Risk Factors Associated with Gambling on Loot Boxes.

BACKGROUND: Loot boxes (LBs) are virtual objects that players open without knowing the value of the item they will obtain. Because of their features, studies have explored their association with gambling, finding commonalities. However, risk factors have been overlooked. This study examined risk factors associated with gambling as applied to LBs (gambling in the past year, having family/friends who use LBs/gamble, trait impulsivity, and sensation-seeking). METHOD: 253 participants (82.2% men) with a mean age of 28 years ( SD = 12.11)­in three groups: gamblers ( n = 89), LB purchasers ( n = 63), and free-LB openers ( n = 101)­completed a self-report. RESULTS: Having family/friends who used LBs was related to increased engagement in opening LBs at no cost. However, having gambled in the past year or having family/friends who used LBs or who gambled was not associated with increased purchasing. Gamblers, LB purchasers, and LB openers scored equally highly on impulsivity and sensation-seeking. Because some gamblers used LBs, and LB purchasers also opened free-LBs, further analyses were performed to control for the effects of overlapping groups. Loot boxers had higher scores in sensation-seeking than gamblers. CONCLUSIONS: The results can contribute to the development of prevention and intervention strategies for LB users.

Invisible and stigmatized: A systematic review of mental health and risk factors among sex workers.

INTRODUCTION: Sex work is a common phenomenon, but socially invisible and stigmatized. Due to exposure to work-related risks, sex workers (SWs) are vulnerable to developing health problems. However, little attention has been paid to their mental health. The purpose of this systematic review was to synthesize the existing literature on mental health and to explore risk factors related to psychopathology in sex workers. METHODS: A systematic review (CRD42021268990) was conducted on the Web of Science, PubMed, Scopus, and PsycInfo for peer reviewer papers published between 2010 and 2022. The Newcastle-Ottawa Scale (NOS) was used to examine the quality of the studies. Of the 527 studies identified, 30 met the inclusion criteria. RESULTS: Mental health problems were prevalent among sex workers. Depression was the most common mental health problem; however, other psychological problems were also high, including anxiety, substance abuse, and suicidal ideation. Sex workers are exposed to numerous work-related risks, including violence and high-risk sexual behaviors. Despite the high prevalence of mental health problems, SWs often encounter significant barriers to accessing healthcare services. CONCLUSION: These results suggest the need to focus on preventive measures to promote psychological well-being among sex workers.

Psychological Effects of Professional Exposure to Trauma and Human Suffering: Systematic Review and Meta-Analysis.

Over the past decades, a growing interest has emerged toward understanding the impact that the exposure to human suffering produces in mental health professionals, leading to the identification of three constructs: vicarious traumatization (VT), compassion fatigue (CF), and secondary trauma (ST). However, little is known about how these conditions affect psychologists. A systematic review and a meta-analysis were conducted to examine the evidence about the effects of occupational exposure to trauma and suffering in studies that included psychologists among their samples. Fifty-two studies were included comprising 10,233 participants. Overall, the results showed that most professionals did not experience relevant distress due to their work, yet some of them developed clinically significant symptoms (i.e., PTSD). However, solid conclusions could not be drawn due to the numerous methodological difficulties found in this research field (i.e., group heterogeneity, lack of comparison groups, and conceptual overlap). Thus, it is necessary to further investigate this topic with scientific rigor to understand these stressors and develop evidence-based interventions.

El consumo de loot boxes como una nueva forma de azar en los videojuegos / Loot boxes use as a new form of gambling within video games

