Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey.

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Antibiotic, Pesticide, and Microbial Contaminants of Honey: Human Health Hazards

Medicinal plants have a long history of use in therapy throughout the world and still make an important part of traditional medicine. Thus, medicinal plants and herbal products must be safe for the patient (consumer). This review addresses biological contaminants (microbes and other organisms) and chemical contaminants (mycotoxins, toxic elements such as heavy metals, and pesticide residues) as major common contaminants of medicinal herbs and herbal products. To prevent and screen for contamination and ensure safety and conformity to quality standards, medicinal herbs and herbal products should be included in appropriate regulatory framework.

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Contaminants of medicinal herbs and herbal products.

https://www.pedneur.com/article/S0887-8994(04)00537-5/pdf

Recent advances in infant botulism.

A specific and sensitive combined selection and enrichment PCR procedure was developed for the detection of Clostridium botulinum types B, E, and F in fecal samples from slaughtered pigs. Two enrichment PCR assays, using the DNA polymerase rTth, were constructed. One assay was specific for the type B neurotoxin gene, and the other assay was specific for the type E and F neurotoxin genes. Based on examination of 29 strains of C. botulinum, 16 strains of other Clostridium spp., and 48 non-Clostridium strains, it was concluded that the two PCR assays detect C. botulinum types B, E, and F specifically. Sample preparation prior to the PCR was based on heat treatment of feces homogenate at 70 degrees C for 10 min, enrichment in tryptone-peptone-glucose-yeast extract broth at 30 degrees C for 18 h, and DNA extraction. The detection limits after sample preparation were established as being 10 spores per g of fecal sample for nonproteolytic type B, and 3.0 x 10(3) spores per g of fecal sample for type E and nonproteolytic type F with a detection probability of 95%. Seventy-eight pig fecal samples collected from slaughter houses were analyzed according to the combined selection and enrichment PCR procedure, and 62% were found to be PCR positive with respect to the type B neurotoxin gene. No samples were positive regarding the type E and F neurotoxin genes, indicating a prevalence of less than 1.3%. Thirty-four (71%) of the positive fecal samples had a spore load of less than 4 spores per g. Statistical analysis showed that both rearing conditions (outdoors and indoors) and seasonal variation (summer and winter) had significant effects on the prevalence of C. botulinum type B, whereas the effects of geographical location (southern and central Sweden) were less significant.

Development of a Combined Selection and Enrichment PCR Procedure for Clostridium botulinum Types B, E, and F and Its Use To Determine Prevalence in Fecal Samples from Slaughtered Pigs

Clostridium botulinum is a diverse group of bacteria characterized by the production of botulinum neurotoxin. Botulinum neurotoxins are classified into serotypes (BoNT/A–G), which are produced by six species/Groups of Clostridia, but the genetic background of the bacteria remains poorly understood. The purpose of this study was to use comparative genomics to provide insights into the genetic diversity and evolutionary history of bacteria that produce the potent botulinum neurotoxin. Comparative genomic analyses of over 170 Clostridia genomes, including our draft genome assemblies for 59 newly sequenced Clostridia strains from six continents and publicly available genomic data, provided in-depth insights into the diversity and distribution of BoNT-producing bacteria. These newly sequenced strains included Group I and II strains that express BoNT/A,/B,/E, or/F as well as bivalent strains. BoNT-producing Clostridia and closely related Clostridia species were delineated with a variety of methods including 16S rRNA gene, concatenated marker genes, core genome and concatenated multi-locus sequencing typing (MLST) gene phylogenies that related whole genome sequenced strains to publicly available strains and sequence types. These analyses illustrated the phylogenetic diversity in each Group and the diversity of genomic backgrounds that express the same toxin type or subtype. Comparisons of the botulinum neurotoxin genes did not identify novel toxin types or variants. This study represents one of the most comprehensive analyses of whole genome sequence data for Group I and II BoNT-producing strains. Read data and draft genome assemblies generated for 59 isolates will be a resource to the research community. Core genome phylogenies proved to be a powerful tool for differentiating BoNT-producing strains and can provide a framework for the study of these bacteria. Comparative genomic analyses of Clostridia species illustrate the diversity of botulinum-neurotoxin-producing strains and the plasticity of the genomic backgrounds in which bont genes are found.

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Comparative genomic analyses reveal broad diversity in botulinum-toxin-producing Clostridia.

