Antimicrobial activity of quality brands Spanish honeys

80-90% of patients with head and neck cancer who receives radiation and/or chemotherapy have oral mucositis. Oral mucositis is a complex process involving oxidative damage of oral mucosal, inflammation, mucosal colonization by pathogenic microorganisms and direct damage to DNA. The development of oral mucositis led to the interruption of the treatments, periods of hospitalization, dysphagia with malnutrition in patients and increased healthcare costs in treatments which have isolated mechanisms of action and are not fully satisfactory. As honey has antioxidant, anti-inflammatory, antimicrobial and healing properties, it can be used effectively in the prevention and treatment of oral mucositis by acting simultaneously on different pathophysiological mechanisms. The aim of this study was to evaluate the antimicrobial activity of honeys from different floral sources and to evaluate the possible differences that may happen in such capacity between similar honeys of different years of production. We selected six types of Spanish honey from quality brands avocado honey (Persea sp.) and chestnut honey (Castanea sp.) from DOP Miel de Granada; lavender honey (Lavandula sp.) and rosemary honey (Rosmarinus officinalis) from DOP Miel de La Alcarria; blackberry honey (Rubus sp.) and eucalyptus honey (Eucalyptus sp) from PGI Miel de Galicia and two organic honey, thyme honey (Thymus sp.) and heather honey (Erica sp.), collected during two consecutive harvests (2010 and 2011). We studied antimicrobial activity against microorganisms isolated from oropharyngeal mucosa of patients who suffer oral mucositis, Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) and yeasts (Candida albicans and Candida glabrata). These assays gave us accurate information about what would be expected from the application of honey in those patients. Antimicrobial test were carried out according to Silva et al. (2012) using Nutrient Broth or Brain Heart Infusion to bacterias or Yeasts Peptone Dextrose to yeasts on microplates (96 wells). Honey was diluted in water and transferred into the first well. Serial dilutions were performed. 20 μl of a solution of 1% TTC was used for detect antimicrobial activity Candida albicans and Candida glabrata showed higher resistance and their growth was not inhibited at the honey concentrations used. Further studies using higher concentrations of honey are required. Among bacteria all the tested honeys were able to inhibit their growth but showed different antimicrobial activity depending on the microorganism tested. Minimum inhibitory concentration ranged from 3.9 to 250 mg/ml. Generally gram-negative bacteria were less resistant, something that can be explained by the variability that exists in the resistance in bacterial strains within a specie. Differences were also observed in the antimicrobial activity of similar honeys from different years of production. Being a natural product, honey’s composition is in a constant state of change, depending on factors such as climatology which affect plant species available

Actividad antimicrobiana de mieles españolas acogidas a marcas de calidad

El objetivo del estudio fue valorar la capacidad antimicrobiana frente a diferentes cepas de referencia (Staphylococcus aureus subsp. aureus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa y Candida albicans), de mieles de diferentes orígenes florales y geográficos y valorar las posibles diferencias en dicha capacidad entre mieles similares de diferentes cosechas. Se seleccionaron seis mieles españolas acogidas a marcas de calidad, así como dos mieles ecológicas recogidas durante dos cosechas consecutivas. Los tests antimicrobianos fueron llevados a cabo en microplacas de 96 pocillos utilizando caldo nutritivo o medio BHI para las bacterias y medio YPD para la levadura. El inóculo fue añadido a todas los pocillos y las microplacas fueron incubadas a 37ºC durante 24 horas en el caso de las bacterias y a 25ºC durante 48 horas en el caso de las levaduras. La actividad antimicrobiana fue detectada adicionando 20 Al de una solución de TTC (cloruro de 2,3,5- trifeniltetrazoilo) al 1%. La concentración mínima inhibitoria (CMI) fue definida como la concentración de miel más baja capaz de inhibir el crecimiento microbiano. Según los resultados observados podemos concluir que las mieles estudiadas presentan principalmente actividad antibacteriana a unas CMI en torno al 20%

Evaluation of technological properties and selection of wild lactic acid bacteria for starter culture development

