Abstract The enterotoxigenic Escherichia coli (ETEC) strain is one of the most frequent causative agents of childhood diarrhea and travelers’ diarrhea in low-and middle-income countries. Among the virulence factors secreted by ETEC, the exoprotein EtpA has been described as an important. In the present study, a new detection tool for enterotoxigenic E. coli bacteria using the EtpA protein was developed. Initially, antigenic sequences of the EtpA protein were selected via in silico prediction. A chimeric recombinant protein, corresponding to the selected regions, was expressed in an E. coli host, purified and used for the immunization of mice. The specific recognition of anti-EtpA IgG antibodies generated was evaluated using flow cytometry. The tests demonstrated that the antibodiesdeveloped were able to recognize the native EtpA protein. By coupling these antibodies to magnetic beads for the capture and detection of ETEC isolates, cytometric analyses showed an increase in sensitivity, specificity and the effectiveness of the method of separation and detection of these pathogens. This is the first report of the use of this methodology for ETEC separation. Future trials may indicate their potential use for isolating these and other pathogens in clinical samples, thus accelerating the diagnosis and treatment of diseases. (ETEC travelers lowand low middleincome middle income countries important study E developed Initially prediction regions host mice antiEtpA anti cytometry isolates sensitivity samples diseases

Phytochemical investigations of the stem bark, leaves and twigs of Guatteria citriodora resulted in the isolation of eight alkaloids: liriodenine, lysicamine, O-methylmoschatoline, 3-methoxyoxoputerine, palmatine, 3-methoxyguadiscidine, guattescidine and oxoputerine. The structures of the isolated substances were established by extensive spectroscopic techniques (1D and 2D NMR) and mass spectrometry (MS), as well as by comparison with data reported in the literature. The in vitro antimalarial activity of the alkaloidal fractions of the leaves and twigs against Plasmodium falciparum FCR3 showed significant results, with IC50 = 1.07 and 0.33 mg mL-1, respectively. The alkaloidal fraction of the leaves showed moderate activity against Enterococcus faecalis, with IC50 = 125.0 mg mL-1. Antiplasmodial and antibacterial activities are attributed to alkaloidal constituents.