Prevalence of cagA in relation to clinical presentation of Helicobacter pylori infection in Egypt

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

BACKGROUND

Helicobacter 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).

METHODS

Samples 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.

RESULTS

Twelve 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.

CONCLUSION

The 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.

Prevalence of Helicobacter pylori cagA and iceA Genes and Their Association with Gastrointestinal Diseases

H. pylori infection causes peptic ulcer, chronic gastritis, mucosa-associated lymphoid tissue lymphoma, and gastric carcinoma. It has several virulence factors such as cytotoxin-associated gene A(cagA) and the induced by contact with epithelium antigen (iceA). We aimed to explore the relationship between cagA and iceA of H. pylori and gastrointestinal diseases. One hundred and eighteen patients who attended Gastrointestinal Endoscopy Unit at Zagazig University Hospitals, Egypt, were included in this study. Two gastric biopsies were collected and evaluated by rapid urease test (RUT) and PCR. cagA and iceA genes were amplified by PCR. We found that 54 patients (45.76%) were positive by both RUT and PCR. cagA and iceA genes were present in 57.4% and 46.29% of the studied patients, respectively. cagA was the most prevalent gene in gastritis (33.3%) and peptic ulcer (68.7%). iceA1/iceA2 positive genes were the most prevalent in gastric cancer (75%). iceA1 gene was present in 38.7% of cagA positive cases, but iceA2 gene was present in 45.2% of cagA positive cases. iceA1/iceA2 positive genes were present in 29% of cagA positive cases. In conclusion, cagA and iceA genes could be used as markers for severe gastrointestinal diseases. iceA gene was strongly related to cagA gene.

Endoscopic and histological findings and Helicobacter pylori status in patients with reflux and/or dyspeptic symptoms: a recent Greek cohort study

The associations between symptoms and endoscopic findings have not been clearly defined. We aimed to assess the associations of reflux dyspepsia and/or symptoms with specific endoscopic findings, histological findings, as well as the presence of Helicobacter pylori infection and its CagA subtype. A total of 160 patients with dyspeptic and/or reflux symptoms underwent upper gastrointestinal endoscopy. Type and severity of symptoms during the last week were evaluated according to a questionnaire. Biopsy specimens were obtained from the esophagus and stomach. Presence of H. pylori was tested in tissue specimens and its CagA subtype in serum samples. Of the 160 patients, 70% reported reflux, 73.7% dyspeptic symptoms, while 43.7% of patients reported both. The major endoscopic findings were chronic gastritis (n = 134), hiatal hernia (n = 98), and erosive esophagitis (n = 55). There was no significant difference in the endoscopic findings of patients with and without dyspepsia except for the subgroup of ulcer-like dyspeptic patients with significantly more frequently erosive peptic lesions (25% vs. 8.7%, p = .01). Patients with reflux symptoms had more frequently erosive esophagitis (42.9% vs. 14.6%, p = .001). Types of histological lesions, presence of H. pylori infection, and its cagA subtype had no statistical difference with presence or not of any symptoms. Patients with compared with those without reflux or ulcer-like dyspeptic symptoms had endoscopically more frequently erosive esophagitis and erosive peptic lesions, respectively. On the contrary, there is no statistical difference regarding the histological lesions, the presence of H. pylori, and its cagA subtype in all subgroups of patients.

Correlation Between Mucosal IL-6 mRNA Expression Level and Virulence Factors of Helicobacter pylori in Iranian Adult Patients With Chronic Gastritis

BACKGROUND

Helicobacter pylori infection is associated with gastritis and marked infiltration of the gastric mucosa by several cytokines secreting inflammatory cells that contribute to sustained local inflammation. In this study, we sought to examine IL-6 expression in H. pylori-infected and uninfected gastric mucosa and elucidate the implication in the pathogenesis of H. pylori-associated gastritis in human.

OBJECTIVES

The current study aimed to determine mucosal IL-6 mRNA expression level and their correlation with virulence factors and the grade of chronic gastritis among H. pylori infected patients with chronic gastritis from Shahrekord, Iran.

PATIENTS AND METHODS

Mucosal IL-6 mRNA levels was measured by real-time PCR using endoscopic biopsies taken from the gastric antrum of 58 subjects infected with H. pylori and 44 uninfected subjects. Presence of vacA and cagA virulence factors was evaluated using PCR.

RESULTS

The IL-6 mRNA expression levels were significantly more elevated in H. pylori-positive patients than uninfected individuals and expression of this cytokine was independent from the virulence factors. There was a correlation between IL-6 expression level and the grade of chronic gastritis.

CONCLUSIONS

Enhanced induction of IL-6 may be involved in the pathogenesis of H. pylori-associated gastritis.

Association of smoking, alcohol and NSAIDs use with expression of cag A and cag T genes of Helicobacter pylori in salivary samples of asymptomatic subjects

OBJECTIVE

To determine the association of smoking, alcohol and nonsteroidal anti-inflammatory drugs (NSAIDs) use with presence and virulence of Helicobacter pylori (H. pylori) infection in a representative sample of a random adult population of asymptomatic subjects.

METHODS

Non virulent 16S rRNA and virulent cag A and T genes from salivary samples of 854 asymptomatic subjects were determined using polymerase chain reaction. The presence and absence of virulent and non virulent infection was statistically compared with consumption of smoking, alcohol and NSAIDs.

RESULTS

The prevalence of infection in male and female subjects was found to be 69.25% and 66.90%, respectively. The prevalence of infection in the population of asymptomatic subjects with respect to consumption of alcohol was as follows: current (31.22%), former (52.20%) and never (43.58%). The prevalence of infection in the population of asymptomatic subjects with respect to smoking of cigarettes was as follows: current (88.80%), former (57.14%) and never (33.33%). The prevalence of infection in the subject population consuming NSAIDs and not consuming NSAIDs frequently was found to be 82.75% and 21.16%, respectively. Virulence in male and female subjects was found to be 60.00% and 50.00%, respectively. The presence of virulent infection in the population of asymptomatic subjects with respect to consumption of alcohol was as follows: current (28.57%), former (40.15%) and never (50.00%). The prevalence of virulent infection in the population of asymptomatic subjects with respect to smoking of cigarettes was as follows: current (79.32%), former (75.00%) and never (50.00%). The prevalence of virulent infection in the subject population consuming NSAIDs and not consuming NSAIDs frequently was found to be 88.23% and 66.66%, respectively.

CONCLUSIONS

It can be concluded that smoking and NSAIDs consumption are aggravating factors for virulence of H. pylori and alcohol can inhibit H. pylori infection in asymptomatic subjects.

Helicobacter pylori immunoproteomics in gastric cancer and gastritis of the carcinoma phenotype

Helicobacter pylori infection is linked to the development of gastric cancer. Atrophic body gastritis is considered the first important step in the histogenesis of such neoplasia. H. pylori infection is involved in the induction of atrophic body gastritis, but documentation of H. pylori infection is difficult because of the progressive disappearance of the bacterium. Host-pathogen interactions may be investigated by means of immunoproteomics, which provides global information regarding the host humoral response to H. pylori infection and allows the identification of relevant specific and nonspecific antigens, and can be used for diagnostic or prognostic purposes. In the present review, we describe how several research groups used H. pylori immunoproteomics to investigate highly immunoreactive bacterial antigens related to the development of gastric cancer.