Las loot boxes son cajas dentro de los videojuegos que los usuarios pagan por abrir y obtener, al azar, un objeto cuyo valor inicialmente desconocen. Tanto la población adolescente como la adulta tiene fácil acceso a ellas, y se han relacionado con el juego de azar. El objetivo de este estudio fue examinar el consumo de loot boxes y explorar si se asociaba con culpabilidad, pérdida de control y malestar. Para ello, 475 participantes (266 adolescentes y 209 adultos) respondieron a un cuestionario ex profeso de elaboración propia. Los resultados mostraron que son los adolescentes los que más dinero invierten en cajas botín. Este gasto se ve aumentado cuando se anuncia nuevo contenido en las plataformas multimedia online (entre ellas, Twitch, YouTube). Además, no obtener los ítems que desean, lo cual es frecuente por su aleatoriedad, predice mayores niveles de culpabilidad y malestar, mientras que su obtención predice la posterior pérdida de control. Así, el 45,5% de los participantes refirieron culpabilidad tras la compra, el 50% malestar y el 17% pérdida de control. En síntesis, las loot boxes están cada vez más presentes en los entornos virtuales de los adolescentes y adultos, y dadas las consecuencias psicológicas y emocionales que parecen tener, es necesario seguir abordando esta problemática en futuras investigaciones en aras de prevenir y apoyar a la población vulnerable. (AU)

Loot boxes are items within video games which players pay to open and, ultimately, to randomly obtain an object whose value is initially unknown. Being easily accessible for both teenagers and adults, loot boxes have been associated with gambling. The purpose of this study was to explore the use of loot boxes and to analyze whether it is associated with guilt, loss of control, and emotional distress. To this end, 475 participants (266 adolescents and 209 adults) were surveyed on their habits regarding loot boxes and gaming. The results showed that teenagers invest more money in loot boxes than adults. This expenditure increases when a new item is announced on online platforms (Twitch, YouTube). Additionally, not obtaining the coveted items, which is common due to loot box randomness, predicts greater levels of guilt and emotional distress, while obtaining them predicts subsequent loss of control. Thus, 45.5% reported guilt over purchasing, 50% distress and 17% loss of control. Summarizing, loot boxes are increasingly present in video games, and owing to their psycho-emotional outcomes, it is necessary for future research to address this matter in order to develop prevention strategies and to provide support to vulnerable populations. (AU)

Risk Factors Associated with Gambling on Loot Boxes / Factores de Riesgo Asociados al Juego de Azar en Cajas Botín

Background: Loot boxes (LBs) are virtual objects that players open without knowing the value of the item they will obtain. Because of their features, studies have explored their association with gambling, finding commonalities. However, risk factors have been overlooked. This study examined risk factors associated with gambling as applied to LBs (gambling in the past year, having family/friends who use LBs/gamble, trait impulsivity, and sensation-seeking). Method: 253 participants (82.2% men) with a mean age of 28 years (SD = 12.11)—in three groups: gamblers (n = 89), LB purchasers (n = 63), and free-LB openers (n = 101)—completed a self-report. Results: Having family/friends who used LBs was related to increased engagement in opening LBs at no cost. However, having gambled in the past year or having family/friends who used LBs or who gambled was not associated with increased purchasing. Gamblers, LB purchasers, and LB openers scored equally highly on impulsivity and sensation-seeking. Because some gamblers used LBs, and LB purchasers also opened free-LBs, further analyses were performed to control for the effects of overlapping groups. Loot boxers had higher scores in sensation-seeking than gamblers. Conclusions: The results can contribute to the development of prevention and intervention strategies for LB users.(AU)

Antecedentes: Las loot boxes (LBs) son objetos virtuales que se abren desconociendo el valor del artículo que contienen. Aunque se han relacionado con el juego de azar, sus factores de riesgo apenas han sido explorados. Este estudio examina los factores de riesgo del juego de azar en LBs (jugar a juegos de azar, tener familiares/amigos que usan LBs/juegan a juegos de azar, impulsividad-rasgo y búsqueda de sensaciones). Método: 253 participantes (M = 28, DT = 12.11, 82.2% hombres), distribuidos en tres grupos: jugadores de azar (n = 89), compradores de LBs (n = 63) y abridores de LBs gratuitas (n = 101), completaron un autoinforme. Resultados: Tener familiares/amigos que usaban LBs se relacionaba con la apertura gratuita, pero jugar a juegos de azar o tener familiares/amigos que usaban LBs/jugaron a juegos de azar no se relacionaba con la compra. Los tres grupos puntuaron igual en impulsividad y búsqueda de sensaciones. Tras controlar el solapamiento (algunos jugadores de azar usaban LBs, y los compradores de LBs abrían LBs gratuitas), los loot boxers puntuaron más alto en búsqueda de sensaciones que los jugadores de azar. Conclusiones: Conocer las comunalidades entre LBs y juegos de azar puede contribuir a su prevención e intervención.(AU)

Loot boxes use as a new form of gambling within video games. / El consumo de loot boxes como una nueva forma de azar en los videojuegos.

