High prevalence of Helicobacter pylori in saliva demonstrated by a novel PCR assay

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

Helicobacter pylori (H. pylori), a gram-negative bacterium that colonizes the stomach, can cause chronic gastritis and peptic ulcers, as well as gastric cancer as a Class I carcinogen. However, the modes of H. pylori transmission are not clear. This review aims to clarify the transmission routes and patterns of H. pylori and identify efficacious prevention measures.

METHODS

Studies of H. pylori transmission were identified using PubMed, the Web of Science, and Cochrane Central; the retrieval deadline was October 2022.

RESULTS

The transmission routes of H. pylori are discussed, focusing on the five primary transmission routes, namely fecal-oral, oral-oral, gastric-oral, anal-oral, and genital-oral. We propose that H. pylori is contracted through multiple transmission routes. Additionally, we summarize the key transmission patterns of H. pylori, including person-to-person and animal-to-human transmission, as well as foodborne and occupational exposure.

CONCLUSION

Fecal-oral appears to be the most common H. pylori transmission routes. Although the oral-oral pathway is also important, the evidence does not support that this route of transmission is universal. The gastric-oral route occurs primarily in children and patients who are prone to vomiting. Meanwhile, the anal-oral and genital-oral routes remain hypothetical. Person-to-person and foodborne infections represent the predominant transmission patterns of H. pylori, whereas strong environmental and occupational limitations are associated with animal-to-human and occupational exposure.

The validity evaluation of different 16srRNA gene primers for helicobacter detection urgently requesting to design new specific primers

Molecular diagnosis of helicobacters by PCR is simpler, more accurate, and feasible compared to other diagnostic methods. Validity and accuracy are highly dependent on the PCR primer design, diffusion time, and mutation rate of helicobacters. This study aimed to design 16srRNA -specific primers for Helicobacter spp. and H. pylori. Application of comparative statistical analysis of the diagnostic utility of the most available 16srRNA genus-specific primers. The new primers were designed using bioinformatics tools (MAFFT MSA and Gblocks command line). A comparative study was applied on nine genus-specific 16srRNA primers in comparison to the ConsH using in silico and laboratory evaluation. The results demonstrated that the best specificity and sensitivity of the primers designed for this study compared to other primers. The comparative study revealed that the heminested outer/inner primers were the worst. Although H276, 16srRNA(a), HeliS/Heli-nest, and Hcom had acceptable diagnostic utility, false positive and false negative results were obtained. Specificity testing on clinical samples indicated a surprising result; that H. pylori was not the sole enemy that we were looking for, but the Non-Helicobacter pylori Helicobacters should be considered as a real risk prognostic for gastric diseases, consequently, a specific diagnosis and treatment should be developed. This study concluded that our designed primers were the most specific and sensitive in comparison with other primers. In addition, in silico evaluation is not accurate enough for primer assessment and that the laboratory evaluation is mandatory.

Dentists Are at a Higher Risk for Oral Helicobacter pylori Infection

Oral cavity has been taken as one of the major reservoirs for Helicobacter pylori, the bacteria responsible for gastric infection and cancers. Dentists are frequently exposed to saliva; thus, theoretically, they are at a higher risk for oral H. pylori infection. In the present study, to test this hypothesis and to find out the potential factors associated with the increased risk, a cross-sectional study was carried out on a large scale of dentists (N = 90) and nondentist controls (N = 110). By using nested polymerase chain reaction to amplify a specific DNA fragment of H. pylori, we found 7.27% of saliva samples from the nondentist group and 16.67% of saliva samples from the dentist group were oral H. pylori positive, and the difference between groups was statistically significant (χ² = 4.292, p = 0.038). Importantly, however, after stratifying enrolled subjects with factors which might interfere with the comparison of H. pylori detection rate between groups, we still observed a higher H. pylori frequency in the dentists than that in the controls in subgroups, including those with good individual hygiene, healthy lifestyle, and physical condition, as well as those living with families to be gastric disease free and not sharing meals with H. pylori-positive persons, respectively. Moreover, the frequency of clinical practice per week of the investigated dentists was closely associated with an oral H. pylori infection risk. Our data indicates that dentists are at a higher risk for H. pylori infection, and intensive attention needs to be paid on this issue.

Helicobacter pylori gastric infection in patients with laryngeal cancer and chronic laryngitis

BACKGROUND

The purpose of this study was to investigate the pathohistological status of mucous lining infected with Helicobacte pylori as the possible cause of chronic laryngitis and laryngeal carcinoma.

MATERIALS AND METHODS

The prospective examination included 51 patients suffering from planocellular laryngeal cancer and 26 examinees suffering from chronic laryngitis. The examinees and the control group were subjected to esophagogastroduodenoscopy which described the local status of the esophagus and stomach. Two biopsy samplings are taken from the stomach antrum and corpus. One part of the biopsies was colored using the histological technique used in the pathohistological detection of H. pylori, while the other part was incorporated in paraffin cubes where the H. Pylori gene expression was determined using the deparaffinization and PCR method DNA isolation.

