Kátia Eliane Santos Avelar

Production of bacteriocin by Bacteroides fragilis and partial characterization

The ability of Bacteroides fragilis strains, isolated from various sources, to produce bacteriocin was evaluated. All strains isolated from intestinal infections were producers in high levels and less susceptible to the others. Strains from other origins were found to produce bacteriocin at a medium level and they were variably susceptible. Some properties of one bacteriocin produced by the Bact. fragilis 079298–3 strain were analysed, providing evidence of its protein nature, with stability over a wide range of pH and retained inhibitory activity after heating. This variability seems to suggest that bacteriocin typing is a good method for this species.

New PCR ribotypes of Clostridium difficile detected in children in Brazil

A total of 35 Brazilian isolates of Clostridium difficile from faecal stools and four isolates from hospital environments were analyzed by PCR ribotyping. A whole cell protein profile (as an alternative for serogrouping), in vitro toxin production and susceptibility to vancomycin, metronidazole and clindamycin were also investigated. All strains were typeable by both phenotypic and genotypic methods, and a total of 13 different PCR ribotypes were identified, of which seven (132, 133, 134, 135, 136, 142 and 143) were considered new types and accounted for 78.5% of all samples evaluated (including hospital environments). A non-toxigenic C. difficile PCR ribotype 133 was detected in all children groups examined (inpatients, outpatients and healthy children), whilst toxigenic PCR ribotypes 015, 131, 134 and 135 were associated mostly with symptomatic children. Serogroups G and D were disseminated both in patients from the community and from the pediatric hospital, with group G prevalent among outpatient children. All strains were susceptible to vancomycin and metronidazole but high levels of resistance to clindamycin were found, especially among serogroups G and D. Co-existence of different ribotypes and serogroups in the same individual was observed. The new seven ribotypes found in this investigation may represent strains characteristic of this region of Brazil.

Presence of the cfxA gene in Bacteroides distasonis.

In this study we investigated the presence of the cfxA gene (encoding a class A beta-lactamase) in 73 strains of the Bacteroides fragilis group belonging to the species B. distasonis (34), B. vulgatus (14), B. thetaiotaomicron (8), B. merdae (6), B. caccae (9) and B. ovatus (2) isolated from human intestinal microflora of healthy children and adults. Employing specific primers to the cfxA gene, a 312-bp amplified fragment was obtained in 2 strains of B. vulgatus and 9 strains, the majority from children, of B. distasonis. The expression of this enzyme was analysed by determining the MICs to cefoxitin and cefotaxime and values varied from 2 to >256 microg/ml of both cefoxitin and cefotaxime. Sequence analysis of the amplicons corresponding to the cfxA gene from B. distasonis and B. vulgatus revealed identical sequences between these isolates and high similarity with other beta-lactamase genes of anaerobes such as cfxA of B. vulgatus (99%) and cfxA2 of Prevotella intermedia (99%), both sequences of which deposited in Genbank under accession numbers U38243 and AF118110, respectively. However, a fragment obtained from a B. distasonis strain (EC17-4) showed a unique RFLP profile and 87% nucleotide similarity with cfxA and cfxA2 genes. These results seem to suggest a dissemination of these resistance determinants among Bacteroides species.

Surface vesicles : A possible function in commensal relations of Bacteroides fragilis

Surface vesicles (SV) defined by electron microscopy as outer membrane (OM) extrusions were detected in Bacteroides fragilis strains from distinct sources. A partial identity between SV and OM electrophoretic protein profiles, in addition to the microscopic analysis, may suggest the designation of OMSV. Sialidase activity, a virulence determinant, was associated with these sub-cellular structures in all the strains, but in an inverse relation to the vesicle quantity per cell. A commensal strain, previously defined as avirulent in an animal model, presented the lowest vesicle-associated sialidase activity and the greatest SV expression as opposed to what happened with clinical and environmental strains. These results seem to suggest that these surface components have a function in commensal stages of B. fragilis.

Decreased Susceptibility to Nitroimidazoles Among Bacteroides Species in Brazil

In this study, 197 strains of Bacteroides genus from different species and origins were evaluated with regard to their susceptibility to 5-nitroimidazoles (5-Ni)—such as tinidazole, ornidazole, and metronidazole—using the agar dilution method. The presence of nim genes was also investigated by polymerase chain reaction. It was found that 5.6% of Bacteroides strains among all origins showed decreased susceptibility (minimum inhibitory concentrations varying from 4 to 16 μg/ml) to at least one of the imidazoles studied without any known nim gene associate. Also, we detected one strain isolated from a polluted aquatic environment in which one nim gene was found and characterized as nim B using restriction fragment length polymorphism and sequencing. Hence, resistance to 5-Ni should be monitored closely because they constitute, among few drugs, the ones quite effective in treating Bacteroides infections.