Loot boxes are items within video games which players pay to open and, ultimately, to randomly obtain an object whose value is initially unknown. Being easily accessible for both teenagers and adults, loot boxes have been associated with gambling. The purpose of this study was to explore the use of loot boxes and to analyze whether it is associated with guilt, loss of control, and emotional distress. To this end, 475 participants (266 adolescents and 209 adults) were surveyed on their habits regarding loot boxes and gaming. The results showed that teenagers invest more money in loot boxes than adults. This expenditure increases when a new item is announced on online platforms (Twitch, YouTube). Additionally, not obtaining the coveted items, which is common due to loot box randomness, predicts greater levels of guilt and emotional distress, while obtaining them predicts subsequent loss of control. Thus, 45.5% reported guilt over purchasing, 50% distress and 17% loss of control. Summarizing, loot boxes are increasingly present in video games, and owing to their psycho-emotional outcomes, it is necessary for future research to address this matter in order to develop prevention strategies and to provide support to vulnerable populations.

Las loot boxes son cajas dentro de los videojuegos que los usuarios pagan por abrir y obtener, al azar, un objeto cuyo valor inicialmente desconocen. Tanto la población adolescente como la adulta tiene fácil acceso a ellas, y se han relacionado con el juego de azar. El objetivo de este estudio fue examinar el consumo de loot boxes y explorar si se asociaba con culpabilidad, pérdida de control y malestar. Para ello, 475 participantes (266 adolescentes y 209 adultos) respondieron a un cuestionario ex profeso de elaboración propia. Los resultados mostraron que son los adolescentes los que más dinero invierten en cajas botín. Este gasto se ve aumentado cuando se anuncia nuevo contenido en las plataformas multimedia online (entre ellas, Twitch, YouTube). Además, no obtener los ítems que desean, lo cual es frecuente por su aleatoriedad, predice mayores niveles de culpabilidad y malestar, mientras que su obtención predice la posterior pérdida de control. Así, el 45,5% de los participantes refirieron culpabilidad tras la compra, el 50% malestar y el 17% pérdida de control. En síntesis, las loot boxes están cada vez más presentes en los entornos virtuales de los adolescentes y adultos, y dadas las consecuencias psicológicas y emocionales que parecen tener, es necesario seguir abordando esta problemática en futuras investigaciones en aras de prevenir y apoyar a la población vulnerable.

El Conocimiento y el Uso en la Práctica Clínica de los Tratamientos Psicológicos Basados en la Evidencia / Knowledge and use of evidence-based psychological treatments in clinical practice

Este trabajo pretende conocer el impacto que los tratamientos basados en la evidencia (TBE) ejercen sobre la psicología aplicada, así como los factores que podrían estar relacionados con dicho impacto. La muestra estuvo compuesta por 242 psicólogos formados en España, a los que se les administró un cuestionario ad hoc constituido por preguntas que recogían información acerca de determinadas variables sociodemográficas y sobre el uso o conocimiento de los TBE para los trastornos mentales en población adulta. Los resultados señalan que, a excepción de las terapias cognitivo-conductuales, el impacto de los tratamientos basados en la evidencia es limitado, pudiendo influir en dicho impacto el tipo de acreditación profesional y los años de experiencia clínica. Los hallazgos de este estudio apoyan la idea de que los resultados de la investigación no se implementan ni consolidan del todo en los ámbitos aplicados

This paper aims to know the impact of evidence-based treatments (EBTs) on applied psychology, as well as the factors that could be related to this impact. The sample consisted of 242 psychologists trained in Spain, who were administered an ad hoc questionnaire consisting of questions that gathered information about certain sociodemographic variables and about the use or knowledge of EBTs for mental disorders in adults. The results indicate that, with the exception of cognitive-behavioral therapies, the impact of EBTs is limited, and the professional accreditation and the years of clinical experience may influence this impact. The findings of this study support the idea that the results of the research are not fully consolidated in applied areas