RESULTS

In the group of examinees suffering from laryngeal tumor, there were a higher number of patients suffering also from chronic gastritis (32/51) than in the other group, suffering from chronic laryngitis (9/26). In the chronic laryngitis group, there were more examinees with acute gastritis (12/26) than in the examined group (11/51). The difference is statistically significant (p = 0.0457).

CONCLUSION

Chronic gastritis and H. pylori infection are risk factors for laryngeal carcinoma formation; therefore, acute gastritis with helicobacter pylori infection must be immediately treated to not let infection to become chronic.

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

AIM

This study was aimed to investigate the presence of H. pylori and its virulence genotypes in dental plaques of Iranian patients with chronic periodontitis.

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Diagnosis of Lingual Atrophic Conditions: Associations with Local and Systemic Factors. A Descriptive Review

Atrophic glossitis is a condition characterised by absence of filiform or fungiform papillae on the dorsal surface of the tongue. Consequently, the ordinary texture and appearance of the dorsal tongue, determined by papillary protrusion, turns into a soft and smooth aspect.

Throughout the years, many factors, both local and systemic, have been associated with atrophic glossitis as the tongue is currently considered to be a mirror of general health. Moreover, various tongue conditions were wrongly diagnosed as atrophic glossitis. Oral involvement can conceal underlying systemic conditions and, in this perspective, the role of clinicians is fundamental.

Early recognition of oral signs and symptoms, through a careful examination of oral anatomical structures, plays a crucial role in providing patients with a better prognosis.

Helicobacter-negative gastritis: polymerase chain reaction for Helicobacter DNA is a valuable tool to elucidate the diagnosis

BACKGROUND

Helicobacter-negative gastritis has been increasingly reported. Molecular techniques as the polymerase chain reaction (PCR) may detect bacterial DNA in histologically negative gastritis.

AIM

To evaluate of Helicobacter PCR in gastric biopsies for the daily diagnostics of Helicobacter-negative gastritis.

METHODS

Over a 5-year period, routine biopsies with chronic gastritis reminiscent of Helicobacter infection, but negative by histology, were tested by using a H. pylori specific PCR. Subsequently, PCR-negative samples were re-evaluated using PCR for other Helicobacter species.

RESULTS

Of the 9184 gastric biopsies, 339 (3.7%) with histological-negative gastritis and adequate material were forwarded to PCR analysis for H. pylori and 146 (43.1%) revealed a positive result. In 193 H. pylori DNA-negative biopsies, re-analysis using PCR primers for other Helicobacter species, revealed further 23 (11.9%) positive biopsies, including 4 (2.1%) biopsies with H. heilmannii sensu lato. PCR-positive biopsies showed a higher overall inflammatory score, more lymphoid follicles/aggregates and neutrophils (P < 0.05). No Helicobacter DNA was found in control biopsies of 48 patients with neither primer set (P < 0.0001). In 274 patients with an endoscopic description, detection of H. pylori DNA was associated with ulcers and erosions (P < 0.01). Over all, in 339 histologically-negative gastric biopsies, Helicobacter DNA was detected in 169 (49.9%) samples with at least one primer set.

CONCLUSION

Molecular testing offers a sensitive and specific diagnosis to a selected group of patients, in whom adequate searches for bacteria by conventional histology have resulted in the unsatisfactory diagnosis of H. pylori-negative gastritis.

A Newly Developed Nested PCR Assay for the Detection of Helicobacter pylori in the Oral Cavity

GOALS

To develop a new nested polymerase chain reaction (PCR) assay for identifying Helicobacter pylori DNA from dental plaque.

BACKGROUND

H. pylori is one of the most common chronic bacterial pathogens in humans. The accurate detection of this organism is essential for proper patient management and for the eradication of the bacteria following treatment.

STUDY

Forty-nine patients (24 males and 25 females; mean age: 51; range, 19 to 94 y) were investigated for the presence of H. pylori in dental plaque by single-step PCR and nested PCR and in the stomach by single-step PCR, nested PCR, and histologic examination.

RESULTS

The newly developed nested PCR assay identified H. pylori DNA in gastric biopsies of 18 patients who were histologically classified as H. pylori-positive and 2 additional biopsies of patients who were H. pylori-negative by histologic examination (20/49; 40.8%). Dental plaque samples collected before and after endoscopy from the 49 patients revealed that single-step PCR did not detect H. pylori but nested PCR was able to detect H. pylori DNA in 40.8% (20/49) patients. Nested PCR gave a higher detection rate (40.8%, 20/49) than that of histology (36.7%, 18/49) and single-step PCR. When nested PCR results were compared with histology results there was no significant difference between the 2 methods.

CONCLUSIONS

Our newly developed nested PCR assay is at least as sensitive as histology and may be useful for H. pylori detection in patients unfit for endoscopic examination.

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.

Detection of the Helicobacter pylori dupA gene is strongly affected by the PCR design

The Helicobacter pylori virulence gene dupA is usually detected by PCR, but the primer binding sites used are highly variable. Our newly designed qPCR against a conserved region of dupA was positive in 64.2% of 394 clinical isolates while the positivity rate of the commonly used PCRs ranged from 29.9% to 37.8%.

