ABSTRACT

Thechemical composition, antioxidant and antimicrobial activities of the essential oil from aerial parts (leaves and flowers) of Chuquiraga arcuataHarling grown in the Ecuadorian Andes were studied. One hundred and twenty-six compounds were identified in the essential oil. Monoterpene hydrocarbons (45.8%) and oxygenated monoterpenes (44.1%) had the major percentages. The most abundant compounds were camphor (21.6%), myrcene (19.5%), and 1,8-cineole (13.4%). Antioxidant activity was examined using DPPH, ABTS,and FRAP assays. The essential oil had a moderate scavenging effect and reduction of ferric ion capacity through FRAP assay. Antimicrobial activity of the essential oil was observed against four pathogenic bacteria and a fungus. The essential oil exhibited activity against all microorganism strains under test, particularly against Candida albicansand Staphylococcus aureuswith MICs of 2.43-12.10 µg/mL.

Se estudió la composición química, actividades antioxidantes y antimicrobianas del aceite esencial procedente de las partes aérea (hojas y flores) de Chuquiraga arcuataHarling cultivadas en los Andes ecuatorianos. Se identificaron 126 compuestos en el aceite esencial. Los hidrocarburos monoterpénicos (45,8%) y los monoterpenos oxigenados (44,1%) tuvieron el mayor porcentaje. Los compuestos más abundantes fueron alcanfor (21,6%), mirceno (19,5%) y 1,8-cineol (13,4%). La actividadantioxidante se examinó mediante ensayos DPPH, ABTS y FRAP. El aceite esencial tuvo un efecto eliminador moderado y una reducción de la capacidad de iones férricos mediante el ensayo FRAP. Se observó actividad antimicrobiana del aceite esencial contra cuatro bacterias y un hongo patógenos. El aceite esencial mostró actividad contra todas las cepas de microorganismos bajo prueba, particularmente contra Candida albicansy Staphylococcus aureuscon CMI de 2,43-12,10 µg/mL.

ABSTRACT

The aim of this study was to optimize by response surface design, the extraction of the leaf essential oil (EO) from Minthostachys mollis [HBK] Griseb., grown in Ecuador, using steam distillation. The factors used were extraction time (XTIE) of 60, 105 and 150 min and plant material/water ratio (XRMA) of 1:3, 1:4 and 1:5. The optimal combination was reached with XRMA 1:5 and XTIE 150 min, obtaining a process yield of 0.67%. The chemical composition of the EO analyzed by GC - MS was determined, where the main compounds were carvacryl acetate (44.01%), carvacrol (16.51%) and menthone (8.20%). The anti oxidant capacity of EO was evaluated using the FRAP and ABTS methodologies, with an IC 50 243.21 µmol Fe 2+ /g and 0.12 mg/mL, respectively. In addition, the antimicrobial activity of EO was found against Pseudomonas aeruginosa , Salmonella enterica , Escherich ia coli and Staphylococcus aureus .

El objetivo del estudio fue optimizar, mediante un diseño de superficie respuesta, la extracción d el aceite esencial (AE) de hojas de Minthostachys mollis [HBK] Griseb. del Ecuador, mediante destilación por arrastre de vapor. Los factores fueron el tiempo de extracción (XTIE) de 60, 105 y 150 min, y relación de material vegetal/ agua destilada (XRMA) d e 1:3, 1:4 y 1:5. La combinación óptima se logró con XTIE 150 min y XRMA 1:5 para un rendimiento de 0,67%. Se determinó la composición química del AE por GC - MS donde los compuestos mayoritarios fueron acetato de carvacrilo (44,01%), carvacrol (16,51%) y me ntona (8,20%). Se evaluó la capacidad antioxidante del AE por las metodologías FRAP y ABTS, con CI 50 de 243,21 µmol Fe 2+ /g y 0,12 mg/mL, respectivamente. Además, se demostró la actividad antimicrobiana contra Pseudomonas aeruginosa , Salmonella enterica , Es cherichia coli y Staphylococcus aureus .

ABSTRACT

Although numerous studies have demonstrated the biomedical potential of Myrtus communis L., (Myrtaceae) data on myrt le from Montenegro are scarce. T o evaluate antioxidant, antimutagenic and antibacterial activity of myrtle methanolic extracts. Antioxidant activity was evaluated by measuring free radicals scavenging activity, reducing power and enzyme inhibition. The strongest scavenging activity was towards DPPH radical ( 2,2 - diphenyl - 1 - picry lhydrazyl) (IC 50 1.69 - 2.25 mg/mL) and superoxide anion (IC 50 0.56 to 0.88 mg/mL), followed by high reducing power (428 - 472 mgAA/g.DE) and inhibition of XOD (IC 50 0.308 - 0.6261mg/mL). Antimutagenic activity was evaluated in reverse mutation assays with Esche richia coli WP2 oxyR mutant IC202 and deficient in the induction of antioxidant enzymes. The myrtle extracts strongly inhibited mutagenesis induced by t - BOOH, reaching 70% at the highest concentration applied. Antimicrobial activity was examined on eight different bacterial strains. Gram - positive bacteria, S. epidermis , S. aureus and M. flavus demonstrated the highest sensitivity towards extracts (MICs 4.5 - 9 mg/mL), but significantly lower towards essential oil (MIC 0.42 - 3.32 mg/mL).

