Evaluación de la actividad bactericida de aceites esenciales de hojas de guayabo, pitango y arazá / Evaluation of the bactericidal action of essential oils from guava, Surinam cherry and strawberry guava

Introducción: guayabo, pitango y arazá son árboles fructíferos, nativos de América del Sur. El té de sus hojas es utilizado popularmente en el tratamiento de la diarrea. Objetivo: evaluar la actividad antimicrobiana de los aceites de las hojas Psidium guajava L., Eugenia uniflora L. y Psidium cattleyanum Sabine y sus constituyentes. Métodos: los aceites esenciales fueron extraídos con un aparato tipo Clevenger modificado. Su análisis se realizó en cromatógrafo (GC/MS). Se evaluó la actividad antimicrobiana de los aceites obtenidos frente a Escherichia coli, Salmonella typhimurium y Staphylococcus aureus, mediante la técnica de microdilución en caldo con determinación de la concentración bactericida mínima del aceite. Resultados: el aceite del guayabo presentó actividad bactericida frente a E. coli en la concentración de 2 y 8 por ciento frente al Staphylococcus aureus y Salmonella typhimurium. El aceite de arazá no presentó actividad bactericida frente a los microorganismos testados y el aceite de pitango presentó actividad bactericida en la concentración de 8 por ciento frente al Staphylococcus aureus y Salmonella typhimurium. Los constituyentes principales encontrados en común en los aceites de las 3 plantas fueron el a-copaeno y a-humuleno. Conclusiones: los aceites presentaron actividad bactericida frente a los microorganismos testados y los constituyentes en ellos encontrados son compatibles con los encontrados en otros trabajos.

Introduction: Guava, Surinam cherry and strawberry guava are native South American fruit trees and the tea from their leaves is traditionally used to treat diarrhea. Objective: to evaluate the antimicrobial action of Psidium guajava L., Eugenia uniflora L. and Psidium cattleyanum Sabine and their constituents. Methods: the essential oils were extracted by a modified Clevenger. The analysis of essential oils was performed on chromatograph (GC/MS). The antimicrobial activity of obtained oils against Escherichia coli, Salmonella typhimurium and Staphylococcus aureus was evaluated by broth microdilution assay to determine their minimum bactericidal concentration. Results: the guava oil showed bactericidal activity against E. coli at 2 percent and 8 percent concentration rates against S. aureus and S. typhimurium. The strawberry guava oil showed no bactericidal activity against tested microorganisms whereas Surinam cherry had bactericidal activity at 8 percent concentration against S. aureus and S. typhimurium. The main constituents commonly found in the three plant oils were a-copaene and a-humulene. Conclusions: the oils showed bactericidal activity against tested microorganisms and the constituents are comparable to those found in other studies.

Disease progression of dermatophytic pseudomycetoma in a Persian cat

AntecedentesEl pseudomicetoma dermatofítico es una infección fúngica subcutánea causada por Microsporum canis.ObjetivosEste trabajo describe un caso de pseudomicetoma dermatofítico presentado por un gato persa.Paciente y métodoUna gata de raza Persa, de 3 años de edad, con signos de alopecia, eritema y nódulos ulcerados, los dos primeros distribuidos en todo el cuerpo, presentó exudado granuloso de color amarillento en los nódulos ulcerados de la región dorsal, próxima a la cola. Fueron realizados exámenes micológicos e histopatológicos.ResultadosEl diagnóstico de pseudomicetoma dermatofítico fue confirmado a través del cultivo y examen histopatológico de las muestras extraídas. El tratamiento se basó en el suministro de griseofulvina y extirpación quirúrgica, obteniéndose una respuesta eficaz durante los primeros meses con reducción en el número de nódulos observados. Con el transcurso del tiempo, y aún bajo tratamiento, fue constatada la reincidencia de las lesiones que finalmente llevaron a la muerte del animal.ConclusionesLa evolución clínica evidenció el carácter progresivo y recurrente del pseudomicetoma dermatofítico(AU)

BackgroundDermatophytic pseudomycetoma is a subcutaneous fungal infection by Microsporum canis.AimsThis work describes a case of dermatophytic pseudomycetoma in a Persian cat.Patient and methodsA 3-year old female Persian cat showing alopecia, scaling and ulcerated nodules throughout the body, with presence of ulcerated nodules with yellow granular discharges on the dorsum, close to the tail. Mycological and histopathological examinations were realized.ResultsDiagnosis of dermatophytic pseudomycetoma was established. The cat was treated with griseofulvin, and surgical excision was carried out. Response to therapy was effective during the first months, during which a reduction in nodule frequency was observed. However, despite maintaining the therapy levels, the lesions relapsed and progressed to the point of causing the animal's death.ConclusionThe clinic evolution showed the progressive and recurrent character of dermatophytic pseudomycetoma(AU)

Role of melanin in the pathogenesis of cutaneous sporotrichosis.

In this study, we evaluate the clinical, histopathological and ultra structural aspects of the infection by field strain (MEL(+)) and mutated strain (MEL(-)) of Sporothrix schenckii. The development of sporotrichosis at the inoculation sites was similar for both groups of animals after the second week of the experimental period. Statistical differences appeared only at weeks 3 and 5. The pigmented isolate had greater tissue invasive capacity, promoting the formation of multifocal granulomas, whereas the albino isolate induced an enhanced inflammatory response, restraining the agent to the core of the granulomas.

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%), carvacrol (9.42%), thymol (8.42%) and □-terpineol (7.57%). 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.