Dynamics of Polyphenol Biosynthesis by Calli Cultures, Suspension Cultures and Wild Specimens of the Medicinal Plant Ligaria cuneifolia (Ruiz & Pav.) Tiegh. (Loranthaceae). Analysis of Their Biological Activity.

Ligaria cuneifolia (R. et P.) Tiegh. (Loranthaceae) is a South American hemiparasitic species with antioxidant, antitumoral, antimicrobial, and antilipidemic activities attributed to its polyphenolic content. We studied the polyphenolic pattern of L. cuneifolia during different phenological stages: flowering, fruiting, and post-fruiting. The highest total phenolic content was found in stems at post-fruiting (214 ± 12.1 mg gallic acid eq·g-1 DW) and fruiting (209 ± 13.7 mg gallic acid eq·g-1 DW), followed by post-fruiting leaves (207 ± 17.5 mg gallic acid eq·g-1 DW). Flavonoids accumulated at higher levels in leaves and hydroxycinnamic acids in leaves at flowering and post-fruiting. The polyphenolic pattern was similar between organs from wild plants and in vitro cultures, although at a significantly lower level in the latter ones. The performance of calli growing under a 16 h photoperiod in a modified White medium with 1-naphthalene acetic acid (2.50 µM) and Kinetin (9.20 µM) was better than in the dark. When calli grew in media only with auxins (IAA, NAA, and 2,4-D, all at 2.50 µM concentration), its growth and polyphenolic content improved. Cell suspensions with 2.50 µM NAA and 9.20 µM KIN grew slowly and produced very small amounts of polyphenols. As for the antioxidant activity, it was detected in all samples (approximately 1000 µmol trolox eq·g-1 DW) except fruits, where a lower value was found (328 µmol trolox eq·g-1 DW). In vitro cultures have the lowest antioxidant activity when compared to methanolic extracts from organs of wild specimens. Finally, antimutagenic or mutagenic activity in wild plants and in vitro culture extracts was not detected by the Ames test.

Comparación de medios de cultivo selectivos para el aislamiento de especies del Taxón K perteneciente al complejo Burkholderia cepacia / Comparison of selective culture media for the isolation of Taxon K species belonging to the Burkholderia cepacia complex

Objetivo: Dentro del complejo Burkholderia cepacia (cBc), el Taxón K, integrado por B. contaminans y B. lata, es frecuentemente aislado de muestras clínicas e industriales. Los métodos para aislar bacterias del cBc están consensuados en el ámbito clínico pero no para muestras de origen industrial y tampoco hay información documentada sobre la capacidad de recuperación de los medios de cultivo frente a especies del Taxón K. Dada la importancia del uso correcto de medios selectivos para la recuperación de microorganismos, el objetivo de este trabajo fue comparar el agar Trypan Blue-Tetraciclina (TB-T), el agar selectivo para Burkholderia cepacia (BCSA) y el BCSA comercial modificado (BCSAm) en el aislamiento de cepas del Taxón K. Métodos: empleamos el método ecométrico utilizado en el control de calidad de medios de cultivo. Analizamos criterios de productividad, selectividad y especificidad frente a cepas de referencia del cBc, aislamientos clínicos e industriales del Taxón K y cepas de otras especies. Resultados: no se observaron diferencias de productividad y selectividad entre los medios BCSA. Con ambos se obtuvo adecuada productividad y selectividad parcial por permitir el crecimiento de especies taxonómicamente cercanas al cBc. El medio TB-T presentó menor productividad (especialmente con B. contaminans) y menor selectividad. Por otra parte, no se observaron diferencias atribuibles al origen clínico o industrial de los aislamientos. Conclusión: los resultados permiten sugerir al BCSA o BCSAm como los medios selectivos de elección para el aislamiento del Taxón K, tanto en muestras de origen clínico como industrial

