babA2 Genes Research Articles

Usefulness of rapid urease test samples for molecular analysis of clarithromycin resistance in Helicobacter pylori

Helicobacter pylori is a gastric pathogen that is widely recognized as a causative agent of gastric disease. Its eradication is variable, mainly due to increased resistance to clarithromycin. Our objective was: to evaluate (i) if the biopsy specimen used for the rapid urease test is a useful sample to detect resistance to clarithromycin by PCR-RFLP and (ii) the distribution of A2142G and A2143G point mutations in the 23S rRNA gene, in relation to virulence factors in our region. Gastric specimens were collected from adult dyspeptic patients (n=141) and H. pylori was investigated by the rapid urease test, histopathological analysis and PCR for the hsp60 gene. Clarithromycin resistance was detected by PCR-RFLP in 62 H. pylori (+) paired biopsy specimens submitted to molecular analysis and the rapid urease test. H. pylori virulence factors were analyzed by multiplex PCR using specific primers for the cagA, vacA and babA2 genes. Thirteen out of 62 strains (20.9%) were resistant to clarithromycin: 6/13 (46.2%) harbored the A2143G mutation whereas 7/13 (53.8%) carried the A2142G point mutation. vacA m1s1 was the most frequent genotype among the resistant strains. In conclusion, the biopsy specimens used for the rapid urease test were suitable samples for clarithromycin resistance detection in patients infected with H. pylori, which became especially useful in cases where the number or size of the biopsies is limited. In addition, this is the first report of a molecular analysis for clarithromycin resistance performed directly from gastric biopsies in our region.

Helicobacter pylori in a poultry slaughterhouse: Prevalence, genotyping and antibiotic resistance pattern.

Although Helicobacter pylori (H. pylori) is a highly significant pathogen, its source remains unclear. Many people consume chicken daily as a source of animal protein worldwide; thus, hygienic methods of supplying chickens for consumption are critical for public health. Therefore, our study examined the distribution of the glmM (ureC), babA2, vacA and cagA virulence genes in H. pylori strains in chicken meat and giblets (gizzards and livers) and the resistance of the strains to various antibiotics. Ninety chicken meat, gizzard and liver samples were obtained from a semi-automatic abattoir in Sadat City, Egypt, and were cultured and preliminarily analyzed using biochemical tests. The presence of the ureC, babA2, vacA and cagA genotypes was tested for in samples positive for H. pylori by multiplex polymerase chain reaction (Multiplex-PCR). The resistance of H. pylori to various antimicrobial drugs was tested using the disc diffusion method. In total, 7 of the 90 chicken samples were positive for H. pylori (7.78%); in 3/7 (42.85%) samples, the bacteria were found in the chicken liver, while the bacteria were found in the meat in 2/7 (28.57%) and in the gizzard in 2/7 (28.57%) samples. The total prevalence of both the ureC and babA2 genes in the isolated H. pylori strains was 100%, while the prevalence of the vacA and cagA genes was 57.1% and 42.9%, respectively. The resistance of H. pylori to the antibiotics utilized in our study was 100% for streptomycin; 85.7% for amoxicillin and penicillin; 71.4% for oxytetracycline, nalidixic acid and ampicillin; 57.1% for sulfamethoxazole and erythromycin; and 42.9% for neomycin, chloramphenicol and norfloxacin. In conclusion, the chicken meat and giblets were tainted by H. pylori, with a higher occurrence of the ureC, babA2, vacA and cagA genotypes. Future investigations should investigate the resistance of H. pylori to various antimicrobial agents in Egypt.

VacA s1m1 genotype and cagA EPIYA-ABC pattern are predominant among Helicobacter pylori strains isolated from Mexican patients with chronic gastritis.

