Phenotypic and genotypic characteristics of Escherichia coli strains of non-enteropathogenic E-coli (EPEC) serogroups that carry eae and lack the EPEC adherence factor and shiga toxin DNA probe sequences

This study was conducted to characterize the virulence potential of 59 Escherichia coli strains carrying eae and lacking the enteropathogenic E. coli adherence factor and Shiga toxin probe sequences. in hybridization studies, all strains carried the locus of enterocyte effacement (LEE)-associated DNA sequences. of the other 15 virulence DNA sequences tested, hly was the most frequent (44.1%); 17 combinations of these sequences were found, but strains carrying eae only (eae profile) were the most frequent (35.6%). Except for 1 cytodetaching strain, all others adhered to HeLa and Caco-2 cells, most of which (similar to 75.0%) showed variations of the localized adherence pattern. Actin accumulation was detected in 75.9% of the nondetaching strains. Most strains had LEE, probably inserted in pheU (49.2%), and presented a nontypeable intimin (83.1%). Translocated intimin receptor-derived DNA sequences correlated with enteropathogenic and enterohemorrhagic E. coli in 61.0% and 32.0% of the strains, respectively. Thirty-five different serotypes were found. Only strains with the eae profile were associated with diarrhea (P = .039).Universidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilUniv São Paulo, Inst Butantan, Lab Especial Microbiol, São Paulo, BrazilUniv São Paulo, Inst Adolfo Lutz, Secao Bacteriol, São Paulo, BrazilUniv São Paulo, Hosp Clin, Inst Crianca, São Paulo, BrazilUniv Estado Rio de Janeiro, Dept Microbiol, Rio de Janeiro, BrazilUniv London Imperial Coll Sci Technol & Med, Dept Biochem, London, EnglandUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilWeb of Scienc

Hypericum sp.: essential oil composition and biological activities

Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/ 13283/2003

Yield performance of half-sib families of physic nut (Jatropha curcas L.)

Among the oilseed plants, physic nut stands out for its yield potential and for the quality of its oil for biodiesel and biokerosene production. Currently, low seed yield, uneven fruit maturation and the lack of high yielding genotypes limit the viability of this crop. Here we evaluated the yield performance of a population, structured in 16 half-sib families, in the 2nd, 3rd and 4th years after planting (2009-11). Seed yield showed variability. The families maintained their relative performance over time. Contrary to expectations, seed yield was lower in the 4th year, probably due the increased competition between plants and leafhopper (Empoasca spp) incidence. Temporal yield stability and adaptability estimates indicated a trend toward maintaining plant superiority over time, and families 7 (1059 kg ha-1) and 12 (984 kg ha-1) showed the best stability and yield performance. Physic nut has the potential for greater yield gains.Dentre as oleaginosas alternativas destaca-se pinhão-manso pelo seu potencial de rendimento de grãos e pela qualidade de seu óleo para biodiesel e bioquerosene. Atualmente, a baixa produção de grãos, a desuniformidade na maturação de frutos e a inexistência de genótipos de alto rendimento limitam a competitividade desse cultivo. Avaliamos o desempenho de uma população estruturada em famílias de meios-irmãos, no 20, 30e 40anos pós-plantio (2009-2011). A produção de grãos mostrou variabilidade. As famílias mantiveram seu desempenho relativo ao longo do tempo. Contrariando as expectativas, a produtividade de grãos foi menor no 40ano, devido provavelmente à maior competição entre plantas e ao ataque de cigarrinhas (Empoasca spp). Estimativas de estabilidade e adaptabilidade temporal da produção indicaram tendência de manutenção da superioridade das plantas ao longo dos anos, destacando-se as famílias 7 (1059 kg ha-1) e 12 (984 kg ha-1) como as mais estáveis e produtivas. Pinhão manso apresenta potencial para maiores ganhos de produtividade

Hypericum perforatum plant cells reduce Agrobacterium viability during co-cultivation

Plant recalcitrance is the major barrier in developing Agrobacterium-mediated transformation protocols for several important plant species. Despite the substantial knowledge of T-DNA transfer process, very little is known about the factors leading to the plant recalcitrance. Here, we analyzed the basis of Hypericum perforatum L. (HP) recalcitrance to Agrobacterium-mediated transformation using cell suspension culture. When challenged with Agrobacterium, HP cells swiftly produced an intense oxidative burst, a typical reaction of plant defense. Agrobacterium viability started to decline and reached 99% mortality within 12 h, while the plant cells did not suffer apoptotic process. This is the first evidence showing that the reduction of Agrobacterium viability during co-cultivation with recalcitrant plant cells can affect transformation