Helicobacter pylori and oral pathology: Relationship with the gastric infection

Helicobacter pylori (H. pylori) has been found in the oral cavity and stomach, and its infection is one of the most frequent worldwide. We reviewed the literature and conducted a Topic Highlight, which identified studies reporting an association between H. pylori-infection in the oral cavity and H. pylori-positive stomach bacterium. This work was designed to determine whether H. pylori is the etiologic agent in periodontal disease, recurrent aphthous stomatitis (RAS), squamous cell carcinoma, burning and halitosis. Record selection focused on the highest quality studies and meta-analyses. We selected 48 articles reporting on the association between saliva and plaque and H. pylori-infection. In order to assess periodontal disease data, we included 12 clinical trials and 1 meta-analysis. We evaluated 13 published articles that addressed the potential association with RAS, and 6 with squamous cell carcinoma. Fourteen publications focused on our questions on burning and halitosis. There is a close relation between H. pylori infection in the oral cavity and the stomach. The mouth is the first extra-gastric reservoir. Regarding the role of H. pylori in the etiology of squamous cell carcinoma, no evidence is still available.

Laryngopharyngeal reflux and Helicobacter pylori

Laryngopharyngeal reflux (LPR) occurs when gastric contents pass the upper esophageal sphincter, causing symptoms such as hoarseness, sore throat, coughing, excess throat mucus, and globus. The pattern of reflux is different in LPR and gastroesophageal reflux. LPR usually occurs during the daytime in the upright position whereas gastroesophageal reflux disease more often occurs in the supine position at night-time or during sleep. Ambulatory 24-h double pH-probe monitoring is the gold standard diagnostic tool for LPR. Acid suppression with proton pump inhibitor on a long-term basis is the mainstay of treatment. Helicobacter pylori (H. pylori) is found in many sites including laryngeal mucosa and interarytenoid region. In this paper, we aim to present the relationship between LPR and H. pylori and review the current literature.

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.

Helicobacter pylori identification: a diagnostic/confirmatory method for evaluation

The Helicobacter pylori extra gastric reservoir is probably the oral cavity. In order to evaluate the presence of this bacterium in patients with periodontitis and suspicious microbial cultures, saliva was collected from these and non-periodontitis subjects. PCRs targeting 16S rRNA gene and a 860 bp specific region were performed, and digested with the restriction enzyme DdeI. We observed that the PCR-RFLP approach augments the accuracy from 26.2 % (16/61), found in the PCR-based results, to 42.6 % (26/61), which is an excellent indicator for the establishment of this low-cost procedure as a diagnostic/confirmatory method for H. pylori evaluation.

Does tonsillectomy affect the outcome of drug treatment for the eradication of gastric H pylori infection? A pilot study

Eradication of Helicobacter pylori, which is associated with diverse gastroduodenal pathologies of varying severity, is sometimes challenging. We conducted a prospective study to determine the effect of tonsillectomy on the eradication of H pylori from the gastrointestinal tract. Our study population was made up of 46 patients-32 females and 14 males, aged 14 to 58 years (mean: 28.84 ± 9.65)-who had chronic tonsillitis and concomitant dyspepsia. An initial gastrointestinal endoscopy was performed to obtain specimens for histology and a rapid urease test. These gastroscopies revealed that 32 patients were H pylori-positive (69.6%) and 14 were H pylori-negative (30.4%); these groups were designated A and B, respectively. The 32 H pylori-positive patients were divided into three subgroups based on the sequence in which they underwent drug therapy and tonsillectomy. All 3 subgroups received the same 14-day combination-drug regimen for eradication of gastric H pylori. The patients in group A1 (n = 12) underwent tonsillectomy prior to receiving drug treatment; 2 months after the cessation of drug therapy, they underwent a second gastroscopy. The patients in group A2 (n = 10) received drug treatment first followed by tonsillectomy; 2 months later, they underwent their second gastroscopy. The patients in group A3 (n = 10) received drug treatment first, then they underwent a second gastroscopy, and then they were taken for tonsillectomy. The success or failure of H pylori eradication was determined by the second gastroscopy. Also, analyses were performed after tonsillectomy to look for H pylori infection in tonsillar specimens. Eradication of gastric H pylori was achieved in 9 of the 12 group A1 patients (75.0%), 8 of the 10 group A2 patients (80.0%), and 7 of the 10 group A3 patients (70.0%); there were no statistically significant differences among the three groups. Likewise, there were no significant differences between any subgroups or combination of subgroups in terms of tonsillar positivity. As far as we know, this is the first study to investigate the effect of tonsillectomy on the outcome of H pylori eradication treatment. In light of our findings, we may speculate that tonsillar tissue does not seem to be a reservoir for H pylori infection. Although tonsillectomy had no significant effect on gastric H pylori eradication in our study, our results might have been skewed by the relatively small size of our sample.

A Cross-Sectional Survey of Dental Caries, Oral Hygiene, and Helicobacter pylori Infection in Adults

We explored the epidemiological risk factors for dental caries to help explain differences in the prevalence of adult dental caries. We examined 841 people for the presence of Helicobacter pylori in their dental plaque and for dental caries. Of the 841 subjects, 574 (68.25%) were infected with H pylori, and 516 (61.36%) were diagnosed with dental caries. Among the 574 subjects with H pylori, the prevalence of dental caries was 73.52% (422/574), while the prevalence among the 267 cases without H pylori was 35.21% (94/267). A correlation existed between the presence of H pylori and the occurrence of dental caries (χ2 = 112.8, P < .01, odds ratio = 5.110, 95% confidence interval = 3.740-6.982). The 574 persons with H pylori had a higher mean dental plaque index than those without. In conclusion, H pylori infection in the oral cavity is associated with dental caries and poor dental hygiene.

