Prevalence Of cagA Research Articles

Prevalence of cagA, cagM, vacA and oipA genes in isolates of Helicobacter pylori obtained from hospital patients in Northeast Brazil.

Helicobacter pylori is a major cause of gastrointestinal disorders such as chronic gastritis, peptic ulcers, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. It is estimated that around half of the world's population is infected with this pathogen, with underdeveloped countries reporting the highest frequencies. The genes cagA, cagM, vacA, and oipA are some of the most important virulence factors of H. pylori; however, there are no recent studies from Recife-PE demonstrating their frequency, and their relationship with severe gastric modifications. This work aims to use qualitative PCR to detect the virulence genes cagA, cagM, vacA, and oipA in H. pylori isolates obtained from patients in a public hospital in Recife (PE). We collected samples from the stomach's body and antrum of 147 patients, from which 71 (48%) tested positive for H. pylori. Among positive samples, the most frequently infected gender was female (44/71, 62%), and the most frequently infected age group was those above the age of 46 (31/71, 44%). Histological examination of H. pylori-positive samples revealed alterations other than chronic gastritis, including metaplasia and atrophy. The frequency of cagA, cagM, and oipA genes were identified in 84%, 56%, and 69% of the samples tested, respectively, as well as the vacA-s1m1 allelic combination (77%). However, there was no statistically significant variation in the occurrence of these genes, therefore they cannot be considered unique markers of severity in our setting. New research with larger samples and investigations of other genetic markers can aid uncover local risk factors and lead to a better understanding of H. pylori's pathogenesis.

CagA toxin and risk of Helicobacter pylori-infected gastric phenotype: A meta-analysis of observational studies.

Helicobacter pylori (H. pylori) is frequently associated with non-cardia type gastric cancer, and it is designated as a group I carcinogen. This study aimed to systematically review and meta-analyze the evidence on the prevalence of CagA status in people with gastric disorders in the Indo-Pacific region, and to examine the association of CagA positive in the risk of gastric disorders. This study focused on the Indo-Pacific region owing to the high disability adjusted life-years related to these disorders, the accessibility of efficient treatments for this common bacterial infection, and the varying standard of care for these disorders, particularly among the elderly population in the region. Relevant studies were identified in the health-related electronic databases including PubMed, Ovid, Medline, Ovid Embase, Index Medicus, and Google Scholar that were published in English between 1 January 2000, and 18 November 2023. For pooled prevalence, meta-analysis of proportional studies was done, after Freeman-Tukey double arcsine transformation of data. A random-effect model was used to compute the pooled odds ratio (OR) and 95% confidence interval (CI) to investigate the relationship between CagA positivity and gastric disorders. Twenty-four studies from eight Indo-Pacific countries (Bhutan, India, Indonesia, Malaysia, Myanmar, Singapore, Thailand, Vietnam) were included. Overall pooled prevalence of CagA positivity in H. pylori-infected gastric disorders was 83% (95%CI = 73-91%). Following stratification, the pooled prevalence of CagA positivity was 78% (95%CI = 67-90%) in H. pylori-infected gastritis, 86% (95%CI = 73-96%) in peptic ulcer disease, and 83% (95%CI = 51-100%) in gastric cancer. Geographic locations encountered variations in CagA prevalence. There was a greater risk of developing gastric cancer in those with CagA positivity compared with gastritis (OR = 2.53,95%CI = 1.15-5.55). Findings suggest that the distribution of CagA in H. pylori-infected gastric disorders varies among different type of gastric disorders in the study countries, and CagA may play a role in the development of gastric cancer. It is important to provide a high standard of care for the management of gastric diseases, particularly in a region where the prevalence of these disorders is high. Better strategies for effective treatment for high-risk groups are required for health programs to revisit this often-neglected infectious disease.

The Relation Between Host TLR9 -1486T/C, rs187084 Gene Polymorphisms and Helicobacter pylori cagA, sodB, hsp60, and vacA Virulence Genes among Gastric Cancer Patients.