Aunque numerosos estudios han demostrado el potencial biomédico de Myrtus communis L., (Myrtaceae), los datos sobre el mirto de Montenegro son escasos. E valuar la actividad antioxidante, antimutagéni ca y antibacteriana de extractos metanólicos de mirto. La actividad antioxidante se evaluó midiendo la actividad de eliminación de radicales libres, el poder reductor y la inhibición enzimática. La actividad secuestrante más fuerte fue hacia DPPH radical ( IC 50 1.69 - 2.25 mg/mL) y radicales de anión superóxido (IC 50 0.56 a 0.88 mg/mL), seguido de alto poder reductor (428 - 472 m gAA/g.DE) e inhibición de XOD (I C 50 0,308 - 0,6261 mg/m L ). La actividad antimutagénica se evaluó en ensayos de mutación inversa con Esche richia coli WP2 oxyR mutante IC202 y deficiente en la inducción de enzimas antioxidantes. Los extractos de mirto inhibieron fuertemente la mutagénesis inducida por t - BOOH, alcanzando el 70% a la mayor concentración aplicada. La actividad antimicrobiana se examinó en octo cepas bacterianas diferentes. Las bacterias grampositivas, S. epidermis , S. aureus y M. flavus demostraron la sensibilidad más alta hacia los extractos (MIC 4.5 - 9 mg/mL), pero significativamente más baja hacia el aceite esencial (MIC 0.42 - 3 .32 mg/mL). Los resultados muestran la gran perspectiva nutrafarmacéutica de la especie montenegrina Myrtus communis .

ABSTRACT

Aim: To investigate the bacteriological profile of oral and maxillofacial infections and the pattern of sensitivity to a specific group of antibiotics in a reference emergency hospital in Brazil. Methods: This is a prospective cohort institutional study that studied patients affected by oral and/ or maxillofacial infections in a Brazilian emergency hospital, over a 12-month period, of different etiologies, through data collection, culture and antibiogram tests, and monitoring of the process of resolution of the infectious condition. The variables were analyzed using the chi-square and Mann-Whitney tests, using a significance level of 5%. Results: The sample consisted of 61 patients, 62.3% male. The mean age of participants was 34.3 years. Odontogenic infection was the most frequent etiology and the submandibular space was the most affected. The bacterial species Streptococcus viridans was isolated in 21.6% of cases. Levofloxacin, vancomycin and penicillin were the antibiotics with the highest frequency of bacterial sensitivity, while clindamycin and erythromycin showed the highest percentages of resistance. Conclusions: The results suggest that, among the most used antibiotics for the treatment of these infections, penicillin remains an excellent option of choice for empirical therapy

ABSTRACT

Vegetable extracts have become important raw materials for food, pharmaceutical and cosmetic industries because of their biological potential. The objective of this study was to assess the biological activity of vegetable oils (VOs) extracted from Annona muricata and A. cherimola. Antibacterial activity was determined by plaque microdilution. The assessment of hemolytic inhibition and morphological alterations was performed in erythrocyte cultures by spectrophotometry and microscopy, respectively. Neutrophils were used to analyze both cytotoxicity by the trypan blue exclusion method and the effect on gelatinase granule release (MMP9) via zymography. Whereas VOs showed a mild antibacterial activity (900 µL/mL) on five ATCC bacterial strains, they had no effect on multi-resistant bacteria. In addition, VOs inhibited hydrogen peroxide induced hemolysis and did not cause erythrocyte cell abnormalities. Cytotoxicity was not detected in neutrophils and VOs were able to stimulate MMP9 release. These results support their potential use by the food and cosmetic industries due to their antioxidant, non-cytotoxic, and slight antibacterial capacities.

Los extractos vegetales adquieren importancia en la industria alimentaria, farmacéutica y cosmética, por su potencial biológico. El objetivo de este estudio fue evaluar actividad biológica de los Aceites Vegetales (AV) de semillas de Annona muricata y A. cherimola. La actividad antibacteriana se determinó mediante microdilución en placa; en cultivo de eritrocitos se evaluó inhibición hemolítica por espectrofotometría y alteraciones morfológicas por recuento microscópico; en neutrófilos se evaluó citotoxicidad por método de exclusión con azul de tripán, y el efecto sobre liberación de gránulos de gelatinasa (MMP9) mediante zimografía. Los AV presentaron actividad antibacteriana leve (900 µL/mL) en cinco cepas ATCC, pero no en bacterias multirresistentes; inhibieron la hemolisis inducida por peróxido de hidrogeno; no generaron deformaciones eritrocitarias; no se evidenció citotoxicidad en neutrófilos y estimularon la liberación de MMP9. Los resultados podrían sustentar el uso potencial de estos AV en la industria alimenticia o cosmética, gracias a su capacidad antioxidante, no citotóxica y levemente antibacteriana.

ABSTRACT

In this study, we investigated the influence of mixture design on the chemical profile of Eugenia unifloraleaves, evaluating the antioxidant and antimicrobial activities, the toxic and hemolytic potential, with the focus on the improvement of the polyphenol's extraction for incorporation of the extract in semi-solid forms with antifungal action. The chemical analysis was evaluated by UV-Vis and HPLC. The antimicrobial, antioxidant, and hemolytic activities were monitored. The flavonoid content ranged from 2.63-7.98 %w/w and tannins from 5.42-18.29 %w/w. The extract consisted of gallic acid (0.09-1.29%; w/w), ellagic acid (0.09-0.37%; w/w), and myricitrin (0.18-1.20%; w/w). The most successful solvent system with the highest level of active extract was water: ethanol: propylene glycol. The extracts showed fungicidal properties (3.9 µg/mL), high antioxidant activity (IC50: 9.50 µg/mL), and low toxicity. These solvent mixtures can improve the in vitro bioactivities when compared to pure solvents and this result demonstrates the importance of mixture designs as useful tools for creating high-quality herbal products and elucidate the potential of E. uniflora glycolic extracts as active herbal pharmaceutical ingredients in topical delivery systems.

