Development of a simple and low-cost method using Moringa seeds for efficient virus concentration in wastewater

Effective virus concentration methods are essential for detecting pathogenic viruses in environmental waters and play a crucial role in wastewater-based epidemiology. However, the current methods are often expensive, complicated, and time-consuming, which limits their practical application. In this study, a simple and low-cost method was developed using the extract of Moringa oleifera (MO) seeds (MO method) to recover both enveloped and non-enveloped viruses, including pepper mild mottle virus (PMMoV), murine norovirus (MNV), Aichivirus (AiV), murine hepatitis virus (MHV), and influenza A virus subtype H1N1[H1N1] in wastewater. The optimal conditions for the MO method were determined to be a concentration of MO extract at the UV₂₈₀ value of 0.308 cm^-1 and an elution buffer (0.05 M KH₂PO₄, 1 M NaCl, 0.1 % Tween80 [v/v]) for recovering the tested viruses in wastewater. Compared to other commonly used virus concentration methods such as InnovaPrep, HA, PEG, and Centricon, the MO method was found to be more efficient and cost-effective in recovering the tested viruses. Moreover, the MO method was successfully applied to detect various types of viruses (PMMoV, AiV, norovirus of genotype II [NoV II], enterovirus [EV], influenza A virus [matrix gene] [IAV], and SARS-CoV-2) in raw wastewater. Thus, the developed MO method could offer a simple, low-cost, and efficient tool to concentrate viruses in wastewater.