VacA and CagA Status as Biomarker of Two Opposite End Outcomes of Helicobacter pylori Infection (Gastric Cancer and Duodenal Ulcer) in a Moroccan Population

Helicobacter pylori vacA allelic combination, dupA, cagE and cagA genotypes and their associations with gastric diseases among Moroccan population

The combination of the four regions of vacA with cagA, cagE, dupA genes and cagA-EPIYA motifs, was studied to find the most likely combination that can be used as a disease determinant marker in Moroccan population. A total of 838 H. pylori positive obtained from consenting patients, that were previously analyzed by PCR to characterize vacA-s -m, -i regions, cagE status and cagA 3' region polymorphism, were used to characterize vacA-d region and to determine dupA gene status. The analysis shows the predominance of the less virulent combination (vacA(s2m2i2d2)dupA(-)cagE(-)cagA(-)), and shows that the risk of gastric cancer is 13.33 fold higher (1.06-166.37)) in patients infected by strains harboring vacA(s1m1i1d1)dupA(-)cagE(+)cagA(2EPIYA-C) compared to patients with gastritis without lesions and infected by H.pylori strains harboring vacA(s2m2i2d2)dupA(-)cagE(-)cagA(-). The infection with strains harboring vacA(s1m1i1d1)dupA(+)cagE(+)cagA(1EPIYAC) genotype combination represents a risk factor for gastric ulcer and duodenal ulcer (the Odds Ratio (95% CI) were 16 (1.09-234.24) and 6.54 (1.60-26.69) respectively) compared to patients with gastritis without lesions. These results suggest that the combination of the active form of vacA genotypes, dupA gene status and the number of EPIYA-C motif may be considered helpful markers to discriminate between several gastric diseases.

Helicobacter pylori cagA, vacA, and iceA genotypes and clinical outcomes: a cross-sectional study in central Vietnam

Helicobacter pylori is the most common cause of gastroduodenal diseases. The concept that cagA-positive H. pylori is a risk factor for gastric cancer appears to be true only for H. pylori strains from Western countries. Other virulent genes may have a synergistic interaction with cagA during pathogenesis. This study aims to investigate H. pylori cagA, vacA, and iceA prevalence, genotypes, and their association to clinical outcomes in Vietnamese patients. The cagA status and vacA and iceA genotypes were determined using the PCR technique on DNA extracted from gastric biopsies of 141 patients with gastroduodenal diseases. After performing molecular analysis for cagA, vacA, and iceA genes, samples with mixed H. pylori strains, positivity, or negativity for both cagA and cagPAI-empty site, or unidentified genotypes were excluded. Finally, 107 samples were examined. The presence of the cagA, vacA, and iceA genes were detected in 77.6%, 100%, and 80.4% of cases, respectively. Notably, cagA( +) with EPIYA-ABD, vacA s1i1m1, vacA s1i1m2, iceA1, and iceA2 accounted for 73.8%, 44.9%, 33.6%, 48.6%, and 31.8% of cases, respectively. Four iceA2 subtypes (24-aa, 59-aa, 94-aa, and 129-aa variants) were found, with the 59-aa variant the most prevalent (70.6%). The cagA( +)/vacAs1i1m1/iceA1 and cagA( +)/vacAs1i1m2/iceA1 combinations were found in 26.2% and 25.1% of cases, respectively. A multivariable logistic regression analysis was performed, after adjusting for age and gender, with the gastritis group was used as a reference control. Statistically significant associations were found between the vacA s1i1m2 genotype, the iceA1 variant, and the cagA( +)/vacAs1i1m2/iceA1 combination and gastric cancer; the adjusted ORs were estimated as 18.02 (95% CI: 3.39-95.81), 4.09 (95% CI: 1.1-15.08), and 16.19 (95% CI: 3.42-76.66), respectively. Interestingly, for the first time, our study found that vacA s1i1m2, but not vacA s1i1m1, was a risk factor for gastric cancer. This study illustrates the genetic diversity of the H. pylori cagA, vacA, and iceA genes across geographical regions and contributes to understanding the importance of these genotypes for clinical outcomes.