En este estudio investigamos la influencia del diseño de mezclas en el perfil químico de hojas de Eugenia uniflora, evaluando las actividades antioxidantes y antimicrobianas, el potencial tóxico y hemolítico, con el foco en la mejora de la extracción de polifenoles para la incorporación del extracto en formas semi-sólidas con acción antifúngica. El análisis químico se evaluó mediante UV-Vis y HPLC. Se monitorizaron las actividades antimicrobianas, antioxidantes y hemolíticas. El contenido de flavonoides osciló entre 2,63 y 7,98% p/p and taninos de 5,42-18,29% p/p. El extracto consistió en ácido gálico (0.09-1.29%; p/p), ácido elágico (0.09-0.37%; p/p) y miricitrina (0.18-1.20%; p/p). El sistema de disolventes más exitoso con el nivel más alto de extracto activo fue agua: etanol: propilenglicol. Los extractos mostraron propiedades fungicidas (3.9 µg/mL), alta actividad antioxidante (IC50: 9.50 µg/mL) y baja toxicidad. Estas mezclas de disolventes pueden mejorar las bioactividades in vitro en comparación con los disolventes puros y este resultado demuestra la importancia de los diseños de mezclas como herramientas útiles para crear productos a base de hierbas de alta calidad y dilucidar el potencial de los extractos glicólicos de E. uniflora como ingredientes farmacéuticos a base de hierbas en sistemas de entrega activos.

ABSTRACT

Currently, in developing countries, parasitic and bacterial diseases as amebiasis, giardiasis, trichonomiasis, leishmaniasis, trypanosomiasis, tuberculosis, and nocardiasis are a public health problem. The pharmacological treatment for these diseases is not completely effective and causes several side effects in patients. Therefore, the search for new compounds with biological activity is very important to develop new drugs safely and more efficiently. In this study, different organic extracts obtained from thirty-seven species of the Salvadoran flora were evaluated in several in vitro models to determine their potential activity against five protozoa (Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis, Leishmania mexicana, and Trypanosoma cruzi) and three bacteria (Acinetobacter baumanni, Mycobacterium tuberculosis, and Nocardia brasiliensis). The results showed the activity of eight extracts with IC50values of less than 100 µg/mL against L. mexicanaand five extracts with MICs values less than <50 µg/mL against M. tuberculosis. Besides, seven plant species showed MICs ≤3.125 µg/mL against N. brasiliensis. Additionally, secondary metabolites (flavonoids and monoterpene oxygenate) previously reported as active were fingerprint by UPLC-MS to establish a potential correlation with the biological activity showed.

Actualmente, en los países en vías de desarrollo, enfermedades parasitarias y bacterianas como la amebiasis, giardiasis, trichonomiasis, leishmaniasis, tripanosomiasis, tuberculosis y nocardiasis son un problema de salud pública. El tratamiento farmacológico de estas enfermedades no es del todo eficaz y provoca varios efectos secundarios en los pacientes. Por lo tanto, la búsqueda de nuevos compuestos con actividad biológica es muy importante para desarrollar nuevos fármacos, seguros y eficaces. En este estudio se evaluaron diferentes extractos orgánicos obtenidos de treinta y siete especies de la flora salvadoreña en varios modelos in vitro para determinar su actividad potencial contra cinco parásitos (Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis, Leishmania mexicana y Trypanosoma cruzi) y tres bacterias (Acinetobacter baumanni, Mycobacterium tuberculosis y Nocardia brasiliensis). Los resultados mostraron la actividad de ocho extractos con valores de CI50 menores a 100 µg/mL contra L. mexicana y cinco extractos con valores de CIMs <50 µg/mL contra M. tuberculosis. Además, siete especies de plantas presentaron CIM ≤3,125 µg/mL frente a N. brasilienses. Finalmente, los metabolitos secundarios (flavonoides y monoterpenos oxigenados) previamente reportados como activos fueron determinados por UPLC-MS para establecer una posible correlación con la actividad biológica mostrada.

ABSTRACT

Com o avanço da medicina e o aumento do uso de antimicrobianos, a resistência microbiana vem se tornando um problema sério na saúde pública. Para que uma bactéria se torne resistente, são necessários vários fatores, entre eles, o uso indiscriminado e prolongado de antimicrobianos e as resistências intrínsecas e adquiridas. Nesse contexto, o objetivo do trabalho foi explorar os mecanismos de ação dos antimicrobianos, de resistência e a sua importância na saúde pública. Foram utilizadas para a presente pesquisa, as bases de dados Pubmed, Google acadêmico e Scielo. Segundo a Organização Mundial da Saúde define-se resistência ao antibiótico quando o mesmo não produz mais efeito. A inserção cada vez mais frequente de antimicrobianos favorece a resistência, onde provocam uma pressão seletiva sobre os microrganismos, tornando-os resistentes a diversas drogas. O uso indiscriminado de antimicrobianos é o principal fator de resistência microbiana, assim como o uso de antimicrobianos sem exame de cultura e teste de sensibilidade. Neste sentido, conclui-se que é de suma importância a atualização de protocolos que contenham os mecanismos de resistência bacteriana a fim de minimizar o uso indiscriminado de antimicrobianos, assim como capacitar os profissionais da saúde para este problema na saúde pública.