Caracterización química y actividad antimicrobiana del aceite esencial de las hojas de Libanothamnus neriifolius (Asteraceae) / Chemical characterization and antimicrobial activity of the essential oil of the leaves of Libanothamnus neriifolius (Asteraceae)

El aceite esencial de las hojas frescas de Libanothamnus neriifolius (B. ex H) Ernst., fue obtenido por el método de hidrodestilación utilizando la trampa de Clevenger, obteniendo 1.8 mL (rendimiento 0.087%). El aceite esencial se caracterizó por el método de cromatografía de gases acoplado a espectrometría de masas (CG-EM), identificando como compuestos principales β-felandreno (29.04%), α-felandreno (19.86%), α-pineno (13.57%) y α-tujeno (12.35%). La actividad antimicrobiana se determinó por el método de difusión en agar con discos, frente a bacterias y levaduras de referencia internacional (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 23357, Pseudomonas aureginosa ATCC 27853, Candida albicans CDC-B385, Candida krusei ATCC 6258). El aceite esencial inhibió el desarrollo de S. aureus, C. albicans y C. Krusei, con un valor de Concentración Inhibitoria Mínima (CIM) de 50 μL/mL, 700 μL/mL y 500 μL/mL, respectivamente. Este es el primer reporte sobre actividad antimicrobiana para L. neriifolius y para el género Libanothamnus.

The essential oil of the fresh leaves of Libanothamnus neriifolius (B. ex H) Ernst. was obtained by the hydrodistillation method using the Clevenger trap, obtaining 1.8 mL (0.087% yield). The essential oil was characterized by the method of gas chromatography coupled to mass spectrometry (GC/MS), identifying as main compounds, that β-phelandrene (29.0%), α-phelandrene (19.9%), α-pinene (13.6%), and α-tujene (12.4%) were the most abundant constituents. Antimicrobial activity of the oil was tested Staphylococcus aureus ATCC25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 23357, Pseudomonas aureginosa ATCC 27853, Candida albicans CDC-B385, Candida krusei ATCC 6258 by the agar difusion method. It showed activity against S. aureus with MIC of 50 μL/mL. With respect to antifungic activity it was active against C. albicans and C. krusei with MIC of 700 μL/mL and 500 μL/mL respectively. This is the first report on the antimicrobial activity of this L. neriifolius and for the genere Libanothamnus.

Antimicrobial activity of four Valeriana (Caprifoliaceae) species endemic to the Venezuelan Andes / Actividad antimicrobiana de cuatro especies de Valeriana (Caprifoliaceae) endémicas de los Andes venezolanos

Abstract Valeriana L. genus is represented in Venezuela by 16 species, 9 of these are endemic of Venezuelan Andes growing in high mountains at 2 800 masl. In this investigation, four species were analyzed in order to determine the main secondary metabolites and antimicrobial activity of extracts obtained from aerial parts of Valeriana parviflora, V. rosaliana, V. triplinervis and V. phylicoides. Alkaloids, flavonoids, tannins, sterols, triterpenoids and saponins were qualitatively observed in all methanolic extracts tested. The color intensity or a precipitate formation was used as analytical response to these tests. Antimicrobial activity was evaluated against Gram positive, Gram negative bacterial strains and yeast, using disc diffusion method. N-hexane extracts of V. triplinervis and V. rosaliana showed the highest efficiency against Staphylococcus aureus, exhibiting inhibition zones of 16 mm and 15 mm; MIC (Minimal Inhibition Concentration) values were observed at 116 mg/mL and 150 mg/mL, respectively. Dichloromethane and methanolic extracts of V. triplinervis and methanolic extract of V. rosalianashowed a rather moderate activity (MIC between 200 to 316 mg/ml) but a very weak antibacterial activity was observed in V. phylicoides and V. parviflora extracts (MIC > 420 mg/mL). None of the extracts assayed in this investigation showed any activity against Candida albicansand Candida krusei. Statistical analysis showed no significant differences on the different polarity extracts assayed with respect to antimicrobial activity against S. aureus (P > 0.10), however it was observed significant differences between the Valeriana species analyzed (P < 0.10) in relation to the minimal inhibitory concentration (MIC). Rev. Biol. Trop. 66(3): 1282-1289. Epub 2018 September 01.