The Association Between Oral Helicobacter pylori and Gastric Complications: A Comprehensive Review

Helicobacter pylori (H. pylori) is linked to chronic gastritis, duodenal or gastric ulcers, and gastric cancer (GC). Because the oral cavity is the first component of the gastrointestinal tract (GIT) and the entrance point for H. pylori, it has been proposed as a possible reservoir of H. pylori. As a result, a putative oral-oral transmission pathway of H. pylori poses the possibility of whether personal contact, such as kissing or sharing a meal, might trigger H. pylori transmission. As a result, several investigations have been done on this issue using various approaches for detecting H. pylori in oral and stomach samples. Furthermore, the relationship between H. pylori and gastrointestinal disorders has yet to be studied. The evidence for the association between H. pylori and gastric diseases and their complications is still a controversial subject due to the existing literature in this review. The goal of this comprehensive review was to collect all available published articles and critically evaluate existing investigations looking into the relationship between oral H. pylori contamination and the danger of gastric complications. Few studies indicated an association between H. pylori and gastric diseases. Furthermore, more longitudinal randomized clinical studies to further investigate the association between H. pylori and gastric diseases are warranted.

Genome-wide association study of gastric cancer- and duodenal ulcer-derived Helicobacter pylori strains reveals discriminatory genetic variations and novel oncoprotein candidates

Genome-wide association studies (GWASs) can reveal genetic variations associated with a phenotype in the absence of any hypothesis of candidate genes. The problem of false-positive sites linked with the responsible site might be bypassed in bacteria with a high homologous recombination rate, such as Helicobacter pylori, which causes gastric cancer. We conducted a small-sample GWAS (125 gastric cancer cases and 115 controls) followed by prediction of gastric cancer and control (duodenal ulcer) H. pylori strains. We identified 11 single nucleotide polymorphisms (eight amino acid changes) and three DNA motifs that, combined, allowed effective disease discrimination. They were often informative of the underlying molecular mechanisms, such as electric charge alteration at the ligand-binding pocket, alteration in subunit interaction, and mode-switching of DNA methylation. We also identified three novel virulence factors/oncoprotein candidates. These results provide both defined targets for further informatic and experimental analyses to gain insights into gastric cancer pathogenesis and a basis for identifying a set of biomarkers for distinguishing these H. pylori-related diseases.

Potential Non-invasive Biomarkers of Helicobacter pylori-Associated Gastric Cancer

BACKGROUND

Gastric cancer (GC) remains the fifth most common incident cancer with the highest incidence in East Asian countries and the third leading cause of cancer death worldwide. The causal association between non-cardia GC and Helicobacter pylori (H. pylori) has been firmly documented by clinical and epidemiological studies. According to the guidelines for diagnosis and treatment of H. pylori infection, eradication therapy is strongly recommended. Early detection of GC is critical and can save lives through rapid technological advancement. At present, endoscopy remains the most efficient technique. However, it is invasive and costs highly.

METHODS

An extensive bibliographic search was performed via PubMed/Medline, Web of Science, and EBSCO host databases to select studies conducted within the past 8 years. Forty-six relevant analyses were encompassed in this review.

RESULTS

Several non-invasive candidate biomarkers associated with H. pylori, divided into virulence markers, transcriptome markers, genomic markers, and inflammatory markers, have been shown to be potential predictors of GC at an early stage.

CONCLUSION

The discovery of non-invasive biomarkers offers new perspectives for screening, early detection, and monitoring of individuals at risk.

