Browsing by Author "Vilares, Anabela"
Now showing 1 - 10 of 26
Results Per Page
Sort Options
- Co-Circulation of Leishmania Parasites and Phleboviruses in a Population of Sand Flies Collected in the South of PortugalPublication . Amaro, Fátima; Vilares, Anabela; Martins, Susana; Reis, Tânia; Osório, Hugo Costa; Alves, Maria João; Gargaté, Maria JoãoIn the Old World, phlebotomine sand flies from the genus Phlebotomus are implicated in the transmission of Leishmania spp. parasites (Kinetoplastida: Trypanosomatidae) and viruses belonging to the genus Phlebovirus (Bunyavirales: Phenuiviridae). Two of the five sand fly species known to occur in Portugal, Phlebotomus perniciosus and Ph. ariasi, the former being the most ubiquitous, are recognized vectors of Leishmania infantum, which causes visceral leishmaniasis, the most prevalent form of leishmaniasis in the country. Phlebotomus perniciosus is also the vector of the neurotropic Toscana virus, which can cause aseptic meningitis. Entomological surveillance is essential to provide fundamental data about the presence of vectors and the pathogens they can carry. As such, and given the lack of data in Portugal, an entomological survey took place in the Algarve, the southernmost region of the country, from May to October 2018. Polymerase chain reaction assays were performed in order to detect the presence of the above-mentioned pathogens in sand fly pools. Not only were both Leishmania parasites and phleboviruses detected during this study, but more importantly, it was the first time their co-circulation was verified in the same sand fly population collected in Portugal.
- Diagnóstico laboratorial de casos clínicos suspeitos de infeção por Toxoplasma gondii, 2009-2020Publication . Reis, Tânia; Vilares, Anabela; Martins, Susana; Ferreira, Idalina; Gargate, Maria JoãoO estudo foi realizado com o objetivo de descrever as características demográficas de pacientes com quadro clínico suspeito de toxoplasmose. O diagnóstico laboratorial destes casos foi confirmado no Laboratório Nacional de Referência em Infeções Parasitárias e Fúngicas do Instituto Nacional de Saúde Doutor Ricardo Jorge, entre janeiro de 2009 e dezembro de 2020. Toxoplasma gondii é um protozoário intracelular obrigatório e o agente etiológico da toxoplasmose, que pode infetar a grande maioria dos vertebrados, incluindo humanos. A transmissão da infeção toxoplasmática ocorre pela ingestão de qualquer uma das formas de resistência (sejam os cistos contidos na carne de animais infetados ou os oocistos expelidos nas fezes de felinos que, no solo e após a esporulação, tornam-se infeciosos e contaminam os alimentos e a água), bem como a transmissão placentária, por meio da passagem dos taquizoítos da mãe para o feto. Para o diagnóstico laboratorial da infeção adquirida, foram utilizados métodos sorológicos (Aglutinação Direta (AD), Ensaio Fluorescente Enzimático (ELFA), Ensaio de Aglutinação Imunoabsorvente com Imunoglobulina (ISAGA), e Immunoblot (IB) e métodos moleculares (PCR em tempo real) amplificação da região repetida do REP-529pb. Para o diagnóstico laboratorial da infeção congênita (pré e pós-natal), foram realizadas as mesmas metodologias descritas anteriormente, bem como a inoculação em camundongos utilizando diferentes produtos biológicos, nomeadamente sangue materno e recém-nascido, líquido amniótico e placenta. Durante o período de estudo de 12 anos, foram analisadas amostras biológicas de 6.658 casos suspeitos de toxoplasmose, dos quais 1.663 casos positivos foram confirmados (25%). Destes, 1.638 (98,5%) correspondem a pacientes com infeção toxoplasmática adquirida e 25 (1,5%) a pacientes com infeção toxoplasmática congênita. Os resultados indicam que a identificação dos casos de toxoplasmose no estudo corrobora os resultados referenciados em estudos anteriores e demonstra a importância do diagnóstico laboratorial e da vigilância sistemática desta infeção. Essa vigilância é particularmente importante em gestantes e em indivíduos imunocomprometidos, por se tratar de grupos populacionais onde essa parasitose é responsável por elevados índices de morbidade e letalidade.
