Citation:

Parshionikar, S., J L. Cashdollar, AND G S. Fout. DEVELOPMENT OF HOMOLOGOUS VIRAL INTERNAL CONTROLS FOR USE IN RT-PCR ASSAYS OF WATERBORNE ENTERIC VIRUSES. JOURNAL OF VIROLOGICAL METHODS 121(1):39-48, (2004).

Impact/Purpose:

Overarching Objectives and Links to Multi-Year Planning

This task directly supports the 2003 Drinking Water Research Program Multi-Year Plan's long term goal 1 for "regulated contaminants" and long term goal 2 for "unregulated contaminants and innovative approaches" under GRPA Goal 2 (Clean and Safe Water). The overarching objective is to provide the Office of Water, Agency risk assessors and managers, academics, the scientific community, state regulators, water industry and industry spokes-groups the methods they need to measure occurrence of waterborne viral pathogens. The methods developed will improve the quality of risk-based assessments and tools used by the Agency to set regulations, policies and priorities for protecting human health and will allow the Agency to assure the public that the appropriate methods are being used to demonstrate that drinking water is safe from pathogenic agents.

Specific Subtask Objectives:

o Evaluate techniques for enhancement of growth of human enteric viruses in support of CCL #2 and #3 and for use in the UCMR (Subtask A; to be completed by 9/05 in support of LTG 2)

o Develop a multiplex RT-PCR method that incorporates internal controls for use in the UCMR (Subtask B; completed 9/03 in support of LTG 2)

o Develop and evaluate new molecular technologies for use in the UCMR. Included will be real-time RT-PCR methods for Norwalk virus and astroviruses, and integrated cell culture/molecular procedures for detection of infectious viruses (Subtask B; to be completed by 9/05 in support of LTG 2)

Description:

Enteric viruses often contaminate water sources causing frequent outbreaks of gastroenteritis. Reverse transcription-polymerase chain reaction (RT-PCR) assays are commonly used for detection of human enteric viruses in environmental and drinking water samples. RT-PCR provides a means to rapidly detect low levels of these viruses, but it is sensitive to inhibitors that are present in water samples. Inhibitors of RT-PCR are concentrated along with viruses during sample processing. While procedures have been developed to remove inhibitors, none of them completely remove all inhibitors from all types of water matrices. This problem requires that adequate controls be used to distinguish true from potentially false-negative results. To address this problem, we have developed homologous viral internal controls for hepatitis A virus (HAV), poliovirus, Norwalk virus and rotavirus. These internal controls can be used in RT-PCR assays for the detection of the above viruses by competitive amplification, thereby allowing the detection of false negatives in processed water samples. The internal controls developed in this study were successfully tested with virus-seeded environmental water sample concentrates.

Record Details: