Detection and molecular identification of human adenoviruses and enteroviruses in wastewater from Morocco

Aims: Reclaimed wastewater is a considerable water resource in Morocco. Its agricultural reuse requires an assessment of viral contamination. The aim of this study was to detect both infectious and noninfectious human adenoviruses (HAdV) and enteroviruses (EV) in raw wastewater and treat effluent from wastewater treatment plants (WWTPs) and domestic sewage in Morocco. Methods and Results: A total of 22 samples were analysed. A polyethylene glycol (PEG) precipitation method was used, followed by integrated cell culture-PCR (ICC-PCR) using two cell lines: human rhabdomyosarcoma tumour tissue and laryngeal carcinoma cells (RD and Hep2 cells). Furthermore, viral genome amplification was confirmed by sequencing. HAdV were detected in 10 (45.5%) of the 22 samples involving two species: HAdV-B and HAdV-D. EV was detected in 5 (23%) samples belonging to Coxsackievirus B5 and poliovirus vaccine strain (Sabin 2). Conclusions: Human adenoviruses and EV were detected in the analysed samples from two WWTPs and HAdV in domestic sewage. Significance and Impact of the Study: This work is the first study in Morocco using cell culture, PCR and sequencing of enteric viruses from wastewater. The presence of infectious HAdV and EV in treated effluent emphasizes the need of wastewater treatment surveillance.