Infección por Helicobacter pylori y factores asociados en adultos con sospecha clínica de úlcera duodenal / Helicobacter pylori infection and associated factors in adults with a clinical suspicion of duodenal ulcer

RESUMEN Introducción: la infección por Helicobacter pylori es la enfermedad bacteriana crónica que afecta con mayor prevalencia al ser humano. Objetivo: identificar la frecuencia de infección por Helicobacter pylori y su relación con variables consideradas factores de riesgo de esta infección. Materiales y métodos: estudio de corte transversal realizado en el Policlínico Docente Camilo Cienfuegos, del municipio Habana del Este, durante el año 2018, en un universo de 42 pacientes con 18 años y más de edad, con sospecha clínica y hallazgo endoscópico de úlcera duodenal e informe del resultado de estudio histológico para el diagnóstico de la infección. Se confeccionó una planilla de recolección de datos que incluyó variables como hacinamiento, agua de consumo, lugar de nacimiento, estancia en una institución, contacto con animales y antecedentes familiares. Se determinó relación entre variables con la prueba de chi cuadrado (c2) con significación estadística ɒ = 0,05, y se identificaron variables cuyos coeficientes fueron significativamente diferentes de 0 (p < 0,05). La fuerza de asociación se determinó mediante odds ratio. Resultados: la prevalencia fue de 59,5 %. Se encontró asociación estadística y constituyeron factores de riesgo de infección por Helicobacter pylori, el hacinamiento (c2 = 4,37; OR = 3,89), el agua de consumo (c2 = 4,92; OR = 3,43), el contacto con animales (c2 = 7,41; OR = 6,17) y los antecedentes familiares (c2 = 13,18; OR = 13). Conclusiones: el estudio permitió determinar la prevalencia de infección por Helicobacter pylori y las principales variables asociadas, coincidiendo con otros estudios revisados que tratan el tema (AU).

ABSTRACT Introduction: the infection by Helicobacter pylori is the chronic bacterial disease that affects the human being with greater prevalence. Objective: to identify the frequency of the infection by Helicobacter pylori and its relationship with variables considered risk factors for this infection. Materials and methods: a cross-sectional study was carried out in the teaching Polyclinic Camilo Cienfuegos, municipality Habana del Este, during 2018. In a universe of 42 patients aged 18 years and over, with clinical suspicion and endoscopic diagnosis of duodenal ulcer and histological study report for the diagnosis of the infection. A data collection form was made, which included variables such as: overcrowding, consumption water, place of birth, staying in an institution, contact with animals, and family history. The relationship within variables was found using the chi-square test (c2) with statistical significance ɒ = 0.05, and there were identified variables significantly different from 0 (p < 0.05). The association strength was determined through odds ratio. Results: the prevalence was 59.5%. Statistical association was found and overcrowding (c2 = 4.37, OR = 3.89), consumption water (c2 = 4.92; OR = 3.43), contact with animals (c2 = 7.41, OR = 6.17) and family history (c2 = 13.18, OR = 13) were found risk factors for Helicobacter pylori infection. Conclusions: the study allowed to determine the prevalence of Helicobacter pylori infection and the main associated variables, coinciding with other reviewed studies dealing with the subject (AU).

Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.

Infecção por Corynebacterium pseudotuberculosis em equinos: aspectos microbiológicos, clínicos e preventivos / Corynebacterium pseudotuberculosis infection in horses: clinical, microbiological and prevention aspects

Corynebacterium pseudotuberculosis é o agente causador da linfadenite caseosa em caprinos e ovinos, sendo responsável por significativas perdas econômicas na ovinocaprinocultura mundialmente. Esta bactéria Gram-positiva também infecta equinos, causando desde quadros assintomáticos até infecções sistêmicas, podendo levar o animal a óbito. Especificamente no Brasil, não foram relatados casos de infecção em equinos, mas acredita-se que, devido à convivência de pequenos ruminantes infectados com equinos em diversas propriedades rurais, seja natural que ocorra a infecção desses animais. A presente revisão tem como objetivo fornecer informações sobre a bactéria C. pseudotuberculosis, sobre os aspectos epidemiológicos e clínicos da infecção em equídeos, bem como sobre técnicas de manejo para sua prevenção...

Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis in sheep and goats, an infectious disease that is responsible for significant economic losses in small ruminants breeding units worldwide. This Gram-positive bacterium can infect horses, causing symptomatic disease to systemic infections, which can lead to animals' death. Specifically in Brazil, there are no scientific records of equine infections, but it is believed that, due to the maintenance of infected small ruminants in close association to horses in many properties, the infection of horses may be a reality. The present work had the objective to present information on the bacteria C. pseudotuberculosis, on the epidemiological and clinical aspects of the infection in horses, as well as information about breeding procedures that can be adopted in order to prevent the infection...

Corynebacterium diphtheriae putative tellurite-resistance protein (CDCE8392_0813) contributes to the intracellular survival in human epithelial cells and lethality of Caenorhabditis elegans

Corynebacterium diphtheriae, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO3^2-) is toxic to most microorganisms, TeO3^2--resistant bacteria, including C. diphtheriae, exist in nature. The presence of TeO3^2--resistance (Te^R) determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative Te^R determinant (CDCE8392_813gene) in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC-L1 mutant increased susceptibility to TeO3^2- and reactive oxygen species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of Caenorhabditis elegansand the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the Te^R and pathogenic potential of C. diphtheriae.

Principales factores de virulencia de Listeria monocytogenesy su regulación / Main virulence factors of Listeria monocytogenesand its regulation

Listeria monocytogenesis a facultative intracellular pathogen, ubiquitous and aetiological agent of listeriosis. The main way of acquisition is the consumption of contaminated food and can cause serious medical conditions such as septicemia, meningitis and gastroenteritis, especially in children, immunocompromised individuals and seniors and abortions in pregnant women. An increase in cases of listeriosis worldwide has been reported and it is estimated that its prevalence in developed countries is in the range of 2 to 15 cases per one million population. This microorganism is characterized for the transition from the environment into the eukaryotic cell. Several virulence factors have been involved in the intracellular cycle that are regulated, pimarilly, by the PrfA protein, which in turn is regulated by different mechanisms operating at the transcriptional, translational and post-translational levels. Additionally, other regulatory mechanisms have been described as sigma factor, system VirR/S and antisense RNA, but PrfA is the most important control mechanism and is required for the expression of essential virulence factors for the intracellular cycle.

Listeria monocytogeneses un patógeno intracelular facultativo, ubicuo y agente etiológico de listeriosis. La principal vía de adquisición es el consumo de alimentos contaminados, pudiendo ocasionar cuadros clínicos muy graves como septicemia, meningitis y gastroenteritis, especialmente en niños, individuos inmunocomprometidos y de la tercera edad, y aborto en mujeres embarazadas. Se ha informado un aumento en los casos de listeriosis a escala mundial y se estima que su frecuencia en los países desarrollados está en un rango de 2 a 15 casos por millón de habitantes. Este microorganismo se caracteriza por realizar una transición desde el medio ambiente hacia la célula eucariota. Para este proceso se han descrito varios factores de virulencia, los cuales están involucrados en el ciclo intracelular y están regulados, principalmente, por la proteína PrfA, la cual a su vez está regulada por diferentes mecanismos que actúan a nivel transcripcional, traduccional y post-traduccional. Además, se han descrito otros mecanismos regulatorios como: factor Sigma, sistema VirR/S y ARN sin sentido. No obstante, PrfA es el mecanismo de control más importante y el cual es requerido para la expresión de los factores de virulencia esenciales para el ciclo intracelular.

Molecular battles between plant and pathogenic bacteria in the phyllosphere

The phyllosphere, i.e., the aerial parts of the plant, provides one of the most important niches for microbial colonization. This niche supports the survival and, often, proliferation of microbes such as fungi and bacteria with diverse lifestyles including epiphytes, saprophytes, and pathogens. Although most microbes may complete the life cycle on the leaf surface, pathogens must enter the leaf and multiply aggressively in the leaf interior. Natural surface openings, such as stomata, are important entry sites for bacteria. Stomata are known for their vital role in water transpiration and gas exchange between the plant and the environment that is essential for plant growth. Recent studies have shown that stomata can also play an active role in limiting bacterial invasion of both human and plant pathogenic bacteria as part of the plant innate immune system. As counter-defense, plant pathogens such as Pseudomonas syringae pv tomato (Pst) DC3000 use the virulence factor coronatine to suppress stomate-based defense. A novel and crucial early battleground in host-pathogen interaction in the phyllosphere has been discovered with broad implications in the study of bacterial pathogenesis, host immunity, and molecular ecology of bacterial diseases.