Prevalence of Helicobacter pylori in the adolescent oral cavity: dependence on orthodontic therapy, oral flora and hygiene

BACKGROUND

Helicobacter pylori (HP) infection usually occurs in childhood. While there are various studies on the prevalence of HP in dental plaque, ours is the first to analyze its prevalence during orthodontic therapy and its interaction with competitive bacteria in adolescents.

SUBJECTS AND METHODS

The prevalence of HP was examined before and during the first 12 weeks of orthodontic therapy with fixed appliances in 11 patients with a mean age of 12.7 years. A total of 93 plaque samples were analyzed using PCR. The data acquired at every consultation were the following: PCR analysis of dental plaque and (13)C urea breath tests for HP, quantitative analyses of saliva for Lactobacilli and Streptococcus mutans, the interproximal plaque index (API), and sulcus bleeding index (SBI).

RESULTS

The prevalence of HP in plaque was 82% before orthodontic therapy, dropping to 54% during therapy (t test, p≤0.05). In contrast to HP's prevalence, the Lactobacilli count rose (p≤0.05). The number of Streptococcus mutans bacteria in saliva decreased during orthodontic therapy (p≤0.05).

CONCLUSION

The prevalence of HP in dental plaque amounted to 82%. Orthodontic treatment did not reduce its prevalence. The prevalence of Lactobacilli was inversely proportional to that of HP.

The Association between Helicobacter Pylori and Laryngopharyngeal Reflux in Laryngeal Pathologies

We conducted a study to determine the presence or absence of Helicobacter pylori and laryngopharyngeal reflux (LPR) in 43 previously untreated patients who had presented with a laryngeal lesion. Our aim was to determine if there was any association among H pylori, LPR, and laryngeal lesions. H pylori status was determined by real-time polymerase chain reaction (PCR) assays of biopsy tissue obtained during direct laryngoscopy. The presence or absence of LPR was determined on the basis of patients’ reflux symptom index (RSI) and reflux finding score (RFS), which were based on their questionnaire responses and findings on endoscopic examination of the larynx, respectively. Patients with an RSI of 14 or more and/or an RFS of 8 or more were considered to have LPR. H pylori was present in 24 patients (55.8%) and absent in 19 (44.2%)—not a statistically significant difference. The prevalence of LPR was higher than the prevalence of H pylori; it was present in 30 patients (69.8%) and absent in 13 (30.2%). The difference was statistically significant (p = 0.01). We found no association between H pylori status and LPR status. Additionally, we analyzed two subgroups based on whether their lesions were benign or malignant/premalignant and found a significant relationship between LPR positivity and the presence of malignant/premalignant laryngeal lesions (p = 0.03). We found no association between H pylori status and either of the two subgroup categories.

High prevalence of virulence-associated genotypes in Helicobacter pylori clinical isolates in the Region del Maule, Chile

The prevalence of Helicobacter pylori infection and the gastric cancer mortality rate in Chile are remarkably high. This study identified some virulence-associated genes in 78 H. pylori clinical isolates from dyspeptic patients from the Region del Maule, which is the region with the higher gastric cancer mortality rate in the country. The cagA, vacA and babA2 genes were detected in 94.9%, 100% and 97.4%, respectively. Two or more EPIYA C motifs were presented in 48.6% of cagA-positive strains, and this was associated with more severe histopathological findings in the gastric mucosa.

Saliva secretion and efficacy of helicobacter pylori eradication in peptic ulcer patients

OBJECTIVE

It has been noted that the presence of Helicobacter pylori (H. pylori) in the oral cavity may affect the outcome of eradication therapy. This condition is associated with the recurrence of gastric infection. The optimum secretion of saliva promotes oral health consequently influencing H. pylori eradication. The purpose of this study was to investigate the relation between salivary secretion and the efficacy of H. pylori eradication from the stomach.

MATERIALS AND METHODS

Forty five patients with gastric H. pylori infection were enrolled in this study. Diagnosis of H. pylori infection was confirmed by endoscopy, biopsy, urease test and histological examination. Salivary secretion of all participants was determined under standard condition before the beginning of antibacterial treatment. Then the patients were treated with a 14-day course anti-H. pylori regimen consisting of amoxicillin, omeprazole, metronidazole and bismuth. The efficacy of eradication therapy was evaluated 4 weeks after the end of the treatment course. Mann-Whitney U test was used to analyze the variables.

RESULTS

The median of salivary secretion among successful and unsuccessful H. pylori eradication groups was 0.48 ml/min and 0.24 ml/min, respectively (p=0.005).

CONCLUSION

Although the type of drug regimens is challenging, the efficacy of H. pylori eradication from the stomach might be reduced by lower salivary secretion.

