In vitro antagonistic activity of Lactobacillus casei against Helicobacter pylori

Helicobacter pylori is one of the most common causes of chronic infections in humans. Curing H. pylori infection is difficult because of the habitat of the organism below the mucus adherent layer of gastric mucosa. Lactobacilli are known as acid-resistant bacteria and can remain in stomach for a long time than any other organism, we aimed in this study to examine the efficacy of Lactobacillus casei as a probiotic against H. pylori in humans. Particularly, L. casei was opted as it is considered to be one of the widely used probiotics in dairy products. One hundred and seven strains of H. pylori were isolated from dyspeptic patients and were tested for their antibiotic susceptibility to metronidazole (MTZ), clarithromycin (CLR), tetracycline (TET), and amoxicillin (AMX) by the disc diffusion method. The strains were examined for their susceptibility toward L. casei - present in fermented milk products - by well diffusion method. It was found that 74.7% strains were resistant to MTZ; 1.8% to MTZ, TET, and CLR; 3.7% to MTZ and CLR; 4.6% to MTZ and TET; and 0.9% were resistant to MTZ, TET, and AMX. The antibacterial activity of L. casei against H. pylori was determined on all the tested H. pylori isolates including antibiotic resistant strains with different patterns. Our study proposed the use of probiotics for the treatment of H. pylori infection as an effective approach.

Actividad antibacteriana in vitro de propóleos chilenos sobre Helicobacter pylori / In vitro antibacterial activity of Chilean propolis against Helicobacter pylori

Introduction: Propolis is a natural product derived from beekeeping. It has anesthetic, anti-inflammatory, immune-stimulant and antibacterial properties on grampositive and gramnegative bacteria. However, little is known regarding its activity on Helicobacter pylori. This bacteria colonizes about half of the world’s population and is associated with chronic gastritis, peptic ulcer and gastric cancer. Objective: The aim of this study was to evaluate the inhibitory activity of 22 propolis extracts from nine of the 11 beekeeping Chilean regions on 10 strains of H. pylori isolated from gastric mucosa. Methods: The antibacterial activity of the extracts was determined using the well diffusion method and diffusion disks. Results: 100% of the extracts were active on the tested strains, showing inhibition halos equal to or greater than 15 mm by both methods. Conclusions: our results show an effective anti H. pylori activity of propolis. However, additional microbiological studies are needed before a potential clinical utility of these natural products is warranted.

Introducción: El propóleos es un producto natural derivado de la apicultura que tiene propiedades anestésicas, anti-inflamatorias, inmuno-estimulantes y antibacterianas. Ejerce su acción sobre distintas bacterias grampositivas y gramnegativas. Sin embargo, es muy poco lo que se sabe en relación a su actividad sobre H. pylori, bacteria asociada con gastritis crónica, úlcera gastro-duodenal y cáncer gástrico y que coloniza a alrededor de la mitad de la población mundial. Objetivo: Evaluar la actividad inhibitoria de 22 extractos de propóleos de orígenes botánicos diferentes, provenientes de nueve de las once zonas mielíferas de Chile, en la época de otoño, sobre 10 cepas de H. pylori aisladas de mucosa gástrica. Metodología: La actividad antibacteriana de los extractos se determinó a través del método de difusión en pocillos y de difusión en discos. Resultados: 100% de los extractos fueron activos sobre las cepas ensayadas, observándose halos de inhibición iguales o mayores a 15 mm en ambos métodos. Conclusiones: Los datos obtenidos in vitro en el presente estudio muestran una efectiva actividad anti H. pylori de los propóleos chilenos, siendo necesario estudios microbiológicos y farmacológicos adicionales para avanzar en una posible utilidad clínica de estos productos naturales.

Concordancia entre procedimientos diagnósticos invasivos para la infección por Helicobacter pylori en adultos / Concordance among invasive diagnostic procedures for Helicobacter pylori infection in adults

Objetivo. Comparar la concordancia entre cultivo, histología y prueba rápida de la ureasa para el diagnóstico de infección por Helicobacter pylori, así como la relación de hallazgos histopatológicos y frecuencia de positividad entre dichos procedimientos diagnósticos. Material y métodos. Estudio de pruebas diagnósticas. Población de sujetos con endoscopía digestiva y toma de muestras gástricas antrales en un hospital de especialidades en México. Se realizó prueba rápida de la ureasa (una muestra), histología (dos muestras) y cultivo (dos muestras). Análisis estadístico con coeficiente de Kappa. Resultados. Se estudiaron 108 sujetos: 28 (25.9%) hombres y 80 (74.1%) mujeres; la edad promedio fue 49.1 (DE 15.1) años. El coeficiente de Kappa fue 0.729 y 0.377 entre cultivo con histología y prueba rápida de la ureasa respectivamente; asimismo, el coeficiente de Kappa fue 0.565 entre histología y prueba rápida de la ureasa. Conclusiones. La fuerza de concordancia fue mayor entre histología con cultivo y la prueba rápida de la ureasa, por lo cual la histología es lo más recomendable en la práctica clínica para la detección de la infección por Helicobacter pylori.

