RESUMO
Newly designed group-specific PCR primers for denaturing gradient gel electrophoresis (DGGE) were used to investigate foaming mycolata from a bioreactor treating an industrial saline waste-water. Genetic profiles on DGGE gels were different with NaCl at 1.65 and 8.24 g l(-1), demonstrating that mycolata community was affected by salinity. A semi-nested PCR strategy resulted in more bands in community genetic profiles than direct amplification. DNA sequencing of bands confirmed the efficacy of the novel primers with sequences recovered being most similar to foam producing mycolata. The new group-specific primers/DGGE approach is a new step toward a more complete understanding of functionally important groups of bacteria involved in biological treatment of waste-water.
Assuntos
Actinobacteria/genética , Primers do DNA/genética , Resíduos Industriais/análise , Reação em Cadeia da Polimerase/métodos , Gerenciamento de Resíduos/métodos , Actinobacteria/isolamento & purificação , Biodegradação Ambiental , Ecossistema , Eletroforese em Gel de Poliacrilamida , Ácidos Micólicos/química , RNA Ribossômico 16S/classificação , Análise de Sequência de DNA/métodos , Purificação da Água/métodosRESUMO
Although molecular studies have revealed potential oral pathogens among the phyla Spirochaetes and Deferribacteres, their occurrence in endodontic infections has not been consistently investigated. In this study, we devised a nested PCR-DGGE approach to survey samples from infected root canals for the presence of members of these two phyla, and to examine their diversity. The primers used also amplified DNA from Atopobium species. Eight of 10 cases showed bands representative of the target bacterial groups. DGGE profiles revealed a mean number of 6.5 intense and faint bands. No single band occurred in all profiles. Sequences from intense bands excised from the gel showed similarities to species/phylotypes of all target groups--Flexistipes species (Deferribacteres phylum), uncharacterized spirochetes, and Atopobium species. Analysis of these data indicates that uncultivated Spirochaetes and Deferribacteres phylotypes are frequent members of the endodontic microbiota and may be potential pathogens involved with the etiology of periradicular diseases.
Assuntos
Doenças da Polpa Dentária/microbiologia , Bactérias Gram-Negativas/classificação , Spirochaetales/classificação , Actinobacteria/classificação , Actinobacteria/genética , Adulto , Idoso , Bactérias/classificação , Bactérias/genética , Primers do DNA , DNA Bacteriano/análise , Eletroforese em Gel de Poliacrilamida , Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Pessoa de Meia-Idade , Doenças Periapicais/microbiologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Spirochaetales/genética , Infecções por Spirochaetales/microbiologiaRESUMO
Adult rats were submitted to two different behavioral tasks using the same apparantus: the habituation of exploration of the apparatus considered as a novel environment as measured by the decrease in number of reaings and of ambulation between training and testing, and step-down inhibitory avoidance as measured by the increase in the latency to step down from a start platform into an electrified grid between the training and the test session.The training-test interval for both tasks was 20 h.The immediate post-training injection of the benzodiazepine receptor antagonist flumazenil (10 nmol) bilateral into the hippocampus enhanced retention of the two tasks.Application of the same drug, at the same dose to the septum or amygdala had no effect on habituation but enhanced retention of the avoidance task. The data are consistent with previous findings showing that both tasks are accompanied by the release of benzodiazepine like immunoreactivity in the three structures and that this release is greater after the avoidance task. The present findings suggest a differential regional involvement of endogenous benzodiazepine-mediated mechanisms in memory modulation, according to the task undertaken