Epidemiology and diagnosis of Helicobacter pylori infection

Management of antibiotic-resistant Helicobacter pylori infection: current perspective in Iran

Helicobacter pylori is a common gastric bacterial pathogen implicated in the pathogenesis of many digestive tract disorders. H. pylori infection prevalence has been reported alarmingly in Iran. A plethora of studies have been conducted to evaluate the efficiency of first-line and second-line eradication attempts in patients diagnosed with H. pylori infections in Iran. The present study, was evaluated the efficacy of first-line and second-line therapy in H. pylori infections in Iran. We aimed to consider the literature review of the various library and electronic databases (Science Direct, PubMed, and Google Scholar) until 2020. The frequency of bacterial resistance to tetracycline, ampicillin, trimethoprim, erythromycin, ofloxacin, and metronidazolewas found to be high in Iran, while the most effective antibiotics were clarithromycin, rifampin, rifampicin, tetracycline, amoxicillin, ciprofloxacin, levofloxacin, moxifloxacin, and azithromycin. The therapeutic choice for H. pylori eradication in Iran could be quadruple therapy using two antibiotics amoxicillin and metronidazole/clarithromycin for the first-line regimen, and a combination of furazolidone plus tetracycline/amoxicillin and bismuth plus proton pump inhibitor for the second-line regimen. Due to increased antibiotic resistance in our region, empirical therapy must be replaced by more targeted treatment based on antimicrobial drug resistance profiles obtained from patients. Although we limited our investigation on the H. pylori eradication regimens in Iran, the results can be generalized to any region as long as the patterns of resistance are the same.

Evaluation of Invasive and Noninvasive Methods for the Diagnosis of Helicobacter Pylori Infection

Objective:

The present study was conducted to evaluate invasive and noninvasive diagnostic methods for detection of Helicobacter pylori (H. pylori) in patients admitted with dyspeptic complaints and to compare sensitivities and specificities.

Method:

Sets of four gastric biopsy specimens were obtained from a total of 126 patients included in the study. The presence of H. pylori was determined by invasive tests including culture, rapid urease test, polymerase chain reaction (PCR) and histopathology. Among noninvasive tests, urea breath test, serological tests and enzyme-linked immunosorbent assay (ELISA) were performed.

Results:

H. pylori was isolated in 79 (62.7%) gastric biopsy cultures, whereas positivity was concluded for 105 (83.3%) patients by rapid urease test, for 106 (84.1%) by PCR, for 110 (87.3%) by histopathology, for 119 (94.4%) by urea breath test, and for 107 (84.9%) by ELISA. In the present study, the culture findings and histopathological examination findings were accepted as gold standard. According to the gold standard, urea breath test had the highest sensitivity (96.5%) and the lowest specificity (30%), whereas culture and histopathology had the highest specificities (100%).

Conclusion:

The use of PCR invasively with gastric biopsy samples yielded parallel results with the gold standard. PCR can be recommended for routine use in the diagnosis of H. pylori.

Detection of helicobacter pylori in bronchoalveolar lavage of patients with chronic obstructive pulmonary disease by real time polymerase chain reaction

Background:

Chronic obstructive pulmonary disease (COPD) is one of the most important causes of disability and mortality in the world. Although cigarette smoking and environmental pollutants have been recognized as the major causes of COPD, the role of infection in the pathogenesis and progression of COPD has also been reported.

Objectives:

The aim of the present study was to find the relationship between Helicobacter Pylori infection and COPD through anti H. pylori IgG serology, real time PCR of bronchoalveolar lavage and trans bronchial biopsy urease tests.

Patients and Methods:

This descriptive cross-sectional study was carried out on 60 adults with COPD. After obtaining the patient’s history, physical examination, spirometry and confirmation of COPD diagnosis by pulmonologist, subjects were selected through convenience sampling. In order to determine the severity and prognosis of disease, the global initiative for chronic obstructive lung disease (GOLD) criteria and BODE index were used. Subjects underwent bronchoscopy for obtaining bronchoalveolar lavage (BAL) samples and biopsy was performed. Biopsy and BAL samples were investigated respectively by urease test and real time PCR. Moreover, patients’ serum samples were serologically studied for detection of anti H. pylori IgG.

Results:

Mean age of the participants was 60.65 ± 9.15 years, and 25% were female and 75% were male. The prevalence rate of H. pylori in COPD patients was 10% according to real time PCR, 88.3% according to the serology test and 0% based on the urease test. According to the results of PCR and considering the severity of disease based on the GOLD criteria, from those with a positive PCR, one patient (16.6%) had very severe obstruction, three (50%) had severe obstruction and two patients (33.3%) had moderate obstruction. The relationship between H. pylori presence (based on PCR) and disease severity and prognosis was not statistically significant.

