Article

Methods to detect infectious human enteric viruses in environmental water samples

Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, Germany.
International journal of hygiene and environmental health (Impact Factor: 3.28). 09/2011; 214(6):424-36. DOI: 10.1016/j.ijheh.2011.07.014
Source: PubMed

ABSTRACT Currently, a wide range of analytical methods is available for virus detection in environmental water samples. Molecular methods such as polymerase chain reaction (PCR) and quantitative real time PCR (qPCR) have the highest sensitivity and specificity to investigate virus contamination in water, so they are the most commonly used in environmental virology. Despite great sensitivity of PCR, the main limitation is the lack of the correlation between the detected viral genome and viral infectivity, which limits conclusions regarding the significance for public health. To provide information about the infectivity of the detected viruses, cultivation on animal cell culture is the gold standard. However, cell culture infectivity assays are laborious, time consuming and costly. Also, not all viruses are able to produce cytopathic effect and viruses such as human noroviruses have no available cell line for propagation. In this brief review, we present a summary and critical evaluation of different approaches that have been recently proposed to overcome limitations of the traditional cell culture assay and PCR assay such as integrated cell culture-PCR, detection of genome integrity, detection of capsid integrity, and measurement of oxidative damages on viral capsid protein. Techniques for rapid detection of infectious viruses such as fluorescence microscopy and automated flow cytometry have also been suggested to assess virus infectivity in water samples.

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    • "Fruits and vegetables can be contaminated either at the pre-harvest stage through contact with fecally contaminated irrigation water or during harvesting, packaging, processing, or cooking due to poor hand sanitation (Bitler et al., 2013; Kotwal and Cannon, 2014; Mathijs et al., 2012; Rodriguez-Lazaro et al., 2012). Most foodborne viruses are difficult or currently impossible to cultivate (Hamza et al., 2011) and sensitive molecular methods are therefore used to detect them in food and environmental samples. Today, RTqPCR is widely used for virus detection because it is sensitive, specific, rapid and can deliver quantitative data. "
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    • "identified by propagating the virus in a cellular model, to discriminate between infectious and non-infectious particles. Some studies have shown that evaluation of the integrity of viral capsid , by pre-treatment of water samples with DNA intercalating dyes (Fittipaldi et al., 2010; Parshionikar et al., 2010; Bae and Wuertz, 2012) or by nuclease pre-digestion (Nuanualsuwan and Cliver, 2002; Seitz et al., 2011), can overcome the drawbacks (Hamza et al., 2011). Another limitation of molecular methods is the presence of naturally-occurring inhibitory compounds that are problematic during genome amplification-based analysis of environmental samples, particularly for large volumes of water samples (Hata et al., 2011). "
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    • "The detection of TTV DNA in water samples may indicate the presence of other enteric viruses and fecal contaminants (Ahmed et al. 2009; Hamza et al. 2011). In the present study, the most populated municipalities, Caxias do Sul and Pelotas, treated their sewage very poorly at the time of sampling. "
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