Avaliacao das atividades antimicrobiana e citotoxica de extratos de plantas do Cerrado do Sul de Minas Gerais

Foi avaliada a atividade antimicrobiana de extratos hidroetanólicos de plantas sobre bactérias Gram positiva, Gram negativa, leveduras, Mycobacterium tuberculosis H37 e Mycobacterium bovis pela técnica de difusão em Agar e microdiluição em caldo. Dentre os extratos avaliados pelo método de difusão em Agar, o extrato da folha de Bidens pilosa apresentou a mais expressiva média de halos de inibição de crescimento frente aos microrganismos, seguido pelo extrato da flor de B. pilosa, da folha e semente de Eugenia pyriformis, da folha de Plinia cauliflora que apresentaram estatisticamente a mesma média de formação de halos inibitórios sobre bactérias Gram positivas, Gram negativas e leveduras. Os extratos de Heliconia rostrata não apresentaram atividade. Mycobacterium tuberculosis H37 e Mycobacterium bovis (BCG) mostraram-se resistentes a todos os extratos. O perfil de sensibilidade dos fungos Candida albicans e Saccharomyces cerevisiae foram comparáveis entre si e entre as bactérias Gram positivas Bacillus subtilis, Enterococcus faecalis e Gram negativa Salmonella typhimurium (p >; 0.05). A avaliação da citotoxicidade foi realizada sobre células C6-36 de larvas de mosquito Aedes albopictus. Os extratos de caule e flor de H. rostrata, folha e caule de P. cauliflora, semente de Anonna crassiflora e caule, flor e raiz de B. pilosa não apresentaram toxicidade nas concentrações avaliadas. Os maiores índices de seletividade foram apresentados pelos extratos de caule de A. crassiflora e flor de B. pilosa para Staphylococcus aureus, apresentando potencial para estudos como futuros candidatos a fármacos.The antimicrobial activity of plant hidroethanolic extracts on bacteria Gram positive, Gram negative, yeasts, Mycobacterium tuberculosis H37 and Mycobacterium bovis was evaluated by using the technique of Agar diffusion and microdilution in broth. Among the extracts evaluated by Agar diffusion, the extract of Bidens pilosa leaf presented the most expressive average of haloes of growth inhibition to the microorganisms, followed by the extract of B. pilosa flower, of Eugenia pyriformis' leaf and seed, of Plinia cauliflora leaf which statistically presented the same average of haloes inhibitory formation on bacteria Gram positive, Gram negative and yeasts. The extracts of Heliconia rostrata did not present activity. Mycobacterium tuberculosis H37 and Mycobacterium bovis (BCG) appeared resistant to all the extracts. The susceptibility profile of Candida albicans and Saccharomyces cerevisiae fungi were compared to one another and to the Gram positive Bacillus subtilis, Enterococcus faecalis and the Gram negative Salmonella typhimurium bacteria (p >; 0.05). The evaluation of cytotoxicity was carried out on C6-36 larvae cells of the Aedes albopictus mosquito. The extracts of stem and flower of Heliconia rostrata, leaf and stem of Plinia cauliflora, seed of Anonna crassiflora and stem, flower and root of B. pilosa did not present toxicity in the analyzed concentrations. The highest rates of selectivity appeared in the extracts of stem of A. crassiflora and flower of B. pilosa to Staphylococcus aureus, presenting potential for future studies about a new drug development

Triagem in vitro da atividade antibacteriana de Bidens pilosa Linné e Annona crassiflora Mart. contra Staphylococcus aureus resistente à oxacilina (ORSA) provenientes do ambiente aéreo na clínica odontológica

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.Atualmente Staphylococcus aureus multirresistente é causa comum de infecções com altas taxas de morbidade e mortalidade mundialmente, o que direciona esforços científicos na busca de novos antimicrobianos. Neste estudo, nove extratos de Bidens pilosa (raiz, caule, flor e folhas) e de Annona crassiflora (casca do fruto, caule, folha, semente e polpa) foram obtidos com etanol:água (7:3, v/v) e suas atividades antibacteriana in vitro avaliadas através de difusão em agar e microdiluição em caldo contra 60 cepas de Oxacillin Resistant S. aureus (ORSA) e contra S. aureus ATCC 6538. Os extratos de B. pilosa e A. crassiflora inibiram o crescimento dos isolados ORSA em ambos os métodos. O extrato da folha de B. pilosa apresentou média dos diâmetros dos halos de inibição significativamente maior que a clorexidina 0,12%, contra os isolados ORSA, e os extratos foram mais ativos contra S. aureus ATCC (p < 0,05). Paralelamente, teste de toxicidade pelo método MTT e triagem fitoquímica foram avaliadas, e três extratos (raiz e folha de B. pilosa e semente de A. crassiflora) não apresentaram toxicidade. Por outro lado, as concentrações citotóxicas (CC50 e CC90) para os outros extratos variaram de 2,06 a 10,77 mg/mL. Observou-se variável presença de alcalóides, flavonóides, taninos e saponinas, apesar de total ausência de antraquinonas. Portanto, os extratos das folhas de B. pilosa revelaram boa atividade anti-ORSA e não exibiram toxicidade

