A Comparative Study for the Efficient Detection of Norovirus from Drinking Water by RT-PCR and Real-Time PCR

Noroviruses (NoV), of the family Caliciviridae, are the most important cause of outbreaks of acute gastroenteritis worldwide. Water can be a source of disease outbreaks. Contamination of drinking water takes place almost exclusively through sewage that contains enteric pathogens. In India, no attempt has been made to detect the presence of norovirus in drinking water earlier and the present study is the first attempt in Chennai to identify norovirus from drinking water. In this study, 100 samples were collected and were concentrated for norovirus using granular activated carbon. The main objective of the study is to compare the efficiency of reverse transcriptase-polymerase chain reaction (RT-PCR) with that of real-time polymerase chain reaction. Conventional RT-PCR was performed using the primers NI and E3 and the results were confirmed by agarose gel electrophoresis as well as by slot blot analysis. Real-time PCR assay was performed using SYBR green RT-PCR Kit. Out of the 100 samples, 18% of the samples were positive by conventional RT-PCR, while 20% were positive by real-time PCR reactions. The real-time PCR assays provide rapid, sensitive, and reliable detection of norovirus and proved to be useful for routine monitoring of drinking water samples.