PurposeVirulent genotypes of Helicobacter pylori vacA s1m1/cagA+/babA2+ have been associated with severe gastric diseases. VacA, CagA and BabA are polymorphic proteins, and their association with the disease is allele-dependent. The aims of this work were: (i) to determine the prevalence of H. pylori by type of chronic gastritis; (ii) to describe the frequency of cagA, babA2 and vacA genotypes in strains from patients with different types of chronic gastritis; (iii) to characterize the variable region of cagA alleles.MethodologyA total of 164 patients with chronic gastritis were studied. Altogether, 50 H. pylori strains were isolated, and the status of cagA, babA2 and vacA genotypes was examined by PCR. cagA EPIYA segment identification was performed using PCR and sequencing of cagA fragments of six randomly selected strains.Results/Key findingsThe overall prevalence of H. pylori was 30.5 %. Eighty percent of the isolated strains were vacA s1m1, and the cagA and babA2 genes were detected in 74 and 32 % of the strains, respectively. The most frequent genotypes were vacA s1m1/cagA+/babA2- and vacA s1m1/cagA+/babA2+, with 40 % (20/50) and 28 % (14/50), respectively. In cagA+, the most frequent EPIYA motif was -ABC (78.4 %), and EPIYA-ABCC and -ABCCC motifs were found in 10.8 % of the strains. A modified EPIYT-B motif was found in 66.6 % of the sequenced strains.ConclusionH. pylori strains carrying vacA s1m1, cagA+ and babA2- genotypes were the most prevalent in patients with chronic gastritis from the south of Mexico. In the cagA+ strains, the EPIYA-ABC motif was the most common.

The Prevalence of Helicobacter pylori Virulence Related Genes (hpa and babA2) in Iranian Patients with Gastrointestinal Disorders

Background: The clinical result severity of Helicobacter pylori infection is determined by a combination of environmental factors, host genetic background, and H. pylori virulence factors. A number of genes containing vacA, iceA, babA2, cagA, cagE, hsp60-70, and hpa have been identified to enhance H. pylori pathogenicity by encoding virulent proteins. The babA and hpa proteins are considered 2 major adhesion molecules, and thus they are key agents in the initial step of H. pylori invasion. Objectives: This study aimed at investigating the existence of babA2 and hpa virulence factors of H. pylori in Iranian patients with gastrointestinal complications. The relationship between these agents and clinical results was also investigated. Methods: A total of 80 positive biopsies out of 156 samples were studied to determine babA2 and hpa gene frequency by PCR. The positive biopsies were collected from patients suffering from gastric cancer (n =18), peptic ulcer (n = 26), and gastritis (n =36). Results: The babA2+ strains were found in 51 (64%) patients and the hpa+ strains in 57 (71%) patients were associated with sex (P = 0.02). However, the frequency of these factors was not significant between gastric disease groups (P > 0.05). Conclusions: Our results revealed different frequency of these virulence factors in Iran, which emphasized the effects of geographical influences. Also, it was found that male patients had higher rate of hpa than females, highlighting the gender specific factors.

Prevalence of Helicobacter pylori genotypes in patients with gastroduodenal pathology in Kazan

Aim. Investigation of the prevalence of various H. pylori genotypes among children and adult population of Kazan with chronic gastroduodenal pathology.
 Methods. The study included 107 patients (49 children and 58 adults) with chronic gastritis/gastroduodenitis and gastric and duodenal ulcer who had H. pylori infection confirmed by molecular genetic method. All patients underwent biospy from antral mucosa during endoscopy for H. pylori verification by polymerase chain reaction and genotyping for сagA and babA genes and iceA and vacA allels. 
 Results. CagA gene was found in 19 (32.8%) out of 58 adults and 13 (26.5%) out of 49 children. VacA gene was detected in all patients (100%). VacAs2 genotype in children was nearly 1.6 times as frequent as the vacAs1 genotype (61.2 and 36.7% respectively). In adult patients vacAs2 genotype was detected 2.5 times less frequently than vacAs1 (27.6 and 70.7%, respectively). VacAm2 genotype was revealed in 71.4% (35/49) of children and 77.6% (45/58) of adults. IceA2 genotype was identified in 46.9% (23/49) of children and 44.8% (26/58) of adult patients, iceA1 gene - in 20.4% of children and 55.2% of adult patients. 
 Conclusion. The strains with vacAs2m2 genotype are prevailing in children (42.9%) and determine low toxigenicity of H. pylori strains; vacAs1m2 genotype is predominant among adult patients (53.4%); high prevalence of cagA-negative strains of H. pylori was found both in children and adults (73.5 and 67.2%, respectively).