The isolation of Clostridium botulinum from honey samples is described. Botulism is characterized as an intoxication provoked by ingestion of contaminated foods with this toxin. Infant botulism happens by the ingestion of spores of C. botulinum together with food that in special conditions of the intestinal tract, such as those present in babies of less than 1 year old, will allow the germination and colonization of the intestine with production and absorption of botulinic toxin. The samples were subjected to dilution and to a thermal shock and cultivated in modified CMM (Difco). Cultures were subjected to Gram smears and toxicity tests in mice. The toxic cultures were purified in RFCA (Oxoid) plates and incubated in anaerobic jars. Positive samples were typed using the mouse assay neutralization test. From the 85 honey samples analyzed, six were positive for C. botulinum (7.06%), and identified as producers of type A, B, and D toxins.

Study of the presence of the spores of Clostridium botulinum in honey in Brazil.

O problema inicial do livro de Mario Porta e o de discutir a aprendizagem e propor um metodo de abordagem da filosofia. Na introducao, o autor pede ao leitor que seu livro seja julgado por sua utilidade, isto e, a de efetivar uma certa pratica de exposicao filosofica preocupada em ser compreensivel e acessivel ao leitor

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A filosofia a partir de seus problemas

We analyzed the National Curriculum for Secondary Schools with respect to the ontological, epistemological, historical, social and conceptual biology. This study aims to bring information and thinking about the inclusion of history and philosophy of biology for secondary education and for teacher training. We performed an analysis of PCNEM, PCNEM+ and Curriculum Guidelines as a whole from established categories. The results indicate a predominance of the ontological view of mechanistic biology. Epistemologically, although acknowledged, the question of scientific method is rarely discussed. The historical approach and social scientific activity and scientific knowledge are recognized by the documents, but an instrumental view prevails. The conceptual aspects are comprehensive and take into account the theories of structural biology. A philosophical discussion on the biology is missing in the parameters, indicating the need for the inclusion of issues related to ideas of determinism, chance and teleology.

https://www.if.ufrgs.br/cref/ojs/index.php/ienci/article/download/228/160

O conhecimento biológico nos documentos curriculares nacionais do ensino médio: uma análise histórico-filosófica a partir dos estatutos da biologia

This work aimed at identifying the most important consequences of Popper's conception of science education, which started a fertile debate in the Philosophy of Science. By following this debate, it is possible to notice the richness of the cientific process, recognizing the contributions brought by those who debated with Popper, and the importance of aspects of science that Popper valued and attempted to preserve. The criticism and the debate over the approaches towards conceptual change contributed to the perception of the wide extent and complexity of this process. However, the maintenance of certain aspects, inherent in the process of conceptual change, may be relevant when the institutional objectives of the schools and the social expectations over the appropriate understanding and over the attempt to overcome current paradigms are considered. In this way, Popper's work may offer important support to valuing rational aspects that could inform the process of learning Science.

http://www.scielo.br/pdf/ciedu/v15n2/a03v15n2.pdf

A concepção de ciência de Popper e o ensino de ciências

The main objective of this survey is describing signly the metaphor learning resource, with focus on biology education. Our teorical reference is the peircean semiotics, because it means solid heritage to code surveys implicated at science education, it led us to do an explanation about the main lines about that reference, addressed to researchers and lecturers interested in those reasonings. In the description yearned, another objectives appear: demonstrate diferences between metaphor/analogy and pragmatic analogy; to list metaphors, from cell representation analysis, and argue about principals diferences and probable cognitive consequences between the metaphor event in the visual representation and speech sentences. Therefore we analysed the animal cell of a high school first grade studying book – biology – cell biology – used by Sao Paulo and another state students. The findings demonstrate the undeniable importance of the metaphor as a learning tool in the biology education, and new findings about that, such as its limits in the concept elaboration, gnosiologic consequences for receptioning, the search needs for propositions– pictures between concept relations – in the science speech construction, and other results.

https://www.if.ufrgs.br/cref/ojs/index.php/ienci/article/download/352/219

Marcelo Carbone Carneiro

Papers

Study of the presence of the spores of Clostridium botulinum in honey in Brazil.

A filosofia a partir de seus problemas

O conhecimento biológico nos documentos curriculares nacionais do ensino médio: uma análise histórico-filosófica a partir dos estatutos da biologia

A concepção de ciência de Popper e o ensino de ciências

Uma descrição semiótica da metáfora no ensino de biologia: asserções sobre a célula animal