Without molecular data microscopic detection does not provide relevant information on the zoonotic potential of the observed oocysts or enable evaluation of the risk of infection to other animals in the vicinity ( Fayer and Santín, 2009). Currently, C. ubiquitum has been reported in a wide variety of hosts

( Ong et al., 2002, Xiao et al., 2002, da Silva et al., 2003 and Ryan et al., 2003), but appears Tyrosine Kinase Inhibitor Library screening most prevalent in lambs ( Ryan et al., 2005 and Santín et al., 2007). Importantly, the diagnosis of this species must be interpreted with caution when RsaI restriction enzymes are used for the COWP gene amplification because C. ubiquitum and C. hominis have the same restriction site ( Ong et al., 2002 and Santín and Fayer, 2007). In a study conducted in Australia, 447 fecal samples from pre-weaned sheep up to eight weeks of age were Veliparib cell line analyzed by nested PCR of the 18S rRNA followed by sequencing of positive samples (Yang et al., 2009). Cryptosporidium ubiquitum was observed in 2.2% of the total samples (10/447), which is similar to the prevalence described in Brazil by this study [1.6% (2/125)]. Geurden et al. (2008) found a slightly higher prevalence in a survey conducted in ten properties in Belgium, where 6.5% (9/137) of fecal samples from lambs up to 10 weeks of age were positive for C. ubiquitum.

A study in the USA by Santín et al. (2007), in which fecal samples were collected at 7, 14 and 21 days of age from 32 lambs and examined by nested PCR, showed a high prevalence of C. ubiquitum in lambs less than a month old. Of these, 22 were eliminating C. ubiquitum and three different sequences of C. ubiquitum (cervine 1–3) were observed. The sequences obtained in the present study (HM772993) have 99.8% homology (656/657) with the cervine 2 genotype described Phenibut by Santín et al. (2007)

(EF362480) in six of the 22 animals. The same sequence of cervine genotype 2 has been reported in the United Kingdom and was previously identified as a novel genotype ( Elwin and Chalmers, 2008). In Brazil, diagnostics based on microscopy in sheep feces have shown prevalence rates ranging between 3.7 and 47.0% (Green et al., 2004, Tembue et al., 2006, Cosendey et al., 2008a and Cosendey et al., 2008b). Féres et al. (2009) collected 460 fecal samples from 21 sheep farms in the State of Sao Paulo (SP). After screening with malachite green, 31 positive samples were analyzed by PCR of the 18S rRNA. After sequencing was performed on one sample from each property in the study, three samples were successfully sequenced: C. parvum type A, C. parvum type B, and C. ubiquitum. Because GenBank access numbers for these sequences were not provided we could not compare those sequences with sequences found in the present study. Also, in SP ( Paz e Silva, 2007), 100 samples from sheep of different ages were collected and analyzed by RFLP PCR.