With the advance of medicine and the increase in the use of antimicrobials, microbial resistance has become a serious problem in public health. For a bacterium to become resistant, several factors are necessary, among them, the indiscriminate and prolonged use of antimicrobials and the intrinsic and acquired resistance. In this context, the objective of the work was to explore the mechanisms of action of antimicrobials, resistance and their importance in public health. Pubmed, Google academic and Scielo databases were used for this research. According to the World Health Organization, resistance to antibiotics is defined when it no longer has an effect. The increasingly frequent insertion of antimicrobials favors resistance, where they put selective pressure on microorganisms, making them resistant to various drugs. The indiscriminate use of antimicrobials is the main factor of microbial resistance, as well as the use of antimicrobials without culture examination and sensitivity test. In this sense, it is concluded that it is extremely important to update protocols that contain the mechanisms of bacterial resistance in order to minimize the indiscriminate use of antimicrobials, as well as to train health professionals for this problem in public health.

Con los avances de la medicina y el mayor uso de antimicrobianos, la resistencia microbiana se ha convertido en un grave problema de salud pública. Para que una bacteria se vuelva resistente son necesarios varios factores, entre ellos, el uso indiscriminado y prolongado de antimicrobianos y la resistencia intrínseca y adquirida. En este contexto, el objetivo de este trabajo fue explorar los mecanismos de acción de los antimicrobianos, la resistencia y su importancia en la salud pública. Para esta investigación se utilizaron las bases de datos Pubmed, Google Scholar y Scielo. Según la Organización Mundial de la Salud, la resistencia a un antibiótico se define cuando deja de producir efecto. El uso cada vez más frecuente de antimicrobianos favorece la resistencia, ya que provocan una presión selectiva sobre los microorganismos, haciéndolos resistentes a varios fármacos. El uso indiscriminado de antimicrobianos es el principal factor de resistencia microbiana, así como el uso de antimicrobianos sin pruebas de cultivo y sensibilidad. En este sentido, se concluye que es de suma importancia actualizar los protocolos que contienen los mecanismos de resistencia bacteriana para minimizar el uso indiscriminado de antimicrobianos, así como capacitar a los profesionales de la salud para este problema en la salud pública.

ABSTRACT

This paper describes the evaluation of the antimicrobial and hemolytic activity of the hexane, dichloromethane, ethyl acetate and methanol extracts from seeds and epicarps of Garcinia madruno; as well garcinol, morelloflavone and volkensiflavone isolated from the same species. In the preliminary test of bacterial susceptibility, hexane extracts from seeds and epicarps and the three compounds tested only displayed inhibitory growth effect against Gram-positive bacteria. The minimum inhibitory concentrations of extract and compounds ranging from 86.6 to 1253.4 µg/mL. The hemolytic activity was assessed; however, except for the methanol extract from seeds, none of the samples studied induced hemolysis. Thus, our results suggest that extracts and compounds from G. madruno have the potential to be used in the control of pathologies associated to Gram-positive bacteria. This is the first report of the antimicrobial and hemolytic activity of extracts of different polarity obtained from seeds and epicarps of this edible species.

El presente artículo describe la evaluación de la actividad antimicrobiana y hemolítica de los extractos de hexano, diclorometano, acetato de etilo y metanol, obtenidos de la semilla y el epicarpio de Garcinia madruno; así como de garcinol, morelloflavona y volkensiflavona; aislados de la misma especie. En el ensayo de susceptibilidad bacteriana, tanto el extracto de hexano obtenido a partir de la semilla y el epicarpio, y los tres compuestos aislados, únicamente mostraron actividad inhibitoria del crecimiento contra bacterias Gram-positivas. La concentración mínima inhibitoria presentó valores entre 86.6 y 1253.4 µg/mL. También se estableció la actividad hemolítica; sin embargo, con excepción del extracto metanólico obtenido a partir de las semillas, ninguna de las muestras evaluadas indujo hemólisis. Por lo tanto, los resultados sugieren que los extractos y compuestos de G. madruno tienen el potencial de ser usados en el control de bacterias Gram-positivas asociadas a diversas patologías. Este es el primer reporte de actividad antimicrobiana y hemolítica de extractos de diferente polaridad obtenidos de las semillas y epicarpios de esta especie comestible.

