Characteristics of Helicobacter pylori infection in Jamaican adults with gastrointestinal symptoms

Department of Pediatrics, Emory University, Atlanta, Georgia, United States
Journal of Clinical Microbiology (Impact Factor: 4.23). 02/2001; 39(1):212-6. DOI: 10.1128/JCM.39.1.212-216.2001
Source: PubMed

ABSTRACT Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this population. To address this issue, we examined the presence of H. pylori infection in 30 sequential adult patients with gastroduodenal symptoms by three biopsy-based methods (rapid urease test, histology, and culture) as well as by one research and two commercial enzyme-linked immunosorbent assays (ELISAs). A patient was considered H. pylori positive if the organism was detected by at least one biopsy-based method. Eighteen (60%) of the 30 patients were H. pylori positive by these criteria, whereas 21 (70%) were seropositive for H. pylori immunoglobulin G by our research ELISA. The presence of H. pylori infection in patients with gastric cancer and those with chronic gastritis was missed by biopsy-based methods but was detected by serologic assays. This observation indicates that serologic assays may be better suited for the detection of this infection in a population in which H. pylori-associated pathology is prevalent. The performance of our research ELISA in detecting biopsy-based H. pylori-positive cases was excellent, with a sensitivity and specificity of 100% and 75%, respectively. Molecular genotyping of the isolates revealed that the predominant H. pylori genotypes in this cohort of Jamaicans were cagA(+) vacA slb-m1, and iceA2. The validated serologic assay enables us to interpret epidemiologic data from population-based studies in Jamaica by comparison to those from other populations.


Available from: Masayuki Hisada, Feb 03, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Helicobacter pylori induces chronic gastritis, the strongest known risk factor for peptic ulcer disease, distal gastric cancer and a number of extra gastric related morbidity. More than 50% of the world's population is infected with this organism lifelong without effective bacterial eradication. Clinical sequelae are dependent upon bacterial virulence factors and host genetic diversity, particularly within immune response genes. The organism is able to evade the harsh acidic environment in the gastric mucosa and host immune response by elaborating a number of factors that aid in the achievement of its persistent colonization. H. pylori possess numerous virulence proteins (cagA, vacA and iceA) and enzymes (urease, catalase, lipase, phospholipase and proteases) with substantial genotypic diversity, which engenders differential host inflammatory responses that influence the pathologic outcome. The hallmark of H. pylori infection is a marked inflammatory response with the infiltration of various immune cells into the infected gastric mucosa; with a polarized Th1 immune response which further attracts inflammatory cells to the gastric mucosa leading to damage. Knowledge on H. pylori reservoirs and transmission remains elusive. However, studies have described the gastro-oral, oral-oral and faecal-oral as possible routes of acquisition and transmission. This paper provides an understanding of H. pylori persistence and pathogenesis as well as its route of transmission.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although the incidence of gastric cancer in the Dominican Republic is not high, the disease remains a significant health problem. We first conducted a detailed analysis of Helicobacter pylori status in the Dominican Republic. A total of 158 patients (103 females and 55 males; mean age, 47.1 ± 16.2 years) were recruited. The status of H. pylori infection was determined based on 4 analyses: rapid urease test, culture test, histological test, and immunohistochemistry. The status of cagA and vacA genotypes in H. pylori was examined using PCR and gene sequencing. The overall prevalence of H. pylori infection was 58.9%. No relationship was found between the H. pylori infection rate and the age range of 17 to 91 years. Even in the youngest group (patients aged less than 29 years), the H. pylori infection rate was 62.5%. Peptic ulcer was found in 23 patients, and gastric cancer in 1 patient. The H. pylori infection rate in patients with peptic ulcer was significantly higher than that in patients with gastritis (82.6 vs. 54.5%, P < 0.01). The cagA-positive/vacA s1m1 genotype was the most prevalent (43/64, 67.2%). Compared to H. pylori-negative patients, H. pylori-positive patients showed more severe gastritis. Furthermore, the presence of cagA was related to the presence of more severe gastritis. All CagA-positive strains had Western-type CagA. In conclusion, we found that H. pylori infection is a risk factor for peptic ulcer in the Dominican Republic. Patients with cagA-positive H. pylori could be at higher risk for severe inflammation and atrophy. .
    Journal of Medical Microbiology 06/2014; 63. DOI:10.1099/jmm.0.075275-0 · 2.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A number of scientific breakthroughs since H pylori first became recognized as a human pathogen have increased our understanding of the pathogenesis of gastroduodenal disease. In particular, advances in molecular bacteriology and the complete sequencing of the H pylori genome in 1999, and soon thereafter the human genome, provide tools allowing better delineation of the pathogenesis of disease. These molecular tools for both bacteria and host should now be applied to multicenter pediatric studies that evaluate disease outcome. More recent developments indicate that a better understanding of the microbial-host interaction is critical to furthering knowledge with respect to H pylori-induced diseases. Studies are needed to evaluate either DNA-based or more traditional protein-based vaccines, to evaluate more specific antimicrobials that confer minimal resistance, and to evaluate probiotics for the management of H pylori infection. Multicenter multinational studies of H pylori infection in the pediatric population, which include specific, randomized controlled eradication trials, are essential to extend current knowledge and develop better predictors of disease outcome.
    Current Problems in Pediatric and Adolescent Health Care 09/2001; 31(8):247–266. DOI:10.1067/mps.2001.118485