Tryptophan usage by Helicobacter pylori differs among strains.

Because of its association with severe gastric pathologies, including gastric cancer, Helicobacter pylori has been subject of research for more than 30 years. Its capacity to adapt and survive in the human stomach can be attributed to its genetic flexibility. Its natural competence and its capacity to turn genes on and off allows H. pylori to adapt rapidly to the changing conditions of its host. Because of its genetic variability, it is difficult to establish the uniqueness of each strain obtained from a human host. The methods considered to-date to deliver the best result for differentiation of strains are Rapid Amplification of Polymorphic DNA (RAPD), Multilocus Sequence Typing (MLST) and Whole Genome Sequencing (WGS) analysis. While RAPD analysis is cost-effective, it requires a stable genome for its reliability. MLST and WGS are optimal for strain identification, however, they require analysis of data at the bioinformatics level. Using the StainFree method, which modifies tryptophan residues on proteins using 2, 2, 2, - trichloroethanol (TCE), we observed a strain specific pattern of tryptophan in 1D acrylamide gels. In order to establish the effectiveness of tryptophan fingerprinting for strain identification, we compared the graphic analysis of tryptophan-labelled bands in the gel images with MLST results. Based on this, we find that tryptophan banding patterns can be used as an alternative method for the differentiation of H. pylori strains. Furthermore, investigating the origin for these differences, we found that H. pylori strains alters the number and/or position of tryptophan present in several proteins at the genetic code level, with most exchanges taking place in membrane- and cation-binding proteins, which could be part of a novel response of H. pylori to host adaptation.

Helicobacter pylori culture as a key tool for diagnosis in Colombia.

INTRODUCTION: The presence of H. pylori in the stomach is associated with gastric pathologies. However, its diagnosis through culture methods is challenging because of its complex nutritional requirements and microaerophilic conditions for optimal growth. The preferred method for rapid diagnosis of H. pylori is the Rapid Urease Test (RUT) from human biopsies, which relies on the high activity of the urease enzyme present in H. pylori. However, RUT cannot say much more information about H. pylori. This makes evident the need for bacterial culture to know essential information such as the strain type, the kind of infection present and the bacteria's antibiotic susceptibility. METHODOLOGY: Gastric biopsies from 347 patients were used for H. pylori isolation. We correlated the culture results with the RUT and histological grading used at Hospital Universitario Fundación SantaFe de Bogotá (HU-FSFB), Colombia. The concordance between techniques was determined by the Cohen's Kappa coefficient (K). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were also calculated. RESULTS: The culture standardization was successful, and it could be applied for diagnosis in the clinical practice. H. pylori was positive by culture in 88 (26.34%) patients. The concordance of RUT and culture was strong (K= 0.805), and between histology and culture was moderate (K= 0.763) as well as for the gold standard defined and culture (K= 0.80). CONCLUSIONS: We present evidence that RUT and histological methods will be better interpreted for diagnosis of H. pylori if combined with bacterial isolation in cholesterol enriched culture.

Phylogroups, pathotypes, biofilm formation and antimicrobial resistance of Escherichia coli isolates in farms and packing facilities of tomato, jalapeño pepper and cantaloupe from Northern Mexico.

The most commonly used indicator of fecal contamination in fresh produce production and packing is Escherichia coli. In depth analysis of the prevalence and characteristics of naturally occurring E. coli strains in these environments is important because it can (1) serve as an indicator of sources of fecal contamination; and (2) provide information on strain pathogenicity, persistence, and other defining characteristics such as multidrug resistance. In this study, we analyzed 341 E. coli strains isolated from the jalapeño pepper, tomato and cantaloupe farm environments, in Northeast Mexico. Strains were isolated from produce, farmworkers' hands, soil and water. Pathotypes, genotypes, biofilm formation and antibiotic resistance were characterized. Phylogenetic subgroups and identification of diarrheagenic E. coli were determined by PCR; biofilm formation was quantified using a plate-based colorimetric method. Antibiotic resistance was analyzed by the Kirby Bauer diffusion disc method. Most isolates (N = 293, 86%) belonged to phylogenetic group A. Only four isolates (1.2%) were diarrheagenic: EPEC (N = 3) and ETEC (N = 1). Antibiotic resistance to tetracycline (23.2%) and ampicillin (19.9%) was high, and only 3.5% of the strains presented resistance to >5 antibiotics. Biofilms were produced by most strains (76%), among which 34.4% were categorized as high producers. The presence of antibiotic resistant E. coli strains that may contain gene markers for pathogenicity and which can form biofilms suggests potential health risks for consumers.

