Evaluation of lasting effects of heat stress on sperm profile and oxidative status of ram semen and epididymal sperm

Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm

Production of a cloned calf from a fetal fibroblast cell line

The present study examined the in vitro and in vivo development of bovine nuclear-transferred embryos. A bovine fetal fibroblast culture was established and used as nucleus donor. Slaughterhouse oocytes were matured in vitro for 18 h before enucleation. Enucleated oocytes were fused with fetal fibroblasts with an electric stimulus and treated with cytochalasin D and cycloheximide for 1 h followed by cycloheximide alone for 4 h. Reconstructed embryos were cultured for 7-9 days and those which developed to blastocysts were transferred to recipient cows. Of 191 enucleated oocytes, 83 (43.5%) were successfully fused and 24 (28.9%) developed to blastocysts. Eighteen freshly cloned blastocysts were transferred to 14 recipients, 5 (27.8%) of which were pregnant on day 35 and 3 (16.7%) on day 90. Of the three cows that reached the third trimester, one recipient died of hydrallantois 2 months before term, one aborted fetus was recovered at 8 months of gestation, and one delivered by cesarian section a healthy cloned calf. Today, the cloned calf is 15 months old and presents normal body development (378 kg) and sexual behavior (libido and semen characteristics)

Fontes de contaminação por Staphylococcus aureus na linha de processamento de queijo prato Identification of main sources of contamination with Staphylococcus aureus in Prato cheese manufacturing process

Com o objetivo de identificar as principais fontes de contaminação por Staphylococcus aureus e Staphylococcus produtores de coagulase (SC+), avaliou-se o processo de fabricação de queijo prato em um laticínio de Lavras, MG, durante os meses de outubro de 2000 a abril de 2001. As análises microbiológicas foram feitas no leite cru, no leite pasteurizado resfriado, nas mãos e antebraços dos funcionários, na salmoura, na água de imersão das fôrmas e no queijo embalado. Contagens elevadas de SC+ e de S. aureus (4x10³ a 4,8x10(6) UFC/ml e 4x10³ a 3,3x10(5) UFC/ml, respectivamente) foram encontradas em quatro avaliações no leite cru. Após a pasteurização, as contagens foram reduzidas a <1 UFC/ml. Em três das cinco avaliações, o queijo prato apresentou contagens de SC+ (10(4), 10(5) e 2,3x10(5) UFC/g) superiores às permitidas pela legislação vigente. A água de imersão das fôrmas e a salmoura apresentaram contagens de SC+ e S. aureus inferiores a 1 UFC/ml não se constituindo em importantes fontes de contaminação. As mãos e os antebraços dos funcionários foram possivelmente as fontes de contaminação do queijo, isto é, alta contagem nos queijos estava associada à contagem elevada nas mãos (4x10² UFC/cm²) ou nos antebraços (4,7x10² e 3,3x10³ UFC/cm²) dos manipuladores.<br>In order to identify the main sources of contamination with Staphylococcus aureus and Staphylococcus coagulase positive (SC+), a manufacture process of prato cheese in a plant located in Lavras, State of Minas Gerais, was evaluated five times from October/2000 to April/2001. Raw and pasteurized milk, hand and forearms of cheese makers, brine, hoops flushing water and cheeses were analyzed for SC+ and S. aureus. High counts of SC+ and S. aureus (4x10³ to 4.8x10(6) CFU/ml and 4x10³ to 3.3x10(5) CFU/ml, respectively) were found in raw milk in four evaluations, but they decreased to values lower than 1 CFU/ml after pasteurization. In three evaluations, counts of SC+ in prato cheese samples were above legal limits (10(4), 10(5) and 2.3x10(5) CFU/g). The hoops flushing water and brine were not important contamination sources, both with counts lower than 1CFU/ml. The cheese makers probably were the main source of contamination, since high counts in cheese were correlated to high counts in their hands (4x10² CFU/cm²) or forearms (4.7x10² and 3.3x10³ CFU/cm²)

Qualidade microbiológica de queijo-coalho comercializado em Aracaju, SE Microbial quality of "coalho" cheese commercialized in Aracaju, SE

Determinou-se a ocorrência de Staphylococcus aureus, Salmonella spp. e de microrganismos indicadores de contaminação fecal em queijos-coalho comercializados em 15 pontos de venda do Mercado Central de Aracaju, SE, durante quatro meses. Dezesseis amostras (26,7%) foram positivas para Salmonella spp. e 28 (46,7%) positivas para estafilococos coagulase positiva. Quanto à contaminação por coliformes totais, 56 (93,3%) das amostras apresentaram valores entre 8,0 x10² e 1,23 x10(4)NMP/g, e de 2,72 x10² a 1,12 x10³NMP/g para coliformes termotolerantes. Estes valores não atenderam à legislação brasileira para queijo-coalho e as amostras analizadas podem ser classificadas como impróprios ao consumo humano.<br>The occurrence of Staphylococcus aureus, Salmonella spp., and microorganisms indicators of fecal contamination in "coalho"cheese commercialized in 15 retail store at the Central Market of Aracaju, SE during four months was determined. Sixteen samples (26.7%) were positive for Salmonella spp. and 28 (46.7%) for coagulase positive staphylococci. In relation to contamination by total coliforms, 56 samples (93.3%) presented values from 8.0 x10² to 1.23 x10(4)NMP/g; and for thermal tolerant coliforms, from 2.72 x10² to 1.12 x10³NMP/g. These values are not acceptable for the Brazilian legislation for "coalho" cheese. This indicates that the analyzed products were inappropriate to the human consumption