To identify the associations between different genotypes of TLR9 -1486T/C (rs187084) with gastric cancer patients and reveal their relation to Helicobacter pylori virulence genes (cagA, sodB, hsp60 and vacA). Patients with gastric cancer were recruited to our study, diagnosed both endoscopically and histopathologically. H. pylori were isolated from gastric samples by culture and PCR amplification of the glmM gene. Virulence genes cagA, sodB, hsp60, and vacA were detected by multiplex PCR. Blood samples were used for genotyping of TLR9 -1486T/C (rs187084) by PCR-RFLP. Out of 132 patients with gastric cancer, 106 (80.3%) were positive for H. pylori. A similar number of healthy participants was recruited as controls. The prevalence of cagA, sodB, hsp60, and vacA genes among H. pylori was 90.6%, 70.8%, 83.0%, and 95.3%, respectively. The vacA gene alleles had a prevalence of 95.3% for vacAs1/s2, 52.8% for vacAm1, and 42.5% for vacAm2. The CC genotype of TLR9 -1486T/C had a significantly higher frequency in gastric cancer patients when compared to healthy participants (p = 0.045). Furthermore, the CC genotype demonstrated a significant association with H. pylori strains carrying sodB, hsp60, and vacAm1 virulence genes (p = 0.021, p = 0.049, and p = 0.048 respectively). Patients with CC genotype of TLR9 -1486T/C (rs187084) might be at higher risk for the development of gastric cancer, and its co-existence with H. pylori strains carrying sodB, hsp60, or vacAm1 virulence genes might have a synergistic effect in the development of gastric cancer. Further studies on a wider scale are recommended.

PREVALENCE OF CAGA GENE AND VACA GENOTYPES OF HELICOBACTER PYLORI AMONG PATIENTS WITH GASTRODUODENAL DISSEASES

Background: Helicobacter pylori is an agent of gastric cancer that was classified as a group I carcinogen. cagA and vacA genes of H. pylori play important roles in the pathogenesis of gastroduodenal diseases. This research aimed to: (1) To determine the prevalence of cagA and vacA genotypes of H. pylori among patients with gastroduodenal diseases. (2) To investigate the association between cagA and vacA genotypes and gastroduodenal diseases. Patients and methods: One hundred and fifteen gastroduodenal disease patients infected with H. pylori were enrolled in this study. cagA and vacA genotypes were determined by PCR. Result: The rate of cagA-positive H. pylori strains was 80%. The most common genotype combinations were cagA (+)/ vacA s1m1i1 (39.1%) and cagA (+)/vacA s1m2i1 (25.2%). The cagA (+)/vacA s1m1i1 strain was predominant in peptic ulcer group (59.3%), whereas the cagA (+)/vacA s1m2i1 strain accounted for a high rate in gastric cancer group (75%). Conclusion: Prevalence of H. pylori strains carrying the cagA gene was quite high, and vacA smi genotypes were diverse. cagA (+)/vacA s1m1i1 strain was associated with peptic ulcer disease while cagA (+)/vacA s1m2i1 strain was associated with gastric cancer. Key words: Helicobacter pylori, gene cagA, gene vacA, gastroduodenal diseases.

Racial Differences in Helicobacter pylori Prevalence in the US: A Systematic Review.

Helicobacter pylori remains an important risk factor for noncardia gastric cancer and a spectrum of disease from H. pylori infection to gastric cancer. As a step toward improved clinical strategies for gastric cancer prevention, we assessed racial differences in prevalence of H. pylori from studies across the United States. This systematic review provides a comprehensive evaluation of the literature regarding racial differences in H. pylori in the United States. MEDLINE, Embase, and Web of Science database searches were performed through May 26, 2021. Ultimately, 25 studies that reported H. pylori infection prevalence by race were included. All studies included in the review documented higher H. pylori prevalence in Blacks and Hispanics than in whites. The ratio of H. pylori prevalence for Blacks compared to non-Hispanic whites ranged from 1.3 to 5.4, and the ratio for Hispanics compared to non-Hispanic whites ranged from 1.8 to 4.4. Of the 5 studies that examined H. pylori CagA prevalence by race, 4 found higher prevalence among Blacks and Hispanics compared to whites, with CagA prevalence ranging from 19% to 77% in whites, 62% to 90% in Blacks, and 64% to 74% in Hispanics. In this review, across 25 studies, varying in underlying population, time period, and geographic location, Blacks and Hispanics appeared to have a higher prevalence of H. pylori infection than whites. This increased prevalence of H. pylori among populations also at a higher risk of gastric cancer is relevant in the clinical setting for decision-making related to H. pylori testing and gastric cancer prevention.

