RESUMEN
Biofilm formation is a major health concern and studies have been pursued to find compounds able to prevent biofilm establishment and remove pre-existing biofilms. While biosurfactants (BS) have been well-known for possessing antibiofilm activities, bioemulsifiers (BE) are still scarcely explored for this purpose. The present study aimed to evaluate the bioemulsifying properties of cell-free supernatants produced by Bacillaceae and Vibrio strains isolated from marine sponges and investigate their antiadhesive and antibiofilm activities against different pathogenic Gram-positive and Gram-negative bacteria. The BE production by the marine strains was confirmed by the emulsion test, drop-collapsing, oil-displacement, cell hydrophobicity and hemolysis assays. Notably, Bacillus cereus 64BHI1101 displayed remarkable emulsifying activity and the ultrastructure analysis of its BE extract (BE64-1) revealed the presence of structures typically observed in macromolecules composed of polysaccharides and proteins. BE64-1 showed notable antiadhesive and antibiofilm activities against Staphylococcus aureus, with a reduction of adherence of up to 100 % and a dispersion of biofilm of 80 %, without affecting its growth. BE64-1 also showed inhibition of Staphylococcus epidermidis and Escherichia coli biofilm formation and adhesion. Thus, this study provides a starting point for exploring the antiadhesive and antibiofilm activities of BE from sponge-associated bacteria, which could serve as a valuable tool for future research to combat S. aureus biofilms.
RESUMEN
The demosponge genus Placospongia includes 13 valid species, of which six occur in the Brazilian Exclusive Economic Zone. In the present study, we describe two new species of Placospongia from Northern (off the Amazon River mouth) and Northeastern Brazilian continental shelf and oceanic islands (i.e., Fernando de Noronha Archipelago), viz., Placospongia beatrizae sp. nov. and Placospongia amphinolastra sp. nov., and redescribe the holotype of Placospongia cristata Boury-Esnault, 1973, a poorly known species. In addition, we revise the Brazilian records of the allegedly cosmopolitan species P. carinata, P. melobesioides and P. intermedia, and provide new records of P. colombiensis and P. ruetzleri from Brazil. We demonstrate that P. carinata sensu Coelho & Mello-Leito and P. intermedia sensu Muricy & Moraes and Jimenez et al. belong in fact to P. ruetzleri, and that P. melobesioides sensu Mothes et al. and Gonzlez-Faras is a new species, described here as Placospongia beatrizae sp. nov. With the description of the two new species and synonymyzation of previous records, six species of Placospongia are currently known in Brazilian waters, two of which are endemic. A key to Placospongia species is also provided.
Asunto(s)
Poríferos , Animales , BrasilRESUMEN
ABSTRACT Although antibiotic-resistant pathogens pose a significant threat to human health, the environmental reservoirs of the resistance determinants are still poorly understood. This study reports the detection of resistance genes (ermB, mecA, mupA, qnrA, qnrB and tetL) to antibiotics among certain culturable and unculturable bacteria associated with the marine sponge Petromica citrina. The antimicrobial activities elicited by P. citrina and its associated bacteria are also described. The results indicate that the marine environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria.
Asunto(s)
Animales , Poríferos/microbiología , Bacterias/efectos de los fármacos , Bacterias/genética , Farmacorresistencia Bacteriana , Organismos Acuáticos/microbiología , Antibacterianos/farmacología , Brasil , Pruebas de Sensibilidad Microbiana , Genes BacterianosRESUMEN
The growing number of bacterial strains resistant to conventional antibiotics has become a serious medical problem in recent years. Marine sponges are a rich source of bioactive compounds, and many species can be useful for the development of new antimicrobial drugs. This study reports the in vitro screening of marine sponges in the search for novel substances against antibiotic-resistant bacteria. Sponge extracts were tested against 44 bacterial strains, including fourteen antibiotic-resistant strains. Ten out of the twelve sponge species studied showed activity in one or more of the bioassays. Aqueous extracts of Cinachyrella sp. and Petromica citrina showed a large action spectrum over resistant-bacteria such as Staphylococcus aureus, coagulase-negative staphylococci and Enterococcus faecalis. Aqueous extract of P. citrina was fractioned and aqueous fraction showed a greatest inhibitory activity on Staphylococcus strains. In addition, this fraction demonstrated a bactericidal effect on exponentially growing S. aureus cells at the MIC (16 µg/mL). The mechanism of action of bioactive fraction is still unclear, but we showed that it affect protein biosynthesis of Staphylococcus. Our results demonstrated for the first time that P. citrina is a potential source of new drugs for the treatment of infections by antibiotic-resistant bacteria.
