Comparison of the virulence factors of Helicobacter pylori isolated in stomach and saliva in Iran

Rate of Helicobacter pylori acquisition in children and evidence of mother-child transmission in a Sub-Saharan setting

BACKGROUND

This study aims to assess age at which Helicobacter pylori infection is acquired and the role of maternal infection status in the transmission of this infection to children.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study conducted at the reference Pediatric Center in Cameroon for 8-months. A total of 204 children from birth to 5 years old and their mothers were enrolled. They were tested for the presence of H. pylori stool antigen. Information on sociodemographic and living conditions of children were collected using a structured questionnaire.

RESULTS

H. pylori stool antigen positivity was 26.0 and 57.4% among children and their mothers respectively. Infection begins two weeks after birth and peaks at 36 to 60 months old (51.6%). The crude odd ratio for H. pylori infection in children whose mothers were infected was 7.0921(2.5510-19.6078; p = 0.0001). Mothers low-income level [2.8901(1.0319-8.0645), p = 0.043] and preschool attendance [6.7567(1.5337-30.3030), p = 0.012] were significantly correlated to H. pylori positivity in children.

CONCLUSIONS

Our finding showed that infected mothers and preschool attendance have a key role in intra-familial and extra-familial transmission of H. pylori infection among children in our milieu, that worse living conditions are the main risk factor for the contamination.

Helicobacter pylori in oral cavity: current knowledge

The oral cavity may play a role as a reservoir and in the transmission and colonization of Helicobacter pylori. The route of transmission for H. pylori is not fully understood. The prevalence of this pathogen varies globally, affecting half of the world's population, predominantly in developing countries. Here, we review the prevalence of H. pylori in the oral cavity, the characteristics that facilitate its colonization and dynamics in the oral microbiome, the heterogeneity and diversity of virulence of among strains, and noninvasive techniques for H. pylori detection in oral samples. The prevalence of H. pylori in the oral cavity varies greatly, being influenced by the characteristics of the population, regions where samples are collected in the oral cavity, and variations in detection methods. Although there is no direct association between the presence of H. pylori in oral samples and stomach infection, positive cases for gastric H. pylori frequently exhibit a higher prevalence of the bacterium in the oral cavity, suggesting that the stomach may not be the sole reservoir of H. pylori. In the oral cavity, H. pylori can cause microbiome imbalance and remodeling of the oral ecosystem. Detection of H. pylori in the oral cavity by a noninvasive method may provide a more accessible diagnostic tool as well as help prevent transmission and gastric re-colonization. Further research into this bacterium in the oral cavity will offer insights into the treatment of H. pylori infection, potentially developing new clinical approaches.

A rapid and high-throughput multiplex genetic detection assay for detection, semi-quantification and virulence genotyping of Helicobacter pylori in non-invasive oral samples

Aim

This study established a high-throughput multiplex genetic detection assay (HMGA) for rapid identification, semi-quantification and virulence analysis of Helicobacter pylori directly from the clinical non-invasive oral samples.

Methods

The gastric mucosa and oral samples were collected from 242 patients in Shanghai from 2021 to 2022. All the samples were detected by routine clinical tests for H. pylori and Sanger sequenced for inconsistent results. A new multiplex PCR assay providing results within 4 hours was designed and optimized involving fluorescent dye-labeled specific primers targeted 16S rRNA gene, semi-quantitative gene ureC and 10 virulence genes of H. pylori. Semi-quantification was carried out by simulating the serial 10-fold dilutions of positive oral samples, and the H. pylori loads in different clinical samples were further compared. The mixed plasmids of virulence genes vacA s1, vacA m1 and vacA m2 were used to evaluate the performance on different genotypes. The consistency of 10 virulence genes in gastric mucosa, saliva, mouthwash and dental plaque of H. pylori-positive patients was compared.

Results

The non-invasive HMGA was highly specific for detection of all 12 targets of H. pylori and human internal reference gene β-globin, and the sensitivity to all target genes could reach 10 copies/μL. Compared with routine clinical tests and sequencing, non-invasive HMGA has a high level (>0.98) of sensitivity, specificity, accuracy, PPV, NPV and kappa coefficient for direct detection of H. pylori in oral samples. Moreover, by detecting peak area levels of ureC, it was confirmed that the H. pylori loads in gastric mucosa were significantly higher than those of the three kinds of oral samples (p<0.05). We also found that 45.0% (91/202) of patients had different H. pylori virulence genes in different oral samples. The concordance of positive detection rates of each virulence gene between saliva and gastric mucosa was more than 78% (p<0.05).