Vaccine development against Helicobacter pylori: from ideal antigens to the current landscape

Introduction: The interest of the world scientific community for an effective vaccine against Helicobacter pylori infection arises from its high prevalence and association with many diseases. Moreover, with an immunological response that is not always effective for the eradication of the bacteria and an increasing antibiotic resistance in the treatment of this infection, the search for a vaccine and new therapeutic modalities to control this infection is urgent.Areas covered: We bring an overview of the infection worldwide, discussing its prevalence, increasing resistance to antibiotics used in its therapy, in addition to the response of the immune system to the infection registered so far. Moreover, we address the most used antigens and their respective immunological responses expected or registered up to now. Finally, we address the trials and their partial results in development for such vaccines.Expert opinion: Although several studies for the development of an effective vaccine against this pathogen are taking place, many are still in the preclinical phase or even without updated information. In this sense, taking into account the high prevalence and association with important comorbidities, the interest of the pharmaceutical industry in developing an effective vaccine against this pathogen is questioned.

Immune response to Helicobacter pylori infection and gastric cancer development

Gastric adenocarcinoma is a global health concern, and Helicobacter pylori (H. pylori) infection is the main risk factor for its occurrence. Of note, the immune response against the pathogen seems to be a determining factor for gastric oncogenesis, and increasing evidence have emphasized several host and bacterium factors that probably influence in this setting. The development of an inflammatory process against H. pylori involves a wide range of mechanisms such as the activation of pattern recognition receptors and intracellular pathways resulting in the production of proinflammatory cytokines by gastric epithelial cells. This process culminates in the establishment of distinct immune response profiles that result from the cytokine-induced differentiation of T naïve cells into specific T helper cells. Cytokines released from each type of T helper cell orchestrate the immune system and interfere in the development of gastric cancer in idiosyncratic ways. Moreover, variants in genes such as single nucleotide polymorphisms have been associated with variable predispositions for the occurrence of gastric malignancy because they influence both the intensity of gene expression and the affinity of the resultant molecule with its receptor. In addition, various repercussions related to some H. pylori virulence factors seem to substantially influence the host immune response against the infection, and many of them have been associated with gastric tumorigenesis.

Three-Decade Failure to the Eradication of Refractory Helicobacter pylori Infection and Recent Efforts to Eradicate the Infection

BACKGROUND

Helicobacter pylori causes dangerous and deadly diseases such as gastric cancer and duodenal ulcers. Eradication and treatment of this bacterium are very important due to the deadly diseases caused by H. pylori and the high cost of treatment for countries.

METHODS

Thus, we present a complete list of the most important causes of failure in the treatment and eradication of H. pylori, and address new therapeutic methods that may be effective in controlling this bacterium in the future.

RESULTS

Many efforts have been made to control and eradicate this bacterium over the years, but no success has been achieved since its eradication is a complex process affected by the bacterial properties and host factors. Previous studies have shown that various factors are involved in the failure to eradicate H. pylori, such as new genotypes of the bacterium with higher pathogenicity, inappropriate patient cooperation, mutations, biofilm formation and dormant forms that cause antibiotic resistance, acidic stomach pH, high bacterial load, smoking, immunosuppressive features and intracellular occurrence of H. pylori. On the other hand, recent studies reported that the use of probiotics, nanoparticles, antimicrobial peptides, natural product and vaccines can be helpful in the treatment and eradication of H. pylori infections.

CONCLUSION

Eradication of H. pylori is crucial for the treatment of important diseases such as gastric cancer. Therefore, it seems that identifying the failure causes of treating this bacterium can be helpful in controlling the infections. Besides, further studies on new therapeutic strategies may help eradicate H. pylori in the future.

Antibiotic resistance pattern and frequency of cagA and vacA genes in Helicobacter pylori strains isolated from patients in Tabriz city, Iran

Objective

Helicobacter pylori is one of the most common causes of gastric infections in humans. It is estimated that approximately 50% of people around the world are infected with this bacterium. This study aimed to determine the antibiotic resistance pattern, as well as the frequency of cagA and vacA genes in H. pylori isolates obtained from patients in the clinical centers in Tabriz city, Iran.

