Simplified techniques for identifying Campylobacter pyloridis.

Gray, Sanjiv; Wyatt, J I; Rathbone, B. J.

doi:10.1136/jcp.39.11.1279-a

Cited by 145 publications

(49 citation statements)

References 2 publications

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“…Histologic parameters were scored from 0 to 3 as outlined in the Sydney System and included assessment of the degree of activity (neutrophil infiltration), lymphocyte and plasma cell infiltration, epithelial degeneration, mucus depletion, epithelial erosion, glandular atrophy, intestinal metaplasia, and colonization density, as previously described (26). Modified Giemsa stain was used for identification of H. pylori (17).…”

Section: Materials and Methods Clinical Specimensmentioning

confidence: 99%

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Peek¹,

Doorn

Donahue

et al. 2000

Infect Immun

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The iceA locus of Helicobacter pylori includes one of two mutually exclusive gene families, iceA1 and iceA2. Colonization with iceA1 strains is associated with enhanced acute mucosal inflammation, and adherence to gastric epithelial cells in vitro induces expression of iceA1 but not iceA2 mRNA; however, both transcripts can be detected in vivo. The aim of this study was to determine whether differing levels of iceA transcription in vivo may contribute to disease pathogenesis. RNA from 41 H. pylori-positive gastric biopsy specimens was reverse transcribed to cDNA. Quantitative PCR was performed using biotinylated iceA1, iceA2, and 16S rRNA primers, and binding of biotinylated products to streptavidin-coated plates was detected by hybridization with a fluoresceinlabeled probe. iceA genotypes were determined by PCR and sequence analysis. All 41 samples contained detectable H. pylori 16S rRNA, with similar levels in iceA1-(n ‫؍‬ 10) and iceA2 (n ‫؍‬ 31)-colonized patients (P ‫؍‬ 0.34). Biopsy specimens from four (40%) and 19 (61%) persons colonized with iceA1 or iceA2 strains, respectively, had detectable iceA RNA. Acute inflammatory scores were significantly higher in iceA1 RNA-positive patients than in iceA1 RNA-negative, iceA2 RNA-positive, or iceA2 RNA-negative subjects (P < 0.05 for each). Within the iceA2 RNA-positive group, H. pylori strains with a single 35-amino-acid cassette were associated with significantly higher mucosal iceA2 transcript levels (P ‫؍‬ 0.014 versus strains with two cassettes). These results indicate that the levels of transcription of H. pylori iceA1 and iceA2 and of 16S rRNA are independent and that particular iceA2 gene structures are associated with enhanced transcription. The finding that iceA1 transcription levels are significantly associated with the intensity of neutrophilic infiltration suggests that heterogeneity in inflammatory scores among persons colonized with H. pylori iceA1 strains reflects levels of iceA1 transcription in vivo.Helicobacter pylori induces gastric inflammation in virtually all colonized individuals, and such gastritis increases the risk for peptic ulcer disease and distal gastric adenocarcinoma (8,14,15,21,23,27). However, only a minority of persons carrying H. pylori develop clinical sequelae, suggesting that particular bacterial products may contribute to pathogenesis (4). The first strain-specific gene identified in H. pylori was cagA, a component of the cag pathogenicity island (1, 7, 9, 30); persons colonized with H. pylori cagA-positive strains are at increased risk for developing peptic ulceration and distal gastric cancer compared to persons harboring cagA-negative strains (5, 10-12, 22, 24, 29). The gene vacA represents a second H. pylori locus of heterogeneity, and strains that possess a vacA s1 signal sequence allele are also associated with peptic ulcer disease (3, 32). However, the majority of persons colonized with cagA ϩ vacA s1 strains remain asymptomatic, suggesting that additional H. pylori genes may also be important in disease pathogenes...

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Section: Materials and Methods Clinical Specimensmentioning

confidence: 99%

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Peek¹,

Doorn

Donahue

et al. 2000

Infect Immun

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“…Methods such as culture (4), determination of the presence of the microorganism in stained smears (5) and in histological sections (6), the preformed urease test (7) and PCR (8) require esophagogastroduodenoscopy to obtain fragments of gastric mucosa and, although sensitive and specific, are not indicated for epidemiological surveys. The methods most often used for this purpose are the detection of serum antibodies (9,10) and the respiratory test with 13 C-labelled urea (11).…”

Section: Introductionmentioning

confidence: 99%

Serodiagnosis of Helicobacter pylori infection by Cobas Core ELISA in adults from Minas Gerais, Brazil

Rocha¹,

Oliveira²,

Queiroz³

et al. 1998

Braz J Med Biol Res

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We evaluated the accuracy of a 2nd generation ELISA to detect Helicobacter pylori infection in adults from a developing country in view of variations in sensitivity and specificity reported for different populations. We studied 97 non-consecutive patients who underwent endoscopy for evaluation of dispeptic symptoms. The presence of H. pylori was determined in antral biopsy specimens by culture, by the preformed urease test and in carbolfuchsin-stained smears. Patients were considered to be H. pylori positive if at least two of the three tests presented a positive result or if the culture was positive, and negative if the three tests were negative. Sixty-five adults (31 with peptic ulcer) were H. pylori positive and 32 adults were H. pylori negative. Antibodies were detected by Cobas Core anti-H. pylori EIA in 62 of 65 H. pylori-positive adults and in none of the negative adults. The sensitivity, specificity and positive and negative predictive values of the test were 95.4, 100, 100 and 91.4%, respectively. The Cobas Core anti-H. pylori EIA presented high sensitivity and specificity when employed for a population in Brazil, permitting the use of the test both to confirm the clinical diagnosis and to perform epidemiologic surveys.