EVALUATION OF ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF PLANT EXTRACTS FROM SOUTHERN MINAS GERAIS CERRADO

The antimicrobial activity of plant hidroethanolic extracts on bacteria Gram positive, Gram negative, yeasts, Mycobacterium tuberculosis H37 and Mycobacterium bovis was evaluated by using the technique of Agar diffusion and microdilution in broth. Among the extracts evaluated by Agar diffusion, the extract of Bidens pilosa leaf presented the most expressive average of haloes of growth inhibition to the microorganisms, followed by the extract of B. pilosa flower, of Eugenia pyriformis' leaf and seed, of Plinia cauliflora leaf which statistically presented the same average of haloes inhibitory formation on bacteria Gram positive, Gram negative and yeasts. The extracts of Heliconia rostrata did not present activity. Mycobacterium tuberculosis H37 and Mycobacterium bovis (BCG) appeared resistant to all the extracts. The susceptibility profile of Candida albicans and Saccharomyces cerevisiae fungi were compared to one another and to the Gram positive Bacillus subtilis, Enterococcus faecalis and the Gram negative Salmonella typhimurium bacteria (p > 0.05). The evaluation of cytotoxicity was carried out on C6-36 larvae cells of the Aedes albopictus mosquito. The extracts of stem and flower of Heliconia rostrata, leaf and stem of Plinia cauliflora, seed of Anonna crassiflora and stem, flower and root of B. pilosa did not present toxicity in the analyzed concentrations. The highest rates of selectivity appeared in the extracts of stem of A. crassiflora and flower of B. pilosa to Staphylococcus aureus, presenting potential for future studies about a new drug development

Pesquisa de bioativos com atividade antimicrobiana nos extratos hidroetanólicos do fruto, folha e casca de caule do Zizyphus joazeiro mart doi: http://dx.doi.org/10.5892/ruvrv.2012.102.4351

Zizyphus joazeiro Mart. árvore bastante disseminada no nordeste brasileiro, utilizada como agente de higienização bucal, em substituição aos produtos comerciais. Usa-se o fruto nas perturbações do estômago e as cascas na cicatrização de ferimentos, febres e infecções dos pulmões. O presente estudo objetiva avaliar a atividade antimicrobiana, in vitro dos diferentes extratos de Zizyphus joazeiro Mart frente á microrganismos, incluindo leveduras, bactérias Gram-positiva, Gram-negativa e Mycobacterium bovis. Os extratos foram preparados utilizando as partes aéreas (casca do caule, folhas e frutos) de Zizyphus joazeiro Mart. Esses foram testados quanto a sua atividade antimicrobiana, contra leveduras e bactérias utilizando o método de difusão em agar. Todos os extratos apresentaram atividade antimicrobiana. Dos microrganismos utilizados somente Bacillus subtilis, Staphylococcus aureus e Candida albicans mostraram-se sensíveis. Nenhum dos extratos testados apresentou atividade sobre Mycobacterium bovis. Estes resultados podem explicar em parte a utilização Zizyphus joazeiro Mart. para o tratamento de doenças infecciosas na medicina tradicional

Pesquisa de bioativos com atividade antimicrobiana nos extratos hidroetanólicos do fruto, folha e casca de caule do Zizyphus joazeiro mart

Zizyphus joazeiro Mart. árvore bastante disseminada no nordeste brasileiro, utilizada como agente de higienização bucal, em substituição aos produtos comerciais. Usa-se o fruto nas perturbações do estômago e as cascas na cicatrização de ferimentos, febres e infecções dos pulmões. O presente estudo objetiva avaliar a atividade antimicrobiana, in vitro dos diferentes extratos de Zizyphus joazeiro Mart frente á microrganismos, incluindo leveduras, bactérias Gram-positiva, Gram-negativa e Mycobacterium bovis. Os extratos foram preparados utilizando as partes aéreas (casca do caule, folhas e frutos) de Zizyphus joazeiro Mart. Esses foram testados quanto a sua atividade antimicrobiana, contra leveduras e bactérias utilizando o método de difusão em agar. Todos os extratos apresentaram atividade antimicrobiana. Dos microrganismos utilizados somente Bacillus subtilis, Staphylococcus aureus e Candida albicans mostraram-se sensíveis. Nenhum dos extratos testados apresentou atividade sobre Mycobacterium bovis. Estes resultados podem explicar em parte a utilização Zizyphus joazeiro Mart. para o tratamento de doenças infecciosas na medicina tradicional