- Epidemiological and genetic characterization of Toxoplasma gondii in urban pigeons from the area of Lisbon (Portugal)Publication . Waap, Helga; Vilares, Anabela; Rebelo, Eugénia; Gomes, Salomé; Ângelo, HelenaCircumstantial evidence suggests that birds may be a good indicator of soil contamination, since they feed from the ground. Therefore a study was conducted to assess the prevalence of Toxoplasma gondii in urban pigeons (Columba livia) from different areas of the city of Lisbon and to genetically characterize T. gondii strains isolated from infected animals, in order to assess circulating genotypes. Sera from 695 pigeons captured at 33 different localities of the city of Lisbon were assayed by the direct agglutination test (DAT) showing a 4.6% prevalence. One third of flocks sampled revealed to be infected with T. gondii, with prevalence ranging between 5% and 62.5%. T. gondii DNA could be characterized directly from brain tissue from 12 of 23 seropositive pigeons. Microsatellite typing revealed that 9 strains belonged to type II, 2 were type III and one was type I. No recombinant or atypical genotypes were found. Attempts to recover viable T. gondii strains through bioassay in mice resulted in the isolation of 9 strains.
- First Report of Echinococcus ortleppi in Free-Living Wild Boar (Sus scrofa) from PortugalPublication . Mateus, Teresa Letra; Gargaté, Maria João; Vilares, Anabela; Ferreira, Idalina; Rodrigues, Manuela; Coelho, Catarina; Vieira-Pinto, MadalenaCystic echinococcosis (CE) is a zoonosis that is prevalent worldwide. It is considered endemic in Portugal but few studies have been performed on Echinococcus granulosus sensu lato and their hosts. In this study, CE cysts are reported for the first time in a free-living wild boar (Sus scrofa) in Portugal. The presence of the metacestodes in the liver of the wild boar was identified by morphological features, microscopic examination and molecular analysis. The sequencing of part of the DNA nuclear ribosomal internal transcribed spacer-1 (ITS-1) region revealed a G5 genotype that presently corresponds to Echinococcus ortleppi. This is the first report of E. ortleppi in Portugal and to the best of the authors’ knowledge, in Europe. These results suggest that wild boar may be a host of CE, namely, crossing the livestock–wildlife interface, which has important public health implications. Wildlife reservoirs must be taken into account as CE hosts and surveillance of game as well as health education for hunters should be implemented using a One Health approach, with implementation of feasible and tailor-made control strategies, namely, proper elimination of byproducts in the field.
- 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.
- Hidatidose quística humana: análise retrospetiva de casos diagnosticados e em monitorização entre 2008 e 2013Publication . Reis, Tânia; Vilares, Anabela; Ferreira, Idalina; Martins, Susana; Furtado, Cristina; Gargaté, Maria João
- In vitro isolation and seroprevalence of Toxoplasma gondii in stray cats and pigeons in Lisbon, PortugalPublication . Waap, Helga; Cardoso, R.; Leitão, A.; Nunes, T.; Vilares, Anabela; Gargaté, Maria João; Meireles, José; Cortes, Hélder; Ângelo, HelenaOral contamination with Toxoplasma gondii oocysts shed by cats into the environment has been linked to severe outbreaks of human toxoplasmosis. Pigeons (Columba livia) are highly susceptible to oral infection with oocysts and indirectly indicate soil contamination, since they feed from the ground. A seroprevalence study was performed on cats and pigeons captured in the city of Lisbon. Serum samples collected from 1507 pigeons captured at 64 feeding sites and 423 stray cats were screened for antibodies anti-T. gondii using a commercial direct agglutination test. Seroprevalence in pigeons was 2.6% (39/1507) (95% CI: 1.9–3.5%) and 37.5% (24/64) of pigeon flocks sampled showed to be infected with T. gondii. The proportion of infected pigeons within seropositive flocks ranged between 4.8% and 21.1%. Among cats, seroprevalence was 44.2% (187/423) (95% CI: 39.5–49.1%). Isolation of T. gondii from animal tissues was attempted by in vitro assay. Inoculation of brain homogenates from 20 pigeons and 56 cats into Vero cell cultures allowed isolation of T. gondii from 13 pigeons (65%) and 15 cats (26.8%). Inoculation of muscle homogenates (heart and limbs) prepared by acid-peptic digestion from a subset of 15 cats resulted in the recovery of T. gondii from 10 cats (66.7%).