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

INTRODUCTION

Helicobacter pylori is a microaerophilic, spiral-shaped motile bacterium that is strongly associated with gastroduodenal diseases, but recently, dental plaque and saliva have been implicated as possible sources of H pylori infection. Two virulence factors that are expressed by the alleles of the cytotoxin genes, cagA and vacA, have been identified. The aim of this study was to compare cagA and vacA genotypes of H pylori between stomach and saliva in a same patient.

METHODS

This study was performed on antrum gastric biopsy specimens and saliva samples, which were obtained from 250 patients undergoing upper gastrointestinal tract endoscopy in Hagar Hospital of Shahrekord Township in Iran. Initially, H pylori strains were identified by rapid urease test; then, we applied polymerase chain reaction assay to analyze cagA and vacA genotypes of H pylori from both gastric and saliva specimens.

RESULTS

One hundred eighty-nine (75.6%) and 36 (14.4%) samples were H pylori positive in gastric and saliva samples, respectively. Evaluation of virulence factors in the 36 patients whose saliva and gastric samples were both positive for H pylori showed a great deal of cytotoxin genotypic diversity between stomach and saliva in the same patient; in fact, 14 patients (38.8%) had different H pylori strains in their saliva and gastric samples.

CONCLUSIONS

The data suggest that >1 H pylori strain may exist in stomach and saliva in the same patient.

Diagnosis of amebic liver abscess and amebic colitis by detection of Entamoeba histolytica DNA in blood, urine, and saliva by a real-time PCR assay

The noninvasive diagnosis of amebic liver abscess is challenging, as most patients at the time of diagnosis do not have a concurrent intestinal infection with Entamoeba histolytica. Fecal testing for E. histolytica parasite antigen or DNA is negative in most patients. A real-time PCR assay was evaluated for detection of E. histolytica DNA in blood, urine, and saliva samples from amebic liver abscess as well as amebic colitis patients in Bangladesh. A total of 98 amebic liver abscess and 28 amebic colitis patients and 43 control subjects were examined. The real-time PCR assay detected E. histolytica DNA in 49%, 77%, and 69% of blood, urine, and saliva specimens from the amebic liver abscess patients. For amebic colitis the sensitivity of the real-time PCR assay for detection of E. histolytica DNA in blood, urine, and saliva was 36%, 61%, and 64%, respectively. All blood, urine, and saliva samples from control subjects were negative by the real-time PCR assay for E. histolytica DNA. When the real-time PCR assay results of the urine and saliva specimens were taken together (positive either in urine or saliva), the real-time PCR assay was 97% and 89% sensitive for detection of E. histolytica DNA in liver abscess and intestinal infection, respectively. We conclude that the detection of E. histolytica DNA in saliva and urine could be used as a diagnostic tool for amebic liver abscess.

Real-time PCR detection of Helicobacter pylori and virulence-associated cagA in nasal polyps and laryngeal disorders

OBJECTIVE

To identify Helicobacter pylori and major virulence factor, cagA, in patients with laryngeal diseases and nasal polyps.

STUDY DESIGN

Cross-sectional study with planned data collection.

SETTING

The study was performed on fresh tissue samples from patients with 32 nasal polyps, 29 normal nasal mucosa, and 27 laryngeal diseases presenting to the Otolaryngology-Head and Neck Surgery department of a major military hospital in Istanbul, Turkey.

SUBJECTS AND METHODS

Tissue specimens were evaluated by in-house polymerase chain reaction (PCR) and real-time PCR for bacterial DNA and by real-time PCR for cagA. The impact of commercial and in-house DNA extraction methods was also evaluated.

RESULTS

H pylori DNA was detected only by real-time PCR in 59.4 percent of nasal polyps, 70.4 percent of nasal mucosa samples, and 58.6 percent of larynx samples. cagA was identified in 78.9, 89.5, and 82.4 percent of positive polyp, nasal mucosa, and larynx samples, respectively. No statistically significant differences were observed between groups. DNA purification methods were equally effective.

CONCLUSION

H pylori DNA is present in nasal polyp and larynx tissues as well as normal nasal mucosa, as detected by a sensitive real-time PCR assay. cagA-positive strains dominate in all groups.

Determination of Helicobacter pylori in patients with chronic nonspecific pharyngitis

OBJECTIVES/HYPOTHESIS

To determine if there is a relationship between Helicobacter pylori colonization in the pharynx mucous membrane and chronic nonspecific pharyngitis.

STUDY DESIGN

A prospective clinical study.

METHODS

Seventy patients with chronic pharyngitis and 20 healthy control subjects were examined with polymerase chain reaction (PCR) and culture for H. pylori colonization in the pharynx mucous membrane between March 2008 and October 2008. Patients with pharyngitis were seperated into two groups (35 patients in each) by using C-14 urea breath test, according to the presence of gastric H. pylori infection.

RESULTS

In the control group, none of the patients had H. pylori in the pharynx. In the chronic pharyngitis group, in 12 patients (34.3%) with gastric H. pylori infection and in seven patients (20%) without gastric infection, H. pylori colonization in pharynx mucosa was determined with the PCR method. In only two of chronic pharyngitis patients (5.8%), H. pylori infection was detected with culture. In the pharynx mucosa, the H. pylori infection rate was significantly higher in the chronic pharyngitis groups than in the control group (P = .002 between C-14 positive and control groups, P = .040 between C-14 negative and control groups). There was not a significant difference in H. pylori colonization in the pharynx of patients who had chronic pharyngitis with or without gastric ailments and H. pylori infection (P = .179).

