RESUMO
Students' conceptions and conceptual change are deeply investigated phenomena, and the results of such studies can be implemented in the didactic process. For this research, amphibians and reptiles were chosen, because they are animals which are significant for ecosystems but at the same time are often confused with each other. The goal of this study was to investigate students' conceptions about both groups, and on the basis of the results to design a teaching sequence (TS) which could lead to conceptual and attitudinal change. Authors used questionnaires and in-depth interviews to investigate conceptions and the results of the intervention. The significant correlations show that students tend to classify animals as amphibians or reptiles according to their skin and their living environment. Students' conceptions about animals indicate a tendency of being focused on purposefulness towards environment and evolution, and therefore can be considered an essentialist approach. The alternative conceptions did not change much after intervention, and results did not differ between age or gender groups. On the other hand, conceptions after intervention were more developed, and students asked more diverse questions about evolution and environmental protection, indicating their growing interest in these animals and attitudinal change.
RESUMO
The aim of this study was to estimate virulence potential of Salmonella enterica strains colonizing the gut of free-living sand lizards (Lacerta agilis L.). The strains belonged to three Salmonella serovars: Abony, Schleissheim, and Telhashomer. Adhesion and invasion abilities of the strains were determined in quantitative assays using the gentamicin protection method. Induction of apoptosis was assessed using HeLa cell monolayers. PCR assays were used for detection of 26 virulence genes localised within mobile elements: pathogenicity islands, virulence plasmids, and prophage sequences. In vitro studies revealed that all strains had adhesion and invasion abilities to human epithelial cells. The isolates were cytotoxic and induced apoptosis of the cells. The serovars differed in the number of virulence-associated genes: up to 18 genes were present in Salmonella Schleissheim, 17 in Salmonella Abony, whereas as few as six genes were found in Salmonella Telhashomer. Generally, Salmonella Abony and Salmonella Schleissheim did not differ much in gene content connected with the presence SPI-1 to -5. All of the strains lacked genes localised within bacteriophages and plasmids. The presence of virulence-associated genes and in vitro pathogenicity assays suggest that Salmonella sp. strains originating from autochthonous, free-living lizards can potentially infect and cause disease in humans.