Relationship between histopathological status of the Helicobacter pylori infected patients and proteases of H. pylori in isolates carrying diverse virulence genotypes

Helicobacter pylori is the main cause of several gastroduodenal diseases in Humans. Among various virulence factors of H. pylori, proteases may also be involved in its pathogenicity. In this study, relationship between proteolytic activity of H. pylori strains and histopathological changes of the stomach was investigated in the patients infected with strains carrying diverse virulence factors. H. pylori strains were isolated from the biopsies of 116 patients who referred to hospital for their gastroduodenal disorders, in Tehran, Iran. Biopsies were sent to microbiology and pathology laboratories for further analysis. All the suspected grown colonies were characterized by both biochemical tests and polymerase chain reaction (PCR). Presence of seven protease genes, htrA, clpP, hp0169, hp1012, hp0382, hp1350 and hp1435, and distinct allelic variants of H. pylori virulence factors, cagA, vacA, iceA, babA2 and sabA, were analyzed in each strain. Protease activity of the strains was assessed using spectrophotometric assay. Furthermore, association between diversity in protease genes and virulence genes, protease activity, as well as pathological changes was estimated statistically. Proteases genes, htrA, clpP, hp0169, hp1012, hp0382, hp1350, hp1435, were detected among 100%, 100%, 98%, 98%, 98%, 98%, and 8% of fifty H. pylori strains isolated from the patients, respectively. Status of cagA, vacA s1, vacA s2, vacA m1, vacA m2, iceA1, iceA2, babA2 and sabA genes in isolates were 64%, 68%, 30%, 26%, 74%, 48%, 52%, 100%, and 96%, respectively. Predominant (84%) combined status for protease genes was: htrA/clpP/hp0169/hp1012/hp0382/hP1350/hp1435, while the prevalent combined status (16%) for virulence genes was: cagA+/vacA s1m2/iceA1+/sabA+/babA2+. Although most of the strains (91.4%) presented moderate protease activity in vitro, lowest activity was measured in strains isolated from the patients with chronic gastritis (4.25%). Present study provide the new data on diversity of protease genes in H. pylori, as well as the proteolytic activity of these genes in H. pylori strains from the sick patients. Presence of significant association between lower protease activity of the strains and mildness of the pathological changes propose involvement of these proteases in the pathogenesis of H. pylori in vivo.

In Vitro and In Vivo Antibacterial Activities of Patchouli Alcohol, a Naturally Occurring Tricyclic Sesquiterpene, against Helicobacter pylori Infection.

