Presence of the Genes cagA, cagE, virB11 and Allelic Variation of vacA of Helicobacter pylori Are Associated with the Activity of Gastritis (original) (raw)
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Frequency of virulence factors in Helicobacter pylori-infected patients with gastritis
Microbial Pathogenesis, 2015
The outcome of Helicobacter pylori infection has been related to specific virulence-associated bacterial genotypes. The vacuolating cytotoxin (vacA), cagA gene, oipA and babA2 gene are important virulence factor involving gastric diseases. The objective of this study was to assess the relationship between virulence factors of H. pylori and histopathological findings. Material and methods: Gastroduodenoscopy was performed in 436 dyspeptic patients. Antrum biopsy was obtained for detection of H. pylori, virulence factors and for histopathological assessment. The polymerase chain reaction was used to detect virulence factors of H. pylori using specific primers. Results: vacA genotypes in patients infected with H. pylori were associated with cagA, iceA1 and iceA2. In the patients with H. pylori infection there was a significant relationship between cagA positivity and neutrophil activity (P ¼ 0.004) and chronic inflammation (P ¼ 0.013) and with H. pylori density (P ¼ 0.034). Neutrophil infiltration was found to be more severe in the s1 group than in the s2 group (P ¼ 0.042). Also was a significant relationship between oipA positivity and neutrophil activity (P ¼ 0.004) and with H. pylori density (P ¼ 0.018). No significant relationships were observed between other vacA genotypes and histopathological parameters. Conclusion: H. pylori strains showing cagA, vacA s1 and oipA positivity are associated with more severe gastritis in some histological features but virulence factors of H. pylori do not appear to determine the overall pattern of gastritis.
2005
Helicobacter pylori has been strongly associated with gastritis, gastric and duodenal ulcers, and it is a risk factor for gastric cancer. Two major virulence factors of H. pylori have been described: the cytotoxin-associated gene product (cagA) and the vacuolating toxin (vacA). Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to determine if there is a significant correlation between different H. pylori virulence genes (cagA and vacA) in 68 patients, from Saudi Arabia, and gastric clinical outcomes. H. pylor was recognized in cultures of gastric biopsies. vacA and cagA genes were detected by polymerase chain reaction (PCR). The cagA gene was obtained with 42 isolates (61.8%). The vacA sand m-region genotypes were determined in all strains studied. Three genotypes were found: s1/m1 (28%), s1/m2 (40%) and s2/m2 (26%). The s2/m1 genotype was not found in this study. The relation of the presence of cagA and the development of cases to gastritis and ulcer was statistically significant (P < 0.05). The study showed a significant correlation between the vacA s1/m2 genotype and gastritis cases, and a significant correlation between vacA s1/m1 genotype and peptic ulcer cases. The results of this study might be used for the identification of high-risk patients who are infected by vacA s1/m1 genotype of H. pylori strains. In conclusion, H. pylori strains of vacA type s1 and the combination of s1/m1 were associated with peptic ulceration and the presence of cagA gene.
Arab Journal of Gastroenterology, 2016
Background and study aims: Helicobacter pylori infection is common in Egypt. It has been associated with gastritis, ulcers and it is a risk factor for gastric cancer. We aimed to study the correlation between the presence of H. pylori virulence factors and the histopathological and endoscopic findings in gastric biopsies. Patients and methods: Gastric biopsies from thirty seven patients scheduled for diagnostic endoscopy in Cairo University hospital were included in the study. All gastric biopsies were subjected to histopathological examination and PCR assay for detection of 16S rRNA gene to diagnose H. pylori infection, detection of H. pylori virulence factors by PCR for cagA and vacA genotypes and serological analysis of H. pylori (cagA, vacA, P25, and P19) IgG antibodies by immunoblot assay were done. Results: H. pylori infection was detected in 23 (62.2%) cases by histopathology while 28/37 (75.7%) were positive for H. pylori 16S rRNA gene by PCR. By PCR seventeen samples out of 37 (45.9%) were positive for cagA gene and five (13.5%) for cag empty site gene. Conclusion: The most common vacA genotype identified was vacA s2m2 genotype in 10 (27.02%). No statistical correlation was found between IgG antibodies against different antigens of H. pylori virulence factors (cagA, vacA, p25, and p19) and the degree of gastritis except for IgG antibodies against the UreA antigen.
