Mangroves are environments that have fast cycles associated with high concentration of bacterial decomposers.These are impacted by anthropogenic pollution due to contamination of bacterial species carrying resistance ...Mangroves are environments that have fast cycles associated with high concentration of bacterial decomposers.These are impacted by anthropogenic pollution due to contamination of bacterial species carrying resistance genes.This study aims to evaluate the metabolic profile of the microbiota in mangrove sediments,and verify the presence of Gram-negative bacteria resistant to meropenem.The samples were obtained from location along the Anil river and were seeded in medium supplemented with the antibiotic meropenem in increasing concentrations.The DNA was analyzed by multiplex PCR for detecting resistance genes forβ-lactam antibiotics.The bacteria were identified by Matrix-assisted laser desorption ionization–time of flight mass spectrometry(MALDI-TOF MS).The genes were sequenced by ABI PRISM 3100,analyzed by MEGA 6.0 program,and the sequence identified was assessed by GenBank using the BLAST algorithm.Ecoplate■the kit was used to determine the metabolic profile of the microbiota.The results of the six bacterial isolates showed the blaKPC-2 gene and were identified as Stenotrophomonas maltophilia and Pseudomonas putida.The samples showed a greater diversity Shannon index,a rich substrate consumption and high equity.There was a metabolic richness such as carbon consumption profiles,being a factor of adaptation of pathogenic bacteria carrying resistance genes toβ-lactamics antibiotics.展开更多
The characterization and prevalence of virulence factors associated with enterococcal invasiveness and severity of disease are important areas to be investigated. Recently, we described the production of a heat-stable...The characterization and prevalence of virulence factors associated with enterococcal invasiveness and severity of disease are important areas to be investigated. Recently, we described the production of a heat-stable hemolysin by clinical isolates of Enterococcus faecalis cultived in BHI-GA (BHI with glucose and L-arginine). Now, we purified the hemolysin from the culture supernatant by ultra-filtration (PM-10 membrane) and ethanol extraction followed by chromatography in a mBondapak C18 and Superdex Peptide columns. The hemolytic activity was not affected by the proteolytic enzymes. Cholesterol, phospholipids, EDTA and also bivalent ions did not inhibit the hemolytic activity. Among the various carbohydrates, only dextran 4 protected the erythrocytes against lyse. Scanning electron microscopy showed that lyse of erythrocytes occured at once after the exposure to the hemolysin. The mito-chondrial activity and the cell membrane integrity were significantly affected by the hemolysis, within 20 min of exposure and caused apoptosis after 12 h incubation, 51.92% in HeLa and 68% in HEp-2 cells, analyzed by flow cytometry. These results suggest that the heat-stable pore forming hemolysin might be a putative virulence factor in enterococci infections.展开更多
文摘Mangroves are environments that have fast cycles associated with high concentration of bacterial decomposers.These are impacted by anthropogenic pollution due to contamination of bacterial species carrying resistance genes.This study aims to evaluate the metabolic profile of the microbiota in mangrove sediments,and verify the presence of Gram-negative bacteria resistant to meropenem.The samples were obtained from location along the Anil river and were seeded in medium supplemented with the antibiotic meropenem in increasing concentrations.The DNA was analyzed by multiplex PCR for detecting resistance genes forβ-lactam antibiotics.The bacteria were identified by Matrix-assisted laser desorption ionization–time of flight mass spectrometry(MALDI-TOF MS).The genes were sequenced by ABI PRISM 3100,analyzed by MEGA 6.0 program,and the sequence identified was assessed by GenBank using the BLAST algorithm.Ecoplate■the kit was used to determine the metabolic profile of the microbiota.The results of the six bacterial isolates showed the blaKPC-2 gene and were identified as Stenotrophomonas maltophilia and Pseudomonas putida.The samples showed a greater diversity Shannon index,a rich substrate consumption and high equity.There was a metabolic richness such as carbon consumption profiles,being a factor of adaptation of pathogenic bacteria carrying resistance genes toβ-lactamics antibiotics.
基金Financial support was provided by Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior(CAPES)and Conselho Nacional de Desenvolvimento Científico e Tecnologico(CNPq),Brazil.
文摘The characterization and prevalence of virulence factors associated with enterococcal invasiveness and severity of disease are important areas to be investigated. Recently, we described the production of a heat-stable hemolysin by clinical isolates of Enterococcus faecalis cultived in BHI-GA (BHI with glucose and L-arginine). Now, we purified the hemolysin from the culture supernatant by ultra-filtration (PM-10 membrane) and ethanol extraction followed by chromatography in a mBondapak C18 and Superdex Peptide columns. The hemolytic activity was not affected by the proteolytic enzymes. Cholesterol, phospholipids, EDTA and also bivalent ions did not inhibit the hemolytic activity. Among the various carbohydrates, only dextran 4 protected the erythrocytes against lyse. Scanning electron microscopy showed that lyse of erythrocytes occured at once after the exposure to the hemolysin. The mito-chondrial activity and the cell membrane integrity were significantly affected by the hemolysis, within 20 min of exposure and caused apoptosis after 12 h incubation, 51.92% in HeLa and 68% in HEp-2 cells, analyzed by flow cytometry. These results suggest that the heat-stable pore forming hemolysin might be a putative virulence factor in enterococci infections.