Resumen El género Valeriana, está representado en Venezuela por 16 especies, 9 de las cuales son endémicas de Los Andes y crecen en las altas montañas a 2 800 msnm. En esta investigación cuatro especies fueron analizadas para determinar los principales metabolitos secundarios y la actividad antimicrobiana de los extractos obtenidos de las partes aéreas de Valeriana parviflora, V. rosaliana, V. triplinervis y V. phylicoides. Compuestos como alcaloides, flavonoides, taninos, estroles, triterpenos y saponinas fueron detectados cualitativamente en todos los extractos metanólicos ensayados. La intensidad del color o la formación de un precipitado se tomaron como respuesta positiva para estos análisis. Actividad antimicrobiana fue evaluada frente a bacterias Gram positivas, Gram negativas y levaduras, usando el método de difusión en discos. Los extractos en n-hexano de V. triplinervis y V. rosaliana mostraron la mayor eficiencia frente a Staphylococcus aureus, mostrando zonas de inhibición de 16 mm y 15 mm con valores de CIM (Concentración Inhibitoria Mínima) observados a 116 mg/mL y 150 mg/mL, respectivamente. Los extractos con diclorometano y metanol de V. triplinervis y metanol de V. rosaliana revelaron moderada actividad (CIM entre 200 y 316 mg/ml), mientras actividad muy leve se observó en los extractos de V. phylicoides y V. parviflora (CIM > 420 mg/mL). Ninguno de los extractos ensayados mostraron actividad frente a Candida albicans y Candida krusei. Los análisis estadísticos mostraron que no hay diferencia significativa entre los solventes de diferentes polaridades con relación a la actividad antimicrobiana frente a S. aureus (P > 0.10), sin embargo, sí se observó diferencia significativa (P < 0.10), entre las especies de Valeriana ensayadas con respecto a la concentración inhibitoria mínima (CIM).

Composición química y actividad antibacteriana del aceite esencial de Peperomia acuminata de los Andes venezolanos / Chemical composition and antibacterial activity of essential oil Peperomia acuminata from Venezuelan Andes

El género Peperomia (Piperaceae), es bien conocido por sus especies ornamentales y usos etnomedicinales. En el presente trabajo se describe la caracterización química y la actividad antibacteriana del aceite esencial de Peperomia acuminata Ruiz & Pav. proveniente del Estado Mérida Venezuela. El aceite esencial se obtuvo por hidrodestilación de las hojas y la separación de los componentes se realizó por Cromatografía de gases-Espectrometría de Masas (CG/EM). Se logró la elucidación de ocho compuestos (96,7%), siendo el 2E-dodecenal el componente mayoritario (65%) seguido de dodecanal (14,8%) y tetradecanal (9,2%). Esta investigación muestra el potencial del aceite esencial de P. acuminata frente a bacterias Gram positivas (Staphylococcus aureus ATCC 25923 y Enterococcus faecalis 29212), con un valor de Concentración inhibitoria mínima de 1μL/mL. Este es el primer reporte sobre la composición química del aceite esencial de esta especie, por lo tanto una contribución importante al estudio del género Peperomia.

The genus Peperomia (Piperaceae) is well known for its ornamental species and ethnomedicinal uses. This paper aims to chemically characterize the essential oil of Peperomia acuminata Ruiz & Pav. from Mérida State, Venezuela, and determine its microbiological activity. The essential oil is obtained by hydrodistillation of the leaves and the separation of the components was performed by gas chromatography-mass spectrometry (GC/MS). Eight compounds (96.7%) were elucidated in the oil. The 2E dodecenal was found to be the major component (65%) followed by dodecanal (14.8%) and tetradecanal (9.2%). The essential oil showed high specificity against Gram positive bacteria Staphylococcus aureus ATCC (25923) and Enterococcus faecalis (29212) with a Minimum Inhibitory Concentration of 1 µL/mL. This is the first report about chemical composition of the essential oil from this specie therefore an important contribution to the study of the genus Peperomia.