This study further evaluated the in vitro and in vivo anti-Helicobacter pylori activities and potential underlying mechanism of patchouli alcohol (PA), a tricyclic sesquiterpene. In the in vitro assay, the capacities of PA to inhibit and kill H. pylori were tested on three standard strains at different pH values and on 12 clinical isolates. The effects of PA on H. pylori adhesion (and its alpA, alpB, and babA genes), motility (and its flaA and flaB genes), ultrastructure, and flagellation were investigated. Moreover, the H. pylori resistance to and postantibiotic effect (PAE) of PA were determined. Furthermore, the in vivo effects of PA on H. pylori eradication and gastritis were examined. Results showed that MICs of PA against three standard strains (pH 5.3 to 9) and 12 clinical isolates were 25 to 75 and 12.5 to 50 μg/ml, respectively. The killing kinetics of PA were time and concentration dependent, and its minimal bactericidal concentrations (MBCs) were 25 to 75 μg/ml. In addition, H. pylori adhesion, motility, ultrastructure, and flagellation were significantly suppressed. PA also remarkably inhibited the expression of adhesion genes (alpA and alpB) and motility genes (flaA and flaB). Furthermore, PA treatment caused a longer PAE and less bacterial resistance than clarithromycin and metronidazole. The in vivo study showed that PA can effectively eradicate H. pylori, inhibit gastritis, and suppress the expression of inflammatory mediators (COX-2, interleukin 1β, tumor necrosis factor alpha, and inducible nitric oxide synthase [iNOS]). In conclusion, PA can efficiently kill H. pylori, interfere with its infection process, and attenuate gastritis with less bacterial resistance, making it a potential candidate for new drug development.

Helicobacter pylori vacA s1m1 genotype but not cagA or babA2 increase the risk of ulcer and gastric cancer in patients from Southern Mexico

BackgroundThe vacA, cagA and babA2 genotypes of Helicobacter pylori are associated with gastric pathology. The objectives were to determine the frequency of infection and distribution of the vacA, cagA and babA2 genotypes of H. pylori in patients with gastric ulcer, chronic gastritis and gastric cancer, and to evaluate the association of virulent genotypes with diagnosis.MethodsWe studied 921 patients with symptoms of dyspepsia or with presumptive diagnosis of gastric cancer. The DNA of H. pylori and the vacA, cagA and babA2 genes was detected by PCR in total DNA from gastric biopsies. The association of H. pylori and of its cagA, vacA and babA2 genotypes with diagnosis was determined by calculating the odds ratio (OR).ResultsChronic gastritis was confirmed in 767 patients, gastric ulcer in 115 and cancer in 39. The prevalence of H. pylori was 47.8, 49.6 and 61.5% in those groups, respectively. H. pylori was more frequent in the surrounding tissue (69.2%) than in the tumor (53.8%). The vacA s1m1 genotype predominated in the three groups (45.2, 61.4 and 83.3%, respectively). H. pylori was associated with cancer (ORadjusted = 2.08; 95% CI 1.05–4.13; p = 0.035) but not with ulcer (ORadjusted = 1.07; 95% CI 0.71–1.61; p = 0.728). The s1m1 genotype was associated with ulcer and cancer (ORadjusted = 2.02; 95% CI 1.12–3.62; p = 0.019 and ORadjusted = 6.58; 95% CI 2.15–20.08; p = 0.001, respectively). babA2 was associated with gastric cancer, and cagA was not associated with the diagnosis.ConclusionsIn population from Southern Mexico, H. pylori and the s1m1 genotype were associated with gastric cancer and the s1m1/cagA+/babA2+ strains predominated in tumor and adjacent tissue.

Are non-pylori helicobacters present in the human oral cavity?

Helicobacter pylori (H. pylori) is a human gastric pathogen. Because of presence of H. pylori oral cavity, there is a possibility of H. pylori transmission by oral-oral route. In a crosssectional study, the presence of some virulence factors of H. pylori and also non-pylori Helicobacters in dental plaque samples of participants was investigated. The samples were collected from at least two teeth surfaces. DNA of the samples was extracted using specific kit. The presence of dupA (jhp0917 and jhp0918) and babA2 genes and also Helicobacter genus and H. pylori species was investigated using polymerase chain reaction by specific primers. In total 44% (20/45) and 86.7% (39/45) of samples was positive for ureC and 16SrRNA genes respectively. The frequency of babA2, jhp0917 and jhp0918 genes in H. pylori isolates were 40, 20 and 65% respectively. It seems 19 samples were positive probably non-pylori Helicobacters. In the present study we report for the first time the presence of non-pylori Helicobacter species and also high frequency of babA2 and dupA genotypes in dental plaque samples.

