Towards the Establishment of a Porcine Model to Study Human Amebiasis

BACKGROUND: Entamoeba histolytica is an important parasite of the human intestine. Its life cycle is monoxenous with two stages: (i) the trophozoite, growing in the intestine and (ii) the cyst corresponding to the dissemination stage. The trophozoite in the intestine can live as a commensal leading to asymptomatic infection or as a tissue invasive form producing mucosal ulcers and liver abscesses. There is no animal model mimicking the whole disease cycle. Most of the biological information on E. histolytica has been obtained from trophozoite adapted to axenic culture. The reproduction of intestinal amebiasis in an animal model is difficult while for liver amebiasis there are well-described rodent models. During this study, we worked on the assessment of pigs as a new potential model to study amebiasis. METHODOLOGY/PRINCIPAL FINDINGS: We first co-cultured trophozoites of E. histolytica with porcine colonic fragments and observed a disruption of the mucosal architecture. Then, we showed that outbred pigs can be used to reproduce some lesions associated with human amebiasis. A detailed analysis was performed using a washed closed-jejunal loops model. In loops inoculated with virulent amebas a severe acute ulcerative jejunitis was observed with large hemorrhagic lesions 14 days post-inoculation associated with the presence of the trophozoites in the depth of the mucosa in two out four animals. Furthermore, typical large sized hepatic abscesses were observed in the liver of one animal 7 days post-injection in the portal vein and the liver parenchyma. CONCLUSIONS: The pig model could help with simultaneously studying intestinal and extraintestinal lesion development

Incidence of coccidiosis in different rabbit keeping systems Incidência de coccidiosis em diferentes sistemas de criação de coelhos

<abstract language="por">Amostras fecais de coelhos foram examinadas pela técnica de flutuação para a presença e contagem de oocistos do gênero Eimeria, de acordo com a técnica McMaster, em uma investigação com o objetivo de comparar um sistema alternativo não medicamentoso de criação de coelhos e sistemas convencionais com diferentes níveis de controle higiênico. A presença de oocistos nas diferentes explorações foi baixa, mas muito variável. As maiores concentrações de oocistos foram encontradas nas explorações cujas condições higiênicas não foram boas, independentemente do tratamento ou não com anticoccidiano, ou do sistema de criação. Os melhores resultados foram observados no sistema alternativo com boas condições higiênicas. Neste sistema, a concentração de oocistos nos láparos desmamados, que deveriam apresentar máxima susceptibilidade à infecção por Eimeria, foi muito baixa. Estes resultados indicam que o estrito respeito às condições higiênicas é suficiente para o controle da coccidiose e que a profilaxia farmacológica poderia ser evitada sempre que fossem adotadas altas condições higiênicas so sistema criatório ao ar livre, baseado em células subterrâneas exploráveis (tocas)

Helmintos e protozoários em fezes de javalis (Sus scrofa scrofa) criados em cativeiro Helminths and protozoa in wild boars (Sus scrofa scrofa) feces raised in captivity

<abstract language="eng">Faecal samples from 79 wild boars (Sus scrofa scrofa) were examined by sedimentation method, zinc sulfate flotation method, and centrifugal flotation in sugar solution for endoparasites research. The results showed that 97.5% of the samples were positive for helminths and/or protozoa as follows: strongilides (70.9%), Ascaris suum (46.9%), Trichuris suis (29.1%), Metastrongylus sp. (12.6%), Strongyloides ransomi (3.8%), Balantidium coli (38.0%), Entamoeba spp. (15.2%), Giardia spp. (1.3%), Blastocystis sp. (12.6%). The frequency of Entamoeba was higher in young animals. Coccidian oocysts were observed in 59.5% samples and five species of Eimeria and one Isospora were recovered: Eimeria scabra (31.9%), E. deblieck (31.9%), E. perminuta (23.4%), E. cerdonis (17.0%), E. scrofae (12.8%) and Isospora suis (12.8%)