Results

The culture method detected 100 (45.25%) H. pylori isolates from 221 biopsy samples during 3 years. The results showed that 63% and 81% of the isolates were positive for cagA and vacA genes, respectively. The highest resistance of isolates was seen against metronidazole (79%) and amoxicillin (36%), respectively. Also, the isolates showed the least resistance to tetracycline (8%).

EPIYA motifs of Helicobacter pylori cagA genotypes and gastrointestinal diseases in the Iranian population: a systematic review and meta-analysis

Helicobacter pylori is one of the best risk factors for gastric cancer. Recent studies have examined the relationship between virulence factors, in particular CagA toxin, and the development of gastrointestinal diseases. According to the literature, there is a significant relationship between the polymorphism of cagA-EPIYA motifs and progression to severe clinical outcomes. The main goal of our study was to determine the possible association between cagA genotypes and the risk of severe clinical outcomes in the Iranian population. We investigated these ambiguities using a comprehensive meta-analysis study, in which we evaluated data from 1762 Iranian patients for a potential correlation between all cagA gene genotypes and gastrointestinal diseases. According to statistical analysis, the frequencies of cagA genotypes including ABC, ABCC, AB and ABCCC in the Iranian population were estimated at 80.18%, 22.81%, 5.52% and 2.76%, respectively; the ABD genotype was not detected in these PCR-based studies. There was a significant relationship between cagA genotypes ABCC and ABCCC and severe clinical outcomes of infection such as peptic ulcer and gastric cancer. Overall, it can be concluded that there is a positive correlation with the number of copies of EPIYA-C and the increase of gastric cancer. Therefore, according to our results, it seems that the EPIYA-ABCCC motif has a strong positive relationship with gastric cancer in the Iranian population.

CagE, cagA and cagA 3' region polymorphism of Helicobacter pylori and their association with the intra-gastric diseases in Moroccan population

Helicobacter pylori infection is the most important etiological factor in gastroduodenal diseases development. Its evolution is influenced by several factors, including bacterial virulence genes such as cagA and cagE. This work aimed to evaluate the predictive value of cagE alone and in combination with cagA and CagA-EPIYA-C motifs number as a marker of the infection evolution. A total of 823 H. pylori DNA extracted from biopsies of consenting patients suffering from gastritis, peptic ulcer, or gastric cancer. The cagE, cagA status and cagA 3' region polymorphism were determined by PCR. The analysis shows that the risk of duodenal ulcer is 1.97-fold higher (CI = 1.18-3.30) in patients infected by strains cagA+/cagE+. And the risk of gastric cancer is 5.19-fold higher (CI = 1.18-22.70) in patients harboring strains cagE+/2EPIYA-C. The results suggest that cagE in combination with cagA-EPIYA-C motifs number can be used as predictive biomarker of H. pylori infection evolution.

VacA genotypes and cagA-EPIYA-C motifs of Helicobacter pylori and gastric histopathological lesions

Helicobacter pylori infection induces inflammation of the gastric mucosa, which may progress to precancerous lesions and gastric cancer. The gastric histo-pathological damages may be associated with some virulence genes of the bacterium, notably vacA and cagA genes. To establish correlations between these genes and the lesions, biopsies from 1303 adults consenting patients that were previously analyzed by PCR to characterize vacA-s vacA-m, vacA-i regions and cagA 3' region polymorphism, were used. The highest average age was obtained in patients with intestinal metaplasia (53.65 ± 15.26 years) and gastric cancer (53.60 ± 14.32 years). Thus, these lesions are more frequent in elderly and male subjects. Tobacco smoking was significantly associated with neutrophilic activity (P = .02). No significant association was obtained between patients with chronic inflammation and vacA and cagA H. pylori genotypes. However, a significant association has been obtained between this lesion and cagA+ in aged patients (P = .02), while intestinal metaplasia was significantly associated with vacAi1 and vacAm1 separately (P < .01 and .01). Also, a significant association was obtained between intestinal metaplasia and strains with one EPIYA-C motif in young patients (P = .001). Interestingly, a significant association was obtained between gastric cancer and cagA+, vacAi1, vacAm1 H. pylori genotypes and also with two EPIYA-C motifs independently of age groups (all P < .05). The results of our study show that H. pylori vacAi1 could be more potent than the other H. pylori virulent factors for predicting the precancerous gastric lesions, confirming that this gene may be helpful to identify patients at high risk for gastric cancer.