Objective. Compare the strength of concordance between culture, histology, rapid urease test for diagnosis of Helicobacter pylori infection and histopathological findings relationship and frequency of positivity among such diagnostic procedures. Materials and methods. Diagnostic test study. The study population were subjects with endoscopy and take samples of gastric antral. Rapid urease test (one sample), histology (two samples) and culture (two samples), and histopathological findings of gastric mucosa were performed. Statistical design with Student's t, Fisher exact test, Kappa coefficient. Results. We reviewed 108 subjects, 28 (25.9%) men, 80 (74.1%) women, mean age was 49.1 years (SD 15.1). The Kappa coefficient was 0.729 and 0.377 between culture with histology and rapid urease test, respectively; likewise the Kappa coefficient was 0.565 between histology and rapid urease test. Conclusions. The strength of concordance was higher between histology with culture and rapid urease test; the most recommended being histology in clinical practice for the detection of Helicobacter pylori infection.

Water-induced modulation of Helicobacter pylori virulence properties

While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties. Therefore, we studied the culturability of water-exposed H. pylori and determined whether there was any relation with the bacterium’s ability to adhere, produce functional components of pathogenicity and induce inflammation and alterations in apoptosis in an experimental model of human gastric epithelial cells. H. pylori partially retained the ability to adhere to epithelial cells even after complete loss of culturability. However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system. These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process. The fact that adhesion is maintained by H. pylori to the detriment of other factors involved in later infection stages appears to point to a modulation of the physiology of the pathogen after water exposure and might provide the microorganism with the necessary means to, at least transiently, colonise the human stomach.

Anti-Helicobacter pylori activity and structure-activity relationship study of 2-alkylthio-5-[nitroaryl]-1,3,4-thiadiazole derivatives

Nitro-containing heteroaromatic derivatives structurally related to nitroimidazole [Metronidazole] are being extensively evaluated against Helicobacter pylori isolates. On the other hand, 1,3,4-thiadiazole derivatives have also demonstrated promising antibacterial potential. In present study, we evaluated anti-H. pylori activity of novel hybrid molecules bearing nitroaryl and 1,3,4-thiadiazole moieties. Anti-H. pylori activity of novel 5-[5-nitroaryl]-1,3,4-thiadiazole derivatives bearing different bulky alkylthio side chains at C-2 position of thiadiazole ring, were assessed against three different metronidazole resistant H. pylori isolates by paper disk diffusion method. Most of the compounds demonstrated moderate to strong inhibitory response especially at 25 micro g/disk. The structure-activity relationship study of the compounds demonstrated that introduction of different alkylthio moieties at C-2 position of thiadiazole ring alter the inhibitory activity which is mainly dependent on the type of C-5 attached nitrohetercyclic ring. The promising compound of this scaffold, bearing 1-methyl-5-nitroimidazole moiety at C-5 and alpha -methylbenzylthio side chain at C-2 position of thiadiazole ring, showed strong inhibitory response against metronidazole resistant H. pyloriisolates at 12.5 micro g/disk [the inhibition zone diameter at all evaluated concentrations [12.5-100 micro g/disk] is > 50 mm]. Novel 5-[5-nitroaryl]-1,3,4-thiadiazole scaffold bearing different C-2 attached thio-pendant moieties with promising anti-H. pylori potential were identified. Among different nitroheterocycles, 5-nitrofuran and 5-nitroimidazole moieties were preferable for the substitution at C-5 position of 1,3,4-thiadiazole ring. Introduction of different alkylthio side chains at C-2 position of central ring alter the inhibitory activity which is mainly dependent on the type of C-5 attached nitrohetercyclic ring

Inhibitory and bactericidal activity of selected South African honeys and their solvent extracts against clinical isolates of Helicobacter pylori

The growing problem of antibiotic resistance by Helicobacter pylori demands the search for novel compounds, especially from natural sources. We evaluated the anti-H. pylori activity of six local honeys at different concentrations as well as their solvent extracts by the Hole Plate diffusion method. The minimum inhibitory concentration [MIC[50]] of the two most active extracts of each honey was determined by the broth microdilution method, and the time kill assay of the most active extract of each honey determined by viability studies. Data were analyzed by one-way ANOVA test at 95% significance level. All the honey varieties as well as their solvent extracts demonstrated varying levels of antibacterial activity based on different mean zone diameters [16.0mm [crude] to 22.2mm [extract]] and percentage susceptibilities [73.3% [crude] to 93.3% [extract]] of the test isolates. The chloroform extracts of Pure Honey [PH] and Champagne Royal Train [CRT] recorded MIC[50] ranges of 0.01-10% and 0.625-10% [v/v] respectively; that were not significantly different [P > 0.05] from amoxicillin [0.001-1.25mg/mL], the positive control. The most potent bactericidal effect against the test isolates was obtained with 5% v/v [1/2 MIC] concentration of chloroform extract of PH from 42-72hrs. In conclusion, these honeys and their extracts could be leads for further investigation in the discovery of new natural anti-H. pylori compounds

