Ultrastructural analysis of spores from diverse Bacillales species isolated from Brazilian soil.

Many species in the order Bacillales form a specialized cell type called a spore that is resistant to a range of environmental stresses. Transmission electron microscopy (TEM) reveals that the spore is comprised of a series of concentric shells, surrounding an interior compartment harbouring the spore DNA. The outermost of these shells varies considerably in morphology among species, likely reflecting adaptations to the highly diverse niches in which spores are found. To better characterize the variation in spore ultrastructure among diverse species, we used TEM to analyse spores from a collection of 23 aerobic spore-forming bacteria from the Solo do Distrito Federal (SDF strains), spanning the genera Bacillus, Lysinibacillus, Paenibacillus and Brevibacillus, isolated from soil from central Brazil. We found that the structures of these spores varied widely, as expected. Interestingly, even though these isolates are novel strains of each species, they were structurally very similar to the known examples of each species in the literature. Because in most cases, the species we analysed are poorly characterized, our data provide important evidence regarding which structural features are likely to be constant within a taxon and which are likely to vary.

Cell cycle, DNA replication, repair, and recombination in the dimorphic human pathogenic fungus Paracoccidioides brasiliensis.

DNA replication, together with repair mechanisms and cell cycle control, are the most important cellular processes necessary to maintain correct transfer of genetic information to the progeny. These processes are well conserved throughout the Eukarya, and the genes that are involved provide essential information for understanding the life cycle of an organism. We used computational tools for data mining of genes involved in these processes in the pathogenic fungus Paracoccidiodes brasiliensis. Data derived from transcriptome analysis revealed that the cell cycle of this fungus, as well as DNA replication and repair, and the recombination machineries, are highly similar to those of the yeast Saccharomyces cerevisiae. Among orthologs detected in both species, there are genes related to cytoskeleton structure and assembly, chromosome segregation, and cell cycle control genes. We identified at least one representative gene from each step of the initiation of DNA replication. Major players in the process of DNA damage and repair were also identified.

Draft Genome Sequence of FT9, a Novel Bacillus cereus Strain Isolated from a Brazilian Thermal Spring.

A Bacillus cereus strain, FT9, isolated from a hot spring in the midwest region of Brazil, had its entire genome sequenced.

Avaliação microbiológica da antissepsia pré-operatória das mãos / Microbiological evaluation of preoperative antisepsis of hands

Objetivo: Comparar a carga microbiana após a antissepsia das mãos, utilizando dois protocolos, um de acordo com a técnica da Organização Mundial de Saúde (OMS) e outro modificado. Metodologia: O estudo foi realizado com alunos voluntários do curso de odontologia da Universidade de Brasília, tendo sido composto de fases laboratorial e clínica. A coleta de amostras foi realizada com a técnica modified glove-juice, em três tempos: controle - após a lavagem das mãos com sabão neutro, após a antissepsia e na fase clínica pós-cirurgia. Todos os procedimentos foram realizados com intervalo de sete dias. Os dados foram analisados com o programa estatístico de computador Statistical Package for the Social Sciences (SPSS, versão 18.0 para Windows). Resultados: Foram incluídos, no estudo, cinco alunos, o que gerou 200 campos. As técnicas apresentaram resultados similares na fase laboratorial. Na fase clínica, a comparação do resultado entre as técnicas, utilizando os dados da enumeração das amostras controle e do pós-cirúrgico apresentou tamanho de efeito idêntico (z Wilcoxon = - 3,92; p<0,001; r = 0,88). Conclusões: As técnicas apresentaram resultados similares após a antissepsia e a cirurgia. A técnica modificada exige um menor tempo de antissepsia com menor rigidez, o que pode aumentar sua adesão.

Purpose: Compare the microbial counts after two procedures of hands scrub, one with the technique of the World Health Organization (WHO), and another modified. Methodology: A study was performed with dentistry students of the University of Brasília, encompassing laboratorial and clinical steps. The samples were collected following the modified glove-juice method, and consisted of three periods: control - after hands washing with neutral soap, after hands scrub and in the clinic phase after the surgery. The students did the procedures with an interval of seven days. The data was analyzed with the computer statistic program Statistical Package for the Social Sciences, version 18.0. Results: Five students were included, which produced the inspection of 200 plaques. The techniques were similar in the laboratory step. The techniques were compared in the clinic step using the data from microbiological counts of control and after surgery; the hands scrub in both procedures had the same size effect (z Wilcoxon = - 3,92; p < 0,001; r = 0,88). Conclusion: Both techniques had similar results after the hands scrub and after surgery. The modified technique is faster and easier than the WHO's technique; these results could increase the practice of hands scrub by the surgery team.