Viruses in the environment – presence and diversity of bacteriophage and enteric virus populations in the Umhlangane River, Durban, South Africa

Abstract

Due to the continued persistence of waterborne viral-associated infections, the presence of enteric viruses is a concern. Notwithstanding the health implications, viral diversity and abundance is an indicator of water quality declination in the environment. The aim of this study was to evaluate the presence of viruses (bacteriophage and enteric viruses) in a highly polluted, anthropogenic-influenced river system over a 6-month period at five sampling points. Cytopathic-based tissue culture assays revealed that the isolated viruses were infectious when tested on Hep-G2, HEK293 and Vero cells. While transmission electron microscopy (TEM) revealed that the majority of the viruses were bacteriophages, a number of presumptive enteric virus families were visualized, some of which include Picornaviridae, Adenoviridae, Polyomaviridae and Reoviridae. Finally, primer specific nested polymerase chain reaction (nested-PCR)/reverse transcription-polymerase chain reaction (RT-PCR) coupled with BLAST analysis identified human adenovirus, polyomavirus and hepatitis A and C virus genomes in river water samples. Taken together, the complexity of both bacteriophage and enteric virus populations in the river has potential health implications. Finally, a systematic integrated risk assessment and management plan to identify and minimize sources of faecal contamination is the most effective way of ensuring water safety and should be established in all future guidelines.

Global public health implications of human exposure to viral contaminated water

“…According to Rodriguez-Lazaro et al (2012) , HAV can subsist for about 60 days in tap water, while it can stay alive for more than 6 weeks in river water, can stay above 8 weeks in groundwater, and for about 30 weeks in seawater. The virus has been found in different water environments such as raw wastewaters ( Osuolale and Okoh, 2015 ), treated effluents ( Van Zyl et al, 2019 ), surface waters ( Marie and Lin, 2017 ; Shaheen et al, 2019 ), and drinking waters ( Moreno et al, 2009 ).…”

Occurrence of Human Enteric Viruses in Water Sources and Shellfish: A Focus on Africa

“…Over the last 25 years, many studies have revealed the presence of enteric viruses in South African rivers and dams, which are essential water sources for the surrounding communities (Taylor et al 2001;Sibanda and Okoh 2012;Saïd et al 2014;Potgieter et al 2020). For example, several studies have identified HAdV, HAV and (Kiulia et al 2010) (Shaheen et al 2019b) in some cases EV, NoV and RV in water samples from the Tyume and Buffalo rivers of the Eastern Cape Okoh 2012a, 2012b;Okoh 2012, 2013), the Klip River and Vaal dam in the Gauteng province (Taylor et al 2001), and the Umhlangane river in KwaZulu-Natal (Marie and Lin 2017). From 2008, Mans et al (2013 reported the presence of NoV RNA in 66%, 95% and 21% of water samples from the Klip, Rietspruit and Suikerbosrant rivers, respectively.…”

Analysis of viral and bacterial communities in groundwater associated with contaminated land

“…Up till now, only few studies have been published on viruses of groundwater (Eydal and Jägevall, 2009;Kyle and Eydal, 2008;Pan et al, 2017;Smith et al, 2013) and, to our knowledge, no metagenomic study of viral diversity in this environment has been reported. Moreover, there have only been limited studies of viral diversity and viral roles in polluted waters (Marie and Lin, 2017;O'Brien et al, 2017).…”