Helicobacter pylori: rol del agua y los alimentos en su transmisión / Role of water and foods in helicobacter pylori transmission

Helicobacter pylori es una bacteria Gram negativa, microaerofílica, que coloniza eficientemente la mucosa gástrica humana. Fue aislada por primera vez en el año 1982 y actualmente se considera como un importante patógeno humano que causa diversas enfermedades gastrointestinales y además se reconoce como agente carcinógeno. Se habla de una alta prevalencia en el mundo, con un mayor porcentaje en los países en vías de desarrollo, esto probablemente relacionado con las condiciones de vida. De esta manera, el estatus socio-económico es el determinante más importante para el desarrollo de la infección por H. pylori, siendo las clases sociales más bajas las que exhiben mayor prevalencia. A la fecha, las rutas de transmisión de este microorganismo no se encuentran totalmente esclarecidas. Sobre la base de diversas evidencias epidemiológicas y microbiológicas se han propuesto varias vías. Dentro de estas se incluye al agua y a los alimentos como posibles vectores, a pesar de la compleja detección de esta bacteria en muestras distintas al tejido gástrico. H. pylori puede pasar a un estado viable no cultivable (VNC) bajo condiciones de estrés. No obstante, se han llevado a cabo diversos estudios para evaluar la prevalencia y supervivencia de esta bacteria en diversas fuentes de agua y muestras de alimentos, cuyos resultados indican la posibilidad de que los mismos actúen como un reservorio en su transmisión. Por esta razón, el presente artículo de revisión se enfoca en las evidencias que apoyan la transmisión de H. pylori a través del agua y los alimentos(AU)

Helicobacter pylori is a Gram-negative, microaerophilic, which efficiently colonizes the human gastric mucosa. It was first isolated in 1982 and is now considered an important human pathogen that causes various gastrointestinal diseases and is also recognized as a carcinogen. There is a high prevalence worldwide, with a higher percentage in developing countries, probably related to living conditions. Thus, the socio-economic status is the most important determinant for the development of the infection by H. pylori, being lower social classes exhibiting the highest prevalence. To date, the routes of transmission of this organism are not fully elucidated. Based on numerous epidemiological and microbiological evidences, several transmission paths have been suggested. Among them water and food are included as potential vectors, although the detection of these bacteria is complex in distinct samples to gastric tissue. H. pylori can happen to a viable but non-culturable state (VBNC) under conditions of stress. However, there have been several studies to assess the prevalence and survival of the bacteria in various water sources and food samples. Results indicate the possibility that they act as a reservoir for transmission. For this reason, this review article focuses on the evidence supporting the transmission of H. pylori through water and food(AU)

Estado actual de la resistencia de Helicobacter pylori a tetraciclina:revisión sistemática de la literatura / Current status of Helicobacter pylori resistance to tetracycline: a systematic review of the literature / Estado atual da resistência do Helicobacter pylori à tetraciclina: uma revisão sistemática da literatura

Determinar la prevalencia de resistencia de Helicobacter pylori a tetraciclina y las posibles mutaciones que generan estaresistencia mundialmente. Materiales y método. Se realizó una búsqueda sistemática de literatura en las bases de datos: Medline,Science Direct (Elsevier), Ovid, Pubmed, Lilacs y MEDICLATINA, con el uso de palabras clave relevantes. La extracción de losdatos fue independiente y se realizaron listas de verificación para evaluar la calidad metodológica de los estudios. El análisis de lainformación fue realizado en el programa RevMan 5®. Resultados. Se evidenció resistencia a tetraciclina por Helicobacter pyloricon prevalencias de 1% para Norte América, 8% para Centro y Sur América; 5% para Asia y 2% para Europa . La alta resistencia sedebe a la triple mutación AGA(926-928)-->TTC, en el gen 16S rDNA. Conclusiones. La resistencia antibiótica es una de las causasque más se asocia a falla terapéutica en la erradicación de Helicobacter pylori, así como la poca adherencia al tratamiento y el usoindiscriminado de antibióticos. Se evidenció que la tasa de resistencia a tetraciclina aumenta después de un primer tratamiento con esteantibiótico, sin embargo la prevalencia de la resistencia global a tetraciclina es baja sin aún alcanzar límites que impidan su utilizaciónen los esquemas de tratamiento...