Prevalence of Helicobacter pylori vacA, cagA, cagE, oipA, iceA, babA2 and babB genotypes in Iranian dyspeptic patients.

There is diversity in clinical outcome of Helicobacter pylori infection in different regions. Microbial, host and environmental factors seem to be reason of such variation. Considering microbial factors, we studied H.pylori genotypes and their association with clinical feature of the infection. Overall 160 H. pylori-positive patients were enrolled in this study. Clinical information and biopsy were collected from each patient. The presence of the major virulence genes were determined by PCR. Regardless to clinical outcomes, vacA, cagA, cagE, oipA, iceA1, babA2 and babB genes was positive in 100%, 69%, 51%, 55%, 26%,78% and 28% of 160 strains respectively. The s1m2 was more common vacA allels and s1a and m1a were predominant s and m regions. In patient with gastric cancer (GC), the oipA was less frequent while the iceA1 was the most common. The babA2 was common in all patient groups. The babB was significantly observed in strains isolated from patients with GC. There were significant association among cagA status with presence of vacAs1, vacAm2, cagE, oipA, iceA1 and babA2. Presence of the babB and oipA was connected with higher and lower risk for GC respectively. There was no association between the cagA, vacA, cagE or iceA status and clinical outcome in patients in Iran. We showed that presence of the babB and iceA1 were significantly connected with higher risk for gastric cancer development in Iranian dyspeptic patients while H.pylori isolates with positive oipA had little threat for leading patients to cancer.

Low Rate of babA2 Genotype among Iranian Helicobacter pylori Clinical Isolates.

The Blood Group Antigen-Binding Adhesion (babA), Outer Inflammatory Protein (oipA) and Sialic Acid-Binding Adhesin (sabA) as outer membrane proteins involved in Helicobacter pylori adherence to gastric mucosa have been suggested to have a role in the pathogenesis. To investigate the frequency of H. pylori isolates babA2, oipA and sabA genes in Iranian dyspeptic patients. DNAs were extracted from H. pylori -positive cultures taken from 100 different dyspeptic patients. Genotyping was performed by Polymerase Chain Reaction (PCR), using the specific primers for babA2, oipA and sabA genes. Chi square test was used to investigate association between variables, p<0.05 was considered statistically significant. All (100%) isolates possessed oipA and sabA genotypes, whereas babA2 was detected in 22% of isolates. There was no significant relationship between presence of genes with clinical outcome. The combined genotype oipA +/sabA +/ babA2- was correlated with gastritis. The rate of babA2 genotype in our isolates was lower than other Iranian reports. Frequency of babA2 genotype among H. pylori isolates from Southwest of Iran is considerably less than other regions of Iran. Due to heterogeneity of H. pylori strains in different geographic regions, further work will be needed to understand the role of these virulence genes in H. pylori pathogenesis and their possible association with disease outcome.

Occurrence of Helicobacter pylori and its major virulence genotypes in dental plaque samples of patients with chronic periodontitis in Iran.

This study was aimed to investigate the presence of H. pylori and its virulence genotypes in dental plaques of Iranian patients with chronic periodontitis. Helicobacter pylori is a Gram-negative bacterium that is associated with atrophic gastritis, peptic ulcer, and gastric cancer. Several studies have detected this bacterium in the oral cavity, suggesting it as a potential reservoir. A hundred individuals were divided in 2 groups: 50 patients with chronic periodontitis (case group), and 50 subjects in non-periodontitis (control group). Supragingival and subgingival plaque samples were collected from the individuals using wood wedges and sterile paper points respectively, and prepared for PCR analysis. Totally, H. pylori DNA was detected in 5 out of 100 (5%) dental plaques. Of 5 dental plaques positive for H. pylori, cagA gene was detected in 4 specimen, 3 in periodontitis group and one in non-periodontitis group. The H. pylori vacA s1m1 genotype was predominantly detected in 2/5 samples. The babA2 gene was detected in all (5/5) H. pylori-positive dental plaques. There was no significant correlation between the presence of H. pylori genotypes from dental plaques and chronic periodontitis (P > 0.05). Our results revealed that the rate of H. pylori is very low in the dental plaques of Iranian patients with chronic periodontitis. Majority of H. pylori strains from oral cavity were highly virulent based on the main clinically virulence factors they carried.