Conclusion

The non-invasive HMGA proved to be a reliable method for the rapid H. pylori identification, semi-quantification and detection of 10 virulence genes directly in oral samples, providing a new idea for non-invasive detection of H. pylori.

Diagnostic performance of fecal Helicobacter pylori antigen test in Uganda

We evaluated the diagnostic performance of a qualitative stool antigen test (SAT) in individuals with dyspepsia in rural Uganda using the polymerase chain reaction-based 16S ribosomal RNA assay (16S rRNA) for nucleotide sequences for two common H. pylori-associated genes as the reference standard. We enrolled 150 adults with dyspepsia with no self-reported use of antibiotic and/or antiacid medication medications within a fortnight. We performed blinded SAT on fecal specimens and 16S rRNA tests on gastric specimens. Using nonlinear mixed models, SAT had a sensitivity of 85⋅1% (95%CI 76⋅54%, 93⋅6%), and specificity of 97⋅6% (95%CI 94⋅3, 100). Twelve individuals with dyspepsia need to be tested to correctly diagnose 10 with H. pylori infection using SAT. The SAT is a robust diagnostic test to improve the diagnosis of H. pylori infection in people with dyspepsia in resource-limited settings.

Synthetic Lipopeptide Enhances Protective Immunity Against Helicobacter pylori Infection

Over fifty percent of the people around the world is infected with Helicobacter pylori (H. pylori), which is the main cause of gastric diseases such as chronic gastritis and stomach cancer. H. pylori adhesin A (HpaA), which is a surface-located lipoprotein, is essential for bacterial colonization in the gastric mucosa. HpaA had been proposed to be a promising vaccine candidate against H. pylori infection. However, the effect of non-lipidated recombinant HpaA (rHpaA) to stimulate immune response was not very ideal, and the protective effect against H. pylori infection was also limited. Here, we hypothesized that low immunogenicity of rHpaA may attribute to lacking the immunostimulatory properties endowed by the lipid moiety. In this study, two novel lipopeptides, LP1 and LP2, which mimic the terminal structure of the native HpaA (nHpaA), were synthesized and TLR2 activation activity was confirmed in vitro. To investigate whether two novel lipopeptides could improve the protective effect of rHpaA against the infection of H. pylori, groups of mice were immunized either intramuscularly or intranasally with rHpaA together with LP1 or LP2. Compared with rHpaA alone, the bacterial colonization of the mice immunized with rHpaA plus LP2 via intranasal route was significantly decreased and the expression levels of serum IgG2a, IFN-γ, and IL-17 cytokines in spleen lymphocyte culture supernatant increased obviously, indicating that the enhanced protection of LP2 may be associated with elevated specific Th1 and Th17 responses. In conclusion, LP2 has been shown to improve the protective effect of rHpaA against H. pylori infection, which may be closely related to its ability in activating TLR2 by mimicking the terminal structure of nHpaA.

Prevalence of Helicobacter pylori vacA Genotypes and cagA Gene in Dental Plaque of Asymptomatic Mexican Children

The variability in Helicobacter pylori vacA and cagA genes has been related to the progression of the gastrointestinal disease; also the presence of H. pylori in the oral cavity has been associated with periodontal disease in adults, but, in children without dyspeptic symptoms, little is known about this. We evaluated the prevalence of H. pylori and the presence of vacA/cagA genotypes in the oral cavity of Mexican children without dyspeptic symptoms. The gingival status was measured, and dental plaque samples (n = 100) were taken. 38% of children were positive for H. pylori 16S rRNA gene by qPCR. A significant association between H. pylori oral infection and gingival status was observed (P < 0.001). In 34.6% (9/26) of mild gingivitis cases, s1m2 genotype was found, while s1m1 was typed in 50% (3/6) of moderate gingivitis. The cagA prevalence among H. pylori-positive children was 80.8% (21/26), 83.3% (5/6), and 16.7% (1/6) of cases of mild gingivitis, moderate gingivitis, and nongingivitis, respectively (P < 0.001). The s1m1/cagA+ combinational genotype was the most detected in children with gingivitis. Our results suggest that the prevalence of H. pylori and detection of vacA/cagA genotypes-associated gastrointestinal disease in the oral cavity could be related to the progression of gingivitis in asymptomatic children.