To determinethe prevalence of Helicobacter pylori resistance to and the possible mutations that generate this worldwide resistance. Materials andmethods. A systematic search for literature was performed in the databases Medline, Science Direct (Elsevier), Ovid, PubMed, Lilacsand MedicLatina using relevant key words. Data extraction was independent and checklists were prepared to assess the methodologicalquality of the studies. Analysis of information was done with RevMan 5®. Results. We found Helicobacter pylori resistance prevalencerates of 1% for North America, 8% for Central and South America, 5% for Asia, and 2% for Europe. The mutation associated to thisresistance is in the 16S rDNA gene at nucleotide position 967TTC to AGA965 responsible of high resistance to tetracycline. Conclusions.Antibiotic resistance is one of the causes most associated to treatment failure in the eradication of Helicobacter pylori, as well as pooradherence to treatment and indiscriminate use of antibiotics. We also evidenced that the rate of tetracycline resistance is higher whenit is used in a second treatment scheme. The distribution of resistance is variable in different areas and it is important to know theseresistances to avoid treatment failures...

Determinara prevalência da resistência do Helicobacter pylori à tetraciclina e possíveis mutações que geram esta resistência a nível mundial.Materiais e métodos. Foi realizada uma procura sistemática da literatura nas bases de dados Medline, Science Direct (Elsevier), Ovid,Pubmed, Lilacs e MEDICLATINA, usando palavras-chave relevantes. A extração dos dados foi independente e realizaram-se listas deverificação para avaliar a qualidade metodológica dos estudos. A análise dos dados foi realizada em REVMAN 5®. Resultados. Foievidenciada a resistência de Helicobacter pylori com taxas de prevalência de 1% para a América do Norte, 8% para América Central eAmérica do Sul; 5% para Ásia e 2% para Europa. A mutação associada a estas resistências no gen 16S rDNA nos nucleótidos da posiçãoAGA965 a 967TTC é responsável da alta resistência à tetraciclina. Conclusões. A resistência aos antibióticos é uma das razões maisassociadas à falha do tratamento na erradicação de Helicobacter pylori, assim como a pouca adesão ao tratamento e uso indiscriminadode antibióticos; também foi evidente que a taxa de resistência à tetraciclina é maior quando utilizado em regime de segundo tratamento;a distribuição da resistência varia em diferentes áreas e é importante saber estas resistências a fim de evitar falhas terapêuticas...

Comparison of three methods based on endoscopic gastric biopsies for diagnosis of Helicobacter pylori active infection in a clinical setting / Comparação de três métodos baseados em biopsias gástricas endoscópicas para o diagnóstico da infecção ativa pelo Helicobacter pylori em um ambiente clínico

CONTEXT: The correct diagnosis and effective treatment of Helicobacter pylori gastric infection are essential in controlling this infection. OBJECTIVE: To compare the diagnostic value of three tests based in endoscopic gastric biopsies histopathological evaluation with hematoxylin-eosin (H-E) staining, urease rapid test and microbiological culture for detecting Helicobacter pylori active infection, in order to make recommendations for daily clinical practice. METHODS: Gastric biopsies from 115 adult patients (85 female/30 male) were obtained by upper gastrointestinal endoscopy and studied by histopathological evaluation with H-E (antrum-corpus), urease test in 2 hours (antrum) and microbiological culture (antrum). RESULTS: Helicobacter pylori active infection was diagnosed in 67 percent of patients. Helicobacter pylori active infection was detected by histopathological evaluation with H-E, urease test and microbiological culture in 87 percent, 79 percent and 70 percent of the positive cases, respectively. There were significant differences when histopathological evaluation with H-E and urease test rapid test when compared with microbiological test (P<0.01). There was no significant difference between histopathological evaluation with H-E and urease test (P = 0.7). The kappa index of agreement for histopathological evaluation with H-E/urease test was 0.56, histopathological evaluation with H-E/microbiological culture 0.6, and urease test/microbiological culture 0.64. CONCLUSIONS: In a hospital setting like the one studied, histopathological evaluation with H-E and urease test are the most recommended tests for diagnosis of Helicobacter pylori active infection based in endoscopic biopsies. If pathological information of gastric lesions will be required, histopathological evaluation with H-E is essential. Urease test is mandatory if a prompt diagnosis is necessary. Microbiological culture can be used in cases of persistent or complicated infection, which may require studies on Helicobacter virulence or antimicrobial susceptibility. Selected cases might demand a combination of several tests. The three tests exhibit a good concordance level for Helicobacter pylori active infection diagnosis.

