cagA Genotypes Research Articles

The relationship between gastric cancer and Helicobacter pylori cytotoxin-related gene A genotypes

Gastric cancer has been known as the third leading cause of cancer-related death in the world. It is when cancer cells form on the lining of the stomach. Early symptoms include heartburn, upper abdominal pain, nausea, and loss of appetite. Helicobacter pylori is the most common microscopic creature that has infected humans worldwide. More than half of the world's population is infected with the bacterium. It is the main cause of diseases such as stomach ulcers and stomach and intestinal disorders. H. pylori infection is related to gastric adenocarcinoma and cagA genotype is believed to be related to cancer development. cytotoxin-associated gene A (CagA) is a 120–145kDa protein encoded on the 40kb cag pathogenicity island (PAI). This study investigates the association between cagA H. pylori genotypes and gastric cancer. For this purpose, 65 stomach biopsies of the gastric cancer patients and 100 saliva samples were collected from healthy and H. pylori-infected individuals. Then genomic DNA was purified and Polymerase Chain Reaction (PCR) was performed for the studied gene using specific primers. The presence of H. pylori was investigated by PCR and a pair of specific primers for a protected region in the bacterium glmM gene. Then cagA+ and cagA- genotypes frequencies were determined in H. pylori-infected cases. Statistical analysis showed that there were significant differences between healthy and diseased ones for genotypes cagA+ and cagA-. Then the cagA+ can be a risk factor genotype for gastric cancer.

Prevalence of Helicobacter pylori vacA, cagA, cagE1, cagE2, dupA and oipA Genotypes in Patients With Gastrointestinal Diseases

Helicobacter pylori (H. pylori) is a bacterium that resides in the human stomach, which is associated with gastroduodenal diseases. We investigate the prevalence of cagA, vacA, oipA, cagE1, cagE2 and dupA genotypes in H. pylori isolated from patients with Gastric ulcer, duodenal ulcer, and Gastric Cancer. Collected 74 samples from the Gastroenterology Unit of the Rasool Akram Hospital were included in this study. Gastric disorders were identified by endoscopy .gastric cancer was further confirmed by histopathology. H. pylori were detected by the urease test. Subsequently, DNA was extracted from gastric tissue of the subjects with the CLO-test yielded positive results. In general, 74 patients with a mean age of 53.45 years (Range 22 to 86-year-old), including 45 men and 29 women, were studied. Among 74 H. pylori-positive patients, 70 (94.5%) patients were positive for the cagA gene. About 95.8% (23/24) of the patients with gastric carcinoma were dupA positive and VacA gene (91.8%). The oipA genotype was detected in 71 (96%) of H.pylori positive samples. This gene was more common in patients with gastritis rather than cancer group. Also, 97.2% of 74 H. pylori isolates were cagE2-positive. In 25 patients with PUD, the occurrence percent of cagA+/VacA+, cagA+/Vac- , cagA- /VacA+ and cagA- /VaxA- genotypes were found 80%, 12%, 4.2% and 4.2 respectively. The results of the present study suggest that a high prevalence of virulent factors could contribute to the risk of developing gastroduodenal diseases.

Association of cagA+ Helicobacter pylori strains with high urease activity and dyspepsia in Mexican adults

Introduction and aimsHelicobacter pylori (H. pylori) is associated with a higher risk of peptic ulcer and gastric cancer. The sole presence of the bacterium is not a determinant of clinical outcome, but rather the interaction of strain type and host factors determines the risk of disease. Our aim was to study the association between bacterial load, strain type, and gastric symptoms in H. pylori-positive subjects. Materials and methodsIn a community survey, a diagnostic 13C-urea breath test for H. pylori was performed on 302 volunteers that were not taking antibiotics, antacids, or proton pump inhibitors one month prior to the test. The breath test produced 25 H. pylori-positive subjects, between 25 and 74 years of age, who then took a gastric symptoms survey and were tested for the presence of the cagA genotype in gastric juice, using the Entero-test®. Bacterial load was determined as a measure of urease activity, utilizing the delta over baseline (DOB) value, obtained in the 13C-urea breath test. ResultsA total of 48% of the H. pylori-positive subjects were cagA+. A positive association was found between cagA status and high gastric urease activity (p<0.0001) and the latter was significantly associated with the presence of symptoms (p<0.0001). ConclusionGastric urease activity was strongly associated with dyspeptic symptoms and cagA+H. pylori. Elevated 13C-DOB values could be used as indicators of a higher risk for gastric disease.