Correlation between virulence markers of Helicobacter pylori in the oral cavity and gastric biopsies

BACKGROUND:

The clinical outcome of Helicobacter pylori infection has been associated with virulence factors. The presence of these factors is useful as molecular markers in the identification of the high risk for developing severe gastric pathologies.

OBJECTIVE:

To correlate the presence of virulence markers cagA and bab2A of H. pylori in oral and gastric biopsy samples.

METHODS:

An observational, prospective, descriptive, and cross-sectional study was carried out between September 2011 and September 2012. Patients suffering dyspepsia with indication for upper gastrointestinal video endoscopy who attended the Gastroenterology Service of the Hospital Dr. Julio C. Perrando were included. Epidemiological investigation was completed. To detect the bacteria and their virulence genes, samples of saliva, dental plaque and gastric biopsy were taken and processed by PCR.

RESULTS:

Sixty-one patients were selected for this study (30 women and 31 men). H. pylori was detected in 31 gastric biopsies and 31 oral samples. Significant difference between oral and gastric samples was found in cagA genotype. Agreement between oral and gastric genotypes was found in 38.7% of samples from the same patient.

CONCLUSION:

This study is the first in provide information about the genotypes of the Argentinean Northeast H. pylori strains. Despite the high prevalence of H. pylori infection, the most of patients had less virulent genotypes in oral cavity and gastric tissue. The cagA / babA2 combination was not frequent in the samples studied. There was not a statistical correlation between the virulence genes and gastroduodenal or oral diseases. Although in some patients the same genotype was found both in oral and gastric samples, it cannot be ensure that they corresponding to the same strain because a DNA sequencing was not performed.

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.

Effectiveness of Citrus Fruits on Helicobacter pylori

It is known that Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer, and gastric carcinoma. Due to the increased side effects of the treatment regimens and the development of antimicrobial resistance, a number of natural compounds have been tested as potential alternatives. In this review, we will examine the current knowledge on the effect of Citrus fruits and their derivatives against H. pylori, highlighting the remaining outstanding questions on the development of novel therapeutic strategies.

vacA Genotype Status of Helicobacter pylori Isolated from Foods with Animal Origin

According to controversial theories and results of studies, foods with animal origins play an important role in the transmission of H. pylori to human. The aim of this study was to determine the distribution of vacA genotypes of H. pylori, isolated from milk and meat samples of cow, sheep, goat, camel, and buffalo. Eight hundred and twenty raw milk and meat samples were collected from various parts of Iran. Samples were cultured and those found positive for H. pylori were analyzed for the presence of various genotypes of vacA gene. Out of 420 milk and 400 meat samples, 92 (21.90%) and 105 (26.25%) were positive for H. pylori, respectively. The most commonly detected genotypes in the vacA gene were s1a (86.80%), m1a (79.18%), s1b (69.54%), and m1b (63.45%) and detected combined genotypes were mostly m1as1a (68.52%), m1as1b (60.40%), m1bs1b (55.83%), and m1bs1a (53.29%). High presence of bacteria in the milk and meat samples of sheep represents that sheep may be the natural host of H. pylori. High presence of H. pylori strains in milk and meat samples similar to vacA genotypes in human being suggests that milk and meat samples could be the sources of bacteria for human.

VacA, cagA, iceA and oipA genotypes status and antimicrobial resistance properties of Helicobacter pylori isolated from various types of ready to eat foods

BACKGROUND

Despite the high clinical standing of Helicobacter pylori, its exact routes of transmission and origin have not been determined. Based on the contentious hypothesis, foods play an important roles in the transmission of H. pylori to humans. The present study was carried out to investigate the vacA, cagA, oipA and iceA genotypes status of H. pylori isolated from the various types of ready to eat foods.

METHODS

A total of 550 ready to eat food samples were cultured and tested. H. pylori-positive strains were analyzed for the presence of various genotypes and antimicrobial resistance pattern.

RESULTS

Seventy four out of 550 (13.45 %) samples were positive for H. pylori. Olvie salad (36 %), restaurant salad (30 %), fruit salad (28 %) and soup (22 %) were the most commonly contaminated. H. pylori strains harbored the highest levels of resistance against amoxicillin (94.59 %), ampicillin (93.24 %), metronidazole (89.18 %) and tetracycline (72.97 %). The most commonly detected genotypes were vacA s1a (78.37 %), vacA m2 (75.67 %), vacA m1a (51.35 %) and cagA (41.89 %). The prevalence of iceA1, iceA2 and oipA genotypes were 13.51, 4.05 and 18.91 %, respectively. S1am2 (70.27 %), s1am1a (39.18 %) and m1am2 (31.08 %) were the most commonly detected combined genotypes. Of 40 different genotypic combinations, s1a/cagA+/iceA1/oipA- (12.16 %), s1a/cagA+/iceA1/oipA+ (10.81 %) and s1a/cagA-/iceA1/oipA+ (10.81 %) were the most prevalent.

