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The aim of this study was to evaluate the efficiency of trypsin treatment on the inactivation of bovine herpesvirus type 1 (BoHV-1) on in vitro produced by fertilization and artificially infected bovine embryos. Bovine embryos on day 7 were exposed with 10 microl of BoHV-1, Los Angeles strain 10(7.5) TCID. These embryos and control embryos were divided in two groups: submitted to the sequential washes or to the trypsin treatment according to the International Embryo Transfer Society (IETS) guidelines. The embryos and the last washing drop of each group were used as inoculum to infect Madin Darby bovine kidney (MDBK) cells and submitted to nested PCR reaction using the primer that encodes the gene conserved region of virus glycoprotein gB. The data have shown that the control embryos and their last washing drop were negative. The exposed embryos that were treated with trypsin have shown positive results on the n-PCR and MDBK culture, and their last washing drop were negative. Our data have demonstrated that the trypsin treatment was not able to eliminate the BHV-1 of the embryos, suggesting an interaction between virus and embryo.

The aim of this study was to evaluate the capacity of three semen processing techniques, Percoll gradient centrifugation, Swim-up and a combination of Swim-up and Percoll gradient centrifugation, to reduce the viral load of bovine viral diarrhea virus (BVDV) in experimentally infected semen samples. The evaluation was performed using two approaches: first, searching for the presence of virus in the processed samples (via virus titration and RT-PCR) and second, ascertaining the possible interference on in vitro embryo production. The sperm count and DNA integrity (Comet assay) of the processed samples were analyzed (Experiment 1). The amount of virus in the processed samples was determined by titration in cell culture (Experiment 2). The samples processed by Swim up/Percoll gradient centrifugation were utilized for in vitro embryo production, and the embryos produced were tested for BVDV by RT-PCR (Experiment 3). Sperm concentration, Comet assay and embryo production were analyzed by chi-squared tests (P<0.05). There was a significant difference between sperm separation techniques when the sperm count and Comet assay were analyzed. The sperm count obtained from the Swim up/Percoll gradient centrifugation group was lower than that obtained in either of the two other groups (Swim up and Percoll gradient centrifugation), and the Comet assay showed that the combination of the two semen processing techniques (Swim up/Percoll gradient) produced a 1.1% prevalence of Comet level 2, which was not observed in the other groups. The BVDV titer (10(6.68)TCID(50)/mL) added to experimentally infected semen samples decreased after Percoll gradient centrifugation to 10(2.3)-10(1)TCID(50)/mL; for the Swim up group, the titer range was 10(3.3)-10(1.87)TCID(50)/mL, and in the Swim up/Percoll gradient centrifugation group, BVDV was undetectable. The decreases in titer varied from 99.9% in the Swim up-processed group to 100% in the Swim up/Percoll gradient centrifugation group. In vitro embryo production displayed similar blastocyst development rates among all groups, and RT-PCR was negative for the produced embryos. The data showed that the combination of Swim up/Percoll gradient centrifugation promoted the elimination of BVDV from the semen samples without damaging spermatozoa cells and also allowed successful in vitro embryo production free of BVDV. Hence, the risk of BVDV contamination is negligible for the embryo recipient.

The aims of this study were to assess in vitro if bovine oocytes and oviductal epithelial cells from slaughterhouses for in vitro fertilization use may be infected with bovine herpesvirus 1; to analyze whether the treatment with trypsin according to the International Embryo Transfer Society guideline is efficient to inactivate the bovine herpesvirus 1; to morphologically study the virus-oocyte interaction through optical microscopy. In this study, Madin Darby Bovine Kidney (MDBK) cells that were co-cultured with oocytes matured in vitro and exposed to bovine herpesvirus 1 showed a cytopathic effect. The nested polymerase chain reaction for the supernatant was positive for the bovine herpesvirus 1, thus suggesting that the cytopathic effect observed in the MDBK monolayer was seen due to virus replication and not because of any culture toxicity. It was also observed cytopathic effect and positive nested polymerase chain reaction in MDBK cells co-cultured with in vitro maturated oocytes free of virus, but that were co-cultured in uterine epithelial cells pre-infected with bovine herpesvirus 1 and washed or not with trypsin, demonstrating an oocyte contamination by the virus. When trypsin-washing efficacy was evaluated, we could observe that the trypsin treatment was not able to eliminate the bovine herpesvirus 1 of the oocytes, and it was not observed any morphological difference in the infected oocytes.