Genotipificación de cagA y de la región intermedia de vacA en cepas de Helicobacter pylori aisladas de pacientes adultos colombianos y su asociación con enfermedades gástricas / Genotyping of cagA and the intermediate region of vacA in strains of Helicobacter pylori isolated from Colombian adult patients and associations with gastric diseases

Resumen Objetivo: este estudio caracteriza la diversidad de los genes de virulencia cagA (gen asociado con la citotoxina A) y vacA (citotoxina vacuolizante) en pacientes colombianos para determinar posibles asociaciones entre estos 2 genes y la severidad de los hallazgos endoscópicos teniendo en cuenta todos los genotipos reportados para el gen vacA (s, m e i). Materiales y métodos: Helicobacter pylori fue detectado por cultivo y por métodos moleculares en biopsias de 62 pacientes. Los genotipos de cagA y vacA (m/i/s) se determinaron por reacción en cadena de la polimerasa (PCR) y secuenciación. Resultados: se aislaron 124 cepas de 62 pacientes; de estas, el 48,5% (n = 48) fueron vacA s2/m2/i2-cagA (-) presente en su mayoría en pacientes con gastritis folicular; mientras el 32,3% (n = 32) fueron vacA s1/m1/i1-cagA (+) presentes mayormente en pacientes con gastritis folicular, gastritis crónica y posible metaplasia. Se encontró una asociación significativa entre la presencia de cagA y el genotipo vacA s1/m1/i1 y la ausencia de cagA y el genotipo vacA s2/m2/i2 (p <0,001). No se encontró una asociación significativa entre la severidad de los hallazgos endoscópicos y el estatus cagA-vacA de las cepas. Conclusión: se encontró una baja prevalencia de cepas cagA (+), el estatus cagA-vacA no es un predictor de riesgo en la población estudiada y la presencia de infecciones heterogéneas sin tropismo sugieren la necesidad de tomar biopsias tanto del cuerpo como del antro del estómago en la práctica clínica rutinaria.

Abstract Objective: This study characterizes the diversity of cagA and vacA virulence genes in Colombian patients to determine possible associations between them and the severity of endoscopic findings. It considers all four genotypes reported for the vacA gene (s, m and i). Materials and methods: Helicobacter pylori was detected in biopsies of 62 patients through culturing and by molecular methods. Genotypes of cagA and vacA (m/i/s) were determined by PCR and sequencing. Results: One hundred twenty four strains from 62 patients were isolated. Of these, 48.5% (n = 48) were vacA s2/m2/i2 - cagA (-) which were mostly found in patients with follicular gastritis; 32.3% (n = 32) were vacA s1/m1/i1-cagA (+) which were mostly found in patients with follicular gastritis, chronic gastritis and possible metaplasia. Significant associations were found between the presence of cagA and the vacA s1/m1/i1 genotype and the absence of cagA and the vacA s2/m2/i2 genotype (p <0.001). No significant association was found between the severity of endoscopic findings and the cagA-vacA status of the strains. Conclusion: We found a low prevalence of cagA (+) strains, the cagA-vacA status is not a predictor of risk in this population. Moreover, the presence of heterogenous infections without tropism suggests a need for biopsies from both the corpus and the antrum of the stomach in routine clinical practice.