CONCLUSIONS

The present investigation showed that some types of ready to eat food samples maybe the sources of resistant and virulent strains of H. pylori. Warily use of antibiotics with respect to the results of disk diffusion method and careful health monitoring on food and staffs of food producing companies maybe reduce the risk of H. pylori in foods.

In vitro effect of bergamot (Citrus bergamia) juice against cagA-positive and-negative clinical isolates of Helicobacter pylori

Background

Helicobacter pylori infection has been associated with chronic gastritis, peptic ulcer and gastric carcinoma as over half of the world's population is colonized with this gram-negative bacterium. Due to the increasing antibiotic resistance, its eradication rates fails in a great portion of patients. A number of studies showed that molecules largely distributed in commonly consumed fruits and vegetables may have antimicrobial activity. The aim of the present study was to investigate the effect of bergamot juice (BJ) against Helicobacter pylori in vitro. The potential therapeutic combination between BJ and the antibiotics amoxicillin (AMX), clarithromycin (CLA) and metronidazole (MTZ) has also been evaluated.

Methods

The minimum inhibitory concentration (MIC) of BJ, AMX, CLA and MTZ against 2 ATCC and 32 clinical isolates of H. pylori was assayed according to CLSI. The checkerboard method was used to determine the efficacy of the association BJ with the three reference antibiotics.

Killing curves were performed on the two cagA-positive ATCC strains of H. pylori (ATCC 43504 and ATCC 49503), on the clinical isolate cagA-positive HP6 strain of H. pylori and on the clinical isolate cagA-negative HP61 strain of H. pylori.

Results

BJ (2.5 %, v/v) inhibited the growth of 50 % of the H. pylori clinical isolates, whereas 5 % (v/v) inhibited 90 %. AMX was the most effective antibiotic against the reference strains and the clinical isolates, followed by CLA and MTZ. In the combination assays, synergism was observed between BJ and AMX and between BJ and MTZ against both the reference strains and the clinical isolates. Indifference was observed between BJ and CLA.

Conclusions

BJ was effective in vitro against H. pylori and the genotype status of the clinical strains may have an impact on its susceptibility. The synergistic combination of BJ and antibiotics could be used to prevent or treat resistance.

Milk of livestock as a possible transmission route of Helicobacter pylori infection

AIM

The current investigation aimed to evaluate ruminant raw milk as a reservoir source of Helicobacter pylori and analyze the diversity of cagA and vacA genotypes as H. pylori virulence factors to find any relationship between these genotypes in human and animal H. pylori strains.

BACKGROUND

The way of transmission of Helicobacter pylori as one of the most controversial bacteria in the world, which colonizes the human gastric tissue and is responsible for several gastric diseases is still unknown. The possibility of zoonotic transmission of H. pylori is feasible, but is not proven in ruminant reservoirs.

METHODS

Overall 210 cows, sheep, goats, camels and buffalos' raw milk samples and 100 human gastric biopsies were collected in this survey. We applied PCR assays to identify H. pylori, vacA and cagA genes. Statistical tests were applied for data analysis.

RESULTS

Totally 12(16%) cow, 8(13.79%) sheep, 2 (4.76%) goat, 2(13.33%), buffalo 4(20%) and 82 (82%) of human specimens were confirmed to be H. pylori positive. Among which s1a/m2 genotype was more frequent in isolated H. pylori strains and statistically significant between strains. Based on statistical analyses the s1b allele of sheep had a significant association with human strains.

CONCLUSION

The current survey was prompted by our previous report. According to both results we can conclude that sheep may act as a reservoir for H. pylori and transmit this bacterium to human via its milk. Extended assessments in other geographical regions and other animals are recommended.

The frequency of Helicobacter pylori in dental plaque is possibly underestimated

OBJECTIVE

The commonest bacteria, causing infection across the world is Helicobacter pylori, which colonizes the human stomach. This bacteria has also been detected in some extra-gastric ecological niches such as the oral cavity and water. However, the results of H. pylori detection in extra-gastric ecological niche are controversial. The improvement of the sensitivity and the specificity of the detection methods appear to be some of the main bottleneck issues in providing compelling evidence. The aim of this study was to detect the presence of this organism in dental plaque samples using an analytically sensitive and specific Polymerase Chain Reaction (PCR) as well as a new nucleic acid detection method termed the Loop-mediated Isothermal Amplification (LAMP).