Essential oil composition and antimicrobial activity of Vismia macrophylla leaves and fruits collected in Táchira-Venezuela.

Hydrodistillation of Vismia macrophylla Kunth (Hypericaceae) leaves (L) and fruits (F) yielded 1.3%, v/w, and 5.6%, v/w, of essential oil, respectively. GC and GC-MS analyses showed the presence of twenty-four (96.4%, L) and thirty-one (96.6%, F) components, respectively. Major compounds identified in the leaf oil were γ-bisabolene (44.4%) and ß-bisabolol (14.9%), while those in the fruit oil were germacrene-D (12.1%), 6-cadinene (10.7%) and γ-bisabolene (22.3 %). Oil obtained from the fruits of V. macrophylla showed antibacterial activity against Gram-positive (S. aureus ATCC 25923 and E. faecalis ATCC 29212) as well as Gram-negative bacteria (E. coli ATCC 25922), with MIC values ranging from 150 µL/mL to 740 µL/mL. Oil obtained from leaves were active only on the Gram-positive bacteria S. aureus (100 µL/mL) and E. faecalis (500 µL/mL), but also showed antiyeast activity against Candida albicans CDC-B385 and C. krusei ATCC 6258 (600 µL/mL, each).

A contrastive analysis of the factorial structure of the PCL-R: which model fits best the data? / Análisis de contraste de la estructura factorial de la PCL-R: ¿qué modelo se ajusta mejor a los datos?

The aim of this study was to determine which of the factorial solutions proposed for the Hare Psychopathy Checklist-Revised (PCL-R) of two, three, four factors, and unidimensional fitted best the data. Two trained and experienced independent raters scored 197 prisoners from the Villabona Penitentiary (Asturias, Spain), age range 21 to 73 years (M = 36.0, SD = 9.7), of whom 60.12% were reoffenders and 73% had committed violent crimes. The results revealed that the two-factor correlational, three-factor hierarchical without testlets, four-factor correlational and hierarchical, and unidimensional models were a poor fit for the data (CFI ≤ .86), and the three-factor model with testlets was a reasonable fit for the data (CFI = .93). The scale resulting from the three-factor hierarchical model with testlets (13 items) classified psychopathy significantly higher than the original 20-item scale. The results are discussed in terms of their implications for theoretical models of psychopathy, decision-making, prison classification and intervention, and prevention (AU)

Se diseñó un estudio con el objetivo de conocer cuál de las soluciones factoriales propuestas para la Hare Psychopathy Checklist-Revised (PCL-R) de dos, tres y cuatro factores y unidimensional era la que presentaba mejor ajuste a los datos. Para ello, dos evaluadores entrenados y con experiencia evaluaron de forma independiente a 197 internos en la prisión Villabona (Asturias, España), con edades comprendidas entre los 21 y los 73 años (M = 36.0, DT = 9.7), de los cuales el 60.12% eran reincidentes y el 73% había cometido delitos violentos. Los resultados mostraron que los modelos unidimensional, correlacional de 2 factores, jerárquico de 3 factores sin testlest y correlacional y jerárquico de 4 factores, presentaban un pobre ajuste con los datos (CFI ≤ .86) y un ajuste razonable del modelo jerárquico de tres factores con testlets (CFI = .93). La escala resultante del modelo de tres factores con testlets (13 ítems) mostró un poder de clasificación de la psicopatía significativamente superior al de la escala original (20 ítems). Se discuten las implicaciones de los resultados para los modelos teóricos de la psicopatía, la toma de decisiones, clasificación e intervención penitenciaria, y la prevención (AU)

Chemical composition of the essential oil from the leaves of Carapa guianensis collected from Venezuelan Guayana and the antimicrobial activity of the oil and crude extracts.

The essential oil obtained by hydrodistillation of Carapa guianensis Aubl. (Meliaceae) leaves was analyzed by GC-FID and GC-MS. Twenty-three components were identified, which made up 93.7% of the oil. The most abundant constituents were bicyclogermacrene (28.5%), alpha-humulene (17.2%), germacrene B (11.9%), and trans-beta-caryophyllene (9.9%). Antimicrobial activity of the essential oil, as well as the crude extracts of the leaves obtained by refluxing the dried leaves with n-hexane, dichloromethane, and methanol, was determined using the disc diffusion assay. Activity against Staphylococcus aureus ATCC 29923 and Enterococcus faecalis ATCC 29212 was only found for the essential oil and the methanolic extract, at minimal inhibitory concentrations (MIC) of 400 microg/mL and 50 microg/mL.