Modern Pathology, 2007
The histological parameters of Helicobacter pylori (H. pylori) gastritis are dependent on the virulence factor profile of the microbe, which includes the cytotoxins vacA (vacuolating cytotoxin A) and cagA (cytotoxinassociated gene A) as well as the duration of infection. The virulence factor genotypes vacA and cagA were assessed by the line probe reverse hybridization assay INNO-LiPA and correlated with the histological parameters of H. pylori infection, in particular intestinal metaplasia (IM) as well as with the patient's age. A total of 120 patients were analyzed; 47 patients with IM in the antrum and 73 control patients without this alteration. The vacA s1 cagA þ genotype (high virulence) correlated with the presence of antral IM, a more intense acute inflammation in both antrum and corpus and the formation of ulcer. The vacA m1 genotype (high virulence) correlated with a more intense acute inflammation in only the corpus as well as more prominent Russell bodies in the antrum. H. pylori strains with the vacA s2 m2 cagAÀ genotype (low virulence) were rarely found in these conditions (all P o0.05). No correlation with the virulence status was found for the type and extent of IM, the intensity of chronic inflammation, the formation of lymphoid follicles and the microbial density. Furthermore, patients with IM were 7 years older than their counterparts without (Po0.05). Finally, there was a trend for more virulent vacA s1 m1 cagA þ strains to be found in younger individuals (P40.05). The virulence genotype of the microbe is an important determinant for the severity of the gastritis and the formation of antral IM. Age is an additional factor for the development of IM.
Background: Helicobacter pylori (H. pylori) is a gram-negative, micro-aerophilic, curved rod that causes a transmissible bacterial infection of the gastric mucosal surface and affect about one half of the world's population. It induces chronic gastritis in all infected individuals, but only induces clinical diseases in 10-20% of them. This may be related to differences in genetic susceptibility of the host, environmental factors, and genetic diversity of H. pylori. Aim: This study was conducted to identify the frequency of the genetic virulence factors (cagA, vacA and babA2) of H. pylori and their possible association with gastroduodenal diseases. Methods: The study was conducted on 70 adult patients with upper gastrointestinal complaints. All patients were subjected to full history taking, clinical examination, gastroduodenoscopy. Four antral biopsies were taken for genotyping by PCR, histopathological examination and culture. Results: All the patients (100%) had chronic active H. pylori gastritis by histopathological examination. The most frequent H. pylori genotype was cagA (67.8%) followed by vacA s1a (61%) and vacA m2 (61%), while the least frequent was babA2 (18.6%). CagA was associated with vacA s1a in (83.3%) with statistical significance. Most patients with cagA positive isolates (77.8%) had no heart burn with statistical significance which may support the protective role of cagA against GERD. There was no significant difference between genotypes distribution as regards culture positive and culture negative H. pylori strains. CagA, vacA s1a and vacA m2 had the highest prevalence in patients with PUD, gastritis and duodenitis while babA2 had the least prevalence. Although in patients with PUD and NUD the prevalence of cagA was (65.1%, 75%) and vacA s1 was (62.8%, 56.3%) respectively, the association between these H. pylori genotypes and PUD did not reach a level of statistical significance. Conclusion: None of H. pylori genetic virulence factors individually can accurately predict clinical outcome and one has to recognize the importance of the bacteria-host interaction in the final outcome.
Pattern of gastritis as manipulated by current state of Helicobacter pylori infection
wseas.us
Helicobacter pylori (H. pylori) infection prevails from 60-80% in patients with gastric ulcer and 90-100% in those having duodenal ulcer. Patients with such type of chronic infection are at increased risk to develop peptic ulcers or gastric adenocarcinomas. The present work aims mainly to identify the pattern of chronic gastritis and potential effect of H. pylori infection using certain biomarkers, histological and immunochemical tests. Fifty eight individuals, clinically diagnosed as having chronic gastritis, were participated in the present study. They were categorized into 2 groups, the first one (31%) demonstrated positive reaction to IgM antibodies of Helicobacter pylori (H. pylori) (>40u/ml) and the second group (69%) demonstrated negative reaction. Blood and antral biopsy samples were collected, directed to determination of serum gastrin, pepsinogen I (PgI), pepsinogen II (PgII), prostaglandin E 2 (PGE 2) and interlukin-6 (IL-6). Immunohistochemistry technique was also done in antral biopsy to demonstrate the expression of inducible nitric oxide synthase (iNOS), nitrotyrosine, DNA fragmentation, myeloperoxidase and histopathological examination. Serum gastrin, PgI, PgII, PGE 2 , IL-6 demonstrated significant increase in gastritis patients as compared to normal group. PgI, PgII showed significant increase joined with slight increase of IL-6 in IgM positive group as compared to negative one. Immunostaining testes in antral biopsy showed strong positive reactions for the above mentioned markers as compared to IgM negative group (mild positive reaction). In conclusion, gastritis patients who express IgM antibodies for H. pylori infection showed higher gastrinaemia and more pronounced atrophic, inflammatory and apoptotic damage than those not expressing IgM antibodies.
