First surveillance and molecular identification of the Cryptosporidium skunk genotype and Cryptosporidium parvum in wild raccoons (Procyon lotor) in Osaka, Japan.

Recent research suggests that raccoons (Procyon lotor) can transmit several important pathogens affecting humans, including protozoans. In Japan, the number of wild raccoons has increased since they were first introduced more than 50 years ago. Here, we report the first survey of Cryptosporidium infection using fecal swabs of raccoons captured in Osaka, Japan. Of 116 raccoons examined by PCR targeting of the Cryptosporidium 18S rRNA gene, 7 (6.03%; 2 adults and 5 young animals) were positive, and the isolates were identified as Cryptosporidium skunk genotype (subtype XVIa) and C. parvum based on sequence and phylogenetic analyses. Both species and the genotype are zoonotic; thus, our results suggest that raccoons could transmit Cryptosporidium infections to humans in Japan.

Reduced efficacy of ivermectin treatments in gastrointestinal nematode infections of grazing cattle in Japan.

Fecal egg count reduction tests (FECRT) and larval migration inhibition tests (LMIT) were conducted to assess the efficacy of ivermectin (IVM) against gastrointestinal nematodes on 2 cattle farms in northern Japan in 2009 and 2010. Twelve to 20 calves on each farm were treated topically with 0.5 mg IVM/kg 2 (Farm 2) or 4 times (Farm 1) during the grazing season (May-October). On Farm 1, fecal egg count (FEC) reduction at 14 days post-treatment ranged from 16 to 87% in 2009 and from 24 to 96% in 2010, with relatively low reductions in August and October (16-53%). Conversely, IVM treatment on Farm 2 reduced FEC by 97% in September 2009. Larvae obtained from fecal cultures and identified by PCR-RFLP analysis revealed that the dominant species on both farms prior to IVM administration was Cooperia oncophora. In 2009, the FEC reduction of C. oncophora on Farm 1 decreased from 85% in May to 56% in August. In 2010, the reduction in C. oncophora in August was 28%. In the LMIT using larvae collected from the fecal cultures on Farm 1 in May and August 2009, the EC50 value of IVM in C. oncophora in August (0.892 µg/ml) was 3 times higher than that in May (0.296 µg/ml). The results of the LMIT corroborated the FECRT data, indicating the presence of IVM-resistant C. oncophora on Farm 1, at least in August. This is the first report of IVM-resistant nematodes in Japanese cattle.