Motivaciones y recursos para el consumo de sustancias psicoactivas en universitarios / Motivations and resources for the consumtion of psychoactive substancces by university students / Motivações e recursos para o consumo de substancias psicoativo nos universitarios

Objetivo: describir el consumo de sustancias psicoactivas –SPA– (alcohol, tabaco y drogas ilegales) de jóvenes universitarios colombianos y analizar su relación con las motivaciones y la disponibilidad de recursos para el consumo. Método: participaron 1811 estudiantes de seis universidades colombianas, con edades entre los 15 y 24 años (M=19,6; DT=2,0) seleccionados intencionalmente, quienes contestaron la subescala de consumo de sustancias psicoactivas del “Cuestionario de estilos de vida en jóvenes universitarios (CEVJU)”. Resultados: el 20% de los jóvenes informa consumir alcohol por lo menos una vez a la semana, el 13% fuma por lo menos una vez al día y el 4% consume drogas ilegales (marihuana, cocaína, éxtasis, heroína, popper, otros alucinógenos) por lo menos una vez a la semana. Entre los motivos del consumo se encuentran: sentirse mejor, disminuir la tensión, la ansiedad o el estrés y experimentar nuevas sensaciones. Quienes tienen mayores prácticas de consumo de SPA consideran que podrían cambiarlas pero no saben si lo harán. El consumo es mayor en los jóvenes que cuentan con dinero para comprarlas, que conocen sitios donde las venden dentro de la universidad y cerca de ella, y que frecuentan sitios en los cuales pueden adquirirlas. Conclusiones: a partir de los resultados se discute sobre la importancia de reorientar las acciones de prevención del consumo de SPA en los centros universitarios considerando los principales motivos y recursos que se relacionaron con éste.

Purpose: to describe the use of psychoactive substances –PS– (alcohol, tobacco and illegal drugs) in Colombian young university students and to analyze its relation with motivations and the availability of resources for consumption. Method: 1,811 students from six Colombian universities between 15 and 24 years old (M=19.6; SD=2.0) participated. Participants were selected intentionally and they answered the subscale of psychoactive substances consumption from the “College Youth Lifestyle Questionnaire”. Result: 20% of the students report using alcohol at least once a week; 13% smoke at least once daily, and 4% consume illegal drugs (marijuana, cocaine, ecstasy, heroine, popper, other hallucinogens) at least once a week. Feeling better, reducing stress or anxiety and feeling new sensations were motives to use PS. Those who have a higher use of PS think that they could change their practices but are not sure of doing so. Substance use is higher in students who have money to buy them, in those who know where to buy them in the university and close to it, and in those who go to places where they can get them. Conclusions: From the results, the importance of redirecting drug consumption prevention strategies used in universities is discussed, considering the main motives and resources related to it.

Objetivo: Descrever o consumo de substâncias psicoativas –SPA- (álcool, tabaco e drogas ilegais) de jovens universitários colombianos e analisar sua relação com as motivações e a disponibilidade de recursos para o consumo: Método: participaram 1811 estudantes de seis universidades Colombianas, com idades entre 15 e 24 anos (M=19,6; DT=2,0) selecionados intencionalmente, quem responderam a sub- escada de consumo de sustâncias psicoativas do “Questionário de estilos de vida em jovens universitários (CEVJU)”. Resultados: o 20% dos jovens informa consumir álcool pelo menos uma vez à semana, o 13% fuma pelos menos uma vez ao dia e o 4% consume drogas ilegais (maconha, cocaína, êxtases, heroína, Popper, outros alucinógenos) pelo menos uma vez por semana. Entre os motivos do consumo encontram se: sentir se melhor, diminuir a tensão, a ansiedade o estresse e experimentar novas sensações. Quens tem maiores praticas de consumo de SPA consideram que poderiam cambiar- las, mas não sabem se o farão. O consumo é maior nos jovens que contam com o dinheiro para comprá-las que conhecem sítios onde as vendem dentro da universidade e perto dela, e que frequentam sítios nos quais podem adquiri-las. Conclusões: a partir dos resultados se discute sobre a importância de reorientar as ações de prevenção do consumo de SPA nos centros universitários considerando os principais motivos e recursos que se relacionaram com este.