CONTEXTO: O diagnóstico correto e o tratamento eficaz da infecção pelo Helicobacter pylori são essenciais no controle desta infecção. OBJETIVO: Comparar o valor de três testes de diagnóstico baseado em biopsias gástricas endoscópicas: avaliação histopatológica com hematoxilina-eosina (H-E), teste da urease e cultura microbiológica para a detecção da infecção ativa pelo H. pylori, com a finalidade de recomendações para a clínica diária prática. MÉTODOS: Biopsias gástricas de 115 pacientes (85 mulheres e 30 homens) foram obtidas por endoscopia digestiva alta e estudadas por avaliação histopatológica com H-E (antro-corpo), teste de urease em 2 horas (antro) e cultura microbiológica (antro). RESULTADOS: Infecção ativa pelo H. pylori foi diagnosticada em 67 por cento dos pacientes e detectada pela avaliação histopatológica com H-E, pelo teste de urease e pela cultura microbiológica em 87 por cento, 79 por cento e 70 por cento dos casos positivos, respectivamente. Houve diferenças significativas quando a avaliação histopatológica com H-E e o teste rápido de urease quando comparadas com a cultura microbiológica (P<0,01). Não houve diferença significativa entre a avaliação histopatológica com H-E e o teste de urease (P = 0,7). O índice kappa para avaliação histopatológica com H-E/teste de urease foi de 0,56, avaliação histopatológica com H-E/cultura microbiológica 0,6, e teste de urease/cultura microbiológica 0,64. CONCLUSÕES: Em condições similares ao estudado, avaliação histopatológica com H-E e teste de urease são os testes mais recomendados para o diagnóstico de infecção ativa pelo H. pylori com base em biopsias endoscópicas. A avaliação histopatológica com H-E é essencial quando exigido o estudo de lesões gástricas. O teste de urease é obrigatório no caso de diagnóstico precoce rápido. A cultura microbiológica pode ser usada em casos de infecção persistente ou complicada, que podem exigir estudos sobre a virulência ou susceptibilidade do Helicobacter aos antimicrobianos. Os casos selecionados podem exigir a combinação de vários testes. Os três testes apresentam bom nível de concordância para o diagnóstico da infecção ativa pelo H. pylori.

Evaluación de la posible asociación entre la presencia de parásitos intestinales y Helicobacter pylori en población infantil de la etnia Warao, Venezuela / Evaluation of the possible association between the presence of intestinal parasites and Helicobacter pylori in children of ethnic Warao

Las infecciones por microorganismos gastrointestinales constituyen hoy en día una de las principales causas de morbilidad y mortalidad en países en vías de desarrollo. Nos planteamos como objetivo evaluar la posible asociación entre la presencia de parásitos intestinales y la infección por Helicobacter pylori, y el comportamiento de anticuerpos séricos y secretores en una población infantil de la etnia Warao del Edo. Delta Amacuro, Venezuela. La presencia de parásitos se determinó por examen microscópico directo de las heces. Los niveles séricos de IgE total, IgG anti H. pylori e IgA anti Giardia duodenalis; y los secretores IgA total y específica a G. duodenalis y H. pylori en muestra de saliva, se determinaron utilizando el método de ELISA. El 65% de los niños estaban parasitados por protozoarios, observándose un 47% de poliparasitismo. Encontramos una mayor seroprevalencia de H. pylori en el grupo de niños no parasitados (46%) comparado con los parasitados (25%) (P<0,05). Sin embargo, los niños seropositivos a H. pylori y parasitados con G. duodenalis mostraron niveles séricos de IgE total mayores que los no parasitados (P<0,01); en contraparte, los niveles de IgA secretora total y especifica a H. pylori y G. duodenalis estaban disminuidos (P<0,05). Es posible que la respuesta inflamatoria generada por Giardia pueda aumentar los niveles de IgE total y disminuir la respuesta de IgA secretora favoreciendo la instauración de la infección por H. pylori.

The infections for gastrointestinal microorganisms represent nowadays one of the major reasons of morbidity and mortality in developing countries. We had evaluated both, the possible association between the presence of intestinal parasites and infection by Helicobacter pylori, and the production of serum and salivary antibodies in Amerindian Warao children from the Orinoco Delta, Venezuela. The prevalence of parasites was determined by faecal examination. The levels of serum antibodies (total IgE, specific anti- H. pylori IgG and anti G. duodenalis IgA) and salivary antibodies (total and specific IgA to G. duodenalis and H. pylori), was determined by ELISA. 65% of the child population was parasitized by protozoos, and a 47% of polyparasitism was observed. We found a major seroprevalence of H. pylori in the group of children not parasitized (46 %) compared with the parasitized ones (25 %) (P<0.05). Nevertheless, the seropositive children to H. pylori and parasitized with G. duodenalis showed levels of total IgE higher than the non parasitized ones (P<0.01); in contrast, levels of total and specific secretory IgA to H. pylori and G. duodenalis were decreased (P<0.05). It is possible that the inflammatory response generated by G. duodenalis infection may increase levels of total IgE and diminish secretory IgA response favoring the establishment of infection by H. pylori.