Where to Biopsy to Detect Helicobacter pylori and How Many Biopsies Are Needed to Detect Antibiotic Resistance in a Human Stomach.

This study aims to determine the gastric distribution, density, and diversity of Helicobacter pylori infection. Subtotal resection of the stomachs of three H. pylori-infected and asymptomatic obese patients were collected after a sleeve gastrectomy. Distribution and density of H. pylori were determined using culture and RT-PCR on multiple gastric sites (88, 176, and 101 biopsies per patient). Diversity of H. pylori strains was studied using antibiotic susceptibility testing, random amplified polymorphism DNA (RAPD) typing and cagA gene detection on single-colony isolates (44, 96, and 49 isolates per patient). H. pylori was detected in nearly all analyzed sites (354/365 biopsies, 97%). Antral density was higher in one patient only. The three stomachs were almost exclusively infected by an antibiotic-susceptible strain. One clarithromycin-resistant isolate in one biopsy was detected in two stomachs (1/44 and 1/49 isolates), while in the third one, eight (8/96 isolates) metronidazole-resistant isolates were detected. DNA typing showed infection with cagA-negative strains for one patient, cagA-positive strains for a second patient and the third patient was infected with two different strains of distinct cagA genotypes. Infection with H. pylori is shown to spread to the whole surface of the stomach, but a possibility of minor sub-population of antibiotic-resistant clones, undetectable in routine practice.

Gastric Mucosa-Associated Microbial Signatures of Early Gastric Cancer.

Alterations in the microbiome are associated with the development of gastric cancer. Our study aimed to identify dysbiotic features in early gastric cancer (EC). The gastric microbiome was assessed in EC (n = 30), advanced gastric cancer (AC) (n = 30), and chronic gastritis (CG) (n = 60). The results demonstrated significant differences in the microbial profile and composition between EC and AC, suggesting alterations associated with gastric cancer progression. Linear discriminant analysis (LDA) effect size (LEfSe) analyses identified 32 bacterial genera that were associated with EC. Functional analyses of the gastric microbiome showed that the production of urease and synthesis of bacterial flagella were weakened in EC, while the glycolysis of fructose and hydrolysis of glycosides were enhanced. A classifier based on a random forest (RF) machine learning algorithm identified a microbial signature that distinguished EC from CG or AC with high accuracy. The correct identification of the signature was further validated in independent cohorts. This signature enriched of bacteria with varied abundance, high degree of bacterial interactions and carcinogenic potentials. Constrained principal coordinate analyses revealed that the presence of Helicobacter pylori and the cagA and vacA virulence genotypes influenced the structure of the gastric microbiome. To determine the impacts of host genetic variations on the gastric microbiome, six previously reported single nucleotide polymorphisms (SNPs) were examined. The minor allele of MUC1 rs4072037 was associated with an increased abundance of Ochrobactrum. The gastric microbiome altered in EC, which might be attributed in part to host genetic variations, H. pylori infection, bacterial virulence and environmental adaptations. The identified microbial signature could serve as biomarkers for clinical assessment of gastric cancer risk in high-risk patients.

Genetic variation in the cag pathogenicity island of Helicobacter pylori strains detected from gastroduodenal patients in Thailand.

There is a lack of evidence of genetic variation in the Helicobacter pylori cag-PAI in Thailand, a region with the low incidence of gastric cancer. To clarify this issue, variation in the H. pylori cag-PAI in strains detected in Thailand was characterized and simultaneously compared with strains isolated from a high-risk population in Korea. The presence of ten gene clusters within cag-PAI (cagA, cagE, cagG, cagH, cagL, cagM, cagT, orf13, virB11, and orf10) and IS605 was characterized in H. pylori strains detected from these two countries. The cagA genotypes and EPIYA motifs were analyzed by DNA sequencing. The overall proportion of the ten cag-PAI genes that were detected ranged between 66 and 79%; additionally, approximately 48% of the strains from Thai patients contained an intact cag-PAI structure, while a significantly higher proportion (80%) of the strains from Korean patients had an intact cag-PAI. A significantly higher proportion of IS605 was detected in strains from Thai patients (55%). Analysis of cagA genotypes and EPIYA motifs revealed a higher frequency of Western-type cagA in Thai patients (87%) relative to Korean patients (8%) who were predominately associated with the East Asian-type cagA (92%). Variations in the Western-type cagA in the Thai population, such as EPIYA-BC patterns and EPIYA-like sequences (EPIYT), were mainly detected as compared with the Korean population (p < 0.05). In summary, H. pylori strains that colonize the Thai population tend to be associated with low virulence due to distinctive cag-PAI variation, which may partially explain the Asian paradox phenomenon in Thailand.

