Toxoplasma Gondii Infections in Cats From Paraná, Brazil: Seroprevalence, Tissue Distribution, and Biologic and Genetic Characterization of Isolates

Abstract

Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete environmentally resistant oocysts. The prevalence of T. gondii was determined in 58 domestic cats from 51 homes from Santa Isabel do Ivai, Parana State, Brazil where a water-associated outbreak of acute toxoplasmosis had occurred in humans. Antibodies to T. gondii were found with the modified agglutination test in 49 of 58 (84.4%) cats at a serum dilution of 1:20. Tissues (brain, heart, and skeletal muscle) of 54 of these cats were bioassayed in T. gondii-free, laboratory-reared cats; T. gondii oocysts were excreted by 33 cats that were fed feline tissues. Brains from these 54 cats were bioassayed in mice; T. gondii was isolated from 7. Skeletal muscles and hearts of 15 cats were also bioassayed in mice; T. gondii was isolated from skeletal muscles of 9 and hearts of 13. The results indicate that T. gondii localizes in muscle tissue more than the brains of cats. In total there were 37 T. gondii isolates from 54 cats. Most isolates of T. gondii were virulent for mice. Genotyping of the 37 isolates of T. gondii, using the SAG2 locus, revealed that 15 isolates were type I and 22 were type III. The absence of type II genotype in cats in this study is consistent with the previous studies on T. gondii isolates from Brazil and is noteworthy because most T. gondii isolates from the United States are type II. These findings support the view that Brazilian and North American T. gondii isolates are genetically distinct. This is the first report of genotyping of T. gondii isolates from the domestic cat.

Large-scale serosurvey of Besnoitia besnoiti in free-living carnivores in Spain

“…In addition, the actual seroprevalence may be underestimated because an infected definitive host may not seroconvert. For example, a cat experimentally infected with Toxoplasma gondii shed oocysts but did not seroconvert for at least 6 months (Dubey and Frenkel, 1972), and viable T. gondii has been isolated from seronegative naturally infected cats (Dubey et al, 2004). Similar finding have been reported for Neospora caninum in dogs (Schares et al, 2001(Schares et al, , 2005.…”

Serological detection of Toxoplasma gondii, Leishmania infantum and Neospora caninum in cats from an area endemic for leishmaniasis in Brazil

“…On the other hand, the definitive hosts of N. caninum are domestic dogs, coyotes and Australian dingoes, which shed oocysts (DUBEY & Schares, 2011). Due to the importance of these parasites to public health, many surveys have been conducted worldwide showing the seroprevalence of T. gondii in felines (GARCIA et al, 1999;LANGONI et al, 2001;SILVA et al, 2002;DUBEY et al, 2004;PENA et al, 2006;LOPES et al, 2008;ESTEVES et al, 2014). However, there a few reports about the seroprevalence of N. caninum in cats (DUBEY et al, 2002;BRESCIANI et al, 2007;BRAGA et al, 2012).…”

Gastrointestinal Parasites in Domestic Cats

“…In addition to clinical manifestations, fecal analyses and molecular techniques (Elmore et al, 2010), several serological techniques have been the main methods employed for toxoplasmosis diagnosis (Camargo, 1964;Lappin et al, 1989;Dubey et al, 2004;Coelho et al, 2011b).…”