Anti-Helicobacter pylori activity of plant extracts traditionally used for the treatment of gastrointestinal disorders

The antibacterial activity of plant extracts obtained from Bixa orellana L., Chamomilla recutita L., Ilex paraguariensis A. St.-Hil., Malva sylvestris L., Plantago major L. and Rheum rhaponticum L. has been evaluated against two reference strains and eleven clinical isolates of Helicobacter pylori. All the plant species chosen are used in popular Brazilian cuisine and folk medicine in the treatment of gastrointestinal disorders. Initial screening was made by the disk diffusion test and then minimum inhibitory concentration was determined by the agar dilution method. The results presented in this work demonstrated that among the plant preparations analyzed, B. orellana L., C. recutita L., I. paraguariensis A. St.-Hil. and M. sylvestris L. were capable of inhibiting the in vitro growth of H. pylori.

Propiedades probióticas de Lactobacillus spp aislados de biopsias gástricas de pacientes con y sin infección por Helicobacter pylori / Probiotic properties of Lactobacillus spp isolated from gastric biopsies of Helicobacter pylori infected and non-infected individuals

Background: Gastric microbiota is a complex ecosystem, composed by diverse microorganisms, where H pylori and Lactobacillus are relevant species. Aim: To study the probiotic properties of Lactobacillus spp isolated from gastric biopsies of subjects bearing or not H pylori. Materials and Methods: Gastric biopsies from 197 individuals that consulted for gastrointestinal disorders were cultivated in media specific for H pylori and Lactobacillus spp. Probiotic properties of lactobacilli isolates and histological diagnosis of H pylori colonized patients were performed. Results: Among 197 individuals evaluated, Hpylori was detected in 43 percent, Lactobacillus spp in 24 percent, while 8 percent presented both bacteria simultaneously. Forty one percent of the Lactobacillus spp strains produced hydrogen peroxide, S'3 percent presented a highly hydrophobic surface and 32 percent had an inhibitory effect upon Hpylori ATCC 43504, even greater than Lactobacillus LGG or LAL reference strains. The main pathological diagnosis of patients ivas chronic non-atrophic gastritis (73 percent) followed by intestinal metaplasia (19 percent). A similar proportion of both conditions were observed in patients colonized by Lactobacillus spp, while not colonized individuals developed preferentially chronic non-atrophic gastritis (p =0.002). Conclusions: Lactobacillus spp and H pylori were mutually excluded, suggesting a competitive colonization model between probiotic bacteria and pathogens.

Helicobacter pylori infection in children with growth failure

To examine if helicobacter pylon infection has a role in growth failure in children. 26 children patients with growth failure and 14 normally growing children of the same age group. socioeconomic level and sex ratio as controls were included in the study. All were subjected to full history taking, clinical examination, anthropometry, laboratory investigations and upper endoscopy with gastric biopsy taking for diagnosis M helicobacter pylon infection by histopathology. Positive cases for helicobacter pylon infection were treated by eradication therapy; the group of children with growth failure were followed for 6 months and reevaluated. Helicobacter pylon infection was diagnosed in 77% of children with growth failure, while it was diagnosed in 43% of normal children [p<0.05]. After 6 months of eradication therapy, there was significant increase in height, weight and hemoglobin [p<0.001 for each]. Helicobacter pylon infection is a causative factor in growth failure in children

Assessment of helicobacter pylori viability by flow cytometry

Flow cytometry is a rapid, sensitive, and reliable method for determination of bacterial viability. Here we assayed the capability of flow cytometry to detect Helicobacter pylori viable cells in both forms of spiral and coccoid. Viable bacteria stained with Rhodamin 123 and fluoresced with laser beam of 488nm. The rate of Rh123 absorption was determined in both forms of bacteria. In positive control that consisted of live bacteria, the rate of rh123 absorption was at highest, but negative control that consisted of dead bacteria, the rate of Rh 123 absorption was at lowest absorption. This method showed that non-culturable coccoid forms of H. pylori, which could resist environmental stresses, were alive and might be responsible for bacterial transmission and failure in disease treatment. Due to simplicity, reliability, and sensitivity of flow cytometry, this method is preferred to other expensive and no reliable methods such as autoradiography, PCR and Electron microscopy used for assessment viability

Infeccion por Helicobacter pylori en pediatria / Infection by Helicobacter pylori in pediatria