Determine the Prevalence of cagA and Baba of Helicobacter Pylori Isolated from Gastric Atrophic Patients

Objective: The aim of this study is to determine the prevalence of cagA and babA of helicobacter pylori isolated from gastric atrophic patients. Study Design: Descriptive/Analytical Place and Duration: The study was conducted at Medicine/Gastroenterology department of Khyber Teaching Hospital and Peshawar Institute of Medical Sciences, Peshawar for six months duration from March 2020 to August 2020. Methods: Total one hundred and twenty patients of both genders were presented in this study. Patients were aged between 20-80 years of age. Patients detailed demographics age, sex and body mass index were recorded after taking informed written consent. All patients of gastroduodenal disorders were undergone for isolation of bacteria by using standard techniques. Complete data was analyzed by SPSS 22.0 version. Results: Total 50 (41.7%) patients were males and 70 (58.3%) patients were females. Mean age of the patients were 41.96 ± 16 years with mean BMI 25.24 ± 4.8 kg/m2. Frequency of H pylori was isolated in 30 (25%) patients in which 13 patients had atrophic gastritis, 9 patients had gastric ulcer and 8 patients had acute gastritis. Prevalence of cagA gene was 16 (53.33%) and babA was 10 (33.33%) in H. pylori isolated patients. Significantly difference with p value <0.05 was observed between cagA positive strains and patients of gastric atrophic. The involvement of gastric atrophic patients was not correlated to the babA gene. Conclusion: We concluded in this study that different cagA positive H. pylori can be retrieved from gastric atrophy patients. Keywords: Gastric atrophy, Gastric cancer, cagA, babA, Helicobacter pylori

Identification of New Helicobacter pylori Subpopulations in Native Americans and Mestizos From Peru.

Region-specific Helicobacter pylori subpopulations have been identified. It is proposed that the hspAmerind subpopulation is being displaced from the Americans by an hpEurope population following the conquest. Our study aimed to describe the genomes and methylomes of H. pylori isolates from distinct Peruvian communities: 23 strains collected from three groups of Native Americans (Asháninkas [ASHA, n = 9], Shimaas [SHIM, n = 5] from Amazonas, and Punos from the Andean highlands [PUNO, n = 9]) and 9 modern mestizos from Lima (LIM). Closed genomes and DNA modification calls were obtained using SMRT/PacBio sequencing. We performed evolutionary analyses and evaluated genomic/epigenomic differences among strain groups. We also evaluated human genome-wide data from 74 individuals from the selected Native communities (including the 23 H. pylori strains donors) to compare host and bacterial backgrounds. There were varying degrees of hspAmerind ancestry in all strains, ranging from 7% in LIM to 99% in SHIM. We identified three H. pylori subpopulations corresponding to each of the Native groups and a novel hspEuropePeru which evolved in the modern mestizos. The divergence of the indigenous H. pylori strains recapitulated the genetic structure of Native Americans. Phylogenetic profiling showed that Orthogroups in the indigenous strains seem to have evolved differentially toward epigenomic regulation and chromosome maintenance, whereas OGs in the modern mestizo (LIM) seem to have evolved toward virulence and adherence. The prevalence of cagA+/vacA s1i1m1 genotype was similar across populations (p = 0.32): 89% in ASHA, 67% in PUNO, 56% in LIM and 40% in SHIM. Both cagA and vacA sequences showed that LIM strains were genetically differentiated (p < 0.001) as compared to indigenous strains. We identified 642 R-M systems with 39% of the associated genes located in the core genome. We found 692 methylation motifs, including 254 population-specific sequences not previously described. In Peru, hspAmerind is not extinct, with traces found even in a heavily admixed mestizo population. Notably, our study identified three new hspAmerind subpopulations, one per Native group; and a new subpopulation among mestizos that we named hspEuropePeru. This subpopulation seems to have more virulence-related elements than hspAmerind. Purifying selection driven by variable host immune response may have shaped the evolution of Peruvian subpopulations, potentially impacting disease outcomes.

