Pre-analytical and analytical procedures for the detection of enteric viruses and enterovirus in water samples

Practical pre-analytical and analytical procedures were developed and validated for detection of enteric viruses in three water matrices. Both RNA viruses (norovirus, coxsackievirus, echovirus, and rotavirus) and DNA virus (adenovirus 41) were included in the study. The NanoCeram 90 mm laminated disc with electropositive filter and procedures of filtration, elution and flocculation were utilized to concentrate known amount of viruses in different water matrices. Real time quantitative PCR was used to evaluate the recovery of virus and cell culture to assess viral infectivity. There was no PCR inhibition using various concentrations and pH of beef extract eluting buffer. A good recovery of the viruses spiked in 10 L of deionized water was achieved for serial dilutions of coxsackievirus (41–67%), echovirus (22–90%), norovirus (23–44%) and rotavirus (24–46%). Relatively lower recovery was observed for adenovirus 41 (24–35%). There was no significant difference in viral recovery from deionized, tap and river water samples. The infectivity of recovered adenovirus, coxsackievirus and echovirus was demonstrated using in vitro cell culture. The pre-analytical and analytic procedures attained consistent recovery of RNA and DNA viruses both as infectious viral particles and viral genome, provided effective removal of inhibitory substances, achieved reliable reproducibility, and were relatively inexpensive for monitoring viruses in water.

► The virus concentration in water using an inexpensive filter was optimized.
► The recovery of virus in water samples was evaluated using a quantitative PCR.
► Viral infectivity after the concentration procedure was assessed by cell culture.
► A reliable recovery of the viruses in 10 L of different water types was achieved.
► RNA viruses were recovered at a higher rate than DNA viruses.