Whole-cell and Periplasmic Protein Banding Patterns of Environmental and Human Bacteroides fragilis Strains

In order to investigate the relationship among virulent and avirulent Bacteroides fragilis strains, SDS-PAGE of whole-cell proteins (WP) and periplasmic proteins (PP) were used to establish a protein profile of strains isolated from human infections, fecal flora and environmental water. Despite different sources of the strains, no significant differences were observed as determined by the WP SDS-PAGE analysis. In contrast, the proteins obtained from the bacterial periplasm showed differences in the electrophoretic protein profile. Two distinct PP profile patterns were obtained. Pattern A included 6 out of the 8 virulent strains and pattern B, 6 out of 8 avirulent strains. Interestingly, an environmental strain that was capable of inducing abscesses in mice, had a PP profile highly similar to that of the virulent strains from human infections. These data indicate that PP from B. fragilis may be useful to characterize differences among virulent and avirulent strains. Moreover, strains isolated from environmental water may also be a source of exogenous infections by B. fragilis.

Electrophoretic characterization of exposed outer membrane proteins in environmental and human Bacteroides fragilis strains

Bacteriodes fragilis isolated from aquatic environment, from infectious process and from human feces were compared as to their outer membrane protein electrophoretic profiles after staining with Coomassie blue and reacting with antibodies prepared against whole-cell antigens of a reference strain from a clinical source. A marked homogeneity was found among the strains with these methodologies. The profiles of all strains obtained after radio-iodination of the intact cell showed qualitative similarity when compared with the profiles obtained by the other methods. Thus, these data allow us to suggest the designation of the peptides observed in the autoradiograms as surface-exposed proteins. Differences observed in the autoradiograms in the expression of bands mainly detected at a molecular weight of 28 in the commensal strain 118,310 defined previously as avirulent, in addition to a distinction in the titres of agglutination with the sera tested and lower reactivity in the immunoblotting assays, suggest a relationship of the B. fragilis surface architecture with the virulence potential as well as with the origin of the strain.

O DESENVOLVIMENTO LOCAL SOB A PERSPECTIVA DO TRABALHO: UM ESTUDO DE CASO DA FÁBRICA DE TECIDOS DE BANGU

Este artigo visa entender a relacao entre o trabalho e o desenvolvimento local, como fatores impulsionadores do esforco para a diminuicao da exclusao social. Por meio da analise conceitual de pobreza e privacao de capacidades, verifica-se quais as variaveis impactam no quadro de exclusao social. A partir dessa analise, o estudo faz uma comparacao entre os programas de qualificacao profissional PLANFOR e PNQ, oferecidos a populacao e seus respectivos resultados. Para ilustrar o estudo de caso, foi descrito o surgimento do bairro de Bangu e a forma como a atividade da Fabrica de tecidos promoveu o desenvolvimento do entorno, gerando trabalho, renda e bem-estar social, por meio de acoes em beneficio da saude, da educacao e da qualificacao profissional da populacao.

CONHECIMENTO DE ESTUDANTES DA EDUCAÇÃO BÁSICA SOBRE IGUALDADE DE GÊNERO

A escola, na visao de muitas pessoas, ainda detem certa neutralidade que se sabe nao condiz com a realidade, ja que e lugar de producao, reproducao e/ou transformacao da sociedade. Dentro do universo escolar, dependendo das atitudes de professores, esses conhecimentos vao encontrar reforco e legitimacao e, assim, o posicionamento das criancas pode ser observado em atitudes, gestos, brincadeiras, palavras e preferencias. Isso ira refletir na escola, pois as atividades que envolvem calculos sao de preferencia masculinas, e apesar de terem a mesma possibilidade, as meninas acreditam ser menos capazes, ou nao aptas, para a Matematica. A presente pesquisa parte da premissa de que para combater desigualdades como essa, a educacao desempenha papel fundamental. Na busca de contribuir com a tematica, o projeto “Implicacoes do Ambiente no Processo de Ensino-Aprendizagem: Estudos sobre Escolas Publicas do Complexo do Alemao”, apoiada pelo Programa Observatorio da Educacao, OBEDUC, da Coordenacao de Aperfeicoamento de Nivel Superior, CAPES, do Ministerio da Educacao do Brasil, buscou identificar a percepcao sobre a igualdade de genero por adolescentes do Colegio Estadual Prof. Jose de Souza Marques, localizado, na cidade do Rio De Janeiro, RJ, por meio de pesquisa qualitativa, realizada com as turmas de 1° ano do Ensino Medio. Apos a analise dos dados, foi observado que 72% dos alunos acreditavam que a separacao de genero nao deva ser praticada, afirmando que as discussoes sobre genero na escola podem melhorar a conscientizacao e respeito a diversidade de valores, crencas e comportamentos, com garantia da dignidade do ser humano.

Seroprevalence of and risk factors for leptospirosis in the City of Manaus, State of Amazonas, Brazil

INTRODUCTION Leptospirosis is caused by a bacterium of the genus Leptospira. This study aimed at investigating the seroprevalence of and risk factors for leptospirosis in humans in Manaus, State of Amazonas. METHODS Interviews were performed, and 1,000 blood serum samples were examined using a microscopic agglutination test. RESULTS Forty-three cases were positive; there were 10 serotypes, with coagglutination in 8 cases. The most frequently occurring serotypes were Icterohaemorrhagiae (20.7%), Cynopteri (20.7%), Australis (18.8%), and Copenhageni (16.9%), and the Midwest (54.7%) and South (23.8%) had the most cases; these areas lack basic sanitation. CONCLUSIONS Disease occurrence might be reduced through improved basic infrastructural conditions.