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, cagC, virB2, and vacA Subtypes of Helicobacter pylori with Adenocarcinoma Development in Iranian Patients

Background: Gastric cancer has been introduced as the second cause of cancer death worldwide. Helicobacter pylori infection is considered one of the main risk factors for this type of cancer, so that it has been classified as group I carcinogens. Objectives: The present research intended to examine the prevalence of cagA, cagC, virB2, vacA, and genotype distribution in H. pylori-infected biopsies and adenocarcinoma cases. Methods: Thirty-four H. pylori gastric biopsies taken from Western Iranian patients that were diagnosed as gastritis, gastric ulcers, and adenocarcinoma were used in this study. Two samples were taken from each patient. These samples were selected based on endoscopic observations and histological examinations. The presence of H. pylori was confirmed by the Rapid Urease test (RUT) and the ureC gene by the polymerase chain reaction (PCR) technique. Then, specific primers for vacA and cagPAI were used for genotyping H. pylori by PCR-typing. Results: The obtained results showed that 86.8% of the samples were H. pylori-positive. Moreover, the cagA gene prevalence was 51.50% in the samples. In addition, the adenocarcinoma outcome was significantly related to all selected genes. Likewise, some gastric diseases such as gastric ulcers, duodenal ulcer (DU), gastritis, lymphoid, and gastroesophageal reflux disease (GERD) were observed in adenocarcinoma cases. It was also found that the vacAs1m1i1 genotype plays an important role in gastric malignancies. The most frequent vacA genotype in the H. pylori-infected isolates was s1m1i1, and the observed frequency of vacA and cagA genes in adenocarcinoma was statistically significant. Conclusions: The findings showed that H. pylori vacA and cagA gene virulence factors are associated with adenocarcinoma in Western Iranian patients.

Existence of Helicobacter pylori with low virulence rate in dental plaque and gastric mucosa of patients with periodontal disease

Objective: Helicobacter pylori is associated with gastric and peptic ulcer leading to gastric cancer progress. Gingival teeth grooves among patients with chronic periodontitis can act as reservoirs for H. pylori proliferation. The purpose of our study was assessment the association of H. pylori from dental plaques of patients with periodontitis with gastric colonization. Methods: Among patients with periodontitis admitted to dentistry centers, 250 dental plaque and 250 gastric biopsy samples were obtained during 2016–2019. After bacterial identification, virulence genes including cagA, cagT, cagE, vacA and hrgA were screened using PCR technique. Results: Fifty and 75 isolates were identified in periodontitis and biopsy specimens, respectively. In periodontitis strains, the rete of cagA, cagT, cagE, vacA and hrgA were as 18 (36%), 15 (30%), 14 (28%), 6 (12%) and 6 (12%), respectively. Among 75 biopsy strains, prevalence of cagA, cagT, cagE, vacA and hrgA were as 28 (34%), 24 (32%), 19 (25.3%), 11 (14.66%) and 7 (0.14%), respectively. There was higher rate of gastric ulcer among ages more than 45 years compared with age ranges 1–15 and 20–45 years (P < 0.01 and P = 0.004, respectively). No significant difference between men and women (35/75 vs. 40/75) was observed. Conclusion: Although the prevalence of virulence genes was low among H. pylori strains from dental plaques, a relatively high-density of H. pylori among both sources was considerable. Accordingly, H. pylori possibly spread from dental plaque into gastric mucosa. Furthermore, the possible role of dental plaques among patients with periodontitis as sources for peptic ulcer by pathogenic H. pylori needs more in-depth verifications.