ABSTRACT

INTRODUCCIÓN: La neumonía asociada a ventilación mecánica (NAVM) es frecuente en pacientes críticos con COVID-19. Su diagnóstico precoz es fundamental para su pronóstico. OBJETIVO: Demostrar la utilidad del panel FilmArray Pneumo (PFA-P) en la confirmación o descarte de NAVM en estos pacientes. MÉTODOS: Estudio retrospectivo de 71 pacientes críticos con COVID-19 con sospecha de NAVM en quienes se realizó cultivos y PFA-P para confirmación diagnóstica. Se describen las características clínicas, microbiología y mortalidad. Se define la validez y seguridad de PFA-P. RESULTADOS: El uso de FAP-P y cultivos descartó NAVM en 29 pacientes (40,8%). En 41 pacientes se confirmó NAVM y la mortalidad a 30 días fue 48,8%. Se estudiaron 48 muestras, los cultivos fueron positivos en 30 (62,5%) y se detectaron 33 bacterias, PFA-P detectó 32 de estas 33 bacterias; 37 bacterias fueron detectadas exclusivamente por PFA-P. Las bacterias prevalentes fueron Klebsiella pneumoniae (31,4%) Pseudomonas aeruginosa (21,4%) y Acinetobacter calcoaceticusbaumannii (14,2%). La sensibilidad, especificidad, valor predictor positivo y valor predictor negativo de PFA-P con respecto a cultivos fue 96,9%, 92,5%, 46,4% y 99,8, respectivamente. Un paciente tuvo NAVM por Burkholderia cepacia bacteria no detectada por FAP-P. CONCLUSIONES: La FAP-P es una técnica molecular eficaz para descartar y diagnosticar la NAVM permitiendo una suspensión rápida de los antimicrobianos o un tratamiento dirigido temprano.

BACKGROUND: Ventilator-associated pneumonia (VAP) is frequent in critical COVID-19 patients. Its early diagnosis is essential for its prognosis. AIM: To demonstrate the usefulness of the FilmArray Pneumo panel (FAP-P) in confirming or ruling out VAP in these patients. METHODS: Retrospective study of 71 critical COVID-19 patients with suspected VAP in whom cultures and FAP-P were performed for diagnostic confirmation. Clinical characteristics, microbiology and mortality are described. The validity and safety of FAP-P is defined. RESULTS: The use of FAP-P and cultures ruled out VAP in 29 patients (40.8%). In 41 patients, VAP was confirmed and the 30-day mortality was 48.8%. Forty-eight samples were studied, the cultures were positive in 30 (62.5%) and 33 bacteria were detected, FAP-P detected 32 of these 33 bacteria; 37 bacteria were exclusively detected by PFA-P. The most prevalent bacteria were Klebsiella pneumoniae (31.4%), Pseudomonas aeruginosa (21.4%) and Acinetobacter calcoaceticus-baumannii (14.2%). The sensitivity, specificity, positive predictive value and negative predictive value of FAP-P with respect to cultures were 96.9%, 92.5%, 46.4% and 99.8%, respectively. One patient had VAP due to Burkholderia cepacia bacteria not detected by FAP-P. CONCLUSIONS: FAP-P is an effective molecular technique to rule out and diagnose VAP, allowing rapid suspension of antibiotics or early targeted treatment.

ABSTRACT

This review describes the geographical distribution, botanical data, popular use, chemical composition, pharmacological activities and genetic aspects related to Eugenia luschnathiana, a native Brazilian plant popularly known as "bay pitomba". E. luschnathiana leaves are characterized morphologically by the presence of a petiole, an attenuated base, acuminated apex, elliptical shape, and parallel venation. The major chemical compounds found in E. luschnathiana are sesquiterpenes. Literature reports showed that E. luschnathiana extracts have antioxidant properties and antimicrobial activity against Gram-negative and Gram-positive bacteria. The extractsfrom the leaf, fruit and stem, and a concentrated residual solution of its essential oil, displayed negligible toxicity. Lastly, a cytogenetic analysis indicated that some markers can be used for the study of genetic diversity, population structure, and genetic improvements. The information available on E. luschnathiana supports the hypothesis that this plant may be a source of compounds with promising pharmacological activity.

Esta revisión describe la distribución geográfica, datos botánicos, uso popular, composición química, actividad farmacológica y el análisis genético de Eugenia luschnathiana, una planta originaria del Brasil conocida popularmente como "pitomba da baía". Las hojas de E. luschnathiana se caracterizan por la presencia de pecíolo, base atenuada, ápice acuminado, forma elíptica y venación paralela. Su composición química presenta mayormente sesquiterpenos. Los informes en la literatura muestran que los extractos de E. luschnathiana presentan propiedades antioxidantes y actividad antimicrobiana contra las bacterias Gram-negativas y Gram-positivas. Los extractos de la hoja, fruto y tallo, y una solución residual concentrada del aceite esencial, presentaron baja toxicidad. Por último, un análisis citogenético indicó que algunos marcadores pueden utilizarse para estudios de diversidad genética, estructura poblacional y mejoramiento genético. Las informaciones disponibles acerca de E. luschnathiana proponen la hipótesis de que esta planta puede ser una fuente de compuestos con actividad farmacológica prometedora.

ABSTRACT

The aim of this study was to undertake a screening experiment on essential oils (EO) of Myrcia lundiana, Ocimum basilicum and Lippia alba against six food-spoiling pathogenic bacteria. Seventy-two (72) samples were initially analyzed fo antimicrobial activity based on the agar diffusion test. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations were determined for the 12 samples which showed greatest antimicrobial potential in this stage. Two samples of L. alba, three samples of M. lundiana and seven samples of O. basilicum showed a MIC of 0.12-125 µL/mL for the six tested bacteria. Of these, the EO of O. basilicum cultivar Maria Bonita stood out with the lowest MIC and MBC. Thus, a mixture simulating this essential oil was prepared from commercial standards of the compounds (±)-linalool, geraniol and 1,8-cineole. Significantly higher MIC and MBC were detected in the simulation compared to the respective EO, suggesting a synergistic effect between compounds.