DESIGN

In a descriptive cross-sectional study 45 participants enrolled and dental plaque samples were collected from at least two teeth surfaces (one anterior and one posterior tooth) using a sterile periodontal curette. The DNA content was extracted from the samples and the presence of H. pylori was determined by PCR and LAMP reactions.

RESULTS

The frequency of detection of H. pylori in the dental plaque samples were 44% (20/45), 66.67% (30/45) and 77.78% (35/45) using PCR, LAMP and positivity for both tests, respectively.

CONCLUSION

The high frequency of H. pylori was detected in the dental plaque samples of the participants, which concurs with the high prevalence of this bacteria in the population. This is one of the highest reported rates around the world. The results reveal that dental plaque can be one of the main causes of re-infection and also be the cause of oral-oral transmission.

Role of dental plaque, saliva and periodontal disease in Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections in humans. Although H. pylori may be detected in the stomach of approximately half of the world's population, the mechanisms of transmission of the microorganism from individual to individual are not yet clear. Transmission of H. pylori could occur through iatrogenic, fecal-oral, and oral-oral routes, and through food and water. The microorganism may be transmitted orally and has been detected in dental plaque and saliva. However, the role of the oral cavity in the transmission and recurrence of H. pylori infection has been the subject of debate. A large number of studies investigating the role of oral hygiene and periodontal disease in H. pylori infection have varied significantly in terms of their methodology and sample population, resulting in a wide variation in the reported results. Nevertheless, recent studies have not only shown that the microorganism can be detected fairly consistently from the oral cavity but also demonstrated that the chances of recurrence of H. pylori infection is more likely among patients who harbor the organism in the oral cavity. Furthermore, initial results from clinical trials have shown that H. pylori-positive dyspeptic patients may benefit from periodontal therapy. This paper attempts to review the current body of evidence regarding the role of dental plaque, saliva, and periodontal disease in H. pylori infection.

Study of Helicobacter pylori genotype status in cows, sheep, goats and human beings

Background

Helicobacter pylori is one of the most controversial bacteria in the world causing diverse gastrointestinal diseases. The transmission way of this bacterium still remains unknown. The possibility of zoonotic transmission of H. pylori has been suggested, but is not proven in nonprimate reservoirs. In the current survey, we investigate the presence of H. pylori in cow, sheep and goat stomach, determine the bacterium virulence factors and finally compare the human H. pylori virulence factors and animals in order to examine whether H. pylori might be transmitted from these animals to human beings.

Methods

This cross- sectional study was performed on 800 gastric biopsy specimens of cows, sheep, goats and human beings. The PCR assays was performed to detection of H. pylori, vacA and cagA genes. The PCR products of Ruminant’s samples with positive H. pylori were subjected to DNA sequencing analysis. Statistical tests were applied for data analysis.

Results

Overall 6 (3%) cows, 32 (16%) sheep and 164 (82%) human beings specimens were confirmed to be H. pylori positive; however we were not able to detect this bacterium in all 200 goat samples. The vacA s1a/m1a was the predominant H. pylori genotype in all three kinds of studied population. There was 3.4–8.4% variability and 92.9-98.5% homology between sheep and human samples.

Conclusions

Considering the high sequence homology among DNA of H. pylori isolated from sheep and human, our data suggest that sheep may act as a reservoir for H. pylori and in the some extent share the ancestral host for the bacteria with human.

Genetic variation of Helicobacter pylori in the oral cavity and stomach detected using thymine adenine cloning in children with chronic gastritis

OBJECTIVES

To investigate the DNA sequence variations of Helicobacter pylori in the oral cavities and stomachs of children with chronic gastritis.

METHODS

Dental plaques and gargle on 235 patients were obtained before gastroscopy. Gastric H. pylori infection was diagnosed using rapid urease test or Giemsa staining. H. pylori 16S rDNA and CagA gene were analyzed using PCR methods. Thymine adenine cloning-based sequencing was performed in patients with CagA gene positive from oral cavities. The sequence alignments and V1 variable region were evaluated by comparison with the sequence of the standard H. pylori 26695 strain.