The prevalence of Helicobacter pylori cagA (+ve) among patients with gastric cancer: an Egyptian study

Introduction and aimsGastric cancer is currently the second most common cause of cancer-related death in the world and the fifth most common cancer and the fourth leading cause of cancer-related death in Europe. It has been evident for more than the past 20 years that Helicobacter pylori is involved in the development of gastric adenocarcinoma. The cagA gene of H. pylori is the main virulence factor that leads to the development of gastric adenocarcinoma through the derangement of cellular architecture and signaling. The objective of our work is to study the prevalence of cagA among patients with gastric cancer.Patients and methodsThis descriptive study was done on 60 patients with gastric cancer underwent serum anti-H. pylori IgM and anti-cagA IgG assessment, computed tomography, upper endoscopy, and biopsy taking, and if needed, computed tomography-guided biopsy, followed by histopathological examination.ResultsA total of 34 (56.67%) patients were cagA +ve and 26 (43.33%) patients were cagA -ve, with no statistically significant difference regarding sex or age.ConclusionH. pylori cagA plays a significant role in development of gastric cancer, so we recommend not only H. pylori screening but also cagA virulence strain.

Clarithromycin-Susceptible But Virulent Helicobacter pylori Strains Infecting Iranian Patients' Stomachs.

IntroductionHelicobacter pylori was discovered first in the stomachs of patients with gastritis and ulcers by Marshall and Warren in 1982. This discovery majorly affected many research areas of gastroenterology. Since then, the main aim has been to eradicate this microaerophilic bacterium from the stomachs of infected subjects.MethodsWe studied symptomatic cases by endoscopic surgery and examined the prevalence of cagA–vacA genotypes among the H. pylori isolates. H. pylori isolated from antral biopsies of patients with gastritis and duodenal ulcer were subjected to antimicrobial susceptibility testing and PCR genotyping by using routine bacterial cultures. Clarithromycin-susceptibility profiling was done by the E-test. DNA was extracted using standard manufacturer protocols with minor modifications and cagA and vacA genotyping was done PCR.ResultsIn our study, all strains identified as H. pylori in culture (61/81) were confirmed by PCR by amplifying a fragment of the glmM gene. Totally, 61 patients were confirmed to be positive for H. pylori and they were included in the genotyping and antibiotic-susceptibility testing. Thirteen H. pylori strains were determined to be resistant to clarithromycin.DiscussionCurrent accumulating data indicate that both clarithromycin-resistant and susceptible isolates of H. pylori need to be screened and tracked in populations.

Concurrent detection of cagA, vacA, sodB and hsp60 virulence genes and their relationship with clinical outcomes of disease in Helicobacter pylori isolated strains of southwest of Iran

Helicobacter pylori is a Gram-negative spiral-shaped bacterium that contaminates more than half of the world's inhabitants, and infection with this bacterium is associated with some gastric disorders. Also, 5% to 10% of H. pylori genes are specific to this bacterium and many bacterial virulence factors fall into this group. The cagA, vacA, sodB and hsp60 are among important virulence factors of H. pylori. A gastric biopsy specimen was taken from 341 gastric patients and cultivated on a Colombia agar plate, containing various antibiotics, such as vancomycin, amphotericin B, and trimethoprim & polymyxin B, and incubated for 3 to 10 days under microaerophilic conditions at 37°C. PCR was used to detect the ureC, cagA, vacA, sodB and hsp60 genes. In this study, 131 isolates were identified as H. pylori. The prevalence of cagA, vacA, sodB and hsp60 were 74%, 100%, 92.4% and 96.2%, respectively. The correlation between the clinical forms of the disease and the virulence genes were analyzed by statistical tests and no significant correlation was found. The obtained results are similar to some studies conducted in different parts of the world and is different in other cases. This discrepancy is due to the difference in the type of gastric disorders, sample size and methodology.

