Browsing by Author "Waap, H."
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- Genetic and virulence characterization of Toxoplasma gondii strains isolated from pigeons in Lisbon regionPublication . Vilares, Anabela; Gargate, M.J.; Ferreira, I.; Martins, S.; Waap, H.; Ângelo, H.habitat with cats and humans, bands are observed in recreational areas such as urban parks, playgrounds and parks. The interaction between cats, birds and human population is quite evident favoring the fecal-oral transmission of T. gondii between the definitive host and intermediate hosts, in the urban cycle of the parasite. The results of the inoculation in vivo of the brain homogenates showed pigeon isolation rates (58.5%) significantly higher when compared with previous studies, including the preliminary study in 2006 that the isolation rate in mice was 39,1% (9/23) (Waap 2008) and another that was not achieved any isolation in mouse (Godoi 2010). The genotypic analysis revealed a majority of strains of type II, which is consistent with what has been described in Portugal, the rest of Europe and the USA (Ajzenberg 2005, Fazaeli 2000, Honoré 2000, Howe 1997, Waap 2008) . We also isolated strains of type III and type I. The identification of type III strains in animals have been reported by other authors, but the type I have been rarely found in animals has not been previously described in Portugal except in a preliminary study of our team at the 2008 (Waap 2008). The type I strains are usually associated with high virulence in laboratory mice, leading to death within days. This strain was identified by molecular biology and has not been isolated in vivo. The difficulty in isolation of strain may be related to the small number of cysts of the type I strains can develop, these type strains are considered low cystogenic. Genetic characterization of strains of T. gondii is far from its terminus, more sequences of different genes should be studied to help the understanding of the molecular epidemiology and genetic characterization of T. gondii, a relevant parasite for which these data are lacking. The combination of data from humans and animals, through the use of high resolution genetic characterization should improve our perceptive of T. gondii, which will be ultimately beneficial for the control of T. gondii transmission.
- Isolation and molecular characterization of Toxoplasma gondii isolated from pigeons and stray cats in Lisbon, PortugalPublication . Vilares, A.; Gargaté, M.J.; Ferreira, I.; Martins, S.; Júlio, C.; Waap, H.; Angelo, H.; Gomes, João PauloCats and pigeons are important factors in the epidemiology of Toxoplasma gondii as felidsare the only definitive hosts that can excrete environmentally resistant oocysts, andpigeons share the same places of cats and humans constituting a good model and indicatorof the ground field contamination. We aimed to study the virulence and genotypes ofT. gondii isolated from pigeons and stray cats in Lisbon, Portugal. Fresh samples of brainfrom 41 pigeons and 164 cats revealing antibodies to T. gondii were inoculated in mice.Three isolates (one isolated from a cat and two isolated from pigeons) were virulent in themouse model. Sag2-based genotyping of T. gondii was achieved in 70.7% (29/41) of samplesisolated from pigeons (26 samples were type II, two were type III, and one strain was type I).From the cat brain samples, 50% (82/164) yielded Sag2 positive results, where 72 belongedto genotype II and 10 were no type III (it was not possible to discriminate between typeI and II). Further genotyping was obtained by multiplex PCR of 5 microsatellites (TUB2,TgM-A, W35, B17, B18), allowing the identification of two recombinant strains that hadbeen previously identified as type II by Sag2 amplification (one isolated from cat brain andthe other from pigeon brain). This is the first evidence of recombinant strains circulatingin Portugal and the first report of T. gondii genotyping from cats in this country. This studyalso highlights the importance of environmental contamination in the synanthropic cycleconstituting a potential source of human infection.