O número crescente de bactérias resistentes aos antibióticos tem se tornado um sério problema médico nos últimos anos. As esponjas marinhas são uma fonte rica em compostos bioativos e muitas espécies podem ser úteis para o desenvolvimento de novos antimicrobianos. Esse estudo descreve uma triagem in vitro de esponjas para a pesquisa de novas substâncias contra bactérias resistentes. Os extratos de esponjas foram testados sobre 44 estirpes bacterianas, incluindo quatorze resistentes a antibióticos. Dez entre doze espécies de esponjas apresentaram atividade em um ou mais bioensaios. Os extratos aquosos de Cinachyrella sp. e Petromica citrina apresentaram um amplo espectro de ação sobre estirpes bacterianas resistentes, tais como, Staphylococcus aureus, Staphylococcus coagulase-negativos e Enterococcus faecalis. O extrato aquoso de P. citrina foi fracionado e a fração aquosa apresentou atividade inibitória sobre estirpes de Staphylococcus. Esta fração, na concentração do CMI (16 µg/mL), demonstrou efeito bactericida sobre células de S. aureus na fase exponencial de crescimento. O mecanismo de ação da fração ainda não foi elucidado, mas nós observamos que esta afeta a síntese protéica de Staphylococcus. Nossos resultados demonstraram pela primeira vez que Petromica citrina é uma fonte potencial de novas drogas para o tratamento de infecções causadas por bactérias resistentes.
RESUMEN
Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.
Asunto(s)
Animales , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Poríferos/microbiología , Pseudomonas putida/química , Antibacterianos/biosíntesis , Antibacterianos/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Océanos y Mares , Filogenia , Pseudomonas putida/genética , Pseudomonas putida/aislamiento & purificación , Técnica del ADN Polimorfo Amplificado Aleatorio , ARN Bacteriano/genética , /genéticaRESUMEN
Herein we present the results of a screening with 349 crude extracts of Brazilian marine sponges, ascidians, bryozoans and octocorals, against 16 strains of susceptible and antibiotic-resistant bacteria, one yeast (Candida albicans), Mycobacterium tuberculosis H37Rv, three cancer cell lines MCF-7 (breast), B16 (murine melanoma ) and HCT8 (colon), and Leishmania tarentolae adenine phosphoribosyl transferase (L-APRT) enzyme. Less than 15 percent of marine sponge crude extracts displayed antibacterial activity, both against susceptible and antibiotic-resistant bacteria. Up to 40 percent of marine sponge crude extracts displayed antimycobacterial activity against M. tuberculosis H37Rv. Cytotoxicity was observed for 18 percent of marine sponge crude extracts. Finally, less than 3 percent of sponge extracts inhibited L-APRT. Less than 10 percent of ascidian crude extracts displayed antibacterial activity. More than 25 percent of ascidian crude extracts were active against M. tuberculosis and the three cancer cell lines. Only two crude extracts from the ascidian Polysyncraton sp. collected in different seasons (1995 and 1997) displayed activity against L-APRT. Less than 2 percent of bryozoan and octocoral crude extracts presented antibacterial activity, but a high percentage of crude extracts from bryozoan and octororal displayed cytotoxic (11 percent and 30 percent, respectively) and antimycobacterial (60 percent) activities. The extract of only one species of bryozoan, Bugula sp., presented inhibitory activity against L-APRT. Overall, the crude extracts of marine invertebrates herein investigated presented a high level of cytotoxic and antimycobacterial activities, a lower level of antibacterial activity and only a small number of crude extracts inhibited L-APRT. Taxonomic analysis of some of the more potently active crude extracts showed the occurrence of biological activity in taxa that have been previously chemically investigated. These...
