In this paper we report the occurrence of zoonotic species of Cryptosporidium (C. ubiquitum and C. parvum subtype IIaA15G2R1) and the host-specific Giardia duodenalis genotype E in a sheep farm from Brazil. Fecal specimens were collected from 100 animals and screened for the presence of G. duodenalis and Cryptosporidium spp. by enzyme immunoassay (EIA) and polymerase chain reaction (PCR). Restriction fragment length polymorphism (RFLP) and sequence analysis of selected samples was used to confirm the species and to characterize the isolates. Of 100 specimens, 34 were positive for Giardia (34%) and 25 were positive for Cryptosporidium (25%). The prevalence of Giardia and Cryptosporidium was higher in lambs than in ewes. Co-infection was observed in 14% of animals. All G. duodenalis isolates belonged to genotype E. The genetic characterization performed in 22 Cryptosporidium-positive samples revealed the presence of zoonotic C. ubiquitum and C. parvum in 76% (19/25) and 12% (3/25) of infected animals, respectively. The presence of zoonotic Cryptosporidium subtypes in lambs was of epidemiological and public health relevance.

Eighteen young steers were inoculated with Toxoplasma gondii and randomly distributed into three groups of six animals each: GI, 2.5x10(5) "P" strain oocysts, GII, 5.0x10(6) "RH" strain tachyzoites, and GIII (Control). Clinical, serological and parasitemia exams were realized. Parasite investigation by bioassay and PCR was realized on semen and fragments of skeletal musculature, lymph nodes, brain, retina, spleen, liver, lung, testicle, epididymis and seminal vesicle. Blood and semen samples were collected on days -2, -1, 1, 3, 5, 7, 14 and weekly thereafter, up to postinfection day (PID) 84. The inoculated steers (GI and GII) presented hyperthermia from PID 3 to 16. Antibodies against T. gondii were detected through the indirect fluorescence antibody test (IFAT) on PID 5 (1:16) in both inoculated groups (oocysts and tachyzoites), reaching peaks of 1:4096 on PID 7. Parasitemia outbursts occurred in all infected bovines, principally from PID 7 to 28, independent of the strain and inoculate used. Bioassays revealed the presence of parasites in semen samples of animals infected with oocysts (GI) and tachyzoites (GII) on several experimental days between PID 7 and 84. Tissue parasitism by T. gondii was diagnosed by bioassay and the PCR technique in several organ and tissue fragments. These findings suggest the possibility of sexual transmission of T. gondii in the bovine species.