Atividade in vitro do óleo essencial de Origanum vulgare L. em isolados clínicos de Aspergillus spp / In vitro activity of essential oil of Origanum vulgare L. in clinical isolates from Aspergillus spp

Aspergillus fumigatus, A. flavus e A. niger são os mais importantes agentes etiológicos da aspergilose, relevante micose aviária, com tratamento ineficaz e altas taxas de mortalidade. Em vista da importância da aspergilose, da necessidade de prospectar novos fármacos e do potencial terapêutico do óleo essencial de Origanum vulgare L. (OEO), o orégano, objetivou-se avaliar a sensibilidade in vitro de isolados clínicos de Aspergillus spp. em relação ao OEO. O óleo foi obtido por hidrodestilação em Clevenger, e a análise química realizada por cromatografia de massa (GC/MS). Observaram-se 15 diferentes compostos ativos, sendo 4-terpineol, hidrato de sabinene e timol os majoritários. Nos testes de microdiluição em caldo (Reference..., 2008), todos os isolados (n= 23) foram sensíveis ao OEO: A. fumigatus teve CIM entre 28,125mg/mL (0,1875%) e 450mg/mL (3,0%), A. flavus entre 112,5mg/mL (0,75%) e 450mg/mL, e A. niger 112,5mg/mL. CFM variou de 112,5mg/mL a 450mg/mL nos isolados de A. fumigatus, de 225mg/mL (1,5%) a 450mg/mL em A. flavus, e foi de 450mg/mL em A. niger. CIM e CFM foram idênticos em 6/14 isolados, o que demonstra que o óleo com a mesma concentração pode ter capacidade fungistática e fungicida. CIM 90 correspondeu à CIM máxima. Os resultados demonstram a atividade anti-Aspergillus do OEO, com CIM 90 de 450mg/mL (3%).(AU)

Aspergillus fumigatus, A. flavus and A. niger are the most important etiological agents of aspergillosis, a relevant avian mycosis, with innefective treatment and high mortality rates. Due the importance of aspergillosis, the necessity of prospection of new drugs and the therapeutic potential of the essential oil of Origanum vulgare L. (OEO), popularly known as oregano, aims to evaluate the in vitro sensitivity of Aspergillus spp. opposing to OEO. The oil was obtained by hydrodistillation in Clevenger, and the chemical analysis performed by mass chromatography (GC/MS). 15 different active compounds were observed, being 4-terpineol (18.4%), sabinene hydrate (15.6%) and thymol (13.6%), the majority components. In the in vitro susceptibility test, all strains showed sensitivity to OEO, MIC of Aspergillus fumigatus ranged from 28,125mg/mL (0,1875%) to 450mg/mL (3,0%), A. flavus 112,5mg/mL (0,75%) to 450mg/mL, and A. niger 112,5mg/mL. MFC ranged from 112,5mg/mL to 450mg/mL in the A. fumigatus isolates, 225mg/mL (1,5%) to 450mg/mL in A. flavus, and 450mg/mL for A. niger. The MIC and FMC values were identical in 6/14 of the isolated subjects, demonstrating that the oil with the same concentration can have fungistatic and fungicidal capacity. The results demonstrates anti-Aspergillus activities of OEO with CIM90 de 450mg/mL (3%).(AU)

Combination of Origanum vulgare L. essential oil and lactic acid to inhibit Staphylococcus aureus in meat broth and meat model

This study assessed the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and lactic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC) index and cell viability in meat broth and meat model. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the oil was 0.6 and 1.25 µL.mL-1, respectively. Lactic acid showed MIC and MBC of 2.5 and 5µL.mL-1, respectively. FIC indices of the combined application of the oil and lactic acid were 0.5 showing a synergic interaction. The essential oil and lactic acid showed similar (p>0.05) anti-S. aureus effect in meat broth over 96 h of exposure. Treatment with essential oil or lactic acid presented a smaller anti-staphylococcal effect in meat in comparison to meat broth. No significant difference (p>0.05) was found for the microbial counts in meat treated with each antimicrobial alone or in mixture. These results could arise as an interesting approach for the improvement of food preservation using more natural procedures, considering the current demand of consumer and sensory quality of foods.

