Detection and Molecular Characterization of Cryptosporidium spp. from Wild Rodents and Insectivores in South Korea

In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans.

Adiaspiromycosis of an Apodemus agrarius captured wild rodent in Korea / 한국실험동물학회지

Adiaspiromycosis is caused by pulmonary infection with Emmonsia. Inhalated spores of Emmonsia cause asymptomatic infection to necrogranulomatous pneumonia, depending on the burden of adiaspore and host immunity. For disease monitoring of wild rodents captured on Jeju Island in Korea, we examined the lung tissue of wild rodents histopathologically. Spores composed of thick three-layered walls were found following histopathological examination and were diagnosed as adiaspiromycosis. Adiaspiromycosis has been found in mammals in many parts of the world. To our knowledge, this is the first report of adiaspiromycosis of an Apodemus agrarius captured in Korea.

Detection of sarcocystic infection in a wild rodent (Apodemus agrarius chejuensis) captured on Jeju island / 한국실험동물학회지

Sarcocystis spp is a causative agent of sarcocystosis. They have a characteristic life cycle infecting both prey and predator. Sarcocystis can cause myositis, atrophy of the adjacent cells and abortion in cattle. In mice, sarcocystosis causes mild cellular reactions without clinical disease. Severe haemorrhage and abortion were also reported. For monitoring the disease in wild rodents of the Korean peninsula, we captured Apodemus agrarius chejuensis on Jeju island and examined the specimen histopathologically. Intramuscular cysts were found and diagnosed as Sarcocystis. Sarcocystic infection has been reported in worldwide. There have been many reported infections in cattle and pigs in Korea. To our knowledge, this is the first report of Sarcocystis in Apodemus agrarius chejuensis captured in Korea.