Evolutionarily-Related Helicobacter pylori Genotypes and Gastric Intraepithelial Neoplasia in a High-Risk Area of Northern Italy.

Helicobacter pylori (Hp) is the major recognized risk factor for non-cardia gastric cancer (GC), but only a fraction of infected subjects develop GC, thus GC risk might reflect other genetic/environmental cofactors and/or differences in virulence among infectious Hp strains. Focusing on a high GC risk area of Northern Italy (Cremona, Lombardy) and using archived paraffin-embedded biopsies, we investigated the associations between the Hp vacA and cagA genotype variants and gastric intraepithelial neoplasia (GIN, 33 cases) versus non-neoplastic gastroduodenal lesions (NNGDLs, 37 cases). The glmM gene and the cagA and vacA (s and m) genotypes were determined by polymerase chain reaction (PCR) and sequencing. Hp was confirmed in 37/37 (100%) NNGDLs and detected in 9/33 GINs (27%), consistently with the well-known Hp loss in GC. CagA was detected in 4/9 Hp-positive GINs and in 29/37 NNGDLs. The vacA s1a and m1 subtypes were more common in GINs than in NNGDLs (6/7 vs. 12/34, p=0.014, for s1a; 7/7 vs. 18/34, p=0.020 for m1), with significant vacA s genotype-specific variance. The GIN-associated vacA s1a sequences clustered together, suggesting that aggressive Hp strains from a unique founder contribute to GC in the high-risk area studied.

CagA gene EPIYA motif genetic characterization from Colombian Helicobacter pylori isolates: Standardization of a molecular test for rapid clinical laboratory detection.

The aim of this work was to determine current cagA gene EPIYA motifs present in Colombian Helicobacter pylori isolates using a fast and reliable molecular test. DNA from eighty-five Helicobacter pylori-cagA positive strains were analyzed. Strains were obtained from patients diagnosed with functional dyspepsia at Clínica Fundadores in Bogotá. The 3' region of the cagA gene was amplified through conventional Polymerase Chain Reaction (PCR). Obtained amplicons were sequenced using the Sanger method and analyzed with bioinformatics tools. Additionally, a significant Spearman correlation coefficient was determined between the patients' age and the number of EPIYA-C repeats; with p values < 0.05 considered significant. Estimates were obtained using a 95% CI. The 3´ variable region of the cagA gene was amplified and PCR products of the following sizes corresponded to the following EPIYA motifs: 400 bp: EPIYA AB, 500 bp: EPIYA ABC, 600 bp: EPIYA ABCC and 700 bp: ABCCC. A single PCR band was observed for 58 out of 85 Helicobacter pylori isolates, with an EPIYA distribution motif as follows: 7/85 AB (8.2%), 34/85 ABC (40%), 26/85 ABCC (30.6%) and 18/85 ABCCC (21.2%). However, in 27 out of 85 Helicobacter pylori isolates, two or more bands were observed, where the most predominant cagA genotype were ABC-ABCC (26%, 7/27) and ABCC-ABCCC (22.2%, 6/27). A direct proportionality between the number of EPIYA-C repeats and an increase in the patients’ age was observed, finding a greater number of EPIYA ABCC and ABCCC repeats in the population over 50 years old. All isolates were of the Western cagA type and 51.8% of them were found to have multiple EPIYA-C repeats. These standardized molecular test allowed to identify the number of EPIYA C motifs based on band size.

Phenotypic and Genotypic Assessment of Antibiotic Resistance and Genotyping of vacA, cagA, iceA, oipA, cagE, and babA2 Alleles of Helicobacter pylori Bacteria Isolated from Raw Meat.