Objective: Within the Burkholderia cepacia complex (Bcc), the so called Taxon K, integrated by B. contaminans and B. lata, is frequently isolated from clinical and industrial samples. There is consensus in the use of culture media for the isolation of Bcc from clinical origin but not for industrial samples. By the other side there is no documented information about the performance of culture media recovering Taxon K species. Regarding the importance of the proper use of selective media in the recovery of microorganisms from clinical and industrial samples, the objective of this work was to compare Trypan Blue-Tetracycline agar (TB-T), Burkholderia cepacia selective agar (BCSA) and commercial modified Burkholderia cepacia selective agar (BCSAm) in the isolation of Taxon K strains. Methods: we employed the ecometric method for culture media quality control. Productivity, selectivity and specificity criteria were analyzed by testing Bcc reference strains, clinical and industrial Taxon K isolates and non Bcc strains. Results: no differences in terms of productivity and selectivity were observed between BCSA and BCSAm. Both medium, displayed adequate productivity and partial selectivity since the growth of non Bcc isolates was observed. Productivity (especially with B. contaminans isolates) and selectivity in TB-T was lower than BCSA medium. No differences were observed related to the clinical or industrial origin of isolates. Conclusion: results allow us to suggest BCSA or BCSAm selective media for the isolation of Taxon K strains in clinical or industrial samples

Draft Genome Sequences of Burkholderia contaminans FFI-28, a Strain Isolated from a Contaminated Pharmaceutical Solution.

Burkholderia contaminans is a species of the Burkholderia cepacia complex, a group of bacteria that can grow in pharmaceutical products and are capable of infecting the immunocompromised and people with cystic fibrosis. Here, we report draft genome sequences for Burkholderia contaminans FFI-28, a strain isolated from a contaminated pharmaceutical solution.

Antimicrobial Activity of Starch Hydrogel Incorporated with Copper Nanoparticles.

In order to obtain an antimicrobial gel, a starch-based hydrogel reinforced with silica-coated copper nanoparticles (Cu NPs) was developed. Cu NPs were synthesized by use of a copper salt and hydrazine as a reducing agent. In order to enhance Cu NP stability over time, they were synthesized in a starch medium followed by a silica coating. The starch hydrogel was prepared by use of urea and water as plasticizers and it was treated with different concentrations of silica-coated copper nanoparticles (Si-Cu NPs). The obtained materials were characterized by Fourier transform infrared (FT-IR) spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, scanning electron microscopy (SEM), and rheometry. FT-IR and EPR spectra were used for characterization of Cu NPs and Si-Cu NPs, confirming that a starch cap was formed around the Cu NP and demonstrating the stability of the copper nanoparticle after the silica coating step. SEM images showed Cu NP, Si-Cu NP, and hydrogel morphology. The particle size was polydisperse and the structure of the gels changed along with particle concentration. Increased NP content led to larger pores in starch structure. These results were in accordance with the rheological behavior, where reinforcement by the Si-Cu NP was seen. Antimicrobial activity was evaluated against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial species. The hydrogels were demonstrated to maintain antimicrobial activity for at least four cycles of use. A dermal acute toxicity test showed that the material could be scored as slightly irritant, proving its biocompatibility. With these advantages, it is believed that the designed Si-Cu NP loaded hydrogel may show high potential for applications in various clinical fields, such as wound dressings and fillers.

Comparison of the risk of microbiological contamination between samples of breast milk obtained at home and at a healthcare facility.

INTRODUCTION: Breast milk is the best food for preterm infants. Due to their inadequate suction- swallowing action, the administration of expressed breast milk should be done with an orogastric tube. There is little information available regarding the microbiological safety of expressed breast milk. The aim of this article was to evaluate if there were any differences regarding the contamination of breast milk obtained at a healthcare facility versus at home. METHODS: Cross-sectional study that analyzed pairs of breast milk samples (one obtained at home and the other one at a healthcare facility, the same day) from mothers of hospitalized newborn infants with a gestational age =35 weeks. Samples with over 105CFU/mL of mesophilic aerobic bacteria, or with the presence of Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, fungi, and yeast were considered contaminated. RESULTS: A total of 280 breast milk samples (140 pairs) from 53 mothers were analyzed; 139 samples (49.6%; 95% CI: 43.6 to 55.6) were contaminated; contamination was significantly more frequent in the samples obtained at home than in those obtained at a healthcare facility (59.6% versus 39.6%; p = 0.0008; OR 2.25; 95% IC: 1.36 to 3.7). CONCLUSION: Half of the breast milk samples had bacterial growth, which was more frequent in the samples obtained at home than those obtained at a healthcare facility.