RESULTS

Totally, 46 out of the 235 patients were positive for gastric H. pylori infection. Of the 46 patients, 26 cases had amplified H. pylori 16S rDNA in both oral (plaque and gargle) and gastric samples. Of the 26 cases, 12 patients (46.1%) were positive for the H. pylori CagA gene in the oral samples, which was significantly lower than that in the gastric mucosa (80.8%; P = 0.010). The homology of the complete sequence alignment ranged from 74.0% to 92.1% in the oral and gastric samples. The V1 region alleles (positions 75-99) had 7-22 polymorphisms (homology from 12.0% to 72.0%) in 11 patients between the oral and gastric samples, but had 100% homology in 1 patient.

CONCLUSIONS

Our study found that distinct H. pylori strains exist in the oral cavities of children, but we would not support the hypothesis that H. pylori in the oral cavities is an important reservoir of gastric H. pylori infections in children.

Genetic Analysis of cagA and vacA Genes in Helicobacter Pylori Isolates and Their Relationship with Gastroduodenal Diseases in the West of Iran

Background

Helicobacter pylori have different virulence factors which are associated with several gastroduodenal diseases; however, this association is variable in different geographical regions. Data of genotypes of Iranian H. pylori isolates are few.

Objectives

The aim of the current study was to investigate the cagA/vacA genotypes of Helicobacter pylori isolates and determine the relationship between these genotypes with respect to different gastric disorders in patients of Chaharmahalo Bakhtiarian.

Materials and Methods

In this cross-sectional study, gastric biopsies were taken from 200 patients with gastrodoudenal diseases. Histopathological features were recognized by specialist. The samples were subjected to PCR for detection and identification of ureC, cagA and vacA genes.

Results

The frequency of the vacA genotypes, sa1/m1, s1a/m1b, s1a/m2, s1b/m1a, s1b/m1b, s1b/m2, s1c/m1a, s1c/m1b, s1c/m2, s2/m1a, s2/m1b and s2/m2 were 27(6.6%), 8(4.3%), 45(28.04%), 7(3.7%), 5(2.5%), 10 (6.1%), 12 (7.4%), 4 (2.5%), 18(11%), 6(3.7%), 0 and 22(13.5%) respectively. The cagA gene was detected in 92% of strains. Based on our findings, it seemed that cagPAI and vacA s1 genotypes were associated with some gastric disorders in patients with H. pylori. In this region, the isolates carrying s1a/m2 were the most prevalent.

Conclusions

We found considerable relationship between s1a/m1a, s1a/m2, s2/m2 and s1c/m1a and some gastric disorders. Further studies about the role of H. pylori virulence factors and gastric disorders were recommended.

Study of Helicobacter pylori genotype status in saliva, dental plaques, stool and gastric biopsy samples

AIM: To compare genotype of Helicobacter pylori (H. pylori) isolated from saliva, dental plaques, gastric biopsy, and stool of each patient in order to evaluate the mode of transmission of H. pylori infection.

METHODS: This cross-sectional descriptive study was performed on 300 antral gastric biopsy, saliva, dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord, Iran from March 2010 to February 2011. Initially, H. pylori strains were identified by rapid urease test (RUT) and polymerase chain reaction (PCR) were applied to determine the presence of H. pylori (ureC) and for genotyping of voculating cytotoxin gene A (vacA) and cytotoxin associated gene A (cagA) genes in each specimen. Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher’s exact tests to find any significant relationship between these genes and patient’s diseases. P < 0.05 was considered statistically significant.

RESULTS: Of 300 gastric biopsy samples, 77.66% were confirmed to be H. pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva, 71.67% of stool samples. We were not able to find it in dental plaque specimens. The prevalence of H. pylori was 90.47% among patients with peptic ulcer disease (PUD), 80% among patients with gastric cancer, and 74.13% among patients with none ulcer dyspepsia (NUD) by PCR assay. The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens. 94.42% of H. pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions. There was significant relationship between vacA s1a/m1a and PUD diseases (P = 0.04), s2/m2 genotype and NUD diseases (P = 0.05). No statically significant relationship was found between cagA status with clinical outcomes and vacA genotypes (P = 0.65). The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens.

CONCLUSION: Regard to high similarity in genotype of H. pylori isolates from saliva, stomach and stool, this study support the idea which fecal- oral is the main route of H. pylori transmission and oral cavity may serve as a reservoir for H. pylori, however, remarkable genotype diversity among stomach, saliva and stool samples showed that more than one H. pylori genotype may exist in a same patient.