Factors Associated with<i>Helicobacter pylori</i>Infection by a<i>cag</i>A‐Positive Strain in Children

Queiroz, Dulciene Maria Magalhães; Mendes, Edilberto Nogueira; Carvalho, Anfrisina S. T.; Rocha, Gifone A.; Oliveira, Andreia M. R.; Soares, Taciana F.; Santos, Adriana Cavalcanti dos; Cabral, Mônica Maria Demas Álvares; Nogueira, Ana Margarida Miguel Ferreira

doi:10.1086/315262

Cited by 63 publications

(69 citation statements)

References 31 publications

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“…Analysis of the different diseases showed a higher frequency of the cagA gene in H. pylori-positive patients with duodenal ulcer compared to patients with gastritis, gastric ulcer and gastric cancer. Queiroz et al (24) found that, in Brazil, 95.0% and 62.3% of strains isolated from children with and without duodenal ulcers are cagA-positive, respectively. Other studies have reported a higher frequency of the cagA gene in H. pyloripositive patients with peptic ulcer and gastric cancer (17,33,38) .…”

Section: Frequency Of Different Genotypes In Patients With Gastrointementioning

confidence: 99%

Helicobacter Pylori Infection in Patients With Different Gastrointestinal Diseases From Northern Brazil

Vinagre

Queiroz

Júnior³

et al. 2015

Arq. Gastroenterol.

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-Background -The mechanisms whereby Helicobacter pylori produces different pathological manifestations in the stomach and duodenum are not fully understood. Considering the geographic diversity in the prevalence of virulence factors of this microorganism and their association with the development of different diseases, the search for pathogenicity markers such as CagA and VacA alleles by molecular techniques has intensified. Objectives -To investigate the presence of H. pylori infection and the frequency of different genotypes of this bacterium in patients with gastrointestinal diseases from Northern Brazil, and to establish their association with the histopathological findings. Methods -In a prospective study, samples were collected from 554 patients with different gastrointestinal diseases (gastritis, duodenal ulcer, gastric ulcer, and gastric cancer) seen at a referral hospital attending the entire State of Pará, located in the metropolitan region of Belém. Data such as gender and age obtained with an epidemiological questionnaire were analyzed. The presence of H. pylori and the bacterial genotype were investigated by PCR. Gastric biopsies were assessed histologically. Results -The prevalence of H. pylori infection was 91%. Infection was more frequent among patients with gastric ulcer and gastric cancer. In these groups, there was a predominance of men and older patients when compared to the other two groups studied. The predominant bacterial genotype was s1m1cagA+, which was more frequent among patients with gastric ulcer, duodenal ulcer and gastric cancer. A significant association was observed between s1m1cagA+ strains and a higher degree of inflammation, neutrophil activity and development of intestinal metaplasia. Conclusion -The present study demonstrates a high incidence of H. pylori infection in the patients analyzed, especially among those with gastric ulcer and gastric cancer. Virulent s1m-1cagA+ strains predominated and were associated with more severe lesions. HEADINGS -Helicobacter pylori. Helicobacter infections. Gastrointestinal diseases. Genotype.

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Section: Frequency Of Different Genotypes In Patients With Gastrointementioning

confidence: 99%

Helicobacter Pylori Infection in Patients With Different Gastrointestinal Diseases From Northern Brazil

Vinagre

Queiroz

Júnior³

et al. 2015

Arq. Gastroenterol.

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“…The difference in cagA prevalence between the two patient groups may be due to other virulence-associated genes that are associated with the presence of the cagA gene. One suggestion by a previous report stated that bacterial binding to the fucosylated blood group antigen Lewis b (Le b ) is coded by the babA2 gene and is associated with the presence of the cagA gene [30]. Thus, differences in the prevalence of cagA between the two patient groups may depend on other factors such as the level of Le b expression in biliary and gastric cells.…”

Section: Discussionmentioning

confidence: 99%

Genetic characterization of Helicobacter pylori vacA and cagA genes in Thai gastro-duodenal and hepatobiliary patients