Helicobacter pylori-related risk predictors of gastric cancer: The latest models, challenges, and future prospects

Helicobacter pylori is known as an important determinant of preneoplastic lesions or gastric cancer (GC) risk. The bacterial genotypes may determine the clinical outcomes. However, the evidence for these associations has varied between and within continents, and the actual effect of each gene and corresponding allelic variants are still debatable. In recent years, two new models have been proposed to predict the risk of GC; the phylogeographic origin of H. pylori strains and a disrupted co-evolution between H. pylori and its human host, which potentially explain the geographic differences in the risk of H. pylori-related cancer. However, these models and earlier ones based on putative virulence factors of the bacterium may not fully justify differences in the incidence of GC, reflecting that new theories should be developed and examined. Notably, the new findings also support the role of ancestry-specific germline alteration in contributing to the ethnic/population differences in cancer risk. Moreover the high and low incidence areas of GC have shown differences in transmission ecology, largely affecting the composition of H. pylori populations. As a new hypothesis, it is proposed that any high-risk population may have its own specific risk loci (or variants) as well as new H. pylori strains with national/maybe regional gene pools that should be considered. The latter is seen in the Americas where the rapid evolution of distinct H. pylori subpopulations has been occurred. It is therefore proposed that the deep sequencing of both H. pylori and its human host is simultaneously performed in GC patients and age-sex-matched controls from high-risk areas. The expression and functional activities of the identified new determinants of GC must then be assessed and matched with human and pathogen ancestry, because some of risk loci are ancestry-specific. In addition, potential study-level covariates and moderator variables (eg physical conditions, life styles, gastric microbiome, etc) linked to causal relationships, and their impact, should be recognized and controlled.

Genetic diversity and virulence characteristics of Helicobacter pylori isolates in different human ethnic groups

Helicobacter pylori is the most predominant bacterium in almost 50% of the world's population and colonization causes a persistent inflammatory response leading to chronic gastritis. It shows high genetic diversity and individuals generally harbour a distinct bacterial population. With the advancement of whole-genome sequencing technology, new H. pylori subpopulations have been identified that show admixture between various H. pylori strains. Genotypic variation of H. pylori may be related to the presence of virulence factors among strains and is associated with different outcomes of infection in different individuals. This review summarizes the genetic diversity in H. pylori strain populations and its virulence characteristics responsible for variable outcomes in different ethnic groups.

Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa

BACKGROUND

The global prevalence of H. pylori approaches 50%, with prevalence rates between 20 and 40% in developed countries and up to 90% in Africa and other developing nations of the world. Development of H. pylori-associated diseases is determined by a number of virulence factors. This study aimed at determining the prevalence of H. pylori infections and virulence genes (cagA, dupA, and vacA); the relationship between virulence factors and gastroduodenal diseases among patients.

METHODS

Gastric biopsies were obtained from patients and cultured, DNA was extracted from cultured isolates and biopsies for PCR assay after which samples were investigated using standard laboratory procedures. Data of associated risk factors were obtained with the aid of questionnaires.

RESULTS

Of the 444 participants, H. pylori was detected in 115 (25.9%) from culture analysis and 217 (48.9%) by direct PCR method. Ninety-eight (85.2%) of the culture-positive patients were also detected by PCR giving an overall prevalence of 52.7% (234/444). The highest number of H. pylori isolates 76.9% (180/234) was obtained from patients suffering from pangastritis. The CagA virulence gene was found in 62% (145/234), dupA in 53.4% (125/234) and vacA in 90.6% (212/234). VacA genotype s1 m1 was the most prevalent [56.4% (132)] followed by s2 m2 [11.5% (27)], s2 m1 [10.3% (24)] and [s1 m2 9.4% (22)]. There was a significant association observed in vacA s1 and peptic ulcer disease, as well as vacA s1/m2 and gastric erosion (P < 0.05).

