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

Abstract

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.

Comparison of Two Virus Concentration Methods for Enteric Viruses Detection in Moroccan Wastewater and Treated Effluent

“…The results correlate with those obtained in our previous study, in which we have detected more HAdV than HEV using the PEG precipitation method (26) . The same results were obtained by Kokkinos et al, 2010 (4) when the ultracentrifugation method was used, with 40% (10/25) rate of EV and HAdV, and 4% (1/25) of HAV.…”

“…In previous study (26) , we have seen a decrease in infectious viruses in treated effluent for EV and HAdV in 11.5% (1/9) and 22.5% (2/9), respectively. Otherwise, Hewitt et al, 2011 (43) reported that the rate of positive treated effluents samples from activated sludge WWTP has decreased to half for HAdV and quarterback for EV.…”

“…To explain the simultaneously negative and positive results of the CC and PCR, This could be due to that during the transport and treatment of wastewater, some viral particles undergo alterations that reduce their infectivity in vitro which decrease the positive samples by CC (22) . The inactivation of viruses could be caused by virus contact with wastewater treatment lagoons sides or natural inactivation by sunshine (26) . To increase the sensitivity of the cell culture, the ICC-PCR has been widely used for the detection of EV, HAdV, HAstV and HAV from environmental samples (36,42) .…”

Environmental Surveillance of Poliovirus in Sewage Water around the Introduction Period for Inactivated Polio Vaccine in Japan

“…Environmental surveillance is a highly sensitive method for detecting enteroviruses such as PVs in environmental samples, and this practice has been adopted by many countries and regions worldwide (13)(14)(15)(16)(17)(18)(19). It is critically important to routinely monitor sentinel sites for the emergence of novel VDPV strains and the importation of wild PV from countries where the disease is endemic.…”

Polioviruses and other Enteroviruses

“…Integrated cell culture and PCR (i.e., ICC-PCR) developed in the late 1980s still provides a reliable method for practical analysis and direct monitoring of environmental samples for EVs and other viral pathogens recovered from environmental samples (Amdiouni et al, 2012;Chapron et al, 2000;Choo and Kim, 2006;Lee et al, 2005;Reynolds, 2004;Reynolds et al, 1996). More recently, these techniques have been used in combination with viral metagenomics approaches for cell culture evaluation of the virologically quality of wastewater (Aw et al, 2014).…”