No abstract

RESUMOO Mycoplasma é considerado cosmopolita, podendo ser disseminado através do comércio internacional de animais, sêmen industrializado e de produtos de transferência de embriões. A expansão de células do cumulus é utilizada como parâmetro de avaliação de oócitos bovinos cultivados in vitro e suas alterações morfológicas são representativas. O objetivo deste trabalho foi avaliar a interação do Mycoplasma bovigenitalium, exposto experimentalmente à cultura primária de célula do cumulus, após o período de maturação. Complexos oócitos cumulus (COCs) obtidos através de punção folicular de ovários bovinos, provenientes de abatedouro, foram divididos em dois grupos para serem maturados durante 24h em meio de maturação (TCM199 + hormônios) em estufa a 38º C, 5% de CO 2 , 95% de umidade. Posteriormente, os oócitos foram retirados das placas, permanecendo somente com as células do cumulus aderidas. Com o monoestrato celular formado, um grupo foi infectado com 30 mL de M. bovigenitalium, replicado em meio Hayflick modificado a 37º C em estufa de microaerofilia, enquanto o outro foi mantido como controle. Os resultados mostraram que, com 24h de exposição ao patógeno, as culturas apresentaram um pequeno número de células arredondadas e granulosas, quando comparadas as dos controles. Esse efeito persistiu até o sétimo dia, onde se iniciou um processo de descolamento das células. Pode-se concluir que uma contaminação por micoplasma pode ser imperceptível às manipulações da FIV, pois células infectadas por esse grupo de bactérias não apresentam turvações no meio de cultura e, quando não lisam a célula hospedeira, tornam mais suscetível ao ambiente e outros agentes infecciosos. PALAVRAS-CHAVE:Mycoplasma bovigenitalium, complexos oócitos cumulus (COCs), culturas, fecundação in vitro de embriões (FIV). ABSTRACT INTERACTION OF MYCOPLASMA BOVIGENITALIUM WITH PRIMARY-CULTURE CUMULUS CELLS AFTER IN VITRO MATURATION PERIOD. TheMycoplasma is considered cosmopolitan and can be disseminated through international trade of animals, industrialized semen and embryo transfer products. The expansion of cumulus cells is used as a parameter for evaluating cattle oocytes cultivated in vitro, and their morphological changes are representative. The aim of the present study was to evaluate the interaction of Mycoplasma bovigenitalium with primary-culture cumulus cells, after the in vitro maturation period. Cumulus complex oocytes (COCs) obtained through follicular puncture of ovaries from a cattle slaughterhouse were divided into two groups to be matured for 24 hours in the maturation medium (TCM 199 + hormones) in a climate controlled chamber at 38° C, 5% CO 2 , and 95% humidity. Subsequently, the oocytes were removed from the plates, which remained with only the cumulus cells attached. With the monostratum cell formed, one group was infected with 30 mL (5 x 10 6 cells/mL) M. bovigenitalium, replicated in modified Hayflick medium at 37° C in a mycroaerofilic chamber, while the other was kept as a control. The results showed that with 24 hours of ...

Avaliou-se a eficácia dos tratamentos, definidos pela International Embryo Transfer Society (IETS), de oócitos bovinos, maturados in vitro e expostos experimentalmente à Leptospira interrogans sorovar Grippotyphosa. Os oócitos foram obtidos por meio de punção folicular, selecionados e distribuídos em quatro grupos, expostos ao patógeno e submetidos aos diferentes tipos de tratamentos. Foram expostos à cepa na concentração de 4,7.10(5)/µL, virulenta e não adaptada ao meio de manutenção EMJH, e, de 6,3.10(5)/µL, avirulenta e adaptada ao meio, por 24 horas. Os grupos tratados com tripsina ou antibióticos apresentaram eficácia de 21,7%, e o grupo lavado sequencialmente 33,4%. Os tratamentos não foram eficazes para os contaminados com a cepa avirulenta. Concluiu-se que as normas de controle de qualidade estabelecidas pela IETS poderiam ser revisadas e, possivelmente, redefinidas, uma vez que a eficácia dos tratamentos, provavelmente, não depende somente da espécie do patógeno, pois há interferência da virulência e de ação dos tratamentos sobre o tipo de patógeno.

ABSTRACT:The aim of this study was to evaluate the reduction of viral replication (Colorado BoHV-1) in murine embryos after the treatment of ethanol extract of Punica granatum peel (PgEE). Swiss female mice aged 6 to 8 weeks were superovulated with 0.2 mL of the 5 UI hormones (eCG and hCG) and mated with males of the same age. After 18 hours, the females were euthanized in a CO 2 chamber, and through the opening in the peritoneum, zygotes were collected and washed with 0.5% pronase solution. The zygotes were divided into four groups: G 1 (control), G 2 (exposed to the virus Colorado BoHV -1 to 10 8 TCID 50 /mL), G 3 (exposed to PgEE) and G 4 (exposed to the virus and to PgEE). The groups were maintained at 37.5ºC in TCM199 (100 mL) with 10% fetal bovine serum in an incubator at 5% CO 2 and 95% humidity. After 24 h, we analyzed the cleavage rate (Fisher's exact test; p<0.05), the morphology (by light microscopy), the nested-PCR and the titration of embryos in co-culture with MDBK cells after over 72 h of treatment (Mann-Whitney test; p<0.05) and transmission electron microscopy (TEM). The murine embryos treated with PgEE showed satisfactory results: no morphological changes, cleavage rate similar to controls, despite the detection of the presence of virus by nested PCR and TEM, there was a decrease of the viral titer after the treatment with this extract, which suggests interference of this treatment in the viral cycle BoHV-1 Colorado without altering the embryo development.