Evaluación de las conductas de salud en jóvenes universitarios / Assessing young university students' behaviour regarding health

Objetivo Construir y analizar las propiedades psicométricas de un cuestionario que evalúa las conductas de salud que hacen parte del estilo de vida de los universitarios. Métodos Se realizó un estudio de validación con dos fases. La primera con 1485 estudiantes (63,2 por ciento mujeres), de cuatro universidades de Colombia, cuya edad media fue de 20,7 años (DT=2,5). La segunda con 1811 estudiantes (55,8 por ciento mujeres) de seis universidades del país, con una edad media de 19,7 (DT=2,0). Se hicieron análisis para la validez de contenido, análisis de discriminación de ítems, análisis factoriales y de consistencia interna. Resultados La versión final del "Cuestionario de estilos de vida de jóvenes universitarios" [CEVJU-R] quedó constituida por 40 ítems que evalúan conductas en ocho dimensiones del estilo de vida: Actividad física, Tiempo de ocio, Alimentación, Consumo de alcohol, cigarrillo y drogas ilegales, Sueño, Habilidades interpersonales, Afrontamiento y Estado emocional percibido. Adicionalmente, incluyó 28 ítems que evalúan, en siete de las ocho dimensiones, las motivaciones para llevar a cabo o no las prácticas y para cambiarlas, así como los recursos que facilitan o dificultan su realización. El nivel de fiabilidad de las dimensiones fue de aceptable a moderado (entre 0,6 y 0,7). Conclusiones El CEVJU-R presenta propiedades psicométricas adecuadas y constituye un avance en la medición de los estilos de vida de los universitarios. Podría utilizarse para la identificación de las necesidades de los jóvenes y para la definición de las acciones de promoción y prevención dentro de las universidades.

Objective Constructing a questionnaire for assessing university students' behaviour regarding health forming part of their life-styles and evaluating its psychometric properties. Methods A two-phases validation study was conducted; the first covered 1,485 students (63.2 percent female) from four Colombian universities having a mean age of 20.65 years (SD=2.5) and the second covered 1,811 students (55.8 percent female) from six universities having a mean age of 19.65 years (SD=2.0). A content validity analysis, an item discrimination analysis, a factorial analysis and reliability assessment were done. Results The final version of the university students' life-style questionnaire [CEVJU-R, by its Spanish's abbreviations] finally consisted of 40 items related to health and life-style regarding eight factors: physical activity, leisure time, eating habits, alcohol, cigarette and drug use, sleep, interpersonal abilities, coping and perceived emotional state. It also included 28 items evaluating motivation (whether to engage in certain practices regarding health and whether to change them) and the availability of resources facilitating or interfering with such behaviour in seven out of the eight dimensions. Factor reliability level was acceptable (ranging from 0.6 to 0.7). Conclusions The CEVJU-R had suitable psychometric properties and constituted an advance in measuring university students' life-styles and could help identify health need and focus health promotion and prevention strategies in this population.

[Assessing young university students' behaviour regarding health]. / Evaluación de las conductas de salud en jóvenes universitarios.

OBJECTIVE: Constructing a questionnaire for assessing university students' behaviour regarding health forming part of their life-styles and evaluating its psychometric properties. METHODS: A two-phases validation study was conducted; the first covered 1,485 students (63.2 % female) from four Colombian universities having a mean age of 20.65 years (SD=2.5) and the second covered 1,811 students (55.8 % female) from six universities having a mean age of 19.65 years (SD=2.0). A content validity analysis, an item discrimination analysis, a factorial analysis and reliability assessment were done. RESULTS: The final version of the university students' life-style questionnaire [CEVJU-R, by its Spanish's abbreviations] finally consisted of 40 items related to health and life-style regarding eight factors: physical activity, leisure time, eating habits, alcohol, cigarette and drug use, sleep, interpersonal abilities, coping and perceived emotional state. It also included 28 items evaluating motivation (whether to engage in certain practices regarding health and whether to change them) and the availability of resources facilitating or interfering with such behaviour in seven out of the eight dimensions. Factor reliability level was acceptable (ranging from 0.6 to 0.7). CONCLUSIONS: The CEVJU-R had suitable psychometric properties and constituted an advance in measuring university students' life-styles and could help identify health need and focus health promotion and prevention strategies in this population.