No presente estudo apresentamos resultados da triagem biológica realizada com 349 extratos obtidos de esponjas marinhas, ascídias, briozoários e octocorais do Brasil, em testes contra 16 linhagens de bactérias comuns e resistentes à antibióticos, uma levedura (Candida albicans), Mycobacterium tuberculosis H37Rv, três linhagens de células tumorais MCF-7 (mama), B16 (melanoma murínico) e HCT8 (cólon), e de inibição da enzima adenina fosforribosil transferase de Leishmania tarentolae (L-APRT). Menos de 15 por cento dos extratos de esponja marinhas apresentaram atividade antibacteriana, contra linhagens resistentes ou não a antibióticos. Quase 40 por cento dos extratos de esponjas marinhas apresentaram atividade antimicobacteriana contra Mycobacterium tuberculosis H37Rv. Foi observada citotoxicidade para 18 por cento dos extratos de esponjas marinhas. Finalmente, menos de 3 por cento dos extratos de esponjas apresentaram atividade inibitória da enzima L-APRT. Menos de 10 por cento dos extratos de ascídias apresentaram atividade antibacteriana. Mais de 25 por cento dos extratos de ascídias apresentaram atividade contra M. tuberculosis e as três linhagens de células tumorais. Somente dois extratos obtidos da ascídia Polysyncraton sp. coletada em duas diferentes épocas (1995 e 1997) apresentaram atividade contra L-APRT. Menos de 2 por cento dos extratos de briozoários e octocorais apresentaram atividade antibacteriana, mas uma alta percentagem de extratos destes animais apresentaram atividades citotóxica (11 por cento e 30 por cento, respectivamente) e antimicobacteriana (60 por cento). O extrato de somente uma espécie de briozoário, Bugula sp., apresentou atividade inibitória da enzima L-APRT. A análise taxonômica de algumas espécies de invertebrados que forneceram alguns dos extratos mais ativos, indicou a ocorrência de atividade biológica em espécies pertencentes a grupos taxonômicos que já foram anteriormente investigados do ponto de vista...
Asunto(s)
Briozoos , Técnicas In Vitro , Inhibidores Enzimáticos/farmacología , Poríferos , UrocordadosRESUMEN
Analisa-se a relaçäo entre parâmetros numéricos da estrutura das comunidades de esponjas e a qualidade de água em três costöes rochosos na Baía de Arraial do Cabo, Rio de Janeiro. A qualidade da água foi analisada em termos de temperatura, salinidade, pH, transparência, teor de coliformes e teor de óleos e graxas. Foram feitas amostragens qualitativas e quantitativas por meio de mergulho autônomo (SCUBA) sobre perfis em três estaçöes. Em cada estaçäo calculamos o número de espécies, a densidade e o reconhecimento percentual do povoamento, a Diversidade de Shannon e a Quitabilidade de Pielou. Todos esses índices exceto a equitabilidade mostraram valores mais baixos na estaçäo poluída. As espécies mais comuns na regiäo foram Mycale microsigmatosa, Amphimedon viridis, Tedania ignis, Aplysina fistularis, Ulosa ruetzleri e Chondrilla nucula, todas com possibilidade de utilizaçäo na monitoraçäo ambiental. Análise da distribuiçäo local das espécies e da similaridade específica entre as estaçöes reforçam a hipótese de que as descargas de óleos e esgotos domésticos geram alteraçöes quantificáveis na estrutura das comunidades de esponjas, mesmo com níveis baixos de poluentes. Conclui-se que a análise comparativa dos índices comunitários estruturais e da distribuiçäo das esponjas em águas poluídas consiste num bom modelo biológico para a monitoraçäo ambiental