyme-linked immunosorbent method. To analyze the study samples, real-time PCR technique with SYBR Green I fluorescent dye and nested multiplex PCR for rotavirus genotyping were utilized respectively. Result indicated positive rotavirus percentage in two methods of ELISA and real-time PCR was equal to 61.45% (59 cases) and 44.79% (43 cases). In addition, analyzing seasonal distribution of rotavirus shows different distributions as below: in spring (18.64%), summer (20.33%), autumn (35.60%), and winter (25.42%). Finally, rotaviruses illustrate significantly higher frequency in cold seasons. G10 and G1 types are considered the most, among common genotypes which identified in 11 (25.58%) and 5 (11.62%), out of the 43 positive samples in WWTPs, followed by non-typeable genotypes (13.95%) and mix genotypes (11.62%); and different genotypes including G2, G3, G4, G8, G9, and G12 were equal to 2.33, 9.30, 9.30, 2.33, 7, and 7% in the WWTPs, respectively. Such high prevalence underlines the significance of environmental surveillance. Also, to eliminate potential pathogens especially enteric viruses from sewage, the improvement of treatment systems is essential.