Rapid identification method of Omphalotus japonicus by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)

Abstract

Omphalotus japonicus is a poisonous mushroom that grows in Japan. It can be mistaken for edible mushrooms (Shiitake, Hiratake and Mukitake), and if ingested, it causes food poisoning within 30 min to 1 hr. We established a rapid detection method using PCR-RFLP to identify O. japonicus by restriction digestion of the amplified ITS region. By using Sau96I, Bpu10I, SfcI or DrdI/HincII as a restriction enzyme, it was possible to rapidly identify and discriminate O. japonicus based on the fragment length. This study also provided a short PCR-RFLP system comprising amplification and digestion of a short 200-bp DNA fragment within the ITS region. The system could identify and discriminate O. japonicus after in vitro gastric digestion of native and heated mushroom samples as a model of food poisoning. In addition, a confirmatory assay using real-time PCR was developed to achieve more sensitive detection of O. japonicus.