ABSTRACT
O objetivo deste trabalho foi avaliar, por meio de microscopia óptica e eletrônica de transmissão, as alterações na morfologia e a viabilidade do desenvolvimento de embriões bovinos fecundados com sêmen contaminado experimentalmente à Escherichia coli produtora da toxina shiga stx2 (STEC). Para tanto, oócitos foram aspirados de ovários de vacas abatidas e selecionados para maturação in vitro. Após 20-24 horas de maturação, os oócitos foram divididos em 2 grupos. Sendo o primeiro grupo o controle (n = 418), fertilizado com sêmen testado e sem nenhum tipo de contaminante e o segundo, o grupo contaminado (n = 415), fertilizado com sêmen exposto a STEC. Cada sêmen foi tratado pela técnica de gradiente descontínuo de Percoll. Após o período de fecundação, os embriões foram avaliados quanto a sua morfologia e viabilidade, com o auxílio da microscopia óptica e eletrônica. Na ava liação morfológica, os oócitos fecundados com o sêmen contaminado apresentaram retração citoplasmática, falhas na divisão, assimetria de blastômeros, ooplasma granuloso, coloração castanho-escuro, formação de vacúolos, degeneração e rompimento da zona pelúcida. Essas alterações não foram observadas no grupo controle. A avaliação de todos oócitos incluídos mostrou taxas de clivagem de 70,3 e 52,8%, respectivamente, para embriões controle e contaminado (p = 0,0001). Após o 5° dia de desenvolvimento embrionário foram observadas 44,7% de mórulas no grupo controle e 22,4% no grupo contaminado, apresentando diferença significativa (p=0,0001). A presença da STEC interfere na taxa de clivagem dos embriões e também inviabiliza e provoca queda no desenvolvimento embrionário ao estádio de mórula, além de causar alterações morfológicas durante esse desenvolvimento.(AU)
The objective of this study was to evaluate by optical microscopy and transmission electron, changes in morphology and viability of the development of bovine embryos, fertilized with semen experimentally contaminated (STEC). Oocytes were aspirated from ovaries of slaughtered cows and the intact zona pellucida were selected and matured. After 20-24 hours of maturation, the oocytes were divided into 2 groups. The first, control group (n = 4l8),fertilized with semen tested and without any type of contaminant and the second, the infected group (n = 415), fertilized with sperm exposed to STEC. Both semen were treated by the technique of discontinuous Percoll gradient. After the period of fertilization, embryos were evaluated for their morphology and viability by optical and electron microscopy. In morphologic evaluation, the oocytes fertilized with contaminated semen showed cytoplasmic shrinkage, gaps in the division, asymmetry of blastomeres, ooplasm grainy, dark brown color, vacuoles formation, degeneration and zona pellucid disruption. These changes were not observed in the control group. The cleavage rate was 70.3 and 52.8%, respectively, for control and infected groups, significant differences (p = 0.0001). After the 5th day of embryonic development, where it was observed 44.7% of morula in the control group, and 22.4% in the contaminated group, showing a significant difference (p = 0.0001). The presence of STEC interferes with the cleavage rate of embryos and also prevents and causes a decline in embryonic development to the morula stage and cause morphological changes during this development.(AU)
Subject(s)
Animals , Cattle , Semen/virology , Fertilization in Vitro , Reproductive Techniques, Assisted , Embryonic Development , Shiga-Toxigenic Escherichia coli , Health Surveillance , Microscopy, Electron, TransmissionABSTRACT
Ferret enteric coronavirus (FECV) is associated to the epizootic catarrhal enteritis (ECE) in ferrets (Mustela putorius furo). In this study, we report the occurrence of this agent in four diarrheic stool samples of domestic ferrets, analyzed by negative staining transmission electron microscopy and a specific RT-PCR assay targeting the nucleocapsid (N) gene. These findings are the first report of FECV in Brazil and address the importance of this virus on the etiology of enteric disorders in ferrets.
Coronavírus entérico de furões (FECV) é associado à enterite catarral epizoótica (ECE) em furões (Mustela putorius furo). Neste estudo, relatamos a ocorrência deste agente em quatro amostras fecais diarreicas de furões domésticos, analisadas por microscopia eletrônica de transmissão (contrastação negativa) e RT-PCR específica e direcionada ao gene de nucleocapsídeo (N). Estes achados constituem o primeiro relato de FECV no Brasil e remetem para a importância deste vírus na etiologia de quadros entéricos nestes animais.
Subject(s)
Animals , Ferrets/virology , Coronavirus Infections/veterinary , Microscopy, Electron, Transmission , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Entry of human immunodeficiency type 1 virus (HIV-1) into target cells requires both CD4and one of the chemokine receptors. Viruses predominantly use one, or occasionally both, of the major co-receptors CCR5 and CXCR4, although other receptors, including CCR2B and CCR3, function as minor co-receptors. A 32-nucleotide deletion (delta32) within the beta-chemokine receptor 5 gene (CCR5) has been described in subjects who remain uninfected despite extensive exposition to HIV-1. The heterozygous genotype delays disease progression. This allele is common among Caucasians, but has not been found in people of African or Asian ancestry. A more common transition involving a valine to isoleucine switch in transmembrane domain I of CCR2B (64I), with unknown functional consequences, was found to delay disease progression but not to reduce infection risk. As the Brazilian population consists of a mixture of several ethnic groups, we decided to examine the genotype frequency of these polymorphisms in this country. There were 11.5 percent CCR5 heterozygotes among the HIV-1 infected population and 12.5 percent among uninfected individuals, similar to data from North America and Western Europe. The prevalence of CCR2-64I homozygotes and heterozygotes was 0.06 and 15.2 percent, respectively, also similar to what is known for North America and Western Europe