El objetivo de este estudio fue realizar un experimento de detección en aceites esenciales (AE) de Myrcia lundiana, Ocimum basilicum y Lippia alba contra seis bacterias patógenas que estropean los alimentos. Setenta y dos (72) muestras fueron analizadas inicialmente para la actividad antimicrobiana basada en la prueba de difusión en agar. Se determinaron las concentraciones mínimas inhibitoria (CMI) y bactericida (CMB) para las 12 muestras que mostraron el mayor potencial antimicrobiano en esta etapa. Dos muestras de L. alba, tres muestras de M. lundiana y siete muestras de O. basilicum mostraron un CMI de 0.12-125 µL/mL para las seis bacterias analizadas. De estos, el AE de O. basilicum cultivar Maria Bonita se destacó con el CMI y CMB más bajos. Por lo tanto, se preparó una mezcla que simula este aceite esencial a partir de los estándares comerciales de los compuestos de (±)-linalol, geraniol y 1,8-cineol. Se detectaron CMI y CMB significativamente más altos en la simulación en comparación con el AE respectivo, lo que sugiere un efecto sinérgico entre los compuestos.

ABSTRACT

BACKGROUND: Endometritis is the most common disease of dairy cows and traditionally treated with antibiotics. Lactic acid bacteria can inhibit the growth of pathogens and also have potential for treatment of endometritis. Using PacBio single-molecule real-time sequencing technology, we sequenced the fulllength l6S rRNA of the microbiota in uterine mucus samples from 31 cows with endometritis, treated with lactic acid bacteria (experimental [E] group) and antibiotics (control [C] group) separately. Microbiota profiles taken before and after treatment were compared. RESULTS: After both treatments, bacterial species richness was significantly higher than before, but there was no significant difference in bacterial diversity. Abundance of some bacteria increased after both lactic acid bacteria and antibiotic treatment: Lactobacillus helveticus, Lactococcus lactis, Lactococcus raffinolactis, Pseudomonas alcaligenes and Pseudomonas veronii. The bacterial species that significantly decreased in abundance varied depending on whether the cows had been treated with lactic acid bacteria or antibiotics. Abundance of Staphylococcus equorum and Treponema brennaborense increased after lactic acid bacteria treatment but decreased after antibiotic treatment. According to COG-based functional metagenomic predictions, 384 functional proteins were significantly differently expressed after treatment. E and C group protein expression pathways were significantly higher than before treatment (p < 0.05). CONCLUSIONS: In this study, we found that lactic acid bacteria could cure endometritis and restore a normal physiological state, while avoiding the disadvantages of antibiotic treatment, such as the reductions in abundance of beneficial microbiota. This suggests that lactic acid bacteria treatment has potential as an alternative to antibiotics in the treatment of endometritis in cattle.

ABSTRACT

Background: The main objective of this study was to isolate fungi associated with Anthopleura xanthogrammica and measure their antimicrobial and enzymatic activities. A total of 93 fungal strains associated with A. xanthogrammica were isolated in this study, of which 32 isolates were identified using both morphological characteristics and internal transcribed spacer (ITS) sequence analysis. The antibacterial activities of 32 fungal isolates were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Edwardsiella tarda, Vibrio harveyi, Fusarium oxysporum, and Pyricularia oryzae by agar diffusion assay. Extracellular hydrolytic enzyme activities of the fungal isolates were determined by agar diffusion assays. Enzyme activities were detected from clear halo size. Results: The isolated fungi belonged to 18 genera within 7 taxonomic orders of 1 phylum. The genera Aspergillaceae were the most diverse and common. The antimicrobial activities of 32 isolates were evaluated, and 19 (59.4%) of fungi isolate displayed unique antimicrobial activities. All fungal strains displayed at least one enzyme activity. The most common enzyme activities in the fungi isolates were amylase and protease, while the least common were pectinase and xylanase. Conclusions: This is first report on the sea anemone-derived fungi with antimicrobial and enzyme activities. Results indicated that sea anemone is a hot spot of fungal diversity and a rich resource of bioactive natural products.

ABSTRACT

The aim of this paper was to observe the effect of Realgar and arsenic trioxide on gut microbiota. The mice were divided into low-dose Realgar group(RL), medium-dose Realgar group(RM), high-dose Realgar group(RH), and arsenic trioxide group(ATO), in which ATO and RL groups had the same trivalent arsenic content. Realgar and arsenic trioxide toxicity models were established after intragastric administration for 1 week, and mice feces were collected 1 h after intragastric administration on day 8. The effects of Realgar on gut microbiota of mice were observed through bacterial 16 S rRNA gene sequences. The results showed that Lactobacillus was decreased in all groups, while Ruminococcus and Adlercreutzia were increased. The RL group and ATO group were consistent in the genera of Prevotella, Ruminococcus, and Adlercreutzia but different in the genera of Lactobacillus and Bacteroides. Therefore, the effects of Realgar and arsenic trioxide with the same amount of trivalent arsenic on gut microbiota were similar, but differences were still present. Protective bacteria such as Lactobacillus were reduced after Realgar administration, causing inflammation. At low doses, the number of anti-inflammatory bacteria, such as Ruminococcus, Adlercreutzia and Parabacteroides increased, which can offset the slight inflammation caused by the imbalance of bacterial flora. At high doses, the flora was disturbed and the number of Proteobacteria was increased, with aggravated intestinal inflammation, causing edema and other inflammatory reactions. Based on this, authors believe that the gastrointestinal reactions after clinical use of Realgar may be related to flora disorder. Realgar should be used at a small dose in combination with other drugs to reduce intestinal inflammation.