BackgroundFoodstuffs with animal origins, particularly meat, are likely reservoirs of Helicobacter pylori.PurposeAn existing survey was accompanied to assess phenotypic and genotypic profiles of antibiotic resistance and genotyping of vacA, cagA, cagE, iceA, oipA, and babA2 alleles amongst the H. pylori bacteria recovered from raw meat.MethodsSix-hundred raw meat samples were collected and cultured. H. pylori isolates were tested using disk diffusion and PCR identification of antibiotic resistance genes and genotyping.ResultsFifty-two out of 600 (8.66%) raw meat samples were contaminated with H. pylori. Raw ovine meat (13.07%) had the uppermost contamination. H. pylori bacteria displayed the uppermost incidence of resistance toward tetracycline (82.69%), erythromycin (80.76%), trimethoprim (65.38%), levofloxacin (63.46%), and amoxicillin (63.46%). All H. pylori bacteria had at least resistance toward one antibiotic, even though incidence of resistance toward more than eight antibiotics was 28.84%. Total distribution of rdxA, pbp1A, gyrA, and cla antibiotic resistance genes were 59.61%, 51.92%, 69.23%, and 65.38%, respectively. VacA s1a (84.61%), s2 (76.92%), m1a (50%), m2 (39.13%), iceA1 (38.46%), and cagA (55.76%) were the most generally perceived alleles. S1am1a (63.46%), s2m1a (53.84%), s1am2 (51.92%), and s2m2 (42.30%) were the most generally perceived genotyping patterns. Frequency of cagA-, oipA-, and babA2- genotypes were 44.23%, 73.07%, and 80.76%, respectively. A total of 196 combined genotyping patterns were also perceived.ConclusionThe role of raw meat, particularly ovine meat, in transmission of virulent and resistant H. pylori bacteria was determined. VacA and cagA genotypes had the higher incidence. CagE-, babA2-, and oipA- H. pylori bacteria had the higher distribution. Supplementary surveys are compulsory to originate momentous relations between distribution of genotypes, antibiotic resistance, and antibiotic resistance genes.

Helicobacter pylori Infection, DNA Methylation, and Gastric Carcinogenesis

Helicobacter pylori (H. pylori), the major cause of chronic gastritis, peptic ulcers and gastric cancer, infects about 50% of the world population. Although various host and bacterial factors have been suggested, the detailed pathogenic mechanisms remain to be defined. Increasing evidences have demonstrated that epigenetic dysregulation, such as DNA methylation, plays a critical role in gastric carcinogenesis, and is currently under intensive investigation. H. pylori infection result in aberrant DNA methylation in a number of gene promoters in gastric mucosa, eradication of H. pylori can reverse some hypermethylated genes, but had no effect on others. In some methylated genes, the methylation levels persist even after H. pylori eradication, and the fact suggests that DNA methylation accumulation is associated with molecular irreversibleness and gastric diseases progression. DNA methylome and gastric cancer risk analysis indicate that certain gene promoter methylation may serve as potential biomarkers for gastric cancer predication. In addition, H. pylori cagA and vacA s1m1 genotype are independent variables that is associated with higher methylation level. The levels of methylation can be influenced by the degree and length of infection exposure, and certain host gene polymorphisms are also associated with gene methylation in H. pylori-infected subjects. Continued investigation in these areas will be critical to provide insights into the molecular mechanisms of H. pylori induced gastric diseases and develop strategies for disease prevention and intervention. We review recent progress and discuss future research directions in this important area.

Relationship between Helicobacter pylori cagA Genotypes Infection and IL-10 and TGFβ1 Genes' Expression in Gastric Epithelial Cells.

