Toxoplasma gondii in tissues of sheep slaughtered for human consumption in a highly endemic area for toxoplasmosis in Brazil.

Toxoplasma gondii infects warm-blooded animals, including humans, and the ingestion of undercooked meat of infected animals is an important source of infection. We investigated the presence of T. gondii by PCR and histopathology in tissues of 25 seropositive sheep slaughtered for human consumption in Rio de Janeiro and assessed the suitability of different tissues for molecular detection of the parasite. The animals were first screened for T. gondii antibodies by MAT (Modified Agglutination Test), and tissues of seropositive sheep (brain, heart, lungs, kidneys, liver and diaphragm) were subjected to molecular and histological examination. A nested-PCR targeting the P43 gene of T. gondii was performed, and kappa Coefficient was used to assess PCR results among tissues. DNA of the parasite was detected in 60 % (9 of 15) of the animals. and tissue pairs of lungs/heart, lungs/diaphragm or heart/diaphragm had substantial agreement with the global status of the animals. The combination between these three tissues leads to an almost perfect agreement with global status results. Sheep slaughtered for human consumption in Rio de Janeiro, Brazil are infected with T. gondii, and pairs of fragments of lungs and heart, lungs and diaphragm or heart and diaphragm could be used for molecular identification of T. gondii in sheep with substantial agreement with the global status of the animals.

Seroprevalence of anti-Neospora caninum antibodies in sheep from the rapidly expanding flock of Rio de Janeiro, Brazil.

Neosporosis is primarily a disease of cattle and dogs, but Neospora caninum has been linked to abortion and neonatal mortality in sheep. Since the economic, clinical and epidemiological importance of the infection in sheep remains uncertain, this work investigated the seroprevalence of anti-N. caninum antibodies and associated factors in the rapidly expanding flock of Rio de Janeiro state. Blood samples from 388 sheep of 12 farms were collected and sera tested by a commercial Enzyme-Linked Immunosorbent Assay. Seroprevalence at the animal-level was of 6.2% (24/388) and, at the herd-level, 50% (6/12) of the studied farms had at least one seropositive animal. Multivariate analysis detected that occasional veterinary assistance (P < 0.05) was significantly associated to higher seroprevalence, which is also associated to age (P < 0.001) and gender (P < 0.0001). Farmers' investments should focus on making technical assistance more frequent and future studies should assess the association of veterinary assistance with anti-N. caninum antibodies in sheep flocks.

Immunohistochemical identification of Toxoplasma gondii in tissues from Modified Agglutination Test positive sheep.

Toxoplasma gondii is a zoonotic agent of great importance in veterinary and public health. The aim of this study was to identify T. gondii by IHC (immunohistochemistry) in different sheep tissues and to determine if an association exists between the results obtained by this method and those obtained by the Modified Agglutination Test (MAT). Tissue specimens of twenty-six sheep seroreactive for T. gondii were selected for histopathological evaluation. The presence of T. gondii was investigated in brain, liver and heart samples by IHC and a possible anti-T. gondii antibody cross reactions with other parasites. McNemar's, Chi-square and Fisher's Exact Tests were applied for the statistical analysis of the results. The analysed tissues showed at least one of the following histopathological changes: mild-to-moderate congestion, focal polymorphonuclear inflammatory infiltrate and multifocal or focal mononuclear inflammatory infiltrate. Sarcocystis spp. were identified in the histological sections from both the heart and diaphragm tissues of 88.5% (23/26) of the animals. A total of 46.2% (12/26) of the T. gondii seroreactive sheep was also positive for T. gondii by IHC in at least one organ (brain, liver or heart). The liver IHC-positivity for T. gondii was statistically equivalent to the global individual IHC-positivity, according to McNemar's test. In addition, IHC allowed the detection of T. gondii in infected animals regardless of the titration observed in the MAT. The statistical difference observed between the three organs when comparing the low titration group, suggested that the heart might be the most suitable organ to detect T. gondii infection by IHC. The IHC results in this study revealed that almost half of MAT positive animals could serve as potential sources of infection for humans because bradyzoites were identified in different tissues, regardless of the MAT titration.

Occurrence of Cryptosporidium andersoni in Brazilian cattle.

Feces were collected from 68 dairy cattle, 1 to 12 mo of age, on 12 farms in the municipality of Campos dos Goytacazes, Rio de Janeiro, Brazil, and examined for the presence of Cryptosporidium sp. All samples were subjected to molecular analysis by polymerase chain reaction (nested PCR) of the 18S rRNA. Four positive samples (4.54%) were sequenced and identified as Cryptosporidium andersoni. This species represents a risk for Brazilian cattle because infection can affect cattle productivity. Moreover, C. andersoni is considered a zoonotic species.

Cryptosporidium pig genotype II diagnosed in pigs from the state of Rio De Janeiro, Brazil.

Pigs may represent a source of Cryptosporidium sp. infection to humans. The objective of this study was to identify the Cryptosporidium species present in pigs from the State of Rio de Janeiro, Brazil, and verify what risks pigs represent in the transmission of human cryptosporidiosis, because there is no such information to date in Brazil. Ninety-one samples of pig feces were collected from 10 piggeries in 2 municipalities located in the north and northwest regions of the State of Rio de Janeiro, Brazil. A nested polymerase chain reaction (PCR) protocol to amplify an 830-bp fragment of the small subunit rDNA (SSU rRNA) gene was followed by sequencing of all positive PCR samples. Two samples (2.2%) were Cryptosporidium sp. positive and were identified as pig genotype type II (PGII). This genotype has been observed in an immunocompetent person, in cattle without pigs nearby, and from a potential human source. Its potential for zoonotic transmission is little known and should be rigorously studied.

Multi-locus DNA sequencing of Toxoplasma gondii isolated from Brazilian pigs identifies genetically divergent strains.

Five Toxoplasma gondii isolates (TgPgBr1-5) were isolated from hearts and brains of pigs freshly purchased at the market of Campos dos Goytacazes, Northern Rio de Janeiro State, Brazil. Four of the five isolates were highly pathogenic in mice. Four genotypes were identified. Multi-locus PCR-DNA sequencing showed that each strain possessed a unique combination of archetypal and novel alleles not previously described in South America. The data suggest that different strains circulate in pigs destined for human consumption from those previously isolated from cats and chickens in Brazil. Further, multi-locus PCR-RFLP analyses failed to accurately genotype the Brazilian isolates due to the high presence of atypical alleles. This is the first report of multi-locus DNA sequencing of T. gondii isolates in pigs from Brazil.