CONCLUSION

The study revealed a significant association between virulence genes and the development of certain forms of gastric infections while the variations in H. pylori detection and the associated risk factors investigated in the study were not significantly related.

Helicobacter pylori vacA, cagA and iceA genotypes in dyspeptic patients from southwestern region, Saudi Arabia: distribution and association with clinical outcomes and histopathological changes

Background

The aim of this study was to identify the common H. pylori virulence genes among dyspeptic Southwestern Saudi patients and their association with clinical outcomes and histopathological findings to help practitioners and researchers in the region for better management of infections caused by such bacteria.

Methods

Four hundred two gastric biopsy specimens were analyzed using histopathological examination and real time-PCR. The positive 187 specimens by RT-PCR were genotyped using PCR targeting cagA, vacA and iceA genes.

Results

One hundred twenty-eight gastric biopsy specimens were positive in genotyping PCRs. The cagA, vacA, iceA1 and iceA2 genes were detected in rates of 49.2% (63/128), 100%(128/128), 42.2% (54/128), 32.8% (42/128), respectively. The vacA s1as1bm2 subtype was the highest 23.4% (30/128), followed by m2 and s1a1b subtypes which were equally detected [16.4% (21/128) for each]. The iceA genes were significantly associated with gastritis and gastric ulcer. Overall, vacA genotypes were significantly associated with gastritis, gastric and duodenal ulcers. The vacA subtypes: s1as1bm2, s1a1b and s2 m2 showed chronic active gastritis in percentages of 90.0, 81, and 84.2%, respectively. All vacA mixed genotypes showed chronic active gastritis.

Conclusions

H. pylori virulence genes are highly prevalent and diverse among patients with dyspepsia in Southwestern region of Saudi Arabia. The iceA genes and the different vacA subtypes are significantly associated with the clinical outcomes and histopathological changes especially chronic active gastritis.

Helicobacter pylori CagA EPIYA-C motifs and gastric diseases in Moroccan patients

BACKGROUND

The pathogenicity of cagA-positive H. pylori strains is associated with the number and type of repeated sequences named EPIYA located in the C-terminal region of the CagA protein. The aim of this study is to determine the polymorphism of the H. pylori cagA 3' region circulating in Morocco and its association with different gastric pathologies.

METHODS

A total of 1353 consenting patients, were recruited in this study. The gastric biopsies performed during endoscopy were used for histological examination and for molecular characterization of H. pylori. The study of the type and number of "EPIYA" motif was identified by PCR directly on H. pylori positive biopsies.

RESULTS

Of all the biopsies, the infection rate was 61.1%. The cagA gene was amplified in 68.9% of the cases and the analysis of the 3' region of cagA showed the exclusive presence of the "Western CagA" type with a predominance of the EPIYA-ABC motif (71.4%). The number of EPIYA-C motif varies from 0 to 2. The multinomial analysis shows that the infection with strains of H. pylori having two EPIYA-C motifs is a factor that increases the risk of developing gastric cancer compared to gastritis cases with strains lacking this motif (OR = 11.64; CI: 3.34-45.15), whereas this risk is 6 fold higher in comparison with duodenal ulcer cases (OR = 6, CI: 1.29-27.76).

CONCLUSIONS

The results of this study suggest that the number of EPIYA-C motifs might be useful as a predictive marker of the infection evolution and will help in the identification of patients at high risk of developing gastric cancer.

