How come I've got it? (A review of Helicobacter pylori transmission).
ABSTRACT Numerous epidemiological studies have shown the two main risk factors for Helicobacter pylori acquisition: childhood and low socio-economic level both in developing and developed countries. Nevertheless, in the absence of ubiquitous extra-human reservoir(s), the route(s) for person-to-person transmission remains undetermined. Very recent data favour the oro-oral route: besides gastric mucosa, mouth might be a sanctuary site and the oro-oral transmission hypothesis seems applicable worldwide. Nevertheless, the gastro-oral route (vomiting, gastro-oesophageal reflux) is still possible and deserves further research. In developing countries, feco-oral transmission (perhaps through the water supply) might be a significant mechanism of human contamination both for primary infection in children and perhaps, reinfection in adults.
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ABSTRACT: Helicobacter pylori (H. pylori), a common infectious bacterium, has been linked to chronic gastritis, peptic ulcer and gastric cancer. Several invasive and noninvasive techniques are currently used for detecting H. pylori infection. Molecular approaches based on DNA amplification by polymerase chain reaction (PCR) have been developed for the detection of H. pylori in clinical samples but are used only in the research setting. Our objective is to comparatively evaluate the efficiency of using PCR technique for diagnosis of H. pylori infection through determination of glmM gene, and the rapid urease test (RUT), with reference to histological detection of H. pylori as the gold standard. Two hundred gastric biopsy specimens from the antrum of 50 dyspeptic patients were subjected to histology, RUT and PCR; targeting the glmM gene. No age or gender difference regarding H. pylori infection was observed, H. pylori colonization was detected in 82% of cases. The sensitivity and specificity of the RUT and PCR for glmM methods in comparison to histology are as follows: 87.80% and 88.89%; 65.9% and 44.4%, respectively. Histology demonstrating the highest detection rate among cases with superficial gastritis and gastroduodenitis (82% and 80%) compared to RUT (65.5% and 70%) and glmM gene that was expressed in 41.4% and 40% respectively. Colonization of the gastric mucosa by H. pylori was detected in 61.9% of the patients with chronic superficial gastritis, While, RUT was positive in 38.1% of them. Nearly the same percentages were observed for histology and RUT in the other histopathological findings. Similar percentage for glmM gene as RUT was detected in chronic superficial gastritis and in 38.1%, 33.3% of intestinal metaplasia and gastric dysplasia, respectively, while it is not expressed in chronic gastric ulcer and atrophic gastritis. Therefore, we conclude that PCR for glmM gene could be a method with diagnostic value. Nevertheless, histology and RUT were found to be relatively reliable methods for examining gastric biopsy specimens. The low percentage of glmM gene reported here may be attributed to polymorphism and diversity of glmM gene of H. pylori. Therefore, further studies are required to search for the specific sequence of the glmM gene or the presence of mutation in H. pylori strains in Egypt. Key Words: H. pylori; glmM gene; rapid urease test; PCR.Egyptian J Medical Microbiology. 10/2009; 18(4):118-130.
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ABSTRACT: Helicobacter pylori colonizes the stomachs of at least half of the world's human population. The role of the oral cavity in this colonization is not clear and there are, to date, no comprehensive data that clearly demonstrate the isolation of this bacterium from the oral cavity. The aim of this study was to evaluate the prevalence of H. pylori in the oral cavity of 15 patients who tested positive for H. pylori. A comprehensive dental examination of all patients was conducted. Samples were taken from supragingival and subgingival plaque, saliva, periapical exudates and tongue swabs. All samples were taken before the application of antibiotics. A total of 163 oral samples were investigated by PCR using two different H. pylori-specific primer pairs. A PCR inhibition control using a modified plasmid was always included for the most specific primer pair. In addition, a culture technique was used to confirm PCR results. Despite a PCR detection limit of 10(2) bacteria ml(-1), out of 14 patients, H. pylori could not be detected in any of the samples taken. In one patient, H. pylori-positive PCR signals were obtained in two samples using only one primer pair. H. pylori could not be cultivated from these two PCR-positive samples; therefore, no correlation to oral colonization status could be established. This study challenges the misleading preconception that H. pylori resides in the human oral cavity and suggests that this bacterium should be considered transient and independent of the oral status. To date, positive PCR results for H. pylori in the oral cavity have been overestimated and not critically interpreted in literature.Journal of Medical Microbiology 04/2012; 61(Pt 8):1146-52. · 2.30 Impact Factor
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ABSTRACT: The aim of this study is to examine retrospectively the clinical, biological and treatment features of anemia by vitamin B12 deficiency in the Hematology department of CHU Mohamed VI Marrakech. We report the results of a retrospective study conducted during six years (2005-2010). It included all patients with anemia (with or without thrombocytopenia or leukopenia) associated with vitamin B12 levels <200 pg / ml. One hundred twenty one cases were analyzed. The average age of patients was 62 years (38-89 years) with a female predominance (sex ratio F/M: 1.3). The clinical symptomatology is dominated by pallor (97.5%), cardiovascular signs (46%) and digestive symptoms (34.7%). Neurological signs were noted in 17.3% of cases. The blood count showed anemia (hemoglobin: mean= 6.9 g/dl), macrocythemia (MCV: mean= 109 fl). Leukopenia was noted in 35 patients (29%), thrombocytopenia in 34 patients (28%) and pancytopenia in 21 patients (17,3%). The average vitamin B12 was 72 pg/ml. The causes of B12 deficiency are pernicious anemia (43%), food-cobalamin malabsorption (43%), and in 14% of cases no etiology was found. Gastritis was found in 82.7% of our patients and Helicobacter pylori (HP) infection in 72.7% of cases. Reticulocyte crisis was observed after parenteral administration of hydroxocobalamine within an average of 8 days and normalization of blood counts, in all patients, within an average of 51 days. In patients with HP infection, eradication therapy of HP was performed. The cure rate of the HP is 90%.Bulletin de la Société de pathologie exotique 03/2013;