Comparison of the risk of microbiological contamination between samples of breast milk obtained at home and at a healthcare facility / Comparación del riesgo de contaminación de la leche materna extraída en una unidad de cuidados intensivos neonatales y en el hogar

Introduction. Breast milk is the best food for preterm infants. Due to their inadequate suction- swallowing action, the administration of expressed breast milk should be done with an orogastric tube. There is little information available regarding the microbiological safety of expressed breast milk. The aim of this article was to evaluate if there were any differences regarding the contamination of breast milk obtained at a healthcare facility versus at home. Methods. Cross-sectional study that analyzed pairs of breast milk samples (one obtained at home and the other one at a healthcare facility, the same day) from mothers of hospitalized newborn infants with a gestational age =35 weeks. Samples with over 105CFU/mL of mesophilic aerobic bacteria, or with the presence of Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, fungi, and yeast were considered contaminated. Results. A total of 280 breast milk samples (140 pairs) from 53 mothers were analyzed; 139 samples (49.6%; 95% CI: 43.6 to 55.6) were contaminated; contamination was significantly more frequent in the samples obtained at home than in those obtained at a healthcare facility (59.6% versus 39.6%; p = 0.0008; OR 2.25; 95% IC: 1.36 to 3.7). Conclusion. Half of the breast milk samples had bacterial growth, which was more frequent in the samples obtained at home than those obtained at a healthcare facility.

Introducción. La leche materna es el mejor alimento para los prematuros. Debido a su inadecuado mecanismo de succión-deglución, la administración de leche materna extraída debe realizarse mediante una sonda orogástrica. Se dispone de escasa información sobre las condiciones microbiológicas de seguridad para la leche materna extraída. El objetivo del presente trabajo fue evaluar si había diferencia en la contaminación de la leche extraída en la institución y en el domicilio. Métodos. Estudio transversal que analizó pares de muestras de leche (una extraída en el hogar y otra en la institución, el mismo día) de madres de neonatos internados, de edad gestacional = 35 semanas. Se consideraron contaminadas las muestras de leche que tenían más de 105 UFC/ml de aerobios mesófilos, o presencia de Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, hongos y levaduras. Resultados. Se analizaron 280 muestras de leche (140 pares) de 53 madres; 139 muestras (49,6%; IC 95%: 43,6 a 55,6) presentaron contaminación, que fue significativamente más frecuente en las muestras obtenidas en el domicilio que en las obtenidas en la institución (59,6% contra 39,6%; p= 0,0008; OR 2,25; IC 95% 1,36 a 3,7). Conclusión. La mitad de las muestras de leche materna presentaron contaminación, la cual fue más frecuente en las obtenidas en el domicilio.

Comparison of the risk of microbiological contamination between samples of breast milk obtained at home and at a healthcare facility / Comparación del riesgo de contaminación de la leche materna extraída en una unidad de cuidados intensivos neonatales y en el hogar

Introduction. Breast milk is the best food for preterm infants. Due to their inadequate suction- swallowing action, the administration of expressed breast milk should be done with an orogastric tube. There is little information available regarding the microbiological safety of expressed breast milk. The aim of this article was to evaluate if there were any differences regarding the contamination of breast milk obtained at a healthcare facility versus at home. Methods. Cross-sectional study that analyzed pairs of breast milk samples (one obtained at home and the other one at a healthcare facility, the same day) from mothers of hospitalized newborn infants with a gestational age =35 weeks. Samples with over 105CFU/mL of mesophilic aerobic bacteria, or with the presence of Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, fungi, and yeast were considered contaminated. Results. A total of 280 breast milk samples (140 pairs) from 53 mothers were analyzed; 139 samples (49.6%; 95% CI: 43.6 to 55.6) were contaminated; contamination was significantly more frequent in the samples obtained at home than in those obtained at a healthcare facility (59.6% versus 39.6%; p = 0.0008; OR 2.25; 95% IC: 1.36 to 3.7). Conclusion. Half of the breast milk samples had bacterial growth, which was more frequent in the samples obtained at home than those obtained at a healthcare facility.(AU)

