Determination of flagellar types by PCR-RFLP analysis of enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) strains isolated from animals in Sao Paulo, Brazil

This study evaluated the polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) analysis of fliC for typing flagella antigen (H) of Shiga toxin-producing Escherichia coil (STEC) and enteropathogenic E. coli (EPEC) strains isolated from different animals. The molecular typing of the H type was efficient in the determination of 93 (85%) strains. Two nonmotile (H-) E. coil strains showed a PCR-RFLP electrophoretic profile that did not match known H type patterns. The fliC nucleotide sequence of strains B2N and 4a revealed a nucleotide substitution at the restriction site and a nucleotide insertion that generated a stop codon, respectively. The results of this study showed that PCR-RFLP analysis of fliC is faster, less laborious and as efficient for the determination of H type E. coli isolated from animals, compared to serotyping and that it is useful in determining H type in nonmotile strains and strains expressing non-reactive H antigens. Moreover, the fliC sequence of strain B2N suggests that we could have found a new flagellin antigen type. (C) 2010 Elsevier Ltd. All rights reserved.

Molecular detection of enteropathogenic Escherichia coli in asymptomatic captive psittacines

Psittaciformes are one of the most endangered groups of birds, and several Brazilian species are classified between vulnerable and critically endangered. It is thus necessary to identify agents that cause infections in captive wild animals and to assess the risks posed thereof and to design interventions to minimize the possibility of disease outbreaks, leading to the conservation of endangered species. The purpose of this study was to identify enteropathogenic Escherichia coli (EPEC) cloacal isolates from asymptomatic psittacines in captivity and evaluate the distribution of the EPEC pathotype. Cloacal swabs were obtained from 46 asymptomatic birds, and resulting isolates were tested by polymerase chain reaction (PCR) for the presence of the attaching and effacing gene (eae) and bundle-forming pilus structural gene (bfpA) of EPEC. Samples from several species were tested, and three samples were found to be positive for the eae and bfpA genes and characterized as typical EPEC. This is the first report of this pathotype in asymptomatic psittacines. Although certain E. coli strains are more pathogenic than others, various factors should be considered when determining the potential of E. coli isolates to cause disease in captive psittacines. Birds that are positive for the EPEC (typical) strain could be zoonotic sources of infection, and may have acquired these strains through contact with humans or domestic animals. These findings may also be valuable for the long-term management of endangered species ex situ as one EPEC sample was isolated from a Red-tailed Amazon (Amazona brasiliensis).

A critical analysis on "Active Learning" in the light of Cultural-Historical Activity Theory (CHAT): Implications to Physics Education and to experimental activities as a particular case.

This is a research paper in which we discuss “active learning” in the light of Cultural-Historical Activity Theory (CHAT), a powerful framework to analyze human activity, including teaching and learning process and the relations between education and wider human dimensions as politics, development, emancipation etc. This framework has its origin in Vygotsky's works in the psychology, supported by a Marxist perspective, but nowadays is a interdisciplinary field encompassing History, Anthropology, Psychology, Education for example.

Hands-on experiments in the Practicum: repositioning student teachers' autonomy.

Following a worldwide trend, the Initial Teacher Education (ITE) Programmes in Brazil are recently searching for ways of integrating practice into curriculum. It raises question about what practice must be integrated and how. Notably, university-based courses are disconnected from school and have low commitment with school issues (Zeichner, 2009).The student teacher induction into school daily life is not an easy task, mainly when the practitioners are transforming physics classroom practice toward an active learning. Drawing on cultural-historical framework (Wolff-Michael Roth & Lee, 2007; Vygotsky, 1978) this study addresses the articulation between Practicum in Physics Classes and the Hands-on Experiments (HoE) used throughout the Practicum. Although in a different level, both Practicum and HoE are linked with an idea of practice. Particularly, this study focuses on how HoE might foster student teachers' autonomy and agency in the Practicum. Data was gathered in the course Practice of Physics Teaching at University of São Paulo/Brazil in 2010; in a cohort of 60 student teachers doing a year-long Practicum in urban school in São Paulo city. Data was analysed using qualitative research methods (Roth, 2005), based on 14 interviews and video records of the student teacher preparing the HoE for Practicum we will present in general lines the role of HoE for student teacher autonomy.