Chemical composition and antibacterial activity of the essential oil of Espeletia nana.

The essential oil of the leaves of Espeletia nana Cuatrec., obtained by hydrodistillation, was analyzed by GC-MS, which allowed the identification of 24 components, which made up 99.9% of the oil. The most abundant compounds were a-pinene (38.1%), beta-pinene (17.2%), myrcene (15.0%), spathulenol (4.2%), bicyclogermacrene (4.0%), a-zingiberene (4.0%), and gamma-himachalene (3.7%). Antibacterial activity was tested against Gram-positive and Gram-negative bacteria using the agar disk diffusion method. Activity was observed only against Gram-positive bacteria. MIC values were determined for Staphylococcus aureus ATCC 25923 (200 microg/mL) and Enterococcusfaecalis ATCC 29212 (600 microg/mL).

Chemical composition and antibacterial activity of the essential oil of Lantana camara var. moritziana.

The essential oil obtained from the leaves of Lantana camara var. moritziana (Otto & Dietr.) López-Palacios collected at Rubio, Táchira State, Venezuela, was obtained by hydrodistillation in a Clevenger trap (0.1% yield). The oil was analyzed by gas chromatography-mass spectrometry (GC/MS) on HP GC-MS System, model 5973, identifying 33 compounds (97.1%) of which the major components were germacrene D (31.0%), followed by beta-caryophyllene (14.8%), a-phellandrene (6.7%), limonene (5.7%) and 1,8-cineole (5.2%). Evaluation of the antibacterial activity by agar diffusion method with discs against international reference bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Salmonella Typhi, Pseudomonas aeruginosa) showed growing inhibition of E. faecalis and S. aureus at MIC of 350 mg/mL and 400 mg/mL, respectively.

Chemical composition and in vitro antibacterial activity of the essential oil of Phthirusa adunca from Venezuelan Andes.

In this paper, preliminary studies on the chemical characterization of Phthirusa adunca Meyer essential oil, obtained by hydrodistillation, is presented. The separation of the components was performed by GC-MS. Twenty-three compounds (94.5% of the sample) were identified of which the three major ones (76% of the sample) were beta-phellandrene (38.1%), germacrene D (26.8%) and beta-pinene (11.5%). The essential oil showed a broad spectrum of activity against Salmonella Typhi CDC 57 (100 microg/mL), Staphylococcus aureus ATCC 25923 (200 microg/mL), Enterococcus faecalis ATCC 29212 (250 microg/mL), Escherichia coli ATCC 25922 y Klebsiella pneumoniae ATCC 23357 (500 microg/mL). This is the first report on the composition and activity of the essential oil of this species.

Profiles of enteropathogens in asymptomatic children from indigenous communities of Mérida, Venezuela.

INTRODUCTION: In Latin America, gastrointestinal infections represent one of the main causes of death among indigenous groups, with a mortality rate three times greater than in the general population. In this study, the carrier state of enteropathogens and the epidemiological risk factor in asymptomatic children from indigenous communities of Mérida, Venezuela, were determined. METHODOLOGY: Fifty-eight healthy children, 5 years of age and under, were clinically and epidemiologically evaluated. Fecal samples were tested for a range of classic enteropathogens. Antimicrobial susceptibility tests (AST) were performed by dilution methods. RESULTS: Of the specimens studied, there were 34 (58.6%) positive samples, and a single enteropathogen was detected in 22 (64.6%) of these. Associations of two and three enteropathogens were observed in 10 (29.3%) and two (5.8%) cases, respectively. Blastocystis hominis (16; 47.0%) and Salmonella spp. (15; 43.9%) were the most frequently detected enteropathogens. Carriage of enteropathogens was most frequent in children older than two years. The variety of food in the daily diet was the risk factor strongly associated with the presence of parasites and/or enteric bacteria (p = 0.024 < 0.05 and p = 0.000 < 0.05, respectively). The majority of these bacteria were susceptible to the antibiotics tested in vitro. CONCLUSION: This study shows a high prevalence of enteropathogen carriage in asymptomatic children aged five and under from indigenous communities; this result is statistically related to the consumption of food. These findings stress the need of continuous epidemiological surveillance in vulnerable populations, as an important step to prevent the morbidity and mortality due to gastrointestinal infections.