CONCLUSIONS

Chronic nonspecific pharyngitis without gastric H. pylori infection is significantly related to H. pylori colonization in the pharynx, and gastric involvement increases the rate of this spread. The gold standart for detection of H. pylori infection is the PCR method.

Oral cavity is not a reservoir for Helicobacter pylori in infected patients with functional dyspepsia

INTRODUCTION

Helicobacter pylori infection is very prevalent in Brazil, infecting almost 65% of the population. The aim of this study was to evaluate the presence of this bacterium in the oral cavity of patients with functional dyspepsia (epigastric pain syndrome), establish the main sites of infection in the mouth, and assess the frequency of cagA and vacA genotypes of oral H. pylori.

METHODS

All 43 outpatients with epigastric pain syndrome, who entered the study, were submitted to upper gastrointestinal endoscopy to rule out organic diseases. Helicobacter pylori infection in the stomach was confirmed by a rapid urease test and urea breath tests. Samples of saliva, the tongue dorsum and supragingival dental plaque were collected from the oral cavity of each subject and subgingival dental plaque samples were collected from the patients with periodontitis; H. pylori infection was verified by polymerase chain reaction using primers that amplify the DNA sequence of a species-specific antigen present in all H. pylori strains; primers that amplify a region of urease gene, and primers for cagA and vacA (m1, m2, s1a, s1b, s2) genotyping.

RESULTS

Thirty patients harbored H. pylori in the stomach, but it was not possible to detect H. pylori in any oral samples using P1/P2 and Urease A/B. The genotype cagA was also negative in all samples and vacA genotype could not be characterized (s-m-).

CONCLUSION

The oral cavity may not be a reservoir for H. pylori in patients with epigastric pain syndrome, the bacterium being detected exclusively in the stomach.

Frequency of vacA, cagA and babA2 virulence markers in Helicobacter pylori strains isolated from Mexican patients with chronic gastritis

BACKGROUND

Helicobacter pylori has been strongly associated with chronic gastritis, peptic and duodenal ulcers, and it is a risk factor for gastric cancer. Three major virulence factors of H. pylori have been described: the vacuolating toxin (VacA), the cytotoxin-associated gene product (CagA) and the adhesion protein BabA2. Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to establish the H. pylori and vacA, cagA and babA2 gene status in 238 adult patients, from a marginal urban area of Mexico, with chronic gastritis.

METHODS

H. pylori was identified in cultures of gastric biopsies by nested PCR. vacA and cagA genes were detected by multiplex PCR, whereas babA2 gene was identified by conventional PCR.

RESULTS

H. pylori-positive biopsies were 143 (60.1%). All H. pylori strains were vacA+; 39.2% were cagA+; 13.3% were cagA+ babA2+ and 8.4% were babA2+. Mexican strains examined possessed the vacA s1, m1 (43.4%), s1, m2 (24.5%), s2, m1 (20.3%) and s2, m2 (11.9%) genotypes.

CONCLUSION

These results show that the Mexican patients suffering chronic gastritis we have studied had a high incidence of infection by H. pylori. Forty four percent (63/143) of the H. pylori strains analyzed in this work may be considered as highly virulent since they possessed two or three of the virulence markers analyzed: vacA s1 cagA babA2 (9.8%, 14/143), vacA s1 babA2 (4.9%, 7/143), and vacA s1 cagA (29.4%, 42/143). However, a statistically significant correlation was not observed between vacAs1, cagA and babA2 virulence markers (chi2 test; P > 0.05).

Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates

AIM

To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients.

METHODS

DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies.

RESULTS

vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and "triple-positive" (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively).

CONCLUSION

The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied.

Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates

AIM

To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients.

METHODS

DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies.

RESULTS

vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and "triple-positive" (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively).

CONCLUSION

The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied.

Unreliability of results of PCR detection of Helicobacter pylori in clinical or environmental samples

The aim of this study was to compare published Helicobacter pylori primer pairs for their ability to reliably detect H. pylori in gastric biopsy specimens and salivary samples. Detection limits of the 26 PCR primer pairs previously described for detection of H. pylori DNA in clinical samples were determined. Sensitivity and specificity were determined using primers with detection limits of <100 CFU/ml using 50 H. pylori-positive and -negative (by concordance by culture and histology) coded gastric biopsy specimens. These results were then confirmed with gastric biopsy specimens and saliva from patients with confirmed H. pylori status. Five of the twenty-six previously reported primer pairs (HP64-f/HP64-r, HP1/HP2, EHC-U/EHC-L, VAG-F/VAG-R, and ICT37/ICT38) had detection limits of <100 CFU/ml in the presence of gastric tissue. None had 100% specificity or sensitivity; all produced false-positive results. The HP64-f/HP64-r for ureA and HP1/HP2 for 16S rRNA individually had sensitivities and specificities of >90% with gastric biopsy specimens. No combinations of primer pairs improved the results. Using these five primer pairs, 54% of the positive saliva samples were determined to be false positive; both the HP64-f/HP64-r and the HP1/HP2 sets produced false positives with saliva. We conclude that clinicians should not rely on results using current PCR primers alone to decide the H. pylori status of an individual patient or as a basis for treatment decisions. The results of studies based on PCR identification of H. pylori in environmental samples should be viewed with caution. Possibly, specific primers sets can be identified based on the presence of multiple putative virulence factor genes.

Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates

AIM: To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients.

METHODS: DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies.

RESULTS: vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and “triple-positive” (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively).

CONCLUSION: The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied.

Detection of Entamoeba histolytica DNA in the saliva of amoebic liver abscess patients who received prior treatment with metronidazole

Saliva is an easily-accessible and a non-invasive clinical specimen alternate to blood and liver pus. An attempt was made to detect Entamoeba histolytica DNA released in the saliva of amoebic liver abscess (ALA) patients by applying 16S-like rRNA gene-based nested multiplex polymerase chain reaction (NM-PCR). The NM-PCR detected E. histolytica DNA in the saliva of eight (28.6%) of 28 ALA patients. The NM-PCR result was negative for E. histolytica DNA in the saliva of all the eight ALA patients who were tested prior to treatment with metronidazole but was positive in the saliva of eight (40%) of 20 ALA patient who were tested after therapy with metronidazole. The NM-PCR detected E. histolytica DNA in liver abscess pus of all 28 (100%) patients with ALA. The TechLab E. histolytica II enzyme-linked immunosorbent assay was positive for E. histolytica Gal/GalNAc lectin antigen in the liver abscess pus of 13 (46.4%) of the 28 ALA patients. The indirect haemagglutination (IHA) test was positive for anti-amoebic antibodies in the serum of 22 (78.6%) of the 28 ALA patients and 2 (5.7%) of 35 healthy controls. The present study, for the first time, demonstrates the release of E. histolytica DNA in the saliva of ALA patients by applying NM-PCR.

Study on the relationship between Helicobacter pylori in the dental plaque and the occurrence of dental caries or oral hygiene index

BACKGROUND

The aims of our study were to determine the presence of Helicobacter pylori DNA in the dental plaque of Chinese children aged 3-6 years by nested polymerase chain reaction (PCR) and to investigate the relationship between this infection and the occurrence of dental caries or oral hygiene index.

METHODS

Two hundred and fourteen children from a kindergarten in Guangzhou City of China were evaluated. The children's plaques were assessed by plaque indices of Quigley-Hein. Dental plaque was analyzed using nested PCR for two sets of primers directed to the 860-bp fragment of H. pylori genomic DNA, which have been reported to be highly sensitive and specific by other researchers.

RESULTS

H. pylori was detected in dental plaque samples from 126 children, and 70 children with dental caries carried H. pylori in dental plaque. Of these children without infection, only 36 of 88 suffered dental caries. Besides, the average dental plaque index of 126 H. pylori-positive children was higher than that of 88 children without infection. In the present study, there was a significant correlation between H. pylori infection and dental caries or dental hygiene.

CONCLUSION

The oral cavity may be a reservoir for H. pylori infection in children. H. pylori in dental plaque may play a role in the occurrence of dental caries, and poor oral hygiene may represent a risk factor for H. pylori in the oral cavity.

A critical evaluation of the evidence on a causal relationship betweenHelicobacter pyloriand otitis media with effusion

Objective:

There is growing interest in the presence ofHelicobacter pyloriin the upper aerodigestive tract, and in the middle ear in patients with otitis media with effusion. Some studies have reported detectingH pyloriin the middle ear, although reports to the contrary exist. In this study, we critically evaluate the evidence for the theory thatH pyloriin the middle ear plays a role in otitis media with effusion.

Material:

We undertook a systematic review of all available studies investigating the presence ofH pyloriin the middle ear of patients with otitis media with effusion. The current literature was critically analysed using the key words and phrases ‘Helicobacter pylori’ ‘otitis media with effusion’, ‘serous otitis media’, ‘glue ear’ and ‘middle ear’. Six original research papers were identified, studying a total of 203 patients and 27 controls; two of these papers were randomised, controlled studies and four were prospective, cohort studies.

Results:

At present, there is poor evidence for the existence ofH pylori-associated otitis media with effusion.

Conclusions:

Further research in the field is needed in order to delineate the presence ofH pyloriand its role in the pathogenesis of otitis media with effusion.

Development of an internal control for evaluation and standardization of a quantitative PCR assay for detection of Helicobacter pylori in drinking water

Due to metabolic and morphological changes that can prevent Helicobacter pylori cells in water from growing on conventional media, an H. pylori-specific TaqMan quantitative PCR (qPCR) assay was developed that uses a 6-carboxyfluorescein-labeled probe (A. E. McDaniels, L. Wymer, C. Rankin, and R. Haugland, Water Res. 39:4808-4816, 2005). However, proper internal controls are needed to provide an accurate estimate of low numbers of H. pylori in drinking water. In this study, the 135-bp amplicon described by McDaniels et al. was modified at the probe binding region, using PCR mutagenesis. The fragment was incorporated into a single-copy plasmid to serve as a PCR-positive control and cloned into Escherichia coli to serve as a matrix spike. It was shown to have a detection limit of five copies, using a VIC dye-labeled probe. A DNA extraction kit was optimized that allowed sampling of an entire liter of water. Water samples spiked with the recombinant E. coli cells were shown to behave like H. pylori cells in the qPCR assay. The recombinant E. coli cells were optimized to be used at 10 cells/liter of water, where they were shown not to compete with 5 to 3,000 cells of H. pylori in a duplex qPCR assay. Four treated drinking water samples spiked with H. pylori (100 cells) demonstrated similar cycle threshold values if the chlorine disinfectant was first neutralized by sodium thiosulfate.