Characterization of Helicobacter pylori genotypes from Iranian patients with gastric clinical diseases: Predominance of vacA s1a and cagA EPIYA-ABC genotypes

ObjectivesHelicobacter pylori is a causative agent of peptic ulcers and associated with gastric cancer. The major virulence factors of this organism are vacA and cagA genes. The vacA comes in a mosaic structure and the cagA become activated through a repetitive motif including glutamine (E), proline (P), isoleucine (I), tyrosine (Y) and alanine (A), shortly be called EPIYA. The aim of this study was to characterize the genotypes and the antibiotics resistance pattern of H. pylori isolates in Iranian patients with chronic gastritis, non-ulcer dyspepsia (NUD) and peptic ulcer disease (PUD). Methods191 biopsy samples were obtained from patients referred to Afzalipour hospital in Kerman, during November 2017 to October 2018 and cultured to isolate H. pylori. Isolates were confirmed as H. pylori using PCR with the 16s rRNA specific primers. Antimicrobial susceptibility testing was performed using the modified disk diffusion method and genotyping was done by PCR using the specific primers for vacA, cagA and glmM. ResultsFrom 191 samples, 63 H. pylori isolates were obtained. These, isolated from patients with chronic active gastritis (73%, n = 46), PUD (9.5%, n = 6) and NUD (17.5%, n = 11). Resistance to metronidazole was 55.5%, while the resistance to clarithromycin was 37%. There was no resistance to furazolidone. The most prevalent virulence gene among our isolates was vacA with 89%, while the prevalence of cagA and glmM genes were 59% and 81% respectively. CagA-EPIYA-ABC was the most prevalent motif in chronic gastritis (83%), PUD (75%), and NUD (61%). CagA-EPIYA-ABCC was more prevalent in NUD cases (23%). ConclusionIn this study there was no statistical significant relation between the gastric diseases and the genotypes of H. pylori. This is the first report of H. pylori isolates genotyping in south east of Iran which indicating a diversity among these isolates.

Detection of CagA, VacA, IceA1 and IceA2 virulent genes in Helicobacter pylori isolated from gastric ulcer patients

Abstract Background Virulence factors of Helicobacter pylori including cagA, vacA, iceA and their association with clinical manifestation varied widely with different subpopulations. The objective of the study was to determine the prevalence of cagA, iceA1, iceA2, vacA, vacA s1/s2, vacA m1/m2, Western type cagA and East Asian type cagA virulence genes in H. pylori isolated from gastric ulcer patients and evaluate the association of these genes with gender, age, smoking and alcohol consumption. Methods Gastric biopsy samples from 172 patients were collected. H. pylori virulence genes, cagA, vacA, iceA1, iceA2, vacA s1/s2, vacA m1/m2, Western type cagA and East Asian type cagA were detected using polymerase chain reaction (PCR). Results Of the gastric biopsy samples collected, 48.3% of samples grew H. pylori. The vacA (68.7%) was the predominant virulence gene detected and associated with male patients and patients within the age group of 31–40 years. The cagA was the second most common gene detected and significantly associated with alcoholic patients. Conclusions H. pylori infection rate was 48.3% and was associated with patients who were smokers or had a history of smoking. The majority of our isolates were positive for any one of the virulence genes tested indicating that these isolates were highly virulent in nature.