Background:The correlation of Helicobacter pylori infection with gastritis, peptic ulcer, and gastric cancer has been proven. The aim of this study was to determine the effects of cagA+ and cagA− genotypes of H. pylori on genes expression of interleukin (IL) -10 and tumor growth factor (TGF) β1 in gastric epithelial cells of patients with gastritis and H. pylori infection.Methods:In all, 45 gastric biopsy samples were collected from patients with gastritis and H. pylori infection admitted to Tohid Hospital in Sanandaj city. Status of urease and cagA genes of H. pylori were directly determined from the biopsy samples using polymerase chain reaction (PCR) method. Expression of IL-10 and TGF-β1 genes in gastric epithelial cells of patients with gastritis and cagA+ and cagA− genotypes of H. pylori infection was serveyed using real-time PCR method.Results:Overall, 25 samples had infection with H. pylori cagA+ and 20 with cagA− genotypes. This study showed that there is a positive correlation between cagA− genotypes of H. pylori and increasing of IL-10 gene expression in gastric epithelial cells of patients with gastritis (P = 0.001).Conclusions:Level of gene expression of IL-10 as an anti-inflammatory cytokine in gastric epithelial cells of patients with H. pylori infection is connected to cagA- genotypes.

Analysis of babA, cagE and cagA Genes in Helicobacter pylori from Upper Gastric Patients in the North of Iran.

Helicobacter pylori is a Gram-negative bacterium which has a serious effect on up to half of the world's population and has been related to different gastric diseases. The goal of this study was to assess the frequency of babA, cagE and cagA genotypes among H. pylori strains isolated from gastric biopsies of endoscopic patients in the north of Iran. The present study was performed on 90 strains of H. pylori isolated from patients with gastric diseases (Gastric ulcer (GU), Duodenal ulcer (DU), Gastritis (G), Non-ulcer dyspepsia (NUD) and Gastric adenocarcinoma (GC)). DNA was extracted from all isolated strains and PCR method was performed to detect the prevalence of babA2, cagE and cagA genes using specific primers. Among 90 samples of H. pylori, babA2, cagE, and cagA genes were detected in 42.2%, 30% and 82.2% of strains respectively. The statistical analysis showed that the prevalence of cagA gene in GU, G, DU, and NUD was significantly higher than other genes. Moreover, cagA, and babA2 genes were significantly more prevalent in GC patients compared to cagE gene. Our isolates exhibited 8 distinct arrangements of virulence patterns. The occurrence of cagA (35.6%) was the most prevalent pattern followed by cagA/babA2 (20%) and cagA/babA2/cagE (14.4%). In summary, as first report from Guilan province in the north of Iran, we showed significant association between the presence of babA2, cagE, and cagA genes in different types of gastric disorders.

Characterization of a novel Helicobacter pylori East Asian-type CagA ELISA for detecting patients infected with various cagA genotypes.

Currently, Western-type CagA is used in most commercial Helicobacter pylori CagA ELISA kits for CagA detection rather than East Asian-type CagA. We evaluated the ability of the East Asian-type CagA ELISA developed by our group to detect anti-CagA antibody in patients infected with different cagA genotypes of H. pylori from four different countries in South Asia and Southeast Asia. The recombinant CagA protein was expressed and later purified using GST-tag affinity chromatography. The East Asian-type CagA-immobilized ELISA was used to measure the levels of anti-CagA antibody in 750 serum samples from Bhutan, Indonesia, Myanmar, and Bangladesh. The cutoff value of the serum antibody in each country was determined via Receiver-Operating Characteristic (ROC) analysis. The cutoff values were different among the four countries studied (Bhutan, 18.16U/mL; Indonesia, 6.01U/mL; Myanmar, 10.57U/mL; and Bangladesh, 6.19U/mL). Our ELISA had better sensitivity, specificity, and accuracy of anti-CagA antibody detection in subjects predominantly infected with East Asian-type CagA H. pylori (Bhutan and Indonesia) than in those infected with Western-type CagA H. pylori predominant (Myanmar and Bangladesh). We found positive correlations between the anti-CagA antibody and antral monocyte infiltration in subjects from all four countries. There was no significant association between bacterial density and the anti-CagA antibody in the antrum or the corpus. The East Asian-type CagA ELISA had improved detection of the anti-CagA antibody in subjects infected with East Asian-type CagA H. pylori. The East Asian-type CagA ELISA should, therefore, be used in populations predominantly infected with East Asian-type CagA.

Retraction statement: Vacuolating cytotoxin A (vacA) and cytotoxin‐associated gene A (cagA) genotypes of resistant Helicobacter pylori strains isolated from raw and pasteurized milk

The above article from the Journal of Food Safety, published online on November 25, 2018 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/full/10.1111/jfs.12583), has been retracted by agreement between the journal Editor‐in‐Chief, Vivian Wu and Wiley Periodicals, Inc. The retraction has been agreed due to evidence indicating that the peer review of this paper was compromised.