Al abordar el tema de infección por Helicobacter pylori, es sorprendente encontrar reportes de la literatura mundial, en los cuales la infección en los niños son altas; encontrando tasas de prevalencia de hasta el 80 por ciento en países subdesarrollados y en reportes locales de hasta el 61 por ciento. Estos datos abren un panorama de estudio, con el fin de identificar el momento de infección de la población infantil, vías de transmisión, métodos diagnósticos, tratamiento y dilucidar procesos fisiopatológicos que finalmente llevan a un cáncer gástrico que muy seguramente se gesto desde la infección en la niñez. Este evento final, nos da la importancia de realizar estudios de detección sensibles y específicos en población en riego, siendo la prueba de aliento marcada con carbono 13, el parámetro de oro para el diagnóstico. Queda pues, por parte de entes público el mejoramiento de la distribución y desechos del agua y de organismos de salud la educación de la enfermedad. La vacuna, continua siendo motivo de estudio.Palabras clave: Helicobacter pylori, pediatría, diagnóstico, tratamiento de erradicación. Campuzano-Maya G. Infección por Helicobacter pylori en pediatría. Medicina & Laboratorio 2005; 11: 39-78.

The influence of endoscopic procedures upon the contamination of Helicobacter pylori cultures

RACIONAL E OBJETIVOS: Dentre os vários métodos diagnósticos empregados na detecção da infecção por Helicobacter pylori, o diagnóstico histológico e a análise microbiológica de biopsia gástrica são consideradas as técnicas mais sensíveis. Entretanto, a sensibilidade da cultura de H. pylori pode ser reduzida pela presença de outras bactérias. Desse modo, avaliou-se a eficácia da desinfecção do endoscópio e a influência dos procedimentos endoscópicos na contaminação da cultura bacteriana. Para tal, as duas primeiras endoscopias durante 28 dias consecutivos foram estudadas. A sala de endoscopia, o fórceps e o canal do endoscópio foram analisados antes e depois do início dos procedimentos endoscópicos rotineiros. Depois da desinfecção, uma simulação de coleta de biopsia foi realizada para verificar a presença das bactérias gástricas. RESULTADOS: A desinfecção do endoscópio foi capaz de remover todos os organismos do fórceps e do canal do endoscópio. As bactérias não-H. pylori mais freqüentemente detectadas foram Streptococcus bovis, Enterobacter hormaechei e Staphylococcus aureus. Em alguns casos a sensibilidade da cultura do H. pylori foi reduzida pela presença de bactérias contaminantes. CONCLUSAO: Não houve risco de transmissão de microorganismos quando fórceps esterilizados e desinfecção adequada foram empregadas. A presença de S. bovis e E. hormaechei parece ser comum na microflora gástrica; por outro lado, a detecção de P. aeruginosa e S. aureus indica que a manipulação de biopsias pode ser responsável pela contaminação da cultura por essas bactérias.

Inhibitory effect of Lactobacillus acidophilus on Helicobacter pylori in peptic ulcer patients: in vitro study.

Lactobacillus acidophilus (L. acidophilus) have been introduced into many fermented dairy products. The presence of L. acidophilus appears to decrease Helicobacter pylori (H. pylori) density in the human stomach and could enhance antibiotic therapy for H. pylori eradication. This study was designed to determine the optimal density of L. acidophilus that has a maximum inhibitory effect on H. pylori in peptic ulcer patients. To determine whether L. acidophilus has an inhibitory effect on H. pylori isolated from peptic ulcer patients and to determine whether the optimal density of L. acidophilus has a maximum inhibitory effect on H. pylori isolated from peptic ulcer patients. H. pylori was isolated from gastric biopsy specimens of peptic ulcer patients. The suspension of pure H. pylori colonies were inoculated into the broth and adjusted to match the density of No.3 MacFarland standard (approximately 9x10(8) cells/ml). Forty microliters of the suspension were equally spread onto each quadrant of the plate and left to dry. L. acidophilus was prepared from LC-1 (Nestle Research Center, Switzerland). They were grown on blood agar and incubated overnight at 37 degrees C. The suspension of L. acidophilus was inoculated into the broth and adjusted to match the density of No.1, No.2, No.3 and No.4 MacFarland standard (approximately 3x10(8), 6x10(8), 9x10(8) and 12x10(8) cells/ml respectively). Ten microliters of each density of L. acidophilus was dropped onto each quadrant of a previously inoculated H. pylori plate and then the plate was kept under microaerophilic conditions for 72 hours. Inhibition clear halo zone of H. pylori around the colonies of L. acidophilus was interpreted as the inhibitory effect. H. pylori were isolated from gastric biopsy specimens of fifteen peptic ulcer patients (eleven patients with gastric ulcer and four patients with duodenal ulcer). A total of sixty tests of inhibitory effect of L. acidophilus on H. pylori were evaluated in the present study. L. acidophilus had inhibitory effect on H. pylori in 13/15 patients (86.67%) and L. acidophilus in the density of No.3 MacFarland standard had a significantly higher inhibitory effect on H. pylori in the density of No.3 MacFarland than that of No.1 (60% vs 20%; p<0.05), No.2 (60% vs 20%; p<0.05) and No.4 (60% vs 20%; p<0.05) MacFarland standard. In conclusion, L. acidophilus has an inhibitory effect on H. pylori isolated from peptic ulcer patients. Approximately an equal density of L. acidophilus on H. pylori has the most favorable effect. This optimal density of L. acidophilus should have maximum effect on H. pylori clearance and could enhance antibiotic therapy for H. pylori eradication in humans.