[EN] Sixty-six lactic acid bacteria strains, isolated from traditional cheeses, were identified by MALDI-TOF technology, characterised through the evaluation of their enzymatic activities (acidifying and proteolytic capacities and carboxypeptidase, aminopeptidase, dipeptidase and esterase activities) and selected through a scoring system based on activity results in order to select wild strains of technological interest for cheese manufacturing. The strains were identified as Lactococcus lactis (9), Leuconostoc citreum (3), Leuconostoc mesenteroides (2), Leuconostoc pseudomesenteroides (1), Levilactobacillus brevis (7), Lactiplantibacillus plantarum (32), Lactiplantibacillus paraplantarum (7) and Lacticaseibacillus paracasei (5). In general, Lactococcus lactis strains showed the highest degree of acidifying activity, especially in the first hours of fermentation, and extracellular proteolytic activity. In contrast, intracellular activities, assayed from cell-free extracts, were higher in the lactobacilli strains. L. paracasei strains showed the highest level of aminopeptidase activity, while some L. plantarum strains obtained high values of dipeptidase activity. Carboxypeptidase activity was very low or undetectable in many strains, although in others the activity values were exceptionally high. Esterolytic activity was generally low, although L. paracasei strains showed higher activity on short-chain substrates. Finally, 11 strains were selected using the scoring system that could be used in the design of starter cultures and co-cultures.SIUniversidad de Leó

Estudio palinológico de mieles españolas acogidas a marcas de calidad

Muchas de las propiedades bioactivas que presenta la miel han sido relacionadas con su origen botánico por lo que su conocimiento es muy importante. Aunque se están desarrollando métodos más sencillos y rápidos, el análisis palinológico continúa siendo esencial para determinar el origen floral de la miel lo que, por otro lado, permite atribuirle un mayor valor al producto.Se determinó el origen floral de seis tipos de miel acogidas a marcas de calidad y dos muestras de miel ecológica, durante dos cosechas consecutivas 2010 y 2011 analizando un total de 15 muestras. El método utilizado para la preparación de las muestras fue el recomendado por la Comisión Internacional de Botánica Apícola (ICBB) [1]. Se realizó un análisis cualitativo exami-nando cada una de las preparaciones al microscopio óptico a 400 y 1000 aumentos. Se identifica-ron por término medio 650 granos de polen en cada muestra de miel utilizando diversas claves y bibliografía [2,3] así como la palinoteca del Departamento de Biodiversidad y Gestión Ambiental de la Universidad de León.Se identificaron 92 tipos polínicos pertenecientes a 36 familias botánicas. En torno al 73% del polen identificado perteneció a plantas nectaríferas mientras que el 27% restante procedió de plantas poliníferas o productoras de polen y mielatos. En todas las muestras estudiadas se encontró el tipo polínico Cytisus scoparius. Otros tipos polínicos que se presentaron con fre-cuencia fueron Rubus ulmifolius (encontrado en el 93% de las muestras), Castanea sativa (87%), Echium vulgare y Crataegus monogyna (80%) y Prunus spinosa (73%). El número de tipos polínicos presentes en cada muestra varió entre 13 y 47, siendo esta variabilidad el resultado de la vege-tación existente en las diferentes zonas geográficas y de la preferencia de las abejas por algunas especies botánicas. Aunque todas las mieles fueron comercializadas como uniflorales, solo ocho de las quince muestras de miel estudiadas fueron catalogadas como tal, el resto no alcanzó los contenidos mínimos en polen como para ser incluidas dentro de este grupo y fueron clasificadas como mieles multiflorales. Actualmente solo las legislaciones específicas para marcas de calidad contemplan un apartado relativo a los contenidos mínimos en polen necesarios para conseguir la unifloralidad.info:eu-repo/semantics/publishedVersio

Characteristics and proteolysis of a Spanish blue cheese made with raw or pasteurised milk

[EN] Valdeón cheese is a Spanish Protected Geographical Indication of blue-veined cheese produced on an industrial scale from raw or pasteurised cow and/or goat milk. The aim of this work was to evaluate the impact of pasteurisation on the microbiological, physicochemical and sensory characteristics of cheese. Cheeses made with raw milk showed higher counts of lactobacilli and enterococci, as well as lower values of pH and D-lactic acid and salt/moisture ratio. Cheeses made with pasteurised milk showed greater extent of proteolysis, higher concentration of free amino acids and lower concentration of biogenic amines. Pasteurisation produced more elastic and harder cheeses, but with a lower sensory profileSIJunta de Castilla y Leó