ABSTRACT

Quorum sensing(QS) is one of the research hotspots in the fields of microbiology and medicine in recent years. Quorum sensing is a cell communication regulatory system, which is used by bacterial flora to pass on information of population density by sensing specific signaling molecules to the environment. The QS system of bacteria can impact biological functions, such as bacterial growth, proliferation, biofilm formation, virulence factor production, antibiotic synthesis, and ultimately adapt the bacteria to environmental changes. At present, more and more active ingredients can regulate quorum sensing have been found in traditional Chinese medicines(TCM). TCM and their active ingredients can promote the growth of beneficial bacteria, inhibit the proliferation of pathogenic bacteria and finally achieve the purpose of treating diseases. It embodies multi-pathway and multi-target characteristics of traditional Chinese medicine. This article first introduces molecular types and regulation mechanisms of quorum sensing signals between bacteria. On this basis, the human health-related bacterial quorum sensing is summarized, and the regulatory effect of TCM on bacterial quorum sensing system is discussed. Finally, it is noted that the material basis and mechanisms of TCM in improving human health through bacterial quorum sensing system are still unclear. Future research hotspots will focus on quorum sensing active substances, quorum sensing key nodes and relevant targets. In a word, this article provides reference for the treatment of relevant diseases.

ABSTRACT

Abstract: This article describes the chemical composition of Vernonia chalybaea essential oil, and investigates its antimicrobial, antioxidant and hemolytic activities. The evaluation of the antifungal activity was performed by the broth microdilution method using strains of yeasts and dermatophytic fungi. The checkerboard technique to find antimicrobial modulatory effects was performed using ketoconazole as standard drug. The antioxidant activity was evaluated by DPPH scavenging assay and β-carotene/linoleic-acid system. The toxicity was characterized by the brine shrimp lethality test and hemolysis bioassays. The essential oil was obtained by hydrodistillation and analyzed by GC-MS method, showing to be rich in the sesquiterpenes β-caryophyllene (39.06%) and bicyclogermacrene (19.69%), and also demonstrated a relevant antifungal activity against strains of Trichophyton rubrum. In the modulatory activity assay, the essential oil of V. chalybaea and β-caryophyllene demonstrated a synergistic interaction with ketoconazole, with increasing of its antifungal action. The antioxidant activity was evidenced mainly by β-carotene/linoleic acid system, with IC50 value of 35.87 ± 0.32 µg/mL. The results suggest that V. chalybaea essential oil and β-caryophyllene are valuable natural medicinal agents with antioxidant and antimicrobial activities.

ABSTRACT

The use of antimicrobials in fish farming is a reflection of the fast aquaculture development worldwide. The intensification of aquaculture to achieve market demands could lead to an increase in infectious diseases by pathogenic bacteria. Consequently, antimicrobials act as controls for emerging infectious diseases, but their use must follow the rules and regulations of the country where the activity is performed. Although the regulations impose limits to the use of antimicrobials in fish farming, many studies show that resistant bacteria are isolated from this system. The selection of resistant bacteria is not limited only to the use of antimicrobials, but also to co-selection of resistance genes or even with cross-resistance processes. Resistant bacteria from fish farming are a serious concern because they can be acquired by humans with handling or food chain, which may represent a public health problem. In the present review, we present an overview of antimicrobials use in aquaculture, the antimicrobial resistance and the impact of antimicrobial and bacterial resistance from a public health perspective.(AU)

O uso de antimicrobianos na piscicultura é um reflexo do rápido desenvolvimento da aquicultura em todo o mundo. A intensificação da aquicultura para suprir as demandas do mercado pode levar ao aumento de doenças infecciosas por bactérias patogênicas. Consequentemente, os antimicrobianos atuam no controle de doenças infecciosas emergentes, mas seu uso deve seguir as regras e regulamentos do país onde a atividade é realizada. Embora os regulamentos imponham limites ao uso de antimicrobianos na piscicultura, muitos estudos mostram que bactérias resistentes são isoladas desse sistema. A seleção de bactérias resistentes não se limita apenas ao uso de antimicrobianos, mas também à cosseleção de genes de resistência ou mesmo por meio do processo de resistência cruzada. As bactérias resistentes da piscicultura são uma preocupação séria, uma vez que tais bactérias podem ser adquiridas pelos seres humanos no manuseio ou na cadeia alimentar, o que pode representar um problema de saúde pública. Nesta revisão, apresentamos uma visão geral do uso de antimicrobianos na aquicultura, a resistência antimicrobiana e o impacto da resistência antimicrobiana e bacteriana do ponto de vista da saúde pública.(AU)