Introducción. La leche materna es el mejor alimento para los prematuros. Debido a su inadecuado mecanismo de succión-deglución, la administración de leche materna extraída debe realizarse mediante una sonda orogástrica. Se dispone de escasa información sobre las condiciones microbiológicas de seguridad para la leche materna extraída. El objetivo del presente trabajo fue evaluar si había diferencia en la contaminación de la leche extraída en la institución y en el domicilio. Métodos. Estudio transversal que analizó pares de muestras de leche (una extraída en el hogar y otra en la institución, el mismo día) de madres de neonatos internados, de edad gestacional = 35 semanas. Se consideraron contaminadas las muestras de leche que tenían más de 105 UFC/ml de aerobios mesófilos, o presencia de Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, hongos y levaduras. Resultados. Se analizaron 280 muestras de leche (140 pares) de 53 madres; 139 muestras (49,6%; IC 95%: 43,6 a 55,6) presentaron contaminación, que fue significativamente más frecuente en las muestras obtenidas en el domicilio que en las obtenidas en la institución (59,6% contra 39,6%; p= 0,0008; OR 2,25; IC 95% 1,36 a 3,7). Conclusión. La mitad de las muestras de leche materna presentaron contaminación, la cual fue más frecuente en las obtenidas en el domicilio.(AU)

Comparison of the risk of microbiological contamination between samples of breast milk obtained at home and at a healthcare facility. / Comparison of the risk of microbiological contamination between samples of breast milk obtained at home and at a healthcare facility.

INTRODUCTION: Breast milk is the best food for preterm infants. Due to their inadequate suction- swallowing action, the administration of expressed breast milk should be done with an orogastric tube. There is little information available regarding the microbiological safety of expressed breast milk. The aim of this article was to evaluate if there were any differences regarding the contamination of breast milk obtained at a healthcare facility versus at home. METHODS: Cross-sectional study that analyzed pairs of breast milk samples (one obtained at home and the other one at a healthcare facility, the same day) from mothers of hospitalized newborn infants with a gestational age =35 weeks. Samples with over 105CFU/mL of mesophilic aerobic bacteria, or with the presence of Escherichia coli, Staphylococcus aureus, Streptococcus faecalis, enterobacterias, Pseudomonas, Salmonella, fungi, and yeast were considered contaminated. RESULTS: A total of 280 breast milk samples (140 pairs) from 53 mothers were analyzed; 139 samples (49.6

; 95

CI: 43.6 to 55.6) were contaminated; contamination was significantly more frequent in the samples obtained at home than in those obtained at a healthcare facility (59.6

versus 39.6

; p = 0.0008; OR 2.25; 95

IC: 1.36 to 3.7). CONCLUSION: Half of the breast milk samples had bacterial growth, which was more frequent in the samples obtained at home than those obtained at a healthcare facility.

Triclosan-loaded poloxamine micelles for enhanced topical antibacterial activity against biofilm.

Our research group is interested in the study of different technological approaches to treat hospital biofilm as a means to constrain nosocomial-acquired infections. The present work investigated the effect of the incorporation of the antibacterial agent triclosan (TS) into polymeric micelles of poloxamine T1107 (MW=15 kDa, 70 wt% PEO). The aggregation phenomenon was primarily investigated by means of Critical Micellar Concentration in a broad range of pH. Then, the effect of the polymer concentration on the micellar size was evaluated by Dynamic Light Scattering. Solubility levels increased up to 4 orders of magnitude. The drug inclusion affected the micellization, resulting in size increase and micellar fusion. This phenomenon was only apparent in TS-saturated systems. TS-loaded aggregates proved to be active in vitro against a broad spectrum of bacteria but more importantly, also against two representative clinical pathogens: methicilin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VREF). While the former was sensitive to even very low TS levels attainable in poloxamine-free aqueous media, the later was inhibited only when exposed to higher drug levels affordable exclusively using an inclusion system. These findings indicated the release of the drug from the reservoir. Finally, the activity of a TS-containing 5% poloxamine combination of pH 7.4 was assessed on biofilms of Staphylococcus epidermidis. Results showed a significant decrease (p<0.001) in the number of Colony-Formation Units when the biofilm was exposed to the TS/poloxamine as compared to the limited activity of the polymer-free TS control.