Antibacterial action mechanisms of honey: physiological effects of avocado, chestnut, and polyfloral honey upon Staphylococcus aureus and Escherichia coli

Numerous studies have explored the antibacterial properties of di erent types of honey from all around the world. However, the data available describing how honey acts against bacteria are few. The aim of this study was to apply a flow cytometry (FC) protocol to examine and characterize the primary e ects of three varieties of honey (avocado, chestnut and polyfloral) upon physiological status of Staphylococcus aureus and Escherichia coli cells to reveal their antibacterial action mechanisms. The e ects of honey samples on membrane potential, membrane integrity, and metabolic activity were assessed using di erent fluorochromes, in a 180 min time course assay. Time-kill experiments were also carried out under similar conditions. Exposure of S. aureus and E. coli to the distinct honey samples resulted in physiological changes related to membrane polarization and membrane integrity. Moreover, honey induced a remarkable metabolic disruption as primary physiological e ect upon S. aureus. The di erent honey samples induced quite similar e ects on both bacteria. However, the depth of bacteria response throughout the treatment varied depending on the concentration tested and among honey varieties, probably due to compositional di erences in the honey.This work was supported by the Consejería de Sanidad of Junta de Castilla y León; under Grant GRS 551/A/10. Patricia Combarros-Fuertes was funded by Consejería de Educación of Junta de Castilla y León and European Social Fund.info:eu-repo/semantics/publishedVersio

Bioactive components and antioxidant and antibacterial activities of different varieties of honey: a screening prior to clinical application

This study assessed 16 different honey samples in order to select the best one for therapeutic purposes. First, a study of honey's main bioactive compounds was carried out. Then phenolic profiles were determined and specific compounds quantified using a HPLC system coupled to a mass spectrometer. Then, antioxidant activity, by three in vitro methods, and antibacterial activity against reference strains and clinical isolates were evaluated. Great variability among samples was observed regarding ascorbic acid (between 0.34 ± 0.00 and 75.8 ± 0.41 mg/100 g honey; p < 0.001), total phenolic compounds (between 23.1 ± 0.83 and 158 ± 5.37 mg/100 g honey; p < 0.001), and total flavonoid contents (between 1.65 ± 0.11 and 5.93 ± 0.21 mg/100 g honey; p < 0.001). Forty-nine different phenolic compounds were detected, but only 46 of them were quantified by HPLC. The concentration of phenolic compounds and the phenolic profiles varied widely among samples (between 1.06 ± 0.04 and 18.6 ± 0.73 mg/100 g honey; p < 0.001). Antioxidant activity also varied significantly among the samples. All honey varieties exhibited antibacterial activity against both reference and clinical strains (effective concentrations ranged between 0.05 and 0.40 g/mL depending on the honey sample and bacteria tested). Overall, samples with better combinations of bioactive properties were avocado and chestnut honeys.This work was supported by the ConsejeriaFundinǵ de Sanidad of Junta de Castilla y Leoń (Spain); under grant GRS 551/A/10. P.C.-F. was funded by the Consejeriá de Educacioń of Junta de Castilla y Leoń and European Social Fund. Notes The authors declare no competing financial interest.info:eu-repo/semantics/publishedVersio

Evaluation of physiological effects induced by manuka honey upon staphylococcus aureus and escherichia coli

Several studies have explored the antimicrobial properties of manuka honey (MkH). However, the data available regarding antibacterial action mechanisms are scarcer. The aim of this study was to scrutinize and characterize primary e ects of manuka honey (MkH) upon the physiological status of Staphylococcus aureus and Escherichia coli (as Gram-positive and Gram-negative bacteria models, respectively), using flow cytometry (FC) to reveal its antibacterial action mechanisms. E ects of MkH on membrane potential, membrane integrity and metabolic activity were assessed using di erent fluorochromes in a 180 min time course assay. Time-kill experiments were carried out under the same conditions. Additionally, MkH e ect on e ux pumps was also studied in an E. coli strain with an over-expression of several e ux pumps. Exposure of bacteria to MkH resulted in physiological changes related to membrane potential and membrane integrity; these e ects displayed slight di erences among bacteria. MkH induced a remarkable metabolic disruption as primary physiological effect upon S. aureus and was able to block effux pump activity in a dose-dependent fashion in the E. coli strain.This work was supported by the Consejería de Sanidad of Junta de Castilla y León; under grant GRS 551/A/10. Patricia Combarros-Fuertes was funded by Consejería de Educación of Junta de Castilla y León and European Social Fund.info:eu-repo/semantics/publishedVersio