Prevalence of CagA and antimicrobial sensitivity of H. pylori isolates of patients with gastric cancer in Egypt

BackgroundHelicobacter pylori (H. pylori) infection has been recognized as a significant threat for gastric cancer. However, studies that investigated the oncogenic factors and antimicrobial resistance of H. pylori in Egyptian isolates with gastric cancer are rare. The current study aimed to examine: (1) The pattern of antimicrobial resistance of H. pylori isolates of Egyptian gastric cancer patients, and (2) the prevalence of Cytotoxin-associated gene A (CagA).MethodsSamples were collected from patients with gastric cancer. Isolation of H. pylori was performed using Columbia blood agar supplemented with 10% horse blood, and selective supplement of H. pylori for 3 to 5 days at 37 °C under microaerophilic condition. Isolates were identified by biochemical traits of H. pylori: oxidase, urease and catalase tests. Antimicrobial susceptibility of H. pylori isolates was examined against five antimicrobial agents using disc diffusion method. After that, extraction of DNA and Polymerase Chain Reaction (PCR) were performed to amplify the target genes.ResultsTwelve samples were collected from six males and six females Egyptian patients with cancer with an age range from 22 to 65 years. These cases are scarce and samples were collected over a period of almost eleven months. All isolates were confirmed as positive H. pylori through colony morphology and biochemical tests. The most effective antibiotic found was ciprofloxacin whereas all isolates showed resistance to metronidazole and erythromycin. The target CagA oncogene gene with expected product size was reported and seven (out of twelve) isolates (58%) were identified as CagA positive.ConclusionThe current study is unique in two main aspects. First, it reported the pattern of antimicrobial susceptibility and prevalence of CagA gene in H. pylori from Egyptian patients. Second, it exclusively recruited isolates from gastric cancer patients which were confirmed by clinical and laparoscopic examination. The moderately high prevalence of CagA gene in Egyptian cancer patients calls for more vigilance against that oncogene.

Helicobacter pylori Western cagA genotype in Egyptian patients with upper gastrointestinal disease

BackgroundInfection with Helicobacter pylori (H. pylori) causes persistent gastritis that may progress to fatal gastric cancer. The cytotoxin-associated gene A protein (CagA), encoded by the cytotoxin-associated gene A (cagA) is the main virulence factor associated with more severe clinical outcomes. It is further divided into Western-type CagA and East Asian-type CagA. The East Asian-type CagA induces more cytoskeleton changes and is more likely to be associated with gastric cancer. Aim of the studyIn the current study we aimed to identify the most prevalent H. pylori cagA genotype among Egyptian patients suffering from dyspepsia and to examine its possible correlation with the associated clinical condition. Patients and methodsFour biopsies were obtained from the antrum and angularis from each of 113 adult patients, who underwent upper endoscopy at the Endoscopy Unit, Theodor Bilharz Research Institute (TBRI) Hospital for the analysis of H. pylori by rapid urease test and detection of 16S rRNA. Nested PCR assay was used to determine cagA genotype. ResultsSixty (53.1%) dyspeptic patients were found infected with H. pylori. Although Egypt has a high prevalence of H. pylori infection, low prevalence of cagA was detected (26.5%). Western type cagA is the predominant type (62.5%) while East Asian type was not detected and others (37.5%) remain uncharacterized. Western-genotype cagA genotype was found in 80% of patients with peptic ulcer disease and 40% of patients with gastritis. ConclusionAbsence of the more virulent East Asian cagA genotype, which is the strongest risk factor for gastric carcinogenesis, may explain the very low gastric cancer rate among Egyptian population compared to other parts of the world. This finding demands further molecular studies using whole genome sequencing and more samples to determine the exact uncharacterized cagA genotype to identify the actual risk in developing gastroduodenal diseases in Egypt.

When is Helicobacter pylori acquired in populations in developing countries? A birth-cohort study in Bangladeshi children

