Effect of temperature on the detection of porcine epidemic diarrhea virus and transmissible gastroenteritis virus in fecal samples by reverse transcription-polymerase chain reaction

Department of Veterinary Pathology, College of Veterinary Medicine, School of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea.

The effect of storage temperature was determined for the detection of porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) in fecal samples from experimentally and naturally infected pigs by multiplex reverse transcription-polymerase chain reaction (RT-PCR). To examine the effect of storage temperature on the ability to detect PEDV and TGEV RNA by multiplex RT-PCR, fecal samples were stored for different temperatures (4, 21, 36, and 45 C) before extracting viral RNA. The PEDV and TGEV nucleic acids in fecal samples were stable up to 3 days at 4 C. The PEDV and TGEV nucleic acids were consistently detected in fecal samples up to 60 hours at 21 C and 24 hours only at 36 and 45 C. Thereafter, the number of positive signals declined. Positive signals were detected in fecal samples stored at 4 C by 240 hours. The PEDV and TGEV nucleic acids were consistently detected in fecal samples up to 60 hours at 21 C and 24 hours only at 36 and 45 C. The results of this study suggested that storage temperature has significant effect on the detection of PEDV and TGEV nucleic acids from fecal samples by multiplex RT-PCR.