Evaluation of honey cell-induced effects on bacteria

Although there exist numerous studies to establish antimicrobial activity of different types of honey, few studies describe the mechanism of their antimicrobial action. Flow cytometry is an analytical method which allows to characterize cell populations at single cell level.info:eu-repo/semantics/publishedVersio

Mieles españolas con marca de calidad: un enfoque multivariado de parámetros fisicoquímicos, calidad microbiológica y origen floral

This study consisted of a palynological, microbiological, and physicochemical characterization of fifteen samples of Spanish honey sold under quality brands with different botanical and geographical origins from two consecutive harvest years (2010 and 2011). Eight of the fifteen honey samples were classified as monofloral honey from botanical origins Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp., and Thymus sp. With regard to microbiological analyses, mold, and yeast counting, Staphylococcus aureus, Salmonella, sulfite-reducing clostridia, and Escherichia coli were not detected in any of the samples. Aerobic mesophilic microorganisms were detected only in some samples and the counts in these cases were low. Despite the great variability between samples, the results obtained in the physicochemical analysis were consistent with the limits set by the Council Directive 2001/100. Honey samples showed high variability between two consecutive harvests, since, even if they had similar geographical origins they showed different nectar floral origins. Mieles españolas con marca de calidad: un enfoque multivariado de parámetros fisicoquímicos, calidad microbiológica y origen floral Este estudio consistió en la caracterización botánica, microbiológica y fisicoquímica de quince muestras de miel españolas acogidas a marcas de calidad diferenciada de diferentes orígenes botánicos y geográficos y procedentes de dos cosechas consecutivas (años 2010 y 2011). Ocho de las quince muestras de miel estudiadas fueron clasificadas como mieles monoflorales de Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp. y Thymus sp. En relación a los análisis microbiológicos los recuentos de mohos y levaduras, Staphylococcus aureus, Salmonella, clostridios sulfito reductores y Escherichia coli no fueron detectados en ninguna de las muestras. Se detectaron microorganismos aerobios mesófilos solo en algunas muestras y en este caso los recuentos fueron bajos. Aunque se detectaron coliformes, estos podrían estar asociados a un origen ambiental. A pesar de la gran variabilidad entre las muestras, los resultados obtenidos en el análisis fisicoquímico se encontraron dentro de los límites establecidos por la Directiva del Consejo 2001/100. Las muestras de miel mostraron una gran variabilidad entre cosechas porque aunque tuvieron un mismo origen geográfico, hubo diferencias en su origen floral.Este estudio consistió en la caracterización botánica, microbiológica y fisicoquímica de quince muestras de miel españolas acogidas a marcas de calidad diferenciada de diferentes orígenes botánicos y geográficos y procedentes de dos cosechas consecutivas (años 2010 y 2011). Ocho de las quince muestras de miel estudiadas fueron clasificadas como mieles monoflorales de Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp. y Thymus sp. En relación a los análisis microbiológicos los recuentos de mohos y levaduras, Staphylococcus aureus, Salmonella, clostridios sulfito reductores y Escherichia coli no fueron detectados en ninguna de las muestras. Se detectaron microorganismos aerobios mesófilos solo en algunas muestras y en este caso los recuentos fueron bajos. Aunque se detectaron coliformes, estos podrían estar asociados a un origen ambiental. A pesar de la gran variabilidad entre las muestras, los resultados obtenidos en el análisis fisicoquímico se encontraron dentro de los l ımites establecidos por la Directiva del Consejo 2001/100. Las muestras de miel mostraron una gran variabilidad entre cosechas porque aunque tuvieron un mismo origen geográfico, hubo diferencias en su origen floral.This work was supported by the Consejería de Sanidad. Junta de Castilla y León [GRS 551/A/10]; Patricia Combarros- Fuertes PhD Research was funded by Consejería de Educación. Junta de Castilla y León and Fondo Social Europeo.info:eu-repo/semantics/publishedVersio