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“…Durante la endoscopia se tomaron 7 biopsias gástricas: tres en la región prepilórica (1-2 cm del píloro), dos en el cuerpo gástrico (curvatura mayor y cara posterior), una de la incisura angularis y una del cardias. Una muestra de cuerpo y una de antro se fijaron inmediatamente en formalina al 10% por separado para estudio histopatológico y las otras 5 se colocaron en viales para cultivo (16,27 Histología Las dos muestras de biopsia fijadas en formalina al 10%, fueron teñidas de forma rutinaria con hematoxilinaeosina y Giemsa modificada (17,18). La revisión de laminillas fue asignada en forma ciega y al azar a un grupo de patólogos experimentados.…”

Section: Endoscopia Gastrointestinal Alta Y Biopsiasunclassified

Validación de método simplificado de la prueba en aliento con urea-13C para diagnóstico de infección por Helicobacter pylori

Ortiz-Olvera¹,

Villota²,

Wong³

et al. 2007

Rev. esp. enferm. dig.

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INTRODUCCIÓNLa infección por Helicobacter pylori (H. pylori) es la causa principal de gastritis y enfermedad ulcerosa en adultos, y se ha asociado al desarrollo de cáncer y linfoma gástrico (1). Para el diagnóstico se cuenta con diferentes métodos: los invasivos que requieren la realización de endoscopia y toma de biopsia para estudio histopato- RESUMENObjetivo: validar un método simplificado de la prueba en aliento con urea-13 C (PAU-13 Cs) para el diagnóstico de infección por Helicobacter pylori (H. pylori), con administración simultá-nea de 50 mg de urea-13 C y 2 g de ácido cítrico. Material y métodos: se estudiaron 88 pacientes (49 mujeres y 39 hombres); con promedio de edad 45 ± 15 años, referidos para endoscopia gastrointestinal y toma de biopsias. La PAU-13 Cs se realizó en ayuno. Se recolectaron las muestras de aire espirado en tubos de cristal de 10 ml, antes y 30 minutos después de administrar simultáneamente 50 mg de urea-13 C y 2 g de ácido cítrico disueltos en 200 ml de agua. Las muestras se analizaron por espectrometría de masas. El diagnóstico de infección se consideró cuando el cultivo y/o la biopsia y serología fueron positivas para H. pylori.Resultados: cincuenta y un pacientes (57,95%) fueron positivos, 30 (34,10%) negativos para H. pylori y 7 (7,95%) casos se consideraron indeterminados. La sensibilidad, especificidad, valor predictivo positivo y negativo de PAU- Conclusión: la administración simultánea de 50 mg de urea-13 C y 2 g de ácido cítrico, representa una alternativa para el diagnóstico no invasivo de infección por H. pylori, debido a que conserva la certeza diagnóstica de la PAU-13 C.Palabras clave: Helicobacter pylori. Urea-13 C. Prueba en aliento. Ácido cítrico. ABSTRACTObjective: to validate a simplified 13 C-urea breath test ( 13 C-UBT) method for the diagnosis of H. pylori infection.Material and methods: patients referred for gastrointestinal endoscopy and biopsy were included, and a 13 C-UBT was performed after a 6-hour fast. Breath samples were collected in 10 ml glass tubes before and 30 min after the simultaneous administration of 50 mg of 13 C-urea and 2 g of citric acid in 200 ml of water. All breath samples were analyzed using isotope ratio mass spectrometry. The diagnosis of H. pylori infection was established with a positive culture and/or positive histology and serology.Results: eighty-eight patients were included, 49 female and 39 male with a mean age of 45 ± 15 yrs. Fifty-one patients (57.95%) were positive and 30 (34.1%) negative for H. pylori. Seven cases (7.95%) were considered undetermined. The sensitivity, specificity, positive predictive value, and negative predictive value for 13 C-UBT were 90.2, 93.3, 95.83, and 84.8%, respectively. Accuracy was 91.4%.Conclusions: the simultaneous administration of 50 mg of 13 C-urea and 2 g of citric acid represents an alternative for the non-invasive diagnosis of H. pylori infection.

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Simplified techniques for identifying Campylobacter pyloridis.

Cited by 145 publications

References 2 publications

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Quantitative Detection of Helicobacter pylori Gene Expression In Vivo and Relationship to Gastric Pathology

Serodiagnosis of Helicobacter pylori infection by Cobas Core ELISA in adults from Minas Gerais, Brazil

Validación de método simplificado de la prueba en aliento con urea-13C para diagnóstico de infección por Helicobacter pylori

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