Identification of Cryptosporidium felis in a cow by morphologic and molecular methods

Apicomplexan Cryptosporidium parasites infect a wide range of vertebrate ho sts, While some species are limited to a single host group, such as Cryptos poridium baileyi, which infects chickens, other species of this genus, such as C, parvum, infect a wide range of mammalian species from mice to humans . During an investigation of Cryptosporidium infection in cattle on a farm in northern Poland, we identified an infection caused by C. felis, in addit ion to known infections with C. muris and C, parvum. This new infection was identified based on the size of the oocysts (mean size, 4.3 +/- 0.4 mu m; range, 3.5 to 5.0 mu m), as well as by analysis of the molecular sequence o f the variable region of the small-subunit rRNA. This finding demonstrates the complex host specificity and circulation in the environment of Cryptosp oridium species.