The Effect of the Repeated Subcultures of Helicobacter pylori on Adhesion, Motility, Cytotoxicity, and Gastric Inflammation

In vitro subcultures of bacteria can lead to genetic and phenotypic changes. This study aimed at investigating the effect of repeated subcultures on the adhesion, motility, cytotoxicity, and gastric inflammation caused by Helicobacter pylori. H.pylori SS1 strain was subcultured 64 times on agar plates containing Brucella broth and 5% bovine calf serum. The adhesion, motility, cytotoxicity, and gastric inflammation produced in Mongolian gerbils were compared between the first and 64th subcultured strain. The adhesion rates, following 3 hr exposure of AGS cells to either the first strain or the 64th-transferred strain, were 21% and 12%, respectively. The motility of the 64th-transferred strain decreased significantly when compared to the 1st strain (9.1 mm vs. 15.1 mm). The cytotoxicity index tended to be higher in the first strain than in the 64th-transferred strain (73.7% vs. 69.2%). The initial infection rate on the gerbils showed no difference between the two strains. However, chronic gastric inflammation of the first strain-infected gerbils was somewhat more severe than that of the 64th-transferred strain-infected gerbils. Therefore, the use of repeatedly subcultured strains of H. pylori in virulence experiments can lead to different results from thoses of the original strain.

14C-urea breath test for assessment of gastric Helicobacter pylori colonization and eradication.

BACKGROUND AND OBJECTIVE: Urea breath test (UBT) is a reliable noninvasive technique for detecting gastric Helicobacter pylori colonization. 14C isotope-based test requires simple equipment and is inexpensive. We studied the utility of 14C-UBT in diagnosis of gastric H. pylori infection. METHODS: Presence of H. pylori was studied using antral histology and culture in patients with rapid urease test (RUT)-positive peptic ulcer. 14C-UBT was performed using a 185-kBq dose. Radioactivity in 15-min breath samples was measured using a beta-scintillation counter and result expressed as % dose recovered/mmol CO2. H. pylori was considered positive when any two tests were positive. All tests were repeated one month after completion of H. pylori eradication therapy. RESULTS: Among 41 patients (duodenal ulcer 36, gastric ulcer 5), H. pylori was detected by histology in 23 (56%) and by culture in 27 (66%). Overall, H. pylori was detected in 28 (68%) patients. Follow-up assessment was possible in 28 patients: 26 cleared the infection (all three tests negative). Mean 14C recovery values at 15 minutes associated with H. pylori-positive status were significantly higher (12.3 [SD 6.8] x 10(-3); n=30; p<0.001) than those associated with H. pylori-negative status (2.1 [0.9] x 10(-3); n=26). Using receiver-operating-characteristic analysis of 15-minute 14C recovery values, a cut-off of 6.5x10(-3) gave the best separation of H. pylori-positive and -negative cases. 14C-UBT had 93% sensitivity, 96% specificity and 95% accuracy. CONCLUSION: 14C-UBT appears to be a reliable noninvasive test for diagnosis of H. pylori infection.

Ursodeoxycholic acid does not interfere with in vivo Helicobacter pylori colonization

A low frequency of Helicobacter pylori in the gastric mucosa of patients with alkaline gastritis has been reported. At the same time, it can be noted that the growth of bacteria can be inhibited by bile acids. We studied 40 patients with chronic gastritis related to Helicobacter pylori in order to determine the effect of ursodeoxycholic acid on this infection. Diagnoses of the infection and the inflammatory process were obtained by histologic study of gastric biopsies collected during endoscopy. Two groups were studied: group I received ursodeoxycholic acid - 300 mg/day, and group II received the placebo, twice a day, both for 28 days. The colonization by Helicobacter pylori and the intensity of the mononuclear and polymorphonuclear inflammatory infiltrate were determined before (time 1) and after (time 2) treatment. Ursodeoxycholic acid had no effect on the Helicobacter pylori infection. A significant reduction in the intensity of the mononuclear inflammatory infiltrate of the gastric antrum mucosa was observed in patients from group I, when we compared not only times 1 and 2 but also groups I and II. However, this was not the case with the body mucosa. We concluded that ursodeoxycholic acid had no action on the colonization by Helicobacter pylori or on the polymorphonuclear inflammatory infiltrate, but it caused a significant reduction in the intensity of the mononuclear inflammatory infiltrate of the gastric antrum