Lemon juice as a natural biocide for disinfecting drinking water

The natural biocidal activity of lemon juice was studied in order to explore its possible use as a disinfectant and inhibitor of Vibrio cholerae in drinking water for areas lacking water treatment plants. Fron January through July 1993, water samples of varying alkalinity and hardness were prepared artificially, and underground and surface water samples were obtained from a number of different rural and urban areas in Argentina's Buenos Aires Province. After measuring the latter samples' hardness and alkalinity, a range of concentrations of lemon juice and other acidifiers were added to each sample, and the resulting pH as well as the samples' ability to destroy V. cholerae were determined. The results show that lemon juice can actively prevent survival of V. cholerae but that such activity is reduced in markedly alkaline water. For example, treatment of underground drinking water, which is characterized as having the greatest degree of alkalinity in our area, will typically destroy V. cholerae if the alkalinity of the water is the equivalent of that produced by 200 mg CaCO3 per liter, if enough lemon juice is added to bring the lemon juice concentration to 2 percent, and if the lemon juice is allowed to act for 30 minutes. All this points up the need to determine the alkalinity of water from any local source to be treated in the process of assessing the minimum concentration of lemon juice required

El limón como biocida natural para desinfectar las aguas de consumo / Lemon as a natural biocidal agent for disinfecting drinking water

Se estudió la actividad biocida natural del zumo de limón para examinar su posible uso como desinfectante e inhibidor de Vibrio cholerae en las aguas de consumo de lugares sin plantas de tratamiento. De enero a julio de 1993 se prepararon artificialmente aguas de distinta dureza y alcalinidad y se obtuvieron muestras de aguas subterráneas y superficiales de zonas rurales y urbanas de la provincia de Buenos Aires, Argentina. Después de medir su dureza y alcalinidad, se le añadió a cada una zumo de limón en diferentes concentraciones y se determinaron el grado de acidez obtenido y la actividad del limón contra V. cholerae. Los resultados demostraron que el zumo de limón es activo contra V. cholerae, pero que esta actividad se reduce en aguas muy alcalinas. Por consiguiente, el tratamiento de las aguas de consumo subterráneas, que son las de mayor alcalinidad, puede destruir V. cholerae solo a una concentración mínima de limón de 2 por ciento y a un tiempo de acción mínimo de 30 minutos. Se recomienda, sin embargo, conocer la alcalinidad del agua local que se busca tratar antes de fijar la concentración mínima de limón

Lemon juice as a natural biocide for disinfecting drinking water

The natural biocidal activity of lemon juice was studied in order to explore its possible use as a disinfectant and inhibitor of Vibrio cholerae in drinking water for areas lacking water treatment plants. Fron January through July 1993, water samples of varying alkalinity and hardness were prepared artificially, and underground and surface water samples were obtained from a number of different rural and urban areas in Argentina's Buenos Aires Province. After measuring the latter samples' hardness and alkalinity, a range of concentrations of lemon juice and other acidifiers were added to each sample, and the resulting pH as well as the samples' ability to destroy V. cholerae were determined. The results show that lemon juice can actively prevent survival of V. cholerae but that such activity is reduced in markedly alkaline water. For example, treatment of underground drinking water, which is characterized as having the greatest degree of alkalinity in our area, will typically destroy V. cholerae if the alkalinity of the water is the equivalent of that produced by 200 mg CaCO3 per liter, if enough lemon juice is added to bring the lemon juice concentration to 2 percent, and if the lemon juice is allowed to act for 30 minutes. All this points up the need to determine the alkalinity of water from any local source to be treated in the process of assessing the minimum concentration of lemon juice required

Published in Spanish in the BOSP. 117(4), 1994

El limón como biocida natural para desinfectar las aguas de consumo / Lemon as a natural biocidal agent for disinfecting drinking water

Se estudió la actividad biocida natural del zumo de limón para examinar su posible uso como desinfectante e inhibidor de Vibrio cholerae en las aguas de consumo de lugares sin plantas de tratamiento. De enero a julio de 1993 se prepararon artificialmente aguas de distinta dureza y alcalinidad y se obtuvieron muestras de aguas subterráneas y superficiales de zonas rurales y urbanas de la provincia de Buenos Aires, Argentina. Después de medir su dureza y alcalinidad, se le añadió a cada una zumo de limón en diferentes concentraciones y se determinaron el grado de acidez obtenido y la actividad del limón contra V. cholerae. Los resultados demostraron que el zumo de limón es activo contra V. cholerae, pero que esta actividad se reduce en aguas muy alcalinas. Por consiguiente, el tratamiento de las aguas de consumo subterráneas, que son las de mayor alcalinidad, puede destruir V. cholerae solo a una concentración mínima de limón de 2 por ciento y a un tiempo de acción mínimo de 30 minutos. Se recomienda, sin embargo, conocer la alcalinidad del agua local que se busca tratar antes de fijar la concentración mínima de limón

Edición en inglés se publica en Bull. PAHO Vol. 28(4):324-30, 1994