Patrícia Pozzatti

Atividade antimicrobiana dos óleos essenciais de orégano, tomilho e canela frente a sorovares de Salmonella enterica de origem avícola

Essential oils from oregano (Origanum vulgare), thyme (Thymus vulgaris) and cinnamom (Cinnamomum zeylanicum) were tested for their inhibitory activity against sixty Salmonella sp. isolates. These microorganisms were distributed in 20 serovars, all of them isolated from broiler chickens. Based on microdilution technique, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined. The strongest antibacterial activity was obtained for oregano (MIC mean = 529mg ml-1 and MBCmean = 661mg ml-1), followed by a moderate activity for thyme (MICmean=961mg ml-1 and MBCmean=1074mg ml-1) and the lowest obtained activity observed for cinnamon (MICmean= 1335mg ml-1 and MBCmean= 1979mg ml-1). Despite of this activity pattern, the serovars of Salmonella enterica showed significant susceptibility variations. However none of them could be classified as sensitive or resistant to the three essential oils tested. At the moment, when the antibiotics, as growth promoters, are being replaced, the essential oils from spices could be a very reasonable choice and the present results show us two points: the essential oils from oregano and thyme are effective against Salmonella isolates but the variations among the serovars must be considered.

Comparison of the susceptibilities of clinical isolates of Candida albicans and Candida dubliniensis to essential oils.

Here, a microdilution technique based on the M27‐A2 protocol (NCCLS, 2002) was employed to compare the susceptibilities of Candida albicans and Candida dubliniensis to essential oils extracted from plants used as spices. The chemical compositions of the essential oils were defined based on the analysis of retention indices obtained by gas chromatography–mass spectroscopy. Taken together, the results showed that the activity of the compounds against the two species was similar.

Differentiation of Candida dubliniensis from Candida albicans on rosemary extract agar and oregano extract agar

Candida dubliniensis is a recently described pathogenic species which shares many phenotypic features with Candida albicans and therefore, may be misidentified in microbiological laboratories. Because molecular methods can be onerous and unfeasible in routine mycological laboratories with restricted budgets such as those in developing countries, phenotypic techniques have been encouraged in the development of differential media for the presumptive identification of these species. We examined the colony morphology and chlamydospore production of 30 C. dubliniensis isolates and 100 C. albicans isolates on two new proposed media: rosemary (Rosmarinus officinalis) extract agar (REA) and oregano (Origanum vulgare) extract agar (OEA). These substrates are traditionally used as spices and medicinal herbs. In both of these media, all C. dubliniensis isolates (100%) showed rough colonies with peripheral hyphal fringes and abundant chlamydospores after 24 to 48 hr of incubation at 25°C. In contrast, under the same conditions, all isolates of C. albicans (100%) showed smooth colonies without hyphal fringes or chlamydospores. In conclusion, REA and OEA offer a simple, rapid, and inexpensive screening media for the differentiation of C. albicans and C. dubliniensis. J. Clin. Lab. Anal. 22:172–177, 2008.

Sesquiterpenoids of Senecio bonariensis Hook. & Arn., Asteraceae

From the leaves of Senecio bonariensis Hook. & Arn. three sesquiterpenoids were isolated. β-caryophyllene (1), β-caryophyllene oxide (2) and germacrene D (3) were characterized by GC-EI-MS, IR, 1H and 13C-NMR data. Their ecological and chemotaxonomical significance for the genus Senecio are discussed, as well as the biosynthetic correlation between the isolated substances. The antimicrobial activity of substances 1 and 2 were evaluated by the microdilution method against bacterial and fungal strains. Both compounds did not inhibit the microorganism growth at the tested concentrations.

Esenbeckia leiocarpa Engl. inhibits inflammation in a carrageenan‐induced murine model of pleurisy

Objectives  The aim of this study was to investigate the anti‐inflammatory effects of the crude hydroalcoholic extract (CHE) isolated from Esenbeckia leiocarpa Engl., and fractions and subfractions derived from it.

Atividade antimicrobiana de óleos essenciais extraícos de condimentos

Atualmente, grande numero de microorganismos patogenicos ao homem e animais evidencia preocupante perfil de suscetabilidade aos antimicrobianos disponiveis no mercado, demonstrando alarmantes percentuais de resistencia, principalmente no ambiente hospitalar. O impacto da resistencia e critico quando as opcoes terapeuticas restringem-se a poucas drogas ou as opcoes sao nulas. A industria quimico-farmaceutica busca solucoes inovadoras e, neste contexto, metabolitos vegetais, tradicionalmente utilizados na alimentacao humana ou na medicina popular, revestem-se de importância, cujos potenciais antimicrobianos requerem avaliacoes. Desta forma, a presente revisao objetivou ressaltar as atividades antimicrobianas de alguns oleos essenciais extraidos de condimentos popularmente utilizados.