Evaluation of short-interfering RNAs treatment in experimental rabies due to wild-type virus

ABSTRACTWe have evaluated the efficacy of short-interfering RNAs targeting the nucleoprotein gene and also the brain immune response in treated and non-treated infected mice. Mice were inoculated with wild-type virus, classified as dog (hv2) or vampire bat (hv3) variants and both groups were treated or leaved as controls. No difference was observed in the lethality rate between treated and non-treated groups, although clinical evaluation of hv2 infected mice showed differences in the severity of clinical disease (p = 0.0006). Evaluation of brain immune response 5 days post-inoculation in treated hv2 group showed no difference among the analyzed genes, whereas after 10 days post-inoculation there was increased expression of 2',5'-oligoadenylate synthetase 1, tumor necrosis factor alpha, interleukin 12, interferon gamma, and C-X-C motif chemokine 10 associated with higher expression of Ngene in the same period (p < 0.0001). In hv2 non-treated group only higher interferon beta expression was found at day 5. The observed differences in results of the immune response genes between treated and non-treated groups is not promising as they had neither impact on mortality nor even a reduction in the expression of N gene in siRNA treated animals. This finding suggests that the use of pre-designed siRNA alone may not be useful in rabies treatment.

Seroprevalence for brucellosis and leptospirosis in dogs from Belém and Castanhal, State of Pará, Brazil / Soroprevalência para brucelose e leptospirose em cães de Belém e Castanhal, Pará, Brasil

Brucellosis and leptospirosis are widely spread bacterial infections and dogs are the most important source of infection and reservoir for diseases. Dogs can disseminate the agents in the environment and transmit them to humans and/or other animals. The objective of this study was assess the occurrence of reactive to antibodies anti-Leptospira spp., Brucella canis and B. abortus in Belém and Castanhal, State of Pará, Amazon, Brazil. A total of 156 samples were randomly collected in the city of Belém and 158 samples in Castanhal. The anti-B. canis antibodies research was performed by Agar Gel Immunodiffusion (AGID) with and without 2-mercaptoethanol serum treatment (AGID-2ME). To assess the anti-B. abortus antibodies, the technique of Fast Seroagglutination with buffered acidified plate antigen (BAPAT) was used. For anti-Leptospira spp. antibodies research, the Microscopic Agglutination Technique (MAT) was used. No animal reacted to Brucella abortus and one animal was reactive to B. canis at the AGID, but it was negative to the AGID-2ME test. Seventeen percent of dogs (47/274) presented anti-Leptospira spp. antibodies, with prevalence of serovar Canicola. The dogs from Belém and Castanhal are not source of infection for B. abortus and B. canis, however, they are reservoirs for different serovars of Leptospira spp.

Brucelose e leptospirose são enfermidades bacterianas amplamente disseminadas e o cão é importante fonte de infecção e reservatório para ambas, podendo eliminar o agente no meio ambiente, e transmiti-lo para humanos e/ou outros animais. O presente estudo teve como objetivo pesquisar a ocorrência de cães reagentes para anticorpos contra Leptospira spp., Brucella canis e B. abortus em Belém e Castanhal, Pará, Amazônia, Brasil. Foram colhidas de forma aleatória 156 amostras no município de Belém e 158 amostras em Castanhal. A pesquisa de anticorpos anti-B. canis foi realizada pela técnica de Imunodifusão em Gel de Ágar (IDGA) com e sem tratamento do soro com 2-mercaptoetanol (IDGA-2ME) e para pesquisa de anticorpos anti-B. abortus foi utilizada a técnica de Soroaglutinação Rápida com antígeno acidificado tamponado (AAT). Para pesquisa de anticorpos contra-Leptospira spp. utilizou-se a Técnica de Aglutinação Microscópica (MAT). Nenhum animal reagiu para Brucella abortus e um animal foi reagente para B. canis na IDGA, porém foi negativo na IDGA-2ME. Dezessete por cento dos cães (47/274) apresentaram anticorpos contra-Leptospira spp., com predominância do sorovar Canicola. Os cães de Belém e Castanhal não são fontes de infecção para B. abortus e B. canis, no entanto são reservatórios de diferentes sorovares de Leptospira spp.

Prevalence for nematodes of hygiene-sanitary importance in fish from Colares Island and Vigia, Pará, Brasil / Prevalência de nematoides de importância higiênico-sanitária em peixes da ilha de Colares e Vigia, Pará, Brasil

Zoonotic parasites can infect fish and be a serious threat to human health. The objective of this research was to estimate the prevalence for the main fish-borne zoonotic parasitic diseases of freshwater fish marketed in Colares Island and Vigia, Pará, Brazil. In February, 2012, 85 (40 of Colares and 45 of Vigia) fish were randomly sampled by means of net fishing. Eighty and 76% of fish sampled were parasitized, being silver croacker (Plagioscion squamosissimus), kumakuma (Brachyplatystoma filamentosum), and gilded catfish (Brachyplatystoma rousseauxii) the species most parasitized. The most prevalent parasites were Anisakis (50% in Colares and 49% in Vigia) and Contracaecum (60% in Colares and 40% in Vigia), followed by Pseudoterranova (2% in Colares and 11% in Vigia), Eustrongylides (10% in Colares and 0% in Vigia) and Hysterothylacium (2% in Colares and 7% in Vigia) in the species: silver croacker, kumakuma and gilded catfish, in both cities. Mesentery (55%) was the organ with highest level of intense infestation. A greater proportion of massive infestation was observed in females (57%) than in males (12%). Results of this study indicate that fish caught in Colares and Vigia could be of high risk for consumer.

Parasitos zoonóticos podem infectar peixes e causar sérios agravos à saúde humana. O objetivo do presente estudo foi estimar a prevalência e identificar os fatores de risco para doenças parasitárias veiculadas por peixes de água doce comercializados na ilha de Colares e Vigia, Pará, Brazil. Em fevereiro de 2012, 85 peixes (40 de Colares e 45 de Vigia) foram coletados de forma aleatória com redes de pesca. Oitenta por cento e 76% dos peixes amostrados estavam parasitados, sendo a corvina (Plagioscion squamosissimus), piramutaba (Brachyplatystoma filamentosum) e dourada (Brachyplatystoma rousseauxii), as espécies mais parasitadas. Os parasitos mais prevalentes foram: Anisakis (50% em Colares e 49% em Vigia) e Contracaecum (60% em Colares e 40% em Vigia), seguido pelo Pseudoterranova (2% em Colares e 11% em Vigia), Eustrongylides (10% em Colares e 0% em Vigia) e Hysterothylacium (2% em Colares e 7% em Vigia) nas espécies: corvina, piramutaba e dourada, em ambos os municípios. O mesentério (55%) foi o órgão que apresentou infestação maciça em maior quantidade. A infestação maciça também foi observada com maior proporção em fêmeas (57%) do que em machos (12%). Os resultados deste estudo indicam que o peixe capturado em Colares e Vigia pode ser de alto risco para a o consumidor.