Clinical and Histopathological Relevance of Helicobacter pylori BabA2 Genotype

Introduction: H. pylori BabA is an outer membrane protein that mediates bacterial adherence to the gastric epithelium, triggers several pathways during the course of infection, and thus contributes to the disease development. Considering the variability in the presence of BabA coding gene (babA2) among H. pylori clinical strains, the aim of this study was to assess the relationship between the genotype status of H. pylori babA2 and the severity of clinical and histopathological outcomes. Methods: Gastric mucosal biopsy specimens were collected from 30 CLO test-positive patients, 16 with gastritis and 14 with peptic ulcer disease. Polymerase chain reaction was carried out to detect the presence of H. pylori-specific glmM gene and BabA coding gene (babA2). Histopathological examination was performed to evaluate the severity of H. pylori-associated gastric disease according to the Updated Sydney Classification System. Results: The glmM and babA2 genes were present in 100% and 86.7% of the tested H. pylori strains, respectively. Although higher degrees of inflammatory activity and H. pylori density were noted in babA2-positive biopsy specimens, there was no statistically significant association between babA2 genotype status and the severity of gastric disease. Conclusion: The babA2 genotype status of H. pylori may not be considered as a sole marker for determining the infection outcomes.

Helicobacter pylori babA2 Positivity Predicts Risk of Gastric Cancer in Ardabil, a Very High-Risk Area in Iran.

Ardabil, a Northwestern province of Iran, was found to have the highest rate of gastric cancer (GC) in the country (ASRs = 51.8/100,000 for males and 24.9/100,000 for females) and one of the highest gastric cardia cancer rates in the world. The aim of the present study was to assess the associations of the cagA and babA2 status of Helicobacter pylori with GC in the Ardabil population. A total of 103 patients with non-atrophic gastritis (56) and GC (47), who underwent endoscopy at the Imam Khomeini Hospital in Ardabil, were assessed. The status of 16S rDNA, cagA and babA2 genes was determined using PCR and histopathological assessment was performed. The following genotypic frequency was observed: cagA+ (50.6%), cagA- (49.4%), babA2+ (26.5%), babA2- (73.5%) cagA+/babA2+ (19.3%), cagA-/babA2+ (7.2%), cagA+/babA2- (31.3%), cagA-/babA2- (42.2%). Although the frequency of the cagA+, cagA+/babA2+ and cagA-/ babA2+ genotypes in patients with GC (55.6%, 25.9%, and 14.8%, respectively) was higher than in those with NAG (48.2%, 16.1%, and 3.6%, respectively), the difference did not reach significance. In contrast, the presence of the babA2 gene (40.7% vs 19.6%) significantly increased the risk of GC; the age-sex-adjusted odds ratio (95% confidence interval) was 5.068 (1.506-17.058; P=0.009), by multiple logistic regression. It is proposed that the H. pylori babA2 positivity might be considered as an important determinant of GC risk in Ardabil.

Helicobacter pylori strains harboring babA2 from Indian sub population are associated with increased virulence in ex vivo study.