In vitro activity of Origanum vulgare essential oil against Candida species

The aim of this study was to evaluate the in vitro activity of the essential oil extracted from Origanum vulgare against sixteen Candida species isolates. Standard strains tested comprised C. albicans (ATCC strains 44858, 4053, 18804 and 3691), C. parapsilosis (ATCC 22019), C. krusei (ATCC 34135), C. lusitaniae (ATCC 34449) and C. dubliniensis (ATCC MY646). Six Candida albicans isolates from the vaginal mucous membrane of female dogs, one isolate from the cutaneous tegument of a dog and one isolate of a capuchin monkey were tested in parallel. A broth microdilution technique (CLSI) was used, and the inoculum concentration was adjusted to 5 x 10(6) CFU mL-1. The essential oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography. Susceptibility was expressed as Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC). All isolates tested in vitro were sensitive to O. vulgare essential oil. The chromatographic analysis revealed that the main compounds present in the essential oil were 4-terpineol (47.95 percent), carvacrol (9.42 percent), thymol (8.42 percent) and □-terpineol (7.57 percent). C. albicans isolates obtained from animal mucous membranes exhibited MIC and MFC values of 2.72 µL mL-1 and 5 µL mL-1, respectively. MIC and MFC values for C. albicans standard strains were 2.97 µL mL-1 and 3.54 µL mL-1, respectively. The MIC and MFC for non-albicans species were 2.10 µL mL-1 and 2.97 µL mL-1, respectively. The antifungal activity of O. vulgare essential oil against Candida spp. observed in vitro suggests its administration may represent an alternative treatment for candidiasis.

Combined application of origanum vulgare l. essential oil and acetic acid for controlling the growth of staphylococcus aureus in foods / Aplicação combinada do óleo essencial de Origanum vulgare L. e ácido acético para o controle do crescimento de Staphylococcus aureus em alimentos

This study evaluated the occurrence of an enhancing inhibitory effect of the combined application of Origanum vulgare L. essential oil and acetic acid against Staphylococcus aureus by the determination of Fractional Inhibitory Concentration (FIC) index and kill-time assay in nutrient broth, meat broth and in a food model (meat pieces). Acetic acid showed MIC and MFC of 0.6 and 1.25 µL.mL-1, respectively. For O. vulgare essential oil MIC and MBC were 1.25 and 2.5 µL.mL-1, respectively. FIC indexes of the mixture of essential oil and acetic acid at MIC x ½ were £ 1.0, showing an additive effect. No synergy was found at kill-time study. Anti-staphylococcal effect of the antimicrobials alone or in mixture (MIC x ½) was lower in meat than in nutrient and meat broths. The effective combination of essential oils and organic acids could appear as an attractive alternative for the food industry, as the doses to inhibit the microbial growth in foods can be lowered.

Este estudo avaliou a ocorrência de um efeito inibitório potencializado quando da aplicação combinada do óleo essencial de O. vulgare e ácido acético sobre Staphylococcus aureus através da determinação Concentração Inibitória Fracional (FIC) e de ensaios de tempo de morte em caldo nutriente, caldo base carne e em um modelo alimentar (pedaços de carne). O ácido acético mostrou um valor de CIM e CBM de 0,6 e 1,25 µL.mL-1, respectivamente. Estudos prévios encontraram valores de CIM e CBM para o óleo essencial de O. vulgare sobre as cepas teste de S. aureus de 1,25 e 1,5 µL.mL-1, respectivamente. Valores de índices de CIF da mistura do óleo essencial e ácido acético na concentração de CIM x ½ foram £ 1,0 caracterizando uma interação de adição. Nenhum efeito sinérgico foi encontrado nos ensaios de tempo de morte. O efeito anti-estafilocócico dos antimicrobianos isolados ou em combinação (CIM x ½) foi menor quando aplicado em carne em comparação a sua adição em caldo nutriente e caldo carne. A efetiva combinação de óleos essenciais e outros agentes preservativos pode ser reconhecida como uma alternativa promissora para a indústria de alimentos, podendo viabilizando a diminuição de doses de antimicrobianos aplicadas para inibir o crescimento microbiano em alimentos.

