Fate of non O157 Shigatoxigenic Escherichia coli in ovine manure composting

Livestock manure may contain pathogenic microorganisms which pose a risk to thehealth of animal or humans if the manure is not adequately treated or disposed of. Todetermine the fate of Shiga toxigenic Escherichia coli (STEC) nonO157 in composted manure from naturally colonized sheep, fresh manure was obtainedfrom animals carrying bacterial cells with stx1/ stx2 genes. Two composting systems were used, aerated andnon-aerated, and the experiments were done in Dracena city, São Paulo State. Everyweek, for seven weeks, one manure sample from six different points in both systemwas collected and cultured to determine the presence of E. coli, thepresence of the virulence genes in the cells, and also the susceptibility to 10antimicrobial drugs. The temperature was verified at each sampling. STEC non-O157survived for 49 days in both composting systems. E. coli non-STECshowing a high degree of antibiotic resistance was recovered all long the compostingperiod. No relationship was established between the presence of virulence genes andantibiotic resistance. The presence of virulence genes and multiple antibioticresistances in E. coli implicates a potential risk for these genespread in the human food chain, which is a reason for concern.Esterco de animais de criação pode conter microrganismos patogênicos, o querepresenta um risco para a saúde animal e a humana se o esterco não for adequadamentetratado ou descartado. Determinou-se o tempo necessário para a eliminação de Escherichia coli Shiga toxigenica (STEC) não O157 em estercoovino composto, obtido de fezes frescas de ovelhas naturalmente colonizadas com cepaSTEC não O157 que apresentavam os genes stx1/ stx2. Foram utilizados dois sistemas decompostagem, aerado e não aerado, em experimentos realizados na cidade de Dracena,estado de São Paulo. Todas as semanas, durante sete semanas, uma amostra decompostagem proveniente de seis pontos diferentes na leira, nos dois sistemas, foicoletada e semeada para a determinação da presença de E. coli, dapresença de genes de virulência nas células, bem como da sensibilidade dessas célulaa 10 drogas antimicrobianas. Em cada amostragem, a temperatura da leira foianalisada. Células de STEC não O157 sobreviveram por 49 dias nos dois sistemas decompostagem. E. coli não STEC com um alto grau de resistência aantibióticos foi recuperada ao longo de todo o período de compostagem. Não foipossível estabelecer relação entre a presença de genes de virulência e a resistênciaa antibióticos. A presença de genes de virulência e a resistência a múltiploantibióticos em E. coli representam um risco potencial para oespalhamento desses genes na cadeia alimentar humana, o que é motivo de grandepreocupação.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade de São Paulo - FORPUniversidade Estadual Paulista-Unesp FCAVUnespFCAV-UnespUniversidade Estadual Paulista-Unesp FCAVUnespFCAV-UnespFAPESP: 2008/00434-

Microbial and fermentation profiles, losses and chemical composition of silages of buffel grass harvested at different cutting heights

The present study evaluated the microbial population, fermentation profile, losses and dry matter recovery, and chemical composition of silages of buffel grass at different cutting heights. To evaluate the microbial fermentation dynamics, the treatments resulted from a 4 × 5 factorial combination consisting of 4 cutting heights and 5 fermentation periods, in a completely randomized design with three replications. The fermentation was evaluated at the end of 1, 3, 7, 15 and 30 days. The other characteristics of silages with 30 days were evaluated following a completely randomized design with four treatments, consisting of 4 cutting heights (30, 40, 50 and 60 cm), and five replications. Fermentation period and cutting height effects and interaction between both factors were observed on the populations of lactic acid bacteria (LAB), enterobacteria and molds and yeasts. The peak of development of LAB populations was observed on the seventh day of fermentation for the heights of 40 and 50 cm, with 8.25 and 8.30 log cfu/g, respectively. The pH values of silages ranged with different cutting heights, in which at the height of 50 cm the decrease was most pronounced. However, the pH values were similar between the cutting heights at the end of 30 days of fermentation. Quadratic relationship was observed between lactic acid concentrations and cutting heights. The crude protein content behaved linearly, initially showing 128.5 g/kg DM at 30 cm, decreasing as the cutting heights increased. The neutral detergent fiber and ether extract contents increased linearly with the cutting heights. Based on microbial populations, fermentation, losses and chemical composition, it is recommended to harvest buffel grass for silage from 50 cm on

Biosensor capability of the endometrium is mediated in part, by altered miRNA cargo from conceptus‐derived extracellular vesicles

We tested the hypothesis that the biosensor capability of the endometrium is mediated in part, by the effect of different cargo contained in the extracellular vesicles secreted by the conceptus during the peri-implantation period of pregnancy. We transferred Bos taurus taurus embryos of different origin, in vivo (high developmental potential (IV)), in vitro (intermediate developmental potential (IVF)), or cloned (low developmental potential (NT)), into Bos taurus indicus recipients. Extracellular vesicles (EVs) recovered from Day 16 conceptus-conditioned medium were characterized and their microRNA (miRNA) cargo sequenced alongside RNA sequencing of their respective endometria. There were substantial differences in the endometrial response to in vivo versus in vitro and in vivo versus cloned conceptuses (1153 and 334DEGs respectively) with limited differences between in vitro Vs cloned conceptuses (36 DEGs). The miRNA cargo contained in conceptus-derived EVs was similar between all three groups (426 miRNA in common). Only 8 miRNAs were different between in vivo and cloned conceptuses, while only 6 miRNAs were different between in vivo and in vitro-derived conceptuses. Treatment of endometrial epithelial cells with mimic or inhibitors for miR-128 and miR-1298 changed the proteomic content of target cells (96 and 85, respectively) of which mRNAs are altered in the endometrium in vivo (PLXDC2, COPG1, HSPA12A, MCM5, TBL1XR1, and TTF). In conclusion, we have determined that the biosensor capability of the endometrium is mediated in part, by its response to different EVs miRNA cargo produced by the conceptus during the peri-implantation period of pregnancy