CYP2C19 Genotype, CagA Genotype and Antibiotic Resistant Strain of Helicobacter pylori Infection

Background: H. pylori is a class I carcinogen and major cause of gastric cancer. Few previous studies reported relationship between H. pylori infection, CYP2C19 genotype and functional dyspepsia (FD) subtype. The aim of this study was to determine relationship between CYP2C19 genotype and FD subtype patients(host factor) with antibiotic resistant strains of H. pylori infection and CagA genotype(bacterial factor). Methods:FD patients who were investigated with gastroscopy at Thammasat University Hospital, Thailand during March 2017-November 2017 were enrolled. Two antral gastric biopsies were obtained for rapid urease test, E-test and cultures. CagA genotypes (CagA1a and CagA2a) were determined by PCR and CYP2C19 genotype was determined by PCR-RFLP. FD patients were categorized as epigastric pain syndrome(EPS) and postprandial distress syndrome (PDS). Results:93 FD patients with H. pylori infection were enrolled (37 male, 56 female, mean age 54.5 years). There were 33 patients with EPS and 60 patients with PDS. CYP2C19 genotype revealed 55.9% rapid metabolizer (RM), 40.9% intermediate metabolizer (IM) and 3.2% poor metabolizer (PM) genotypes. Antibiotics susceptibility tests demonstrated 62.8% resistant to metronidazole, 12.9% resistant to clarithromycin and 27.1% resistant to fluoroquinolone. CagA 1a and CagA 2a were demonstrated in 6 patients(11.5%) and 46 patients(88.5%). CagA2a genotype was more prevalent in PDS than EPS patients (94.3%vs.76.5%; P =0.08) without significance. In intermediate metabolizer (IM), CagA2a genotype was significant higher in PDS than EPS(100% vs.25%; P=0.004). Conclusions:PDS, CYP2C19 RM genotype and CagA 2a gene of H. pylori infection were the predominant type of FD in Thailand. Metronidazole remain the most common antibiotic resistant strain of H. pylori infection in FD patients. PDS (host factor) was significantly related to CagA2a genotype (bacterial factors) only in patients with intermediate metabolizer. Appropriate dose of proton pump inhibitor (PPI) and correct regimens for H. pylori eradication in FD patients should be consider to improve clinical outcomes.

Association of the Helicobacter pylori cagA, vacA, and iceA genotypes with chronic follicular gastritis in a Colombian population at high risk for gastric cancer.

Follicular gastritis is associated with Helicobacter pylori infection, but little is known of its relation to bacterial genotypes. Our aim was to establish the relation between follicular gastritis and different H. pylori strains. An analytic case-control study was conducted that included 36 patients with follicular gastritis (cases) and 83 with nonatrophic gastritis (controls). The sociodemographic information was obtained through a questionnaire. Biopsies were evaluated according to the Sydney System and the Wotherspoon scoring system. Helicobacter pylori genotyping was performed using the polymerase chain reaction technique. The quantitative variables were presented as mean and standard deviation and the qualitative variables as proportions and absolute frequency. The effect of each variable on outcome (follicular gastritis) was evaluated through the odds ratio and its 95% confidence interval. Statistical significance was set at a P<0.05. Follicular gastritis was associated with Helicobacter pylori infection (OR: 13.41, CI: 1.7-103, P=0.01). The CagA+ genotype was present in 56.5% of the cases and 58% of the controls. The cytotoxic VacAs1m1strain was present in 82% of the isolates in both groups. IceA1 frequency was 34.8% in the cases and 26% in the controls and the difference was not statistically significant. The population studied had elevated frequencies of cytotoxic Helicobacter pylori strains and the iceA1 genotype was more frequent in follicular gastritis.

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

BackgroundThe 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.MethodsFour 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.ResultsOne 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.ConclusionsH. 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.

