Resumen El género Enterococcus puede ser encontrado en agua, suelo y en general en todo ambiente, son parte de la microbiota intestinal de animales, incluyendo a humanos. La prevalencia en alimentos se debe principalmente a la resistencia que presentan a las condiciones adversas del ambiente. Setenta y tres aislados de vísceras de pollo fueron confirmados como pertenecientes al género a través de pruebas bioquímicas y fermentación de carbohidratos. La caracterización bioquímica indicó que la especie predominante fue E. casseliflavus. La resistencia de los aislados a antimicrobianos fue notoria para amikacina (42 %), kanamicina (38 %), estreptomicina (55 %), y eritromicina (33 %). El análisis obtenido por ERIC-PCR mostró una alta variabilidad genética entre los aislados. Así también, los aislados mostraron relación entre los perfiles obtenidos con la susceptibilidad a antimicrobianos y por ERIC-PCR. Estos resultados muestran la multiresistencia de Enterococcus en vísceras de pollo expedidos comercialmente, con una alta variabilidad genética. Además, estos Enterococcus pueden ser potencialmente patógenos en individuos como una bacteria nosocomial y además transferir la resistencia en especies que son estrictamente patógenas y causan enfermedades al humano.

Abstract The genus Enterococcus can be found in water, soil, and food, and above all, they are part of the animal (including human) intestinal microbiota. Food prevalence is mainly due to their resistance to adverse environmental conditions. Seventy-three isolates from chicken viscera were confirmed to belong to the Enterococcus genus by biochemical tests and carbohydrate fermentation. Phenotypic characterization of the species indicates that E. casseliflavus was the predominant specie. Antimicrobial resistance to amikacin (42 %), kanamycin (38 %), streptomycin (55 %) and erythromycin (33 %) in the isolates was notorious. The analysis obtained from ERIC-PCR profiles shows a high genetic variability among the isolates. In addition, a relationship between the antimicrobial and ERIC-PCR profiles was observed among isolates. These results indicate the presence of multiresistant Enterococcus in commercial chicken viscera with high genetic variability, which could be a potential nosocomial bacterium or transfer this resistance to another pathogenic species causing human diseases.

Abstract In this study, cinnamon (Cinnamomum zeylanicum), thyme (Thymus vulgaris) and Schinus molle essential oils (at 125, 250 and 500 µg/mL) were encapsulated in chitosan nanoparticles by ionotropic gelation. Their antimicrobial activity against Staphylococcus aureus ATCC 25923, Enterococcus sp., Escherichia coli ATCC 25922, Klebsiella pneumoniae (BLEE +) and Pseudomona aeruginosa carbapenemase producer was evaluated. The obtained nanoparticles exhibited a regular distribution and spherical shape with size range of 19.7 to 361 nm as observed by using a laser light scattering equipment. It was found that the studied chitosan nanoparticles with essential oils showed high antimicrobial effect than the chitosan and essential oils alone. Enterococcus sp. was the most sensitive bacteria and S. aureus the most resistant. Chitosan nanoparticles and chitosan nanoparticles with cinnamon and thyme essential oils were capable to inhibit growth of Enterococcus sp. and K. pneumoniae. This study demonstrated that chitosan nanoparticles with essential oils were effective against some foodborne pathogens.

Abstract Aspergillus and Fusarium are the fungi genera most frequently isolated from cereal grains and other commodities. They are capable of producing mycotoxins, which can affect the human and animal health. Synthetic fungicides have been used to control these fungi, nevertheless, they have acquired resistance and other alternatives are necessary since they now need higher amounts. Therefore, the aim of this study was to evaluate the efficacy of cinnamon, clove and thyme essential oils (EOs) alone and encapsulated in chitosan on the radial growth, spore germination and mycotoxin production by Fusarium verticillioides and Aspergillus parasiticus. The composition of the EOs was determined by gas chromatography mass spectrometry (GC-MS). EOs inhibited radial growth and spore germination of both fungal species better than when they were encapsulated, plus, they reduced mycotoxin production. The major components were eugenol in cinnamon and clove EO (70 and 63%, respectively) and 2-methyl-5-(1-methyethyl)-phenol (46.2%) in thyme EO. The microparticles with clove and thyme EO showed good surface charges, higher than +30 mV and their average size for the three types of microparticles was about 750 nm. Our findings suggest that EOs both alone and encapsulated in chitosan have a fungistatic effect on Fusarium verticillioides and Aspergillus parasiticus.

Abstract Background: The genus Alternaria in safflower is naturally occurring and synthetic pesticides are commonly used. In substitution of these compounds the use natural compounds such as essential oils (for example terpene) are alternative possible as antifungal in Alternaria. Objective: To evaluate the in vitro antifungal activity of an orange terpenes mix against Alternaria tenuissima isolated from safflower. Methods: The volatile composition of a terpene mixture was quantified with mass-coupled gas chromatography. The minimum inhibitory concentration and mean inhibitory concentration were calculated from the radial growth in A. tenuissima and its effect on spore germination and morphometric parameters was evaluated. Results and conclusions: A. tenuissima showed an incidence of 13.31±2.19 % in safflower seed. A composition of 96 % D-limonene in orange terpenes was determinate. Germination of A. tenuissima spores was inhibited at 538 ppm of terpenes. The orange terpenes can be an alternative for the control of A. tenuissima.

Resumen Antecedentes: El género Alternaria en cártamo es de ocurrencia natural y plaguicidas sintéticos son utilizados para su control. En sustitución de estos compuestos el uso de alternativas de origen natural como los aceites esenciales, entre ellos los terpenos, puede ser viable para el control de estos hongos. Objetivos: Evaluar la actividad antifúngica de una mezcla comercial de terpenos de naranja sobre el crecimiento in vitro de Alternaria tenuissima aislada de cártamo. Métodos: La composición de volátiles de una mezcla de terpenos fue determinada por cromatografía de gases acoplado a masas. Posteriormente se calculó la concentración mínima inhibitoria y la concentración inhibitoria media a partir del crecimiento radial de A. tenuissima y se evaluó su efecto sobre la germinación de esporas y parámetros morfométricos. Resultados y conclusiones: Se encontró una incidencia de 13.31±2.19 % de A. tenuissima en semilla de cártamo. Asimismo, se detectó 96 % de dextro-limoneno en la mezcla de terpenos. En germinación de esporas a 538 ppm (concentración inhibitoria media) de terpenos, se observó inhibición sobre crecimiento del hongo. La mezcla de terpenos de naranja puede ser una alternativa para el control del A. tenuissima.