BackgroundThe babA2 gene along with the cagA and vacA of Helicobacter pylori has been considered as a risk factor for the disease outcome in certain populations. This study was aimed to understand the role of babA2 of H. pylori with the background of cagA and vacA in disease manifestations in Indian sub population.MethodsA total of 114 H. pylori strains isolated from duodenal ulcer (DU) (n = 53) and non-ulcer dyspepsia (NUD) patients (n = 61) were screened for the prevalence of these virulence markers by PCR. The comparative study of IL-8 production and apoptosis were done by co-culturing the AGS cell line with H. pylori strains with different genotypes. Adherence assay was performed with babA2 positive and negative strains. Two isogenic mutants of babA2 were constructed and the aforesaid comparative studies were carried out.ResultsPCR results indicated that 90.6 % (48/53), 82 % (50/61) and 73.6 % (39/53) strains from DU patients were positive for cagA, vacA, and babA2, respectively. Whereas the prevalence of these genes in NUD subjects were 70.5 % (43/61); 69.8 % (37/53), and 65.6 % (39/61), respectively. Although adherence to AGS cells was comparable among strains with babA2 positive and negative genotypes, but the triple positive strains could induce highest degree of IL-8 production and apoptosis, followed by the cagA−/vacA−/babA2+ strains and triple negative strains, respectively. The wild type strains showed significantly higher IL-8 induction as well as apoptosis in ex vivo than its isogenic mutant of babA2.ConclusionPCR study demonstrated that there was no significant association between the distribution of babA2 genotype or of triple positive strains and disease outcome in this sub population. The adherence assay showed that there was no significant difference in the extent of adherence to AGS cells among babA2 positive and negative strains. But the ex vivo study indicated that the triple positive or even the babA2 only positive strains are involved in increased virulence. The wild type strains also exhibited increased virulence compared to the babA2 mutant strains. This inconsistency demonstrated that bacterial genotype along with host genetic polymorphisms or other factors play important role in determining the clinical manifestation of H. pylori infections.

Prevalence of cagA and babA2 positive Helicobacter pylori strains in dyspeptic patients in Iran

Background: Helicobacter pylori genome encodes a large number of virulence and adhesion factors that involved in bacterial adhesion to host cells and exerts its virulence effect with CagA secretion. In this study, we aimed to examine the relationships between babA2 and cagA genotype and presence of gastric disorders in patients from Iran. Material and Methods: The presence of H. pylori and selected genes ( cagA and babA2 ) were detected by PCR method from the genomic DNA of 105 patients who had been diagnosed with gastric disorders like chronic gastritis by endoscopic and histopathologic routes. Results: Presence of H. pylori ( glmM gene ) was detected in 85 out of 105 (80.9%) patients. According to our results cagA gene was found in 66 out of 85 (77.6%) patients and babA2 gene was found in 80 out of 85 (94.1%) patient. Conclusion: In conclusion, the cagA and babA2 genotypes might be considered as useful biomarkers for non-ulcer disease (NUD) patients and gastric disorders in the geographic region of Iran and the presence of H. pylori strains with double-positive status is high clinical relevance to H. pylori -associated diseases.

Frequency of H.Pylory BabA2 and Hpa Genes in Patients with Dysphagia

Background and Objective: BabA2 and Hpa genes are involved in adherence of Helicobacter pylori (H.pylori) to gastric mucosal tissue. This study aimed to investigate the frequency of these genes in isolates of H. pylori from gastric biopsies and their relationship with gastritis, peptic ulcer and gastric cancer. Methods: Gastric biopsy samples were obtained from patients with gastritis, peptic ulcer and gastric cancer. A sample was sent to the laboratory for urease test and histopathology study, and another sample for DNA extraction. The frequency of BabA2 and Hpa genes was investigated using their specific primers by PCR. Results: Among the 80 analyzed biopsy samples, 51 (63%) were BabA2 positive, and the frequency of this gene in the samples of gastric cancer, gastritis and peptic ulcer was 61.1, 58.3 and 73.3%, respectively. In addition, 57 samples (71%) were Hpa positive, and the frequency of this gene in the samples of gastric cancer, gastritis and peptic ulcer was 55.5, 69.4 and 84.6%, respectively. There was no significant correlation between the presence of these genes and the type of H.pylori-related diseases. Conclusion: Frequency of BabA2 and Hpa genes is higher in the samples of peptic ulcer but there was no significant relationship between these genes and H.pylori-related diseases.