Infection Epidemiology and Microbiology
Backgrounds: Helicobacter pylori infections vary in severity and virulence in different populations for various reasons. There are different H. pylori strains with varying degrees of virulence. The genetic diversity of H. pylori strains in gastritis patients in different areas has not been well understood. This study aimed to evaluate the prevalence rate and different genotypes of H. pylori strains in clinical specimens of patients with gastritis in Ilam, Iran. Materials & Methods: Saliva and gastric biopsy samples were collected from 81 patients (55 males and 26 females in the age range of 20 to 90 years) referring to Ilam medical centers. After DNA extraction, the prevalence of H. pylori as well as vacA, cagA, and ureC genes was evaluated using PCR, and then each vacA-positive sample was further evaluated for m1m2 and s1s2 variants. Findings: The cagA and vacA genes were found in 27 (71%) and 36 (94.7%) H. pylori-positive samples, respectively. The cagA gene was detected in patients with gastric pain (44.4%) and anorexia (18.51%). Also, the results showed that the vacA s2m2 genotype and m2 allele were present in 32.9% of H. pylori isolates. Moreover, s2m2 and s1m2 genotypes were detected in 42.1 and 26.3% of vacA-positive samples, respectively. The lowest frequency was related to the m1 allele (17.18%). Conclusion: This study results indicate a plausible relationship between the presence of some genotypes of H. pylori and the progression of gastritis, suggesting these markers as promising biomarkers to predict the disease severity.
Scandinavian Journal of Infectious Diseases, 2010
Several virulence factors of Helicobacter pylori may contribute to gastric mucosal damage. In this study, the prevalence of cag A and vac A genotypes of H. pylori was examined in different patterns of chronic gastritis. Oesophagogastroendoscopy was performed in 147 dyspeptic patients. Antrum biopsies were obtained for isolation of H. pylori and for histopathological assessment. H. pylori vac As1 and cag A genes were directly genotyped in the gastric biopsy specimens by polymerase chain reaction (PCR). A total of 102 dyspeptic patients, all H. pylori-positive by PCR, were included in the study. Of these, 59 had active chronic gastritis and 37 had non-active chronic gastritis. The prevalence of cag A and vac As1 was higher among patients with active chronic gastritis than among those with non-active chronic gastritis (45.8% vs 21.6% ( p ϭ 0.02) and 78.0% vs 40.5% ( p Ͻ 0.001), respectively). In conclusion, both cag A and vac As1 genotypes are associated with the activity of chronic gastritis.
Gastroenterology Research and Practice, 2020
The aim of this study is to evaluate the association between seven important H. pylori virulence factors and antibiotic resistance in patients with gastritis. H. pylori strains isolated from 33 patients with gastritis were examined. Antimicrobial susceptibilities were tested by GenoType® HelicoDR (Hain Life Science, Germany) test kit and RT-PCR. The virulence-factors were determined using conventional PCR. 39% of patients were resistant for clarithromycin and 27% of patients were resistant for fluoroquinolone. 15% of patients were resistant to both clarithromycin and fluoroquinolone. The H. pylori vacA m1/s2 genotype was the most frequent allelic combination. Patients were possessed the vacA s1, m1 (6.1%); s1, m2 (6.1%); s2, m1 (15.1%); and s2, m2 (3.0%) genotypes. 94% of patients with gastritis were positive for H. pylori napA gene. Also, there were no dupA gene-positive gastritis patients. There was no significant correlation between the vacA, cagA, oipA, hpaA, babA, napA, dupA, u...
Non-urease producing Helicobacter pylori in chronic gastritis
Australian and New Zealand Journal of Medicine, 2000
Background: Helicobacter pylori infection is the commonest cause of gastritis. Different patterns of immune response to H. pylori infection and characteristics of bacteria are considered to contribute to clinical outcomes.