First report of detection of Toxoplasma gondii DNA in oysters (Crassostrea sp.) in the state of Maranhão.

The aim of this study was to report on detection of Toxoplasma gondii DNA in oysters (Crassostrea sp.) in the state of Maranhão. To conduct this study, 200 farmed oysters were acquired in the municipality of Raposa and 100 in Paço do Lumiar; and a further 100 oysters were taken from the natural stock in the municipality of Primeira Cruz. This total of 400 specimens sampled was divided into 80 pools composed of five animals each. The gills and visceral mass of each oyster were removed for DNA extraction (per pool of oysters), using a commercial kit. The nested PCR technique (with the primer SAG-1) was then used to investigate any presence of protozoa. This molecular technique demonstrated the presence of DNA of T. gondii in 2.5% of the pools of oysters (n = 2/80): these oysters were exclusively from farms. The results from this study allow the conclusion that oysters of the genus Crassostrea that are farmed in the state of Maranhão are capable of filtering oocysts of T. gondii and maintaining them in their tissues. They are therefore potential sources of contamination for humans and other animals.

First report of detection of Toxoplasma gondii DNA in oysters (Crassostrea sp.) in the state of Maranhão / Primeiro relato da detecção de DNA de Toxoplasma gondii em ostras (Crassostrea sp.) no Estado do Maranhão

Abstract The aim of this study was to report on detection of Toxoplasma gondii DNA in oysters (Crassostrea sp.) in the state of Maranhão. To conduct this study, 200 farmed oysters were acquired in the municipality of Raposa and 100 in Paço do Lumiar; and a further 100 oysters were taken from the natural stock in the municipality of Primeira Cruz. This total of 400 specimens sampled was divided into 80 pools composed of five animals each. The gills and visceral mass of each oyster were removed for DNA extraction (per pool of oysters), using a commercial kit. The nested PCR technique (with the primer SAG-1) was then used to investigate any presence of protozoa. This molecular technique demonstrated the presence of DNA of T. gondii in 2.5% of the pools of oysters (n = 2/80): these oysters were exclusively from farms. The results from this study allow the conclusion that oysters of the genus Crassostrea that are farmed in the state of Maranhão are capable of filtering oocysts of T. gondii and maintaining them in their tissues. They are therefore potential sources of contamination for humans and other animals.

Resumo: Objetivou-se com este estudo relatar a detecção do DNA de Toxoplasma gondii em ostras (Crassostrea sp.) no estado do Maranhão. Para a realização do estudo foram adquiridas 200 ostras de cultivo do município de Raposa, e 100 de Paço do Lumiar, além de 100 ostras extraídas de estoque natural do município de Primeira Cruz. Do total de 400 exemplares amostrados, formaram-se 80 pools em que cada pool foi constituído por cinco animais. De cada ostra foi procedida à retirada das brânquias e massa visceral, seguido da extração de DNA de cada pool de ostras, com a utilização de kit comercial. Posteriormente, realizou-se a pesquisa do protozoário por meio da técnica de nested PCR (primer SAG-1). Com a técnica molecular utilizada, foi diagnosticado o DNA do protozoário pesquisado em 2,5% (n=2/80) pools de ostras oriundas exclusivamente de cultivo. Com os resultados obtidos neste estudo, conclui-se que ostras do gênero Crassostrea sp., cultivadas no estado do Maranhão, são capazes de filtrar e manter nos seus tecidos oocistos de T. gondii, sendo, portanto, fontes potenciais de contaminação para seres humanos e outros animais.

Enemas with N-acetylcysteine can reduce the level of oxidative damage in cells of the colonic mucosa diverted from the faecal stream.

BACKGROUND: Oxidative stress has been related to inflammation of the colonic mucosa in patients with diversion colitis (DC). AIM: The purpose of this study was to evaluate the antioxidants effects of n-acetylcysteine (NAC) in colon segments without faecal stream. METHODS: Thirty-six Wistar rats were subjected to diversion of the faecal stream by proximal colostomy and a distal mucosal colon fistula. They were distributed into three experimental groups of 12 animals each; the animals in each group underwent daily enemas containing saline solution (control group) or either a 25 or 100 mg/kg dose of NAC (treated groups). In each group, animals were sacrificed after 2 or 4 weeks. The degree of inflammation was determined by histopathological analysis and stratified by inflammatory grading scale. Oxidative DNA damage was measured by comet assay. The Mann-Whitney test and ANOVA were used for statistical analysis; p<0.05 was considered significant. RESULTS: The oxidative DNA damage in colon segments without faecal stream was significantly lower in animals treated with either concentration of NAC than in control group, regardless of the duration of intervention (p<0.01). CONCLUSIONS: Intrarectal application of NAC reduces the inflammation as well as DNA oxidative damage and could be beneficial as a complementary agent in the treatment of DC.