The potential of Origanum vulgare L. (Lamiaceae) essential oil in inhibiting the growth of some food-related Aspergillus species / Potencial do óleo essencial de Origanum vulgare L. (Lamiaceae) em inibir o crescimento de algumas cepas de Aspergillus de interesse em alimentos

Origanum vulgare L. (Lamiaceae) has been currently known for their interesting antimicrobial activity being regarded as alternative antimicrobial for use is food conservation systems. This study aimed to evaluate the effectiveness of O. vulgare essential oil in inhibiting the growth of some food-related Aspergillus species (A. flavus, A. parasiticus, A. terreus, A. ochraceus, A. fumigatus and A. niger). The essential oil revealed a strong anti-Aspergillus property providing an inhibition of all assayed mould strains. MIC values were between 80 and 20 µL/mL being found a MIC50 of 40 µL/mL. The essential oil at concentration of 80 and 40 µL/mL provided a fungicidal effect on A. flavus, A. fumigatus and A. niger noted by a total inhibition of the radial mycelial growth along 14 days of interaction. In addition, the essential oil was able to inhibit the mould spores germination when assayed at concentrations of 80 and 40 µL/mL. Our results showed the interesting anti-Aspergillus activity of O. vulgare essential oil supporting their possible use as anti-mould compound in food conservation.

Origanum vulgare L. (Lamiaceae) tem sido atualmente reconhecido por sua intensa atividade antimicrobiana sendo considerado como fonte de compostos antimicrobianos alternativos para uso em sistemas de conservação de alimentos. Este estudo objetivou avaliar a efetividade do óleo essencial de O. vulgare em inibir o crescimento de algumas espécies de Aspergillus (A. flavus, A. parasiticus, A. terreus and A. fumigatus) de interesse em alimentos. O óleo essencial revelou uma forte atividade atni-Aspergillus provocando a inibição de todas as cepas fúngicas ensaiadas. Os valores de MIC estiveram entre 80 e 20 µL/mL sendo encontrado uma MIC50 de 40 µL/mL. O óleo essencial nas concentrações de 80 e 40 µL/mL causou um efeito fungicida sobre A. flavus, A. fumigatus e A. niger notado por uma total inibição do crescimento micelial radial ao longo de 14 dias de interação, bem como foi capaz de inibir a germinação de esporos destas cepas fúngicas. Nossos resultados mostram a intensa atividade anti-Aspergillus do óleo essencial de O. vulgare suportando o seu possível uso como antifúngico em sistemas de conservação de alimentos.

Atividade antimicrobiana da tintura e infusão de origanum vulgare (orégano) / Anti-microbial activity of tincture or infusion of origanum vulgare (oregano)

O crescente interesse pelo uso de extratos naturais como alternativa na prevenção e tratamento de patologias colocam em discussão as propriedades antimicrobianas de diferentes tipos de especiarias como o Origanum vulgare (orégano). O objetivo do estudo foi avaliara atividade antimicrobiana da tintura e da infusão preparada com Origanum vulgare sobre cepas de Candida albicans (ATCC36802), Candida tropicalis (ATCC 13803), Candida parapsilosis (ATCC 22019), Candida krusei (ATCC 6258), Candida guilliermondii (FCF 205), Escherichia coli (ATCC 25922) e Sthaphylococcus aureus (ATCC 6538). Para avaliação da máxima diluição inibitória (MDI), tubos contendo 50 por cento, 25 por cento, 12,5 por cento, 6 por cento, 3 por cento, 1,5 por cento, 0,75 por cento e 0,3 por cento da tintura ou da infusão em meio de cultura foram contaminados com 0,1 ml de suspensões dos microrganismos padronizadas por espectrofotometria. Os tubos foram incubados a 37°C por 24 horas e após este período, foi realizada a avaliação do crescimento microbiano. Todos os testes foram realizados em duplicata...

The increasing interest on the use of natural extracts as an alternative in the prevention and treatment of pathologies leads to the discussion on the antimicrobial properties of different types of plants such as Origanum vulgare. The aim of this study was to evaluate the antimicrobial activity of the tincture and infusion prepared with Origanum vulgare on Candida albicans (ATCC 36802), Candida tropicalis (ATCC 13803), Candida parapsilosis (ATCC 22019), Candida krusei (ATCC 6258), Candida guilliermondii (FCF205), Escherichia coli (ATCC 25922) e Sthaphylococcus aureus (ATCC 6538). For the evaluation of maximum inhibitory dilution (MID), tubes containg 50 percent, 25 percent, 12.5 percent, 6 percent, 3 percent, 1.5 percent, 0.75 percent and 0.3 percent of the tincture or infusion in culture medium were contaminated with 0.1 ml of the standardized suspensions obtained by spectrophotometry. Tubes were incubated at 37°C for 24 h and after this period the evaluation of the microbial growth was performed. All the tests were performed in duplicate