Comparative analysis of genotypes of Helicobacter pylori strains in the Rostov and Astrakhan regions

Objective:to study the infection of the adult and children’s population of the Rostov and Astrakhan regions by the bacteria Helicobacter pylori, to determine the frequency of H. pylori pathogenicity factors in different age groups of the population.Materials and methods:118 adults and 112 children were examined. Te presence of H. pylori DNA and the pathogenicity factors of CagA and VacA in the biopsy material of the mucous membrane of the antrum of the stomach was determined by PCR.Results:a signifcantly smaller percentage of H. pylori–positive patients is characteristic of the child population. Te prevalent H. pylori genotype in the infant population is the avirulent genotype Vac s2m2 (60%) (χ2: p &lt;0.005). Genotype CagA + VacAs1 VacAm1 is a marker of peptic ulcer for adult population of the Rostov region.Conclusion:Te conducted studies allowed to establish differences in infection of the population with H. pylori bacteria and the frequency of the distribution of virulent genotypes depending on the region, age and severity of the pathology.

The Significant Association of the dupA and cagA genes of Helicobacter pylori with Peptic Ulcer

Background: Helicobacter pylori play a significant etiological role in various digestive diseases. Peptic ulcer is caused by H. pylori, which destroys the duodenum mucus and is often observed in the individuals consuming tobacco, spicy and heavy meals, alcohol, coffee, and tranquilizers. Several studies have indicated that duodenal ulcer promoting genes dupA and cagA are involved in H. pylori etiology. The present study aimed to evaluate the correlation between these genes and peptic ulcer. Methods: In this study, 500 stomach biopsy samples were assessed based on the rapid urease test and polymerase chain reaction (PCR) for H. pylori infection, followed by histological and microscopic examinations. Results: The dupA and cagA genes were subjected to PCR. Although dupA showed no significant correlation with peptic ulcer, the cagA genotype had a significant association with peptic ulcer (P less-than 0.05). Similar to the dupA gene, blood group was not observed to be correlated with H. pylori infection. Conclusion: According to the results, there are significant correlations between tobacco use (P less-than 0.05), tranquilizer use (P less-than 0.05), and meteorism (P less-than 0.05) with peptic ulcer. In addition, the expression of the cagA and dupA genes was investigated in patients with non-ulcer dyspepsia and peptic ulcer.

Antimicrobial resistance and genotyping of vacA, cagA, and iceA alleles of the Helicobacter pylori strains isolated from traditional dairy products

AbstractDairy products play a considerable role in transmission of Helicobacter pylori. The current study was done to assess phenotypic characters of antimicrobial resistance and genotyping pattern of vacA, cagA, and iceA alleles among the H. pylori strains isolated from dairy products. Eight‐hundred dairy samples were collected and cultured. Antimicrobial resistance and genotyping patterns were assessed using disk diffusion and polymerase chain reaction, respectively. Thirty‐one out of 800 (3.87%) traditional dairy product samples were positive for H. pylori. Cheese (11.53%) samples had the highest incidence of H. pylori, while yoghurt (1.11%) had the lowest. Helicobacter pylori strains harbored the highest incidence of resistance against ampicillin (93.54%), amoxicillin (93.54%), tetracycline (90.32%), erythromycin (80.64%), and metronidazole (77.41%). VacA s1a (90.32%), m1a (90.32%), s2 (80.64%) and m2 (77.19%), cagA (51.61%), and iceA1 (32.25%) were the most routinely identified genotypes. S1am1a (67.74%), s2m1a (64.51%), and s1am2 (51.61%) were the most routinely identified genotyping pattern. Simultaneous presence of vacA, cagA, and iceA genotypes in antimicrobial resistant H. pylori strains indicates important public health issue regarding the consumption of dairy products. However, additional researches are required to find molecular genetic homology and other epidemiological aspects of H. pylori in dairy products.Practical applicationsDue to the high consumption rate of dairy samples, they should have a high microbial quality. Foods with animal origins and especially dairy samples are considered as a probable source of Helicobacter pylori infections. The incidence of contamination of dairy samples by H. pylori is fairly high, and nearly all of the isolates exhibited resistance against several types of antimicrobials and harbored pathogenic vacA, cagA, and iceA genotypes, so the risk of probable foodborne diseases caused by H. pylori in such products should not be neglected. Additionally, dairy samples may act as a reservoir of H. pylori with ability to transfer antimicrobial resistance and virulent genotypes.