Development of a Highly Sensitive Method for the Detection of Cryptosporidium parvum Virus Type 1 (CSpV1)

概要

Cryptosporidium is one of the most important zoonotic parasites that causes cryptosporidiosis. Although, infection occurs throughout the world in high prevalence rates, none completely effective drugs are available. Therefore, the development of a rapid and accurate diagnostic method and genetic surveillance of Cryptosporidium are critically required to predict and prevent the spread of infection. Recently, some studies have been focused on Cryptosporidium parvum virus type 1 (CSpV1), the first member within Partitiviridae family to infect protozoan host, as a new tool for detection and genetic surveillance of Cryptosporidium. However, these studies followed different molecular detection methods, therefore the relationship between PCR-based CSpV1 detection, the target site of the virus genome, and detection sensitivity remains unclear. In this study, we show that the second half of the coding region of dsRNA2 is effectively detected from various types of clinical samples without the need for oocyst purification by using a nested PCR technique. Importantly, our method showed higher sensitivity in field fecal samples compared with Cryptosporidium 18S rRNA-based detection method. Moreover, this targeted short sequence reveals a high level of genetic polymorphism compared with the Cryptosporidium GP60 gene. Taken together, these results suggest that our method might be good strategy for Cryptosporidium and/or CSpV1 analysis.