- In Vitro isolation and seroprevalence of Toxoplasma gondii in stray cats and pigeons in Lisbon, PortugalPublication . Waap, Helga; Cardoso, Rita; Leitão, Alexandre; Nunes, Telmo; Vilares, Anabela; Gargate, Maria João; Meireles, José; Cortes, Helder; Ângelo, HelenaOral contamination with Toxoplasma gondii oocysts shed by cats into the environment has been linked to severe outbreaks of human toxoplasmosis. Pigeons (Columba livia) are highly susceptible to oral infection with oocysts and indirectly indicate soil contamination, since they feed from the ground. A seroprevalence study was performed on cats and pigeons captured in the city of Lisbon. Serum samples collected from 1507 pigeons captured at 64 feeding sites and 423 stray cats were screened for antibodies anti-T. gondii using a commercial direct agglutination test. Seroprevalence in pigeons was 2.6% (39/1507) (95% CI: 1.9-3.5%) and 37.5% (24/64) of pigeon flocks sampled showed to be infected with T. gondii. The proportion of infected pigeons within seropositive flocks ranged between 4.8% and 21.1%. Among cats, seroprevalence was 44.2% (187/423) (95% CI: 39.5-49.1%). Isolation of T. gondii from animal tissues was attempted by in vitro assay. Inoculation of brain homogenates from 20 pigeons and 56 cats into Vero cell cultures allowed isolation of T. gondii from 13 pigeons (65%) and 15 cats (26.8%). Inoculation of muscle homogenates (heart and limbs) prepared by acid-peptic digestion from a subset of 15 cats resulted in the recovery of T. gondii from 10 cats (66.7%). Copyright © 2012 Elsevier B.V. All rights reserved.
- Isolation and molecular characterization of Toxoplasma gondii isolated from pigeons and stray cats in Lisbon, PortugalPublication . Vilares, Anabela; Gargaté, Maria João; Ferreira, Idalina; Martins, Susana; Júlio, Cláudia; Waap, Helga; Ângelo, Helena; Gomes, João PauloCats and pigeons are important factors in the epidemiology of Toxoplasma gondii as felids are the only definitive hosts that can excrete environmentally resistant oocysts, and pigeons share the same places of cats and humans constituting a good model and indicator of the ground field contamination. We aimed to study the virulence and genotypes of T. gondii isolated from pigeons and stray cats in Lisbon, Portugal. Fresh samples of brain from 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 the mouse model. Sag2-based genotyping of T. gondii was achieved in 70.7% (29/41) of samples isolated 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 belonged to genotype II and 10 were no type III (it was not possible to discriminate between type I 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 had been previously identified as type II by Sag2 amplification (one isolated from cat brain and the other from pigeon brain). This is the first evidence of recombinant strains circulating in Portugal and the first report of T. gondii genotyping from cats in this country. This study also highlights the importance of environmental contamination in the synanthropic cycle constituting a potential source of human infection.
- Leishmaniase: confirmação laboratorial de casos clínicos suspeitos de infeção entre 2008 e 2013Publication . Martins, Susana; Vilares, Anabela; Ferreira, Idalina; Reis, Tânia; Gargaté, Maria João
- «
- 1 (current)
- 2
- 3
- »