Resistance of melanized yeast cells of Paracoccidioides brasiliensis to antimicrobial oxidants and inhibition of phagocytosis using carbohydrates and monoclonal antibody to CD18

Paracoccidioides brasiliensis, a thermal dimorphic fungal pathogen, produces a melanin-like pigment in vitro and in vivo. We investigated the involvement of carbohydrates and monoclonal antibody to CD18, on phagocytosis inhibition, involving macrophage receptors and the resistance of melanized fungal cells to chemically generated nitric oxide (NO), reactive oxygen species (ROS), hypochlorite and H2O2. Our results demonstrate that melanized yeast cells were more resistant than nonmelanized yeast cells to chemically generated NO, ROS, hypochlorite and H2O2, in vitro. Phagocytosis of melanized yeast cells was virtually abolished when mannan, N-acetyl glucosamine and anti-CD18 antibody were added together in this system. Intratracheal infection of BALB/c mice, with melanized yeast cells, resulted in higher lung colony forming units, when compared to nonmelanized yeast cells. Therefore, melanin is a virulence factor of P. brasiliensis.

Bacterial pathogenesis and mediators in apical periodontitis: [review]

Apical periodontitis is a group of inflammatory diseases caused by microorganisms (mainly bacteria) infecting the necrotic root canal system. The pathogenesis of different types of apical periodontitis and even the same type in different individuals is unlikely to follow a stereotyped fashion with regard to the involved bacterial mediators. Disease pathogenesis is rather complex and involves a multitude of bacteria- and host-related factors. This review article discusses the bacterial pathogenesis of acute and chronic apical periodontitis, with the main focus on the bacterial mediators conceivably involved in the different stages of the infectious process, including secreted products (enzymes, exotoxins, N-formyl-methionyl-leucyl-phenylalanine peptides, heat-shock proteins and metabolic end-products) and structural components (lipopolysaccharide, peptidoglycan, lipoteichoic acid, lipoproteins, fimbriae, flagella, outer membrane proteins and vesicles, DNA, and exopolysaccharides). Knowledge of the bacterial factors involved in the pathogenesis of apical periodontitis is important to the understanding of the disease process and to help establishing proper therapeutic measures to inactivate this bacterial "artillery".

Lesões perirradiculares compreendem um grupo de doenças inflamatórias causadas por microrganismos (principalmente bactérias) infectando o sistema de canais radiculares com polpa necrosada. É improvável que a patogênese dos diferentes tipos de lesão perirradicular, e até mesmo daquelas do mesmo tipo, mas em diferentes indivíduos, obedeça um padrão estereotipado com relação aos mediadores bacterianos envolvidos. A patogênese destas doenças é complexa e envolve inúmeros fatores relacionados às bactérias e ao hospedeiro. Este artigo de revisão discute a patogênese bacteriana das lesões perirradiculares agudas e crônicas, enfatizando os fatores bacterianos que estão possivelmente envolvidos nos diferentes estágios do processo infeccioso, incluindo produtos secretados (enzimas, exotoxinas, peptídeos N-formilados, proteínas de choque térmico e produtos terminais do metabolismo) e componentes estruturais (lipopolissacarídeo, peptidoglicano, ácido lipoteicóico, lipoproteínas, fímbrias, flagelos, proteínas e vesículas de membrana externa, DNA e exopolissacarídeos). O conhecimento dos fatores bacterianos envolvidos na patogênese das lesões perirradiculares é importante para o entendimento do processo patológico bem como para ajudar no estabelecimento de medidas terapêuticas adequadas para desativação desta "artilharia" bacteriana.