Frequency of Helicobacter pylori blood-group antigen-binding adhesion 2 and sialic acid binding adhesion genes among dyspeptic patients in Tabriz, Iran

Introduction: The purpose of this research was to analyze blood-group antigen-binding adhesion (babA2) and sialic acid binding adhesion (sabA) genotypes status in Helicobacter pylori (H. pylori) isolates and their relationship with clinical outcomes. Methods: Gastric biopsy specimens were homogenized and placed in Brucella agar medium supplemented with 5% sheep blood and 3 antibiotics and were cultured at 37 °C under microaerophilic conditions and incubated for 4-7 days. H. pylori was identified by typical morphology, gram-staining and urease tests, and babA2 and sabA genes were detected by polymerase chain reaction (PCR). Results: From a total of 100 H. pylori isolates; babA2 and sabA genes were detected in 23.0 and 26.4%, respectively. There was a significant relationship between these genes and clinical outcomes (P < 0.050). Conclusion: We found that the babA2 status was not related to clinical outcomes in Tabriz, Iran. However, sabA was a promoting determinant for disease, and multivariate analysis disclosed sabA to be an independent marker of non-ulcer diseases in our subjects.

The cytokine response in THP-1 (monocyte) and HL-60 (neutrophil-differentiated) cells infected with different genotypes of Helicobacter pylori strains.

Helicobacter pylori (H. pylori) is a microaerophilic bacterium related with peptic ulcer and gastric cancer. Its virulence factors include cytotoxin-associated gene A (CagA) and vacuolating cytotoxin gene A (VacA) proteins. Cytokine release inducted by H. pylori colonization has an important role in pathogenesis of H. pylori. The severity of gastric pathologies depends on the H. pylori genotypes found in different geographical regions. We aimed to determine the relationship between different H. pylori genotypes and their effects on the cytokine release levels. ureC, cagA, vacAs1/s2, vacAm1/m2, and blood group antigen-binding adhesion protein A2 (babA2) virulence related genes were investigated in 21 H. pylori strains. Genotyping of 21 strains were made due to the presence of cagA, vacAs1/s2, vacAm1/m2, and babA2 genes. The H. pylori strains were cultured together with THP-1 and neutrophil-differentiated Human promyelocytic leukemia cells (HL-60) cells. The levels of cytokines interleukin (IL)-1β, IL-6, IL-8, IL-12, tumor necrosis factor-alpha (TNF-α), and IL-10 in these cells were measured after co-culturing with H. pylori strains. The following five different genotypes were detected: Genotype1: cagA and vacAs1m2; Genotype2: cagA and vacAs1m1; Genotype3: cagA, vacAs1m2, and babA2; Genotype4: vacAs2m2; and Genotype5: cagA and vacAs2m2. All these genotypes significantly induced the levels of IL-1β, IL-6, IL-8, IL 10, and TNF-α in THP-1 cells. Genotype 5 caused higher amounts of IL-1β, IL-6, TNF-α, and IL-10, whereas genotype 1 induced the highest levels of IL-8. In neutrophil-differentiated HL-60 cells, genotype 4 increased IL-6 levels and genotype 3 and 4 elevated IL-8 levels significantly. These results suggested that cytokine response of the host varies depending on the specific immune response of the host against different H. pylori strains.

Frequency of virulence factors in Helicobacter pylori-infected patients with gastritis

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 methodsGastroduodenoscopy 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. ResultsvacA 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 = 0.004) and chronic inflammation (P = 0.013) and with H. pylori density (P = 0.034). Neutrophil infiltration was found to be more severe in the s1 group than in the s2 group (P = 0.042). Also was a significant relationship between oipA positivity and neutrophil activity (P = 0.004) and with H. pylori density (P = 0.018). No significant relationships were observed between other vacA genotypes and histopathological parameters. ConclusionH. 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.