Helicobacter pylori associated factors in the development of gastric cancer with special reference to the early-onset subtype

Nowadays, gastric cancer is one of the most common neoplasms and the fourth cause of cancer-related death on the world. Regarding the age at the diagnosis it is divided into early-onset gastric carcinoma (45 years or younger) and conventional gastric cancer (older than 45). Gastric carcinomas are rarely observed in young population and rely mostly on genetic factors, therefore provide the unique model to study genetic and environmental alternations. The latest research on early-onset gastric cancer are trying to explain molecular and genetic basis, because young patients are less exposed to environmental factors predisposing to cancer. In the general population, Helicobacter pylori, has been particularly associated with intestinal subtype of gastric cancers. The significant association of Helicobacter pylori infection in young patients with gastric cancers suggests that the bacterium has an etiologic role in both diffuse and intestinal subtypes of early-onset gastric cancers. In this paper we would like to ascertain the possible role of Helicobacter pylori infection in the development of gastric carcinoma in young patients. The review summarizes recent literature on early-onset gastric cancers with special reference to Helicobacter pylori infection.

Association of oral Helicobacter pylori with gastric complications

AIM

This study was aimed to identify the presence of Helicobacter pylori (H. pylori) genes in oral mucosa and find out their relationship between oral H. pylori infection and gastric complications.

METHODS

This study is a case control study consists of 567 subjects with periodontal infection (278 gastric complication cases and 289 controls normal gastric intestinal mucosa) with age range of 20-80 years. Oral health status was recorded by calculating oral hygiene index (OHI), probing depths (PD) and clinical attachment loss (CAL). Each participant provided gastric biopsy and plaque samples which were subjected to H. pylori detection. Polymerase chain reaction (PCR) with different primers specifically β globulin, 16SrRNA, babA, cagA, ureA, ureC and vacA gene was performed which were then analyzed using gel electrophoresis.

RESULTS

No significant differences (χ² = 11.873, p value > 0.05) were observed between oral H. pylori and gastric infections/complications. However, H. pylori increase the risk of developing gastro-esophageal reflux grade II (OR = 1.458, 95%CI = 0.659-3.226), normal upper GIT mucosa with lax esophageal sphincters (OR = 1.215, 95%CI = 0.285-5.181) and duodenal ulcer/duodenitis (OR = 2.187, 95%CI = 0.225-21.278). This study also showed a significant increased risk of gastritis with babA gene.

CONCLUSION

Oral pathogenic H. pylori genes may enhance the severity of the gastric infection.

Recurrence of infection and diversity of Helicobacter pylori strains in an adult population in Mexico treated with empirical standard triple therapy

BACKGROUND

After eradication treatment for Helicobacter pylori, infection could recur due to recrudescence or re-infection. The objective of this study was to determine the recurrence of Helicobacter pylori infection and identify virulent Helicobacter pylori strains one year after eradication with standard triple therapy.

MATERIAL AND METHODS

A quasi-experimental study was performed that included a patient population with digestive diseases associated with Helicobacter pylori who had received standard triple therapy. Cultures and Polymerase Chain Reaction was performed on gastric biopsies for strain identification in all patients prior to eradication treatment and those with a positive carbon 14 breath test one year after eradication treatment. Statistical analysis was performed using the student T test and Fisher's exact test, statistical significance was set at 0.05.

RESULTS

128 patients were studied, 51 (39.8%) were male and 77 (60.2%) were female with an average age of 54.8 years (DE 13.8). There was an annual recurrence of Helicobacter pylori infection in 12 (9.3%) patients. An annual re-infection and recrudescence occurred in 9 (7 %) and 3 (2.3%) patients respectively. The recrudescence rate for cagA was 1/30 (3.3%) patients and 2/112 (1.8%) patients for vacA. The re-infection rate for cagA was 3/30 (10%) patients and 6/112 (5.3%) patients for vacA.

CONCLUSIONS

The recurrence of infection in this study was higher than that recorded in developed countries with a low prevalence of H. pylori and lower than that recorded in developing countries with a higher prevalence of H. pylori. The cagA or vacA s2/m2 strains were isolated after re-infection and recrudescence.