ABSTRACTHelicobacter pylori colonization is prevalent throughout the world, and is predominantly acquired during childhood. In developing countries, >70% of adult populations are colonized with H. pylori and >50% of children become colonized before the age of 10 years. However, the exact timing of acquisition is unknown. We assessed detection of H. pylori acquisition among a birth cohort of 105 children in Mirzapur, Bangladesh. Blood samples collected at time 0 (cord blood), and at 6, 12, 18, and 24 months of life were examined for the presence of IgG and IgA antibodies to whole cell H. pylori antigen and for IgG antibodies to the CagA antigen using specific ELISAs and immunoblotting. Breast milk samples were analyzed for H. pylori-specific IgA antibodies. Cord blood was used to establish maternal colonization status. H. pylori seroprevalence in the mothers was 92.8%. At the end of the two-year follow-up period, 50 (47.6%) of the 105 children were positive for H. pylori in more than one assay. Among the colonized children, CagA prevalence was 78.0%. A total of 58 children seroconverted: 50 children showed persistent colonization and 8 (7.6%) children showed transient seroconversion, but immunoblot analysis suggested that the transient seroconversion observed by ELISA may represent falsely positive results. Acquisition of H. pylori was not influenced by the mother H. pylori status in serum or breastmilk. In this population with high H. pylori prevalence, we confirmed that H. pylori in developing countries is detectable mainly after the first year of life.

Helicobacter pylori infection increases sirt2 gene expression in gastric epithelial cells of gastritis patients

BackgroundHelicobacter pylori Infection causes some clinical features of the human stomach such as gastritis, duodenal ulcer, and gastric cancer. It has been shown that Helicobacter pylori infection increases proinflammatory cytokine gene expressions in Gastric Epithelial Cells by activation of NF-kB signaling. Sirt1 and sirt2 as deacetylases play a certain role in the progress of inflammation in arthritis and lung infection by impacting the NF-kB. AimsSirt1 and sirt2 gene expressions in Gastric Epithelial cells of gastritis patients were surveyed with and without Helicobacter pylori infection and rate of prevalence of cagA and hopQ genes in Helicobacter pylori strains were investigated. Methods25 biopsy samples of gastritis patients with Helicobacter pylori infection and 25 biopsy samples of gastritis patients without Helicobacter pylori infection were collected from Tohid Hospital in the city of Sanandaj throughout the year 2016. CDNA was made from total RNA extracted from biopsy samples (Qiagen® Kit). Sirt1 and sirt2 gene expressions were determined using the Corbett machine (Rotor-Gene 6000 Software). CagA and hopQ genes of Helicobacter pylori strains were determined by PCR using specific primers. ResultsThe sirt2 gene expression was increased in Gastric Epithelial Cells of gastritis patients with Helicobacter pylori infection. No significant relationship was found between sirt1 and sirt2 gene expressions as well as cagA and hopQ as Helicobacter pylori virulence genes. ConclusionsThis study shows the Helicobacter pylori infection duo to sirt2 gene up-expression. There is not a statistically significance relationship between cagA and hopQ Helicobacter pylori genotypes and sirt2 gene up-expression in Gastric Epithelial Cells of gastritis patients.

The Prevalence of Helicobacter pylori in Estonian Bariatric Surgery Patients.

Helicobacter pylori (Hp) is one of the most important human pathogens that can cause duodenal and gastric ulcers, gastritis and stomach cancer. Hp infection is considered to be a cause of limiting access to bariatric surgery. The aim of this study was to determine the prevalence of Hp in patients with obesity going into bariatric surgery and to reveal the relationship between Hp and clinical data. The study group was formed of 68 preoperative bariatric surgery patients (body mass index (BMI) 44.7 ± 4.8). Gastric biopsies (antrum and corpus) were used for histological and molecular (caqA and glmM genes) examinations. The PCR method revealed Hp infection in 64.7% of obese patients that is higher in comparison with histological analysis (55.9%). The prevalence of cagA and glmM genes in antrum mucosa was 45.6% and 47.0% while in the corpus it was 41.2% and 38.3%, respectively. The coincidence of both cagA and glmM virulence genes in the antrum and corpus mucosa was 33.8% and 22.1%, respectively. Either of the genes was found in 58.8% of antrum and 57.3% of corpus mucosa. Presence of caqA and glmM genes was in association with active and atrophic chronic gastritis. In conclusion, our study demonstrated that two thirds of morbidly obese patients undergoing bariatric surgery are infected with Hp and have a high prevalence of cagA and glmM virulence genes that points out the necessity for diagnostics and treatment of this infection before surgery.