Construcción de mutantes de salmonella enterica por inactivación de los genes invG/invE y ssaJ/ssaK de las islas de patogenicidad 1 y 2 / Construction of mutants of salmonella enterica for inactivation of invG/invE y ssaJ/ssaK genes of pathogenicity islands 1 and 2

Para la comprensión de las bases genéticas de los mecanismos de patogenicidad de Salmonella se han descrito diversas metodologías para manipular el ADN genómico y generar mutantes con características particulares. En este estudio se reporta la construcción de mutantes a partir de varios serotipos de S. enterica, por sustitución e inactivación de los genes invG/invE en SPI-1 y de los genes ssaJ/ssaK en SPI-2 mediante la técnica de recombinasa Red del fago λ descrita por Datsenko y Wanner (2000). Los genes delecionados en las SPI-1 y SPI-2 codifican para las proteínas que participan en la formación de los sistemas de secreción tipo III, responsables de la invasión y supervivencia intracelular de S. enterica en las células hospedadoras. Los resultados de este trabajo permitirán realizar estudios futuros in vivo para evaluar la posible atenuación de la virulencia de las cepas mutantes, así como aportar nuevos conocimientos sobre los mecanismos genéticos involucrados en la fisiopatogenia de las enfermedades producidas por los serovares estudiados. Además, esta técnica se recomienda para generar de manera eficiente mutantes de diferentes serotipos de S. enterica con la finalidad de estudiar los genes cromosómicos y sus productos.

To understand the genetic basis of Salmonella pathogenicity mechanisms, various methods have been described to manipulate and generate mutant genomic DNA with specific characteristics. In this study we report the construction of mutants from several serotypes of S. enterica, substitution and inactivation of genes invG/invE in SPI-1 gene and ssaJ/ssaK in SPI-2 by the technique of phage λ Red recombinase, as described by Datsenko and Wanner (2000). The gene deletion in SPI-1 and SPI-2 encodes proteins involved in the formation of type III secretion systems responsible for the invasion and intracellular survival of S. enterica in the host cells. The results of this work will allow in vivo studies to evaluate the possible attenuation of virulence of the mutant strains, as well as to provide new insights into the genetic mechanisms involved in the pathogenesis of diseases caused by these bacteria. Moreover, this technique is recommended to efficiently generate mutants of different serotypes of S. enterica in order to study the chromosomal genes and their products.

Chemical composition and antibacterial activity of the essential oil from fruits of Bursera tomentosa.

The hydrodistilled oil from the fruits of Bursera tomentosa, obtained in 0.2% yield, was analyzed by GC-MS. Nine components were identified, which made up 99.3% of the oil. The most abundant constituents were cis-ocimene (47.6%), n-nonane (28.2%) and germacrene-D (11.1%). The oil showed antibacterial activity against Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212) and Salmonella typhi (CDC 57), with MIC values of 80 microg/mL, 120 microg/mL and 100 microg/mL, respectively.

Chemical composition and antibacterial activity of the essential oil of Cordia verbenacea from the Venezuelan Andes.

The essential oil of Cordia verbenacea D.C. (Boraginaceae) that grows in Mérida-Venezuela was obtained by hydrodistillation from the aerial parts of the plant, yielding 0.21%. The oil was analyzed by GC-FID and GC-MS. Thirty one components which made up 94.3% of the oil were identified. The most abundant constituents found were: tricyclene (23.9%), bicyclogermacrene (11.7%), germacrene D (9.9%) and beta-caryophyllene (8.2%). Antibacterial activity determination was carried out according to the disc diffusion assay. Activity against Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212, at a minimal inhibitory concentration (MIC) of 170 microg/mL and 200 microg/mL, was found.