Infectivity to experimental rodents of Cryptosporidium parvum oocysts from Siberian chipmunks (Tamias sibiricus) originated in the People's Republic of China

• Published in: Journal of Veterinary Medical Science Vol. 62; no. 5; pp. 487 - 489
• Main Authors: Matsui, T. (Kyorin Univ., Mitaka, Tokyo (Japan)), Fujino, T, Kajima, J, Tsuji, M
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 01.05.2000; Japan Science and Technology Agency
• Subjects: Animals; Animals, Domestic - parasitology; ARDILLA; CHINA; CHINE; CIGOTOS; Cryptosporidiosis - parasitology; Cryptosporidiosis - veterinary; CRYPTOSPORIDIUM PARVUM; Cryptosporidium parvum - classification; Cryptosporidium parvum - isolation & purification; Cryptosporidium parvum - pathogenicity; ECUREUIL; Feces - parasitology; GENERO HUMANO; GENRE HUMAIN; Guinea Pigs; infectivity to rodent; isolation of Cryptosporidium; MANKIND; Mice; Mice, Inbred ICR; Mice, SCID; Parasite Egg Count - veterinary; PATHOGENICITY; PATOGENICIDAD; POUVOIR PATHOGENE; Rabbits; Rats; Rats, Wistar; Rodent Diseases - parasitology; RODENTIA; Sciuridae - parasitology; siberian chipmunk; Specific Pathogen-Free Organisms; SQUIRRELS; Tamias; ZYGOTE; ZYGOTES; China
• ISSN: 0916-7250; 1347-7439
• DOI: 10.1292/jvms.62.487

We isolated Cryptosporidium parvum-type oocysts from naturally infected siberian chipmunks which originated in the People's Republic of China and examined the infectivity to rodents as experimental animals. The naturally infected chipmunks did not show any clinical symptoms. The oocysts were 4.8 × 4.2 μm on average in size. They were ovoid and morphologically similar to the C. parvum oocysts isolated from human and cattle. Experimental rodents were inoculated with 1.6 × 106 original oocysts each. SCID mice began to shed oocysts on day 7 and the OPG value was 105 from 50 days. The oocysts were found from ICR mice on days 13 and 16 by only sugar flotation method, however, any oocysts were not detected from the rats, guinea pigs and rabbits until 30 days. Two infected SCID mice were necropsied on days 100 and 102 and examined for coccidian organisms. Merozoites and oocysts were found in the low part of jejunum and ileum, however, no parasites were detected in the stomach. Consequently, it was considered that the present species was C. parvum and was probably genotype 2 from result of infectivity to rodents.