What is capsid integrity (RT-)qPCR and how does it differ from conventional methods?

Capsid integrity (RT-)qPCR, specifically the SD-CDDP-(RT-)qPCR method, is an advanced molecular technique designed to differentiate between *intact* and inactivated viruses in water samples. Unlike conventional (RT-)qPCR, which detects all viral genetic material, this method assesses the structural integrity of the viral capsid, indicating potential infectivity. This distinction is crucial for accurately evaluating actual viral risks in drinking water.

Why is detecting intact viruses important for assessing drinking water safety?

Detecting intact viruses is critical because only viruses with an intact capsid are potentially infectious and pose a health risk. Conventional qPCR can detect genetic material from both intact and damaged viruses, potentially overestimating risk. By identifying only intact viruses, water treatment facilities can more precisely assess the efficacy of purification processes and ensure public safety.

What intact viruses were detected in tap water samples in Japan according to this study?

In the Kanto region of Japan, the study found intact Pepper Mild Mottle Virus (PMMoV) in 5% of tap water samples using the SD-CDDP-(RT-)qPCR method. While Aichivirus (AiV) was initially detected by conventional qPCR in tap water, no intact AiV was found, indicating damaged capsids. Most other human pathogenic viruses were not detected in tap water by either method.

Can PMMoV reliably serve as a viral indicator for tap water safety?

The study suggests PMMoV can be a useful viral indicator for tap water *produced from surface water*, where its absence could guarantee viral safety. However, its limitation was noted in groundwater-derived tap water, where AiV was present without PMMoV. This highlights the need for comprehensive viral monitoring strategies, especially when considering diverse water sources.

How do AMPAC USA water purification systems address the presence of intact viruses?

AMPAC USA's commercial and industrial reverse osmosis (RO) systems are engineered with advanced membrane technology to effectively remove viruses, including those with intact capsids, from various water sources. Our systems provide a robust physical barrier against pathogens, ensuring purified water meets stringent safety standards for applications ranging from military bases to municipalities. Our 30+ years of field experience ensure reliable viral removal.

Viruses In Surface Water And Tap Water In Japan

Vu Duc Canh¹, Shotaro Torii², Hiroaki Furumai³, Hiroyuki Katayama⁴

PMID: 33279831

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DOI: 10.1016/j.watres.2020.116674

\nFree article\n\n

Abstract

\n\nWe’ve recently developed a method called capsid integrity (RT-)qPCR to tell the difference between active and inactive viruses. But, we haven’t used it much to check for intact viruses in drinking water. This study looked into using capsid integrity (RT-)qPCR, specifically with cis-dichlorodiammineplatinum (CDDP) and a sodium deoxycholate (SD) pretreatment (we call it SD-CDDP-(RT-)qPCR), to find intact viruses in surface water and tap water. We gathered 63 water samples- 20 from surface water and 43 from tap water- in Japan’s Kanto region. Then, we measured them using both standard (RT)-qPCR and our SD-CDDP-(RT-)qPCR method. We looked for pepper mild mottle virus (PMMoV) and seven other viruses that can make people sick: Aichivirus (AiV), noroviruses (genotypes I and II), enterovirus, adenovirus types 40 and 41, and JC and BK polyomaviruses.\n\nIn surface water, conventional (RT)-qPCR found PMMoV in all samples (100%). It found other human pathogenic viruses much less often, only 30%-60% of the time. When we used SD-CDDP-(RT-)qPCR, we found intact PMMoV in 95% of samples, while intact human pathogenic viruses showed up in 20%-45% of samples. For tap water, conventional (RT)-qPCR didn’t find most of the viruses we were looking for, except for PMMoV (9%) and AiV (5%). When we re-tested with SD-CDDP-(RT-)qPCR, PMMoV was still present in 5% of samples, but we didn’t find any AiV. This means some PMMoV had intact capsids, but the AiV had damaged ones. Finding AiV without PMMoV in tap water that came from groundwater might mean PMMoV isn’t always the best indicator for viruses in groundwater. Still, PMMoV was common in surface water and even showed up in tap water, including intact PMMoV. So, if we don’t find intact PMMoV, it could be a good sign that tap water from surface sources is safe from viruses.\n\n

\nKeywords: Capsid integrity (RT-)qPCR; drinking water; intact virus; viral indicator; virus occurrence.\n\n

\nThe post Application of Capsid Integrity (RT-)qPCR to Assessing Occurrence of Intact Viruses in Surface Water and Tap Water in Japan appeared first on Facts About Water.\n\nSource: Water Feed\n