Saliva samples not a reliable tool for diagnosis of Helicobacter pylori infection

The role of Helicobacter Pylori and laryngopharyngeal reflux in recurrent tonsillitis

OBJECTIVES

To detect Helicobacter Pylori [HP] in tonsillar tissue of recurrent tonsillitis cases and assess the possible role of Laryngopharyngeal reflux [LPR] in tonsillar HP infection.

METHODS

A prospective study was done on the cited subject in a sample size of 50 paediatric patients [Age group: 6-18 years] suffering from recurrent tonsillitis. LPR was diagnosed by Reflux Symptom index [RSI] and Reflux Finding score [RFS]. A score of more than 7 and 13 was regarded as significant for RFS and RSI respectively. Patients with both scores significant were regarded to be suffering from LPR. Tonsillar specimen after tonsillectomy were subjected to urease test, histopathology [ Modified Giemsa Staining] and culture to detect HP. A minimum of two positive tests of the mentioned three were taken as gold standard to diagnose colonization of HP. Tabulated data was statistically analysed.

RESULTS

We recorded an incidence of 9% [18 cases] for LPR in recurrent tonsillitis. No case of HP colonization of tonsils was detected in this case series, even in patients of LPR.

CONCLUSION

We conclude that tonsils are not an extra gastric reservoir of HP. In addition, there is no aetiological relationship between recurrent tonsillitis and HP. And lastly, LPR is not a significant factor for colonization of tonsils by HP.

Diagnosis of Helicobacter pylori Using Invasive and Noninvasive Approaches

Helicobacter pylori (H. pylori) as gram-negative and spiral microorganism is responsible for colonization in the gastric microniche for more than 50% of world population. Recent studies have shown a critical role of H. pylori in the development of peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. Over the past decade, there has been a sharp interest to use noninvasive tests in diagnosis of the H. pylori infection. During the years after discovery by Marshall and Warren, it has been frequently declared that the rapid urease test (RUT) is one of the cheapest and rapid diagnostic approaches used in detecting the infection. Although the specificity and sensitivity are durable for this test, clinical experiences had shown that the ideal results are only achieved only if we take biopsies from both corpus and antrum at the same time. Given the diagnosis of the H. pylori in clinical samples, gastroenterologists are facing a long list of various molecular and nonmolecular tests. We need more in-depth researches and investigations to correctly generalize rapid and accurate molecular tests determining both bacterial identity and antibiotic resistance profile.

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.

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.

Does Helicobacter pylori play a role in etiology of nasal polyposis?

OBJECTIVE

Investigation of the possible relation between nasal polyposis (NP) and Helicobacter pylori (HP).

PATIENTS AND METHODS

Biopsy specimens of 25 patients with NP were evaluated. There were 16 men and 9 women enrolled in the study (NP) group. There were 10 men and 4 women in the control group. Campylobacter-like organism (CLO) test, immunohistochemical examination on nasal polyp tissue biopsy specimens and serological analysis were used for detecting HP.

RESULTS

There was only one (4%) positive NP case for CLO test. There were six cases in the study group with positive anti HP IgG test. Two control nasal mucosa were CLO positive. There were three cases in control group with positive anti HP IgG. There were no positive cases with positive anti IgM HP regarding both the study and the control groups. The immunohistochemical examination of the specimens taken from the patients with NP and control patients revealed that all patients were negative for HP. Positive CLO test and serologic test ratios were not statistically significant between NP and control groups.

CONCLUSION

The results of this study did not confirm other investigators. The suggested role of HP in the previous reports regarding NP may demonstrate transient occurrence of HP. It may not be treated as a possible etiological factor in NP.

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.

Is Helicobacter pylori really present in the adenoids of children?

Adenoid hyperplasia is a common cause of nasal obstruction in the pediatric age group. Recently, the adenoids were shown to harbor Helicobacter pylori (HP) based only on the rapid urease test (RUT). We conducted this pilot study to identify the presence of HP in the adenoids histologically and assess the reliability of both the RUT and histology in detecting HP in an extragastric location, using nested (two-steps) polymerase chain reaction (nPCR). Consecutive patients undergoing adenoidectomy for obstructive adenoid hyperplasia were enrolled. Adenoid specimens were subjected to the RUT. Histological sections stained with hematoxylin and eosin, Giemsa and Warthin-Starry were examined. We then used nPCR to detect the presence of HP in the studied specimens. Twenty-five patients (3-10 years; mean of 5.5 years) were enrolled. Twenty-one (84%) adenoids were positive by the RUT. Seventeen (68%) had bacteria on histological sections; four (16%) contained HP-like organisms. However, all specimens were negative by nPCR. No patient had a history of symptoms suggestive of laryngopharyngeal reflux within 6 months of the study. In conclusion, the children enrolled in this study did not have HP in their adenoids. High false positive results can occur with the RUT when used on adenoid tissues. It is not possible to rely solely on morphology to detect HP in an extragastric location. The nPCR remains the best way to identify HP accurately, but does not imply its presence in an active role.

Does Helicobacter pylori colonize the nasopharynx of children and contribute to their middle ear disease?

OBJECTIVE

There is growing interest in studying the presence of HP in the upper aerodigestive tract. It was shown in several pilot studies that it colonizes the area, while other authors found no evidence of its presence there and a third group of authors believed that it had only a transient presence there. In this study we investigated a possible role for HP in middle ear disease in children.

MATERIAL AND METHODS

Consecutive patients undergoing myringotomy and adenoidectomy for chronic otitis media with effusion or recurrent otitis media were enrolled. Middle ear fluids were cultured on three types of agar plate (Brucella + laked horse blood; Brucella + sheep blood; and chocolate). A double polymerase chain reaction (PCR) was run to detect urease-C and adhesion subunit genes. Rapid urease enzyme testing and PCR were used on the adenoid specimens. Parents were interviewed regarding symptoms suggestive of gastroesophageal reflux in their children.

RESULTS

Eighteen patients were enrolled in the study (mean age 4.4 years; age range 3-8 years) with an equal gender distribution. All 28 middle ear fluid cultures were negative in all 3 media. Twenty-one of the 28 samples contained DNA, yet PCR revealed that none of them belonged to HP. Ten of the 13 adenoid specimens obtained were positive on rapid urease testing, but none on PCR. Seven of the 18 patients had at least 1 symptom suggestive of gastroesophageal reflux during the 6 months preceding the study but this did not have an impact on any of the results.

CONCLUSION

There was no evidence from this study that Helicobacter pylori (HP) colonizes the nasopharynx of children with middle ear disease, whether dyspeptic or not. There is also no apparent role for this bacterium in middle ear pathology.