A Survey of Neospora caninum and Toxoplasma gondii Infection in Urban Rodents from Brazil

Abstract

Toxoplasma gondii is a protozoan parasite that infects humans and other warm-blooded animals; it uses feral and domestic cats as the definitive hosts. Neospora caninum is a protozoan parasite of animals whose life cycle is very similar to T. gondii but uses canids as definitive hosts. Small rodents play an important role in the life cycle of T. gondii , and a few findings indicated that they may be natural intermediate hosts for N. caninum . The present study was aimed at identifying infections by T. gondii and N. caninum in urban rodents. Infections by T. gondii were quantified using isolation of the parasite by bioassay in mice; molecular methods were also used for both parasites. Overall, 217 rodents were captured. Brain and heart tissues of all rodents were bioassayed in mice for the detection of T. gondii infection. Brain and heart tissues of 121 rodents had the DNA extracted for molecular analysis. Toxoplasma gondii was isolated by bioassay from a single rodent. From the 121 rodents tested for the presence of T. gondii DNA, 2 animals were positive. In contrast, DNA of N. caninum was not detected in any of the samples. In conclusion, the surveys of N. caninum and T. gondii infection in Rattus rattus , Rattus norvegicus , and Mus musculus captured in urban areas of São Paulo reveal a striking low frequency of occurrence of these infections.

ISOLATION AND GENOTYPING OF Toxoplasma gondii IN SERONEGATIVE URBAN RATS AND PRESENCE OF ANTIBODIES IN COMMUNICATING DOGS IN BRAZIL

“…In Brazil, some studies reported lower prevalences in urban sinantropics rodents; in Umuarama , Paraná State, none of 24 R. rattus and 19 Mus musculus showed positive results in the sorological tests 55 , and in São Paulo, Muradian et al . 56 established the prevalence of 0.46% in 217 captured rodents by means of bioassays. Higher prevalences were found in Costa Rica (30.4% Rattus ), in Panama (23.3% R. norvegicus ), England (59% M. domesticus ) and Pakistan (58.57% R. rattus ; 36.66% M. musculus ) 9 , 13 , 18 , 57 .…”

Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

“…This parallels previous studies where positive urban rodents are usually rare. For instance, surveys in Brazilian cities showed 4.7% (out of 43 M. musculus and R. rattus ), 5% (out of 181 R. rattus ) and 0.46% (out of 217 R. rattus , R. norvegicus and M. musculus ) of Toxoplasma rodent careers in the cities of Umuarama, Londrina and São Paulo, respectively (Ruffolo 2008, Araujo et al 2010, Muradian et al 2012) (see also Supplementary data for a review about data for rodents in the tropics).…”

All about neosporosis in Brazil

“…Similarly, Muradian et al (2012) tested wild urban rodents tissues (Family Muridae), but did not detect N. caninum DNA in four mice (Mus musculus), 20 brown rats (Rattus novergicus), and 193 black rats (Rattus rattus) from São Paulo city. Regarding capybaras, the first study done (YAI et al, 2008) tested animals from 11 counties in SP by IFAT (1:25) and found a prevalence of 9.4% (20/213), suggesting that they can serve as a source of N. caninum infection for wild canids.…”