Verificação de contaminantes de natureza fecal na superfície de torneiras de banheiros públicosdoi: http://dx.doi.org/10.5892/ruvrv.2012.101.297303

Foi realizado um estudo para avaliar a presença de coliformes termotolerantes nas torneiras de banheiros públicos, em onze estabelecimentos localizados no município de Três Corações-MG.. Estas bactérias são indicadores de contaminação por matéria orgânica de origem intestinal.  Os agentes contaminantes são transferidos através de uma cadeia de contaminação. O usuário transfere os contaminantes que porventura possa haver nas suas mãos ao abrir a torneira, e após a lavagem, volta a contaminar as mãos ao fechar a torneira, estabelecendo o quadro infeccioso. Quanto aos resultados, 24% das torneiras e 73% dos estabelecimentos amostrados apresentaram  resultados positivos quanto a presença de coliforme  termotolerantes, o que leva a ineficácia do procedimento de lavagem das mãos,  comprometendo a saúde de seus usuários. Recomenda-se um programa de saúde para a conscientização dos usuários quanto ao processo de lavagem das  mãos

Antifungal susceptibility evaluation of Candida albicans isolated from buccal lesions of hiv-positive and HIV-negative patients

The antifungal minimal inhibitory concentrations (MIC) were determined to 35 samples of Candidaalbicans; 14 of them were isolated from HIV-positive patients, and 21 from HIV-negative patients with oral erythematouscandidosis. The aim of this study was to evaluate the performance of agar dilution method in the determination ofsusceptibility of Candida albicans isolated from buccal lesions of HIV-positive and negative patients to some antifungalsand compare the results with the plasmatic concentration reached by each one of these drugs. The samples were evaluated invitro by the agar dilution method and showed higher MIC values to ketoconazole, fluconazole, itraconazole andamphotericin B than the concentrations achieved by these antifungals in plasma. 88.9% of the samples presented in vitroresistance to ketoconazole and the plasmatic levels of this antifungal varied from 1 to 8 μg/mL. Regarding fluconazole anditraconazole, most samples presented MIC larger than 128 μg/mL and plasmatic concentration varying from 0.4 to 8 μg/mL.Only 11.9% of the samples were susceptible in vitro to fluconazole and 2.7% of them to itraconazol. The usageconcentrations prescribed for the topical antifungals nystatin, fenticonazole and miconazole are markedly higher than thevalues of MIC obtained. Related to nystatin, it was verified that its MIC values were between 1 and 4 μg /mL. Theplasmatic levels to this drug are extremely low. Fenticonazole presented a MIC value larger than 128 μg/mL. Relating tomiconazole, the plasmatic levels vary from 1 to 8 μg/mL and 11.9% of the samples presented in vitro susceptibility to thisdrug. No significant differences (p<0.05) were found in the susceptibility profiles of the samples obtained from HIVpositiveand HIV-negative patients

Antifungal susceptibility evaluation of Candida albicans isolated from buccal lesions of hiv-positive and HIV-negative patients doi: http://dx.doi.org/10.5892/ruvrv.2012.101.156166

The antifungal minimal inhibitory concentrations (MIC) were determined to 35 samples of Candida albicans; 14 of them were isolated from HIV-positive patients, and 21 from HIV-negative patients with oral erythematous candidosis. The aim of this study was to evaluate the performance of agar dilution method in the determination of susceptibility of Candida albicans isolated from buccal lesions of HIV-positive and negative patients to some antifungals and compare the results with the plasmatic concentration reached by each one of these drugs. The samples were evaluated in vitro by the agar dilution method and showed higher MIC values to ketoconazole, fluconazole, itraconazole and amphotericin B than the concentrations achieved by these antifungals in plasma. 88.9% of the samples presented in vitro resistance to ketoconazole and the plasmatic levels of this antifungal varied from 1 to 8 μg/mL. Regarding fluconazole and itraconazole, most samples presented MIC larger than 128 μg/mL and plasmatic concentration varying from 0.4 to 8 μg/mL. Only 11.9% of the samples were susceptible in vitro to fluconazole and 2.7% of them to itraconazol. The usage concentrations prescribed for the topical antifungals nystatin, fenticonazole and miconazole are markedly higher than the values of MIC obtained. Related to nystatin, it was verified that its MIC values were between 1 and 4 μg /mL. The plasmatic levels to this drug are extremely low. Fenticonazole presented a MIC value larger than 128 μg/mL. Relating to miconazole, the plasmatic levels vary from 1 to 8 μg/mL and 11.9% of the samples presented in vitro susceptibility to this drug. No significant differences (p&lt;0.05) were found in the susceptibility profiles of the samples obtained from HIV-positive and HIV-negative patients