Vaccination with Recombinant Microneme Proteins Confers Protection against Experimental Toxoplasmosis in Mice

Toxoplasmosis, a zoonotic disease caused by Toxoplasma gondii, is an important public health problem and veterinary concern. Although there is no vaccine for human toxoplasmosis, many attempts have been made to develop one. Promising vaccine candidates utilize proteins, or their genes, from microneme organelle of T. gondii that are involved in the initial stages of host cell invasion by the parasite. In the present study, we used different recombinant microneme proteins (TgMIC1, TgMIC4, or TgMIC6) or combinations of these proteins (TgMIC1-4 and TgMIC1-4-6) to evaluate the immune response and protection against experimental toxoplasmosis in C57BL/6 mice. Vaccination with recombinant TgMIC1, TgMIC4, or TgMIC6 alone conferred partial protection, as demonstrated by reduced brain cyst burden and mortality rates after challenge. Immunization with TgMIC1-4 or TgMIC1-4-6 vaccines provided the most effective protection, since 70% and 80% of mice, respectively, survived to the acute phase of infection. In addition, these vaccinated mice, in comparison to non-vaccinated ones, showed reduced parasite burden by 59% and 68%, respectively. The protective effect was related to the cellular and humoral immune responses induced by vaccination and included the release of Th1 cytokines IFN-γ and IL-12, antigen-stimulated spleen cell proliferation, and production of antigen-specific serum antibodies. Our results demonstrate that microneme proteins are potential vaccines against T. gondii, since their inoculation prevents or decreases the deleterious effects of the infection

Investigation of reaction mechanisms by electrospray ionization mass spectrometry: characterization of intermediates in the degradation of phenol by a novel iron/magnetite/hydrogen peroxide heterogeneous oxidation system

Electrospray ionization (ESI) mass spectrometry (MS) and tandem mass spectrometry (MS/MS) were used to monitor the oxidation of phenol by a novel heterogeneous Fenton system based on a Fe-0/Fe3O4 composite and H2O2. On-line ESI-MS(/MS) shows that this heterogeneous system promotes prompt oxidation of phenol to hydroquinone, which is subsequently oxidized to quinone, other cyclic poly-hydroxylated intermediates and an acyclic carboxylic acid. A peroxide-type intermediate, probably formed via an electrophilic attack of HOO. on the phenol ring, was also intercepted and characterized. ESI-MS(/MS) monitoring of the oxidation of two other model aromatic compounds, benzene and chlorobenzene, indicates the participation of analogous intermediates. These results suggest that oxidation by the heterogeneous system is promoted by highly reactive HO. and HOO. radicals generated from H2O2 on the surface of the Fe-0/Fe3O4 composite via a classical Fenton-like mechanism. Copyright (c) 2006 John Wiley & Sons, Ltd.20121859186

Atividade antibacteriana de óleos essenciais em cepas isoladas de infecção urinária Antibacterial activity of essential oils on microorganisms isolated from urinary tract infection

A análise da atividade antibacteriana de óleos essenciais de ervas medicinais (Ocimum gratissimum, L., Cybopogum citratus (DC) Stapf. e Salvia officinalis, L.) foi verificada frente a 100 cepas de bactérias isoladas de indivíduos da comunidade com diagnóstico de infecção urinária. Os microrganismos foram semeados em ágar Muller Hinton e os extratos aplicados com replicador de Steers e incubados a 37&deg;C por 24 horas. Verificou-se que Salvia officinalis, L. apresentou ação inibitória superior às outras ervas, tendo eficácia de 100% quando testadas em espécies de Klebsiella e Enterobacter, 96% em Escherichia coli, 83% contra Proteus mirabilis e 75% contra Morganella morganii.<br>The antibacterial activity of essential oils extracted from medicinal plants (Ocimum gratissimum, L., Cybopogum citratus (DC) Stapf., and Salvia officinalis, L.) was assessed on bacterial strains derived from 100 urine samples. Samples were taken from subjects diagnosed with urinary tract infection living in the community. Microorganisms were plated on Müller Hinton agar. Plant extracts were applied using a Steers replicator and petri dishes were incubated at 37&deg;C for 24 hours. Salvia officinalis, L. showed enhanced inhibitory activity compared to the other two herbs, with 100% efficiency against Klebsiella and Enterobacter species, 96% against Escherichia coli, 83% against Proteus mirabilis, and 75% against Morganella morganii