Comportamiento y salud de los jóvenes universitarios: satisfacción con el estilo de vida

El objetivo de este trabajo fue describir los comportamientos que hacen parte de los estilos de vida de losjóvenes universitarios, en diez dimensiones: ejercicio y actividad física, tiempo de ocio, autocuidadoy cuidado médico, alimentación, consumo de alcohol, tabaco y drogas ilegales, sueño, sexualidad,relaciones interpersonales, afrontamiento y estado emocional percibido, y su correspondiente gradode satisfacción con dichas prácticas. Participaron 598 estudiantes (44,7 por ciento hombres y 55,3 por ciento mujeres)de una universidad privada de Colombia, quienes diligenciaron el “Cuestionario de estilos de vidaen jóvenes universitarios” (Cevju). Los resultados obtenidos muestran un predominio de prácticassaludables en todas las dimensiones, con excepción de ejercicio y actividad física y alta satisfaccióncon el estilo de vida y el estado general de salud. Hubo coherencia entre el nivel de satisfacción conel tipo de prácticas realizadas, y esta relación fue analizada siguiendo los lineamientos del modelode etapas de cambio. Finalmente, se propusieron algunos aspectos relevantes para la creación deprogramas de intervención que se orienten a la promoción de un mayor número de conductas positivaspara la salud y a la disminución de aquellas que puedan deteriorarla...

The purpose of this study was to describe behaviors that form part of the life-style of young collegestudents in 10 dimensions: exercise and physical activity, leisure time, self-care and medical care, diet,alcohol, tobacco and illegal drug consumption, sleep, sexuality, interpersonal relationships, copingand perceived emotional state, and their satisfaction with each. 598 students participated (44.7 percent menand 55.3 percent women) from a private university in the southwest of Colombia, who answered the CollegeYouth Lifestyle Questionnaire (Cevju). The results show a high prevalence of healthy practices in alldimensions, except for exercise and physical activity, and satisfaction with lifestyle and general health status. There was coherence between the level of satisfaction and practices (healthy or unhealthy),and this relationship was analyzed following the guidelines of the stages of change model. Finally,some ideas are presented for consideration, with the idea of creating intervention programs aimed atpromoting positive health behaviors and preventing those that adversely affect health...

O objetivo deste trabalho foi descrever os comportamentos que fazem parte dos estilos de vida dosjovens universitários, em dez dimensões: Exercício e atividade física, Tempo de ócio, Cuidado ecuidado médico, Alimentação, Consumo de álcool, Tabaco e drogas ilegais, Sonho, Sexualidade,Relações interpessoais Enfrentamento e Estado emocional percebido, e seu correspondente grau desatisfação com ditas práticas. Participaram 598 estudantes (44,7 por cento homens e 55,3 por cento mulheres) deuma universidade privada do sudoeste colombiano, que diligenciaram o “Cuestionario de estilos devida en jóvenes universitarios” (Cevju). Os resultados obtidos mostram um predomínio de práticassaudáveis em todas as dimensões com exceção de Exercício e atividade física, e alta satisfação como estilo de vida e o estado geral de saúde. Houve coerência entre o nível de satisfação com o tipo depráticas realizadas (saudáveis ou não saudáveis) e esta relação foi analisada seguindo os lineamientosdo modelo de períodos de mudança. Finalmente, foram propostos alguns aspectos relevantes deanálise para a criação de programas de intervenção que se orientem para a promoção de um maiornúmero de condutas positivas para a saúde e para a diminuição daquelas que possam deteriorá-la...