Boonyanugomol

Khuntikeo

Pugkhem

et al. 2017

J Infect Dev Ctries

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Introduction: H. pylori has been detected in patients with hepatobiliary diseases. It is currently unclear whether the H. pylori detected in hepatobiliary patients are genetically similar to those in gastro-duodenal patients. The aim of this study was to determine H. pylori vacA and cagA genotypes in Thai patients with gastro-duodenal and hepatobiliary diseases. Methodology: H. pylori DNA was extracted from samples from gastric biopsies of gastro-duodenal patients (n=100) and from bile samples of hepatobiliary patients (n=80). The vacA and cagA genotypes were performed via polymerase chain reaction (PCR) followed by DNA sequencing. Results: The vacA m1 was found in Thai hepatobiliary patients (90%) at a higher rate compared with gastro-duodenal patients (50%).The combined vacA s1a+c/m1 were mostly found in Thai gastro-duodenal and hepatobiliary patients. The cagA gene was detected in 94% of patients with gastro-duodenal diseases compared with 28.8% in those with hepatobiliary diseases (p<0.05). On the other hand, the Western type cagA was more prominent among hepatobiliary patients (100%) than gastro-duodenal patients (57.4%), and this type was grouped into same cluster with Thai gastro-duodenal patients via phylogenetic analysis. Conclusions: Based on vacA and cagA analysis, we conclude that infection with H. pylori in gastro-duodenal and hepatobiliary patients may be caused by the different H. pylori strains.

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“…Seventy-two (16.5%) H. pylori-positive children had DU. Among them, 52 were included in other studies (6,7).…”

Section: Methodsmentioning

confidence: 99%

“…Because VacA high producer H. pylori strains are also cagA-positive and VacA/cagApositive strain is associated with DU in children in certain populations, cagA was included in the logistic model as the virulence H. pylori marker (6).…”

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confidence: 99%

IL1RN Polymorphism and cagA-Positive Helicobacter pylori Strains Increase the Risk of Duodenal Ulcer in Children

et al. 2005

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Duodenal ulcers in children are associated with Helicobacter pylori gastric infection with cagA-positive strains, but factors linked to the host are poorly known. The authors evaluated the role of proinflammatory interleukin-1 gene cluster polymorphisms in the pathogenesis of duodenal ulcer. They studied prospectively 437 children 1 to years old, 209 of whom were H. pylori positive and 228 of whom were H. pylori negative. IL1B-511-C/T, -31T/C, and IL1RN Variable number of tandem repeats were genotyped by polymerase chain reaction (PCR) restriction fragment length polymorphism, PCR with confronting two-pair primers, and PCR, respectively. cagA status was evaluated by PCR. The role of the proinflammatory cytokine genotypes in the genesis of duodenal ulcer was evaluated before and after stratification of H. pylori status on logistic regression models. In the group of children without duodenal ulcer, no association was observed between H. pylori status and proinflammatory polymorphisms. Furthermore, no association between IL1 cluster genotypes and cagA status was seen in the H. pylori-positive children. However, increasing age, male sex, and IL1RN*2 were independently associated with duodenal ulcer. After stratification, in the H. pylori-positive children, increasing age, male sex, the presence of ILRN*2 allele, and cagA-positive status were independently associated with duodenal ulcer. The risk for the development of duodenal ulcer increased when a combined association of the presence of IL1RN*2 allele and infection by a cagA-positive H. pylori strain was the variable. This study provides evidence supporting independent roles of IL1RN*2 allele and cagA-positive status in the genesis of duodenal ulcer in children. Helicobacter pylori infection is predominantly acquired in childhood and usually persists for life unless treated. In most persons, the natural history of infection is without complications, but peptic ulcer disease, distal gastric carcinoma, or mucosa-associated lymphoid tissue gastric lymphoma will occur in a small percentage of infected individuals (1-3).In children, DU, a severe complication of the infection is much less common than in adults. The pathobiology of the uncommon childhood-onset DU is uncharacterized, but this adverse outcome may be linked to a more marked gastric inflammatory response seen in children with DU than in infected children without DU (4 -6). Contributing factors include host genetics and bacterial virulence markers. In fact, the cagA-PAI and VacA, two of the major bacterial virulence factors involved in host cell modulation, are associated with the disease in childhood (6 -8). Several genes of the cag-PAI code proteins with similarities to components of type IV secretion systems induce an increased inflammation in the gastric mucosa through release of cytokines such as 10). In addition to the VacA properties linked to the gastric mucosa damage, the toxin may increase the inflammatory response of the gastric mucosa by different pathways, such as a recently demonstrated action i...

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Factors Associated withHelicobacter pyloriInfection by acagA‐Positive Strain in Children

Cited by 63 publications

References 31 publications

Helicobacter Pylori Infection in Patients With Different Gastrointestinal Diseases From Northern Brazil

Helicobacter Pylori Infection in Patients With Different Gastrointestinal Diseases From Northern Brazil

Genetic characterization of Helicobacter pylori vacA and cagA genes in Thai gastro-duodenal and hepatobiliary patients

IL1RN Polymorphism and cagA-Positive Helicobacter pylori Strains Increase the Risk of Duodenal Ulcer in Children

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