ABSTRACT

Abstract Different methodologies have been developed throughout the years to identify environmental microorganisms to improve bioremediation techniques, determine susceptibility profiles of bacteria in contaminated environments, and reduce the impact of microorganisms in ecosystems. Two methods of bacterial biochemical identification are compared and the susceptibility profile of bacteria, isolated from residential and industrial wastewater, is determined. Twenty-four bacteria were retrieved from the bacteria bank of the Environmental Microbiology Laboratory at the Institute of Biology (IB) of the Universidade Federal de Pelotas, Pelotas, Brazil. Bacteria were identified by conventional biochemical tests and by the VITEK ®2 automated system. Further, the susceptibility profile to antibiotics was also determined by the automated system. Six species of bacteria (Raoutella planticola, K. pneumoniae ssp. pneumoniae , Serratia marcescens, Raoutella sp., E. cloacae and Klebsiella oxytoca) were identified by conventional biochemical tests, while three species of bacteria (K. pneumoniae ssp. pneumoniae, S. marcescens and K. oxytoca ) were identified by VITEK®2 automated system. VITEK ®2 indicated agreement in 19 (79.17%) isolates and difference in five (20.83%) isolates when compared to results from conventional biochemical tests. Further, antibiotic susceptibility profile results showed that all isolates (100%) were resistant to at least one out of the 18 antibiotics tested by VITEK®2. Thus, no multi-resistant bacteria that may be used in effluent treatment systems or in bioremediation processes have been reported. Results indicate VITEK ® 2 automated system as a potential methodology in the determination of susceptibility profile and identification of environmental bacteria.

Resumo Diferentes metodologias foram desenvolvidas ao longo dos anos para identificar microrganismos ambientais para melhorar as técnicas de biorremediação, determinar perfis de suscetibilidade de bactérias em ambientes contaminados e reduzir o impacto de microrganismos nos ecossistemas. Dois métodos de identificação bioquímica bacteriana são comparados e o perfil de susceptibilidade de bactérias, isoladas de efluentes residenciais e industriais, é determinado. Vinte e quatro bactérias foram coletadas do banco de bactérias do Laboratório de Microbiologia Ambiental do Instituto de Biologia (IB) da Universidade Federal de Pelotas, Pelotas, Brasil. As bactérias foram identificadas por testes bioquímicos convencionais e pelo sistema automatizado VITEK®2. Além disso, o perfil de suscetibilidade aos antibióticos também foi determinado pelo sistema automatizado. Seis espécies de bactérias (Raoutella planticola , K. pneumoniae ssp. pneumoniae, Serratia marcescens, Raoutella sp., E. cloacae e Klebsiella oxytoca) foram identificadas por testes bioquímicos convencionais, enquanto três espécies de bactérias (K. pneumoniae ssp. pneumoniae, S. marcescens e K. oxytoca) foram identificados pelo sistema automatizado VITEK®2. VITEK®2 indicou concordância em 19 (79,17%) isolados e diferença em cinco (20,83%) isolados quando comparados aos resultados de testes bioquímicos convencionais. Além disso, os resultados do perfil de suscetibilidade aos antibióticos mostraram que todos os isolados (100%) foram resistentes a pelo menos um dos 18 antibióticos testados pelo VITEK®2. Assim, não foram relatadas bactérias multirresistentes que possam ser usadas em sistemas de tratamento de efluentes ou em processos de biorremediação. Os resultados indicam que o sistema automatizado VITEK ® 2 é uma metodologia potencial na determinação do perfil de suscetibilidade e identificação de bactérias ambientais.

ABSTRACT

RESUMEN Se describen los principales mecanismos de resistencia antimicrobiana mediante el sistema Vitek® 2 en uropatógenos aislados en adultos mayores de una clínica privada en Lima. Estudio descriptivo realizado entre enero de 2014 y octubre de 2016. Escherichia coli, Klebsiella pneumoniae y Proteus mirabilis obtuvieron una sensibilidad mayor a 80% frente a piperacilina/tazobactam, amikacina y carbapenems. Asimismo, 83,6% de Escherichia coli fueron cepas sensibles a nitrofurantoina. El 41,7% de Escherichia coli, 50,9% de Klebsiella pneumoniae y 50% de Proteus mirabilis fueron productoras de betalactamasas de espectro extendido. De igual modo, 60% de Pseudomonas aeruginosa fueron productoras de carbapenemasas. La modificación de sitio activo (PBP) y la inactivación enzimática por penicilinasas se presentaron en el 7,8% de Enterococcus faecalis. La resistencia a aminoglicósidos se presentó en Escherichia coli (27,1%), Klebsiella pneumoniae (46,7%) y Proteus mirabilis (84,6%) por la producción de enzimas modificadoras. Existe un incremento de la resistencia bacteriana en relación a la edad. La inactivación enzimática de betalactámicos y aminoglicósidos es el mecanismo de resistencia más frecuente.

ABSTRACT The main mechanisms of antimicrobial resistance are described using the Vitek® 2 system in uropathogens isolated in older adults from a private clinic in Lima. Descriptive study conducted between January 2014 and October 2016. Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis obtained a sensitivity greater than 80% against piperacillin/ tazobactam, amikacin, and carbapenems. Moreover, 83.6% of Escherichia coli were nitrofurantoin-sensitive strains. A 41.7% of Escherichia coli, 50.9% of Klebsiella pneumoniae, and 50% of Proteus mirabilis were producers of extended spectrum beta-lactamases (ESBL). Similarly, 60% of Pseudomonas aeruginosa were producers of carbapenemases. Active site modification (PBP) and enzymatic inactivation by penicillinases occurred in 7.8% of Enterococcus faecalis. Resistance to aminoglycosides was presented in Escherichia coli (27.1%), Klebsiella pneumoniae (46.7%), and Proteus mirabilis (84.6%) for the production of modifier enzymes. There is an increase in bacterial resistance in relation to age. Enzymatic inactivation of beta-lactam antibiotics and aminoglycosides is the most common resistance mechanism.