Intranasal Helicobacter pylori colonization does not correlate with the severity of chronic rhinosinusitis

OBJECTIVE

To investigate the prevalence of Helicobacter pylori (HP) in the nasal cavity of patients with chronic rhinosinusitis (CRS) and to correlate it with the severity of CRS.

STUDY DESIGN AND SETTING

Intranasal HP was investigated using rapid urease (CLO) testing and immunohistochemical (IHC) analysis and confirmed with transmission electron microscopy. To evaluate the severity of sinusitis, CT scans were graded according to the Lund-MacKay scoring system, and CRS symptom scores were recorded.

RESULTS

Twelve of 48 patients (25.0%) were positive, but only 1 of 29 (3.4%) controls was positive for both CLO testing and IHC analysis (P = 0.025). The mean preoperative CT grade (P = 0.439) and symptom scores (P = 0.515) were not related to the severity of CRS.

CONCLUSIONS

Intranasal HP was more prevalent in patients with CRS than healthy controls. However, there was no significant correlation observed between the severity of sinusitis and intranasal HP colonization.

SIGNIFICANCE

HP has a limited role in pathogenesis of CRS.

Association of cagA+ Helicobacter pylori with adenotonsillar hypertrophy

Cytotoxin-associated gene A (cagA) of Helicobacter pylori (H. pylori) encodes a highly immunogenic and virulence-associated protein. The presence of cagA(+) H. pylori strains in tonsil and adenoid tissues may affect clinical outcome. The aim of the present study was to determine the presence of H. pylori cagA gene in tonsil and adenoid tissues and to establish the potential association of cagA(+) H. pylori in recurrent adenotonsillitis (RAT) and adenotonsillar hypertrophy (ATH). For this aim, a total of 118 tissue samples (71 tonsil and 47 adenoid tissues) were collected from a total of 71 children: 28 cases with RAT and 43 cases with ATH. The samples were analyzed for glmM gene to detect the infection with H. pylori by polymerase chain reaction (PCR). H. pylori-positive samples were further analyzed for the presence of the cagA gene. The PCR analysis showed that 29 samples (24.6%) were positive for H. pylori. Seventeen out of these 29 samples (58.6%) were found positive for cagA; the cagA gene was detected in 12 samples of ATH and 5 samples of RAT. The presence rate of cagA gene was significantly higher (p < 0.05) in ATH patients than that found in RAT patients. These results suggest that presence of cagA(+) H. pylori may be associated with development of ATH.

Expression of Lewis antigens and their precursors in gastric mucosa: relationship with Helicobacter pylori infection and gastric carcinogenesis

Lewis (Le)-associated antigens are carbohydrates that are related biochemically to the ABO blood groups, and may have a role in Helicobacter pylori adherence. To evaluate their relationship to clinicopathological outcomes, gastric Le expression, including type 1 precursor, type 1 H, Le(a), Le(b), Le(x), Le(y) and sialylated Le(a) (CA19-9), was evaluated immunohistochemically in 233 gastric biopsy specimens obtained at routine gastroscopy. Expression was also investigated in gastric tissues showing chronic gastritis, intestinal metaplasia, and carcinoma from 42 patients with gastric cancer. A polymerase chain reaction was performed for H. pylori and the bacterial babA2 gene. We identified type 1 precursor expression in 34.3%, type 1 H in 55.8%, Le(a) in 44.2%, Le(b) in 82.0%, Le(x) in 44.2%, Le(y) 56.7%, and CA19-9 in 16.3% of the 233 gastric biopsy specimens. Expression of type 1 H, Le(b), and CA19-9 was significantly associated with H. pylori infection and histological features (p < 0.05), and expression of type 1 H was an independent predictive factor for H. pylori infection by multivariate logistic regression (p = 0.020). Positivity for the babA2 genotype correlated significantly with H. pylori infection and type 1 H expression in gastric biopsy specimens (p < 0.05). The babA2 genotype was more frequent in gastric mucosa from the gastric cancer patients than in gastric biopsy specimens from routine gastroscopy (p = 0.009). In the 42 gastric cancer patients, the frequency of type 1 precursor, Le(a), and Le(x) expression was significantly higher in intestinal metaplasia and carcinoma than in chronic gastritis (p < 0.05), but the frequency of type 1 H and Le(b) expression was significantly lower in intestinal metaplasia and carcinoma (p < 0.05). In conclusion, Le expression, especially that of type 1 H, was significantly associated with clinicopathological features. In gastric cancer patients, Le expression was altered in intestinal metaplasia and carcinoma in comparison with chronic gastritis.