Conclusions:

These findings can justify the hypothesis of direct injury and chronic inflammation via inhalation and aspiration resulting in H. pylori colonization. In fact, it is thought that H. Pylori infection, beside the host genetic vulnerability and other environmental risk factors might make the patient susceptible to COPD or lead to COPD worsening. Although we found H. pylori infection in some patients with COPD, the results of this study, could not explain the pathogenic mechanisms of COPD.

Periodontal disease and Helicobacter pylori infection: a community-based study using serology and rapid urease test

AIMS

The aims of the present study were to assess the prevalence of periodontal disease and Helicobacter pylori (H. pylori) infection and their associations within a predefined Indian population.

METHODS

A community-based cross-sectional study of 500 selected individuals using a questionnaire, oral examination, rapid urease testing of dental plaque, and serological examination for immunoglobulin G antibody to H. pylori was carried out.

RESULTS

Periodontal disease and H. pylori infection were prevalent in more than 50% of the population. Age, smoking, and diabetic status of the individuals were risk factors for periodontal disease after multivariate analysis, and a lack of proper sewage and waste disposal facilities were found to increase the risk of H. pylori infection. Although there was no association between periodontal disease and H. pylori seropositivity in the community, a highly-significant association was found between periodontal disease and colonization of H. pylori in dental plaque.

CONCLUSIONS

Because periodontal disease is associated with the increased colonization of H. pylori, new treatment modalities, such as plaque control measures, should be employed for the complete management of H. pylori-associated gastric disease.

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.

Association of Helicobacter pylori infection with the Lewis and ABO blood groups in dyspeptic patients

Background:

Helicobacter pylori infection is a basic risk factor for chronic gastritis, and gastric carcinoma. Based on some studies, the reason is binding of H. pylori to H and Le^b antigens in gastric mucosa. However, some other findings have not determined any association between the infection and these antigens. Because of this controversy and the fact that H. pylori infection and gastric adenocarcinoma are common diseases in Iran, the assessment of the association of H. pylori infection with these blood groups could be valuable.

Materials and Methods:

In a cross sectional study on 135 adult dyspeptic patients in Mashhad, Iran, from 2009 to 2010, H. pylori infection was evaluated by using the Heliprobe ¹⁴C-urea breath test and the ABO and Lewis blood group antigens were determined by the tube method. Association between the Lewis and ABO phenotypes with H. pylori infection were analysed by Fisher's exact test. A P ≤ 0.05 was considered to be significant.

Results:

68 (50.4%) patients were positive for H. pylori infection. The frequencies of the ABO, Lewis and secretion phenotypes were not significant in the infected and non-infected patients. We also did not find a significant association between Le^a and Le^b antigens and this infection.

Conclusion:

We could not establish a significant association between the Lewis, ABO and secretion phenotypes with H. pylori infection. Diversity of sequences of blood group antigen b-binding adhesion (babA gene) of H. pylori may be a reason why our findings are different from other studies in other geographic areas.

Defining causality in emerging agents of acute bacterial diarrheas: a step beyond the Koch’s postulates

Diarrheal illnesses account for significant morbidity and mortality worldwide. Most cases of diarrhea are caused by bacteria, viruses or parasites. Advances in molecular biology and epidemiology have allowed the identification of emerging pathogens that may cause or, at least, may be associated with diarrhea. However, the same advances have also revealed the complexity of the gut microbiome, suggesting that a potential agent of diarrhea may also been found in healthy individuals. In addition, most of the newly identified emerging agents of diarrhea are ubiquitous and have not yet fulfilled Koch’s postulates. Research investigations should address appropriate matched controls and integrate findings from medical microbiology, epidemiology and molecular biology. This integrative approach should provide insights to our knowledge regarding exposition to common source or risk factors. Here, we aim to review some of these emerging bacterial agents of diarrheas and propose guidelines or prescriptions that may help in defining causality.

Marching cohort ofHelicobacter pyloriinfection over two decades (1988–2007): combined effects of secular trend and population migration

The prevalence ofHelicobacter pyloriinfection is decreasing in developed countries. In this study we included 22 612 patients in whom a first culture of gastric biopsy (routinely performed in our medical centres) yielded an interpretable result over a 20-year period (1988–2007) in Brussels. The effects of patients' age, gender and ethnic background were analysed. The overall proportion ofH. pylori-infected patients was 37·7%, with a progressive decline over time (P<10−5). A gender effect was observed in adults. The lowest infection rate was observed in Western European patients (n=11 238) with respectively 36·2% and 15·2% infected subjects in 1988 and 2007, compared to 71·7% and 40% in North African patients (n=3200) (P<10−5). However, no trend of decline was observed over time in North African children aged ⩽9 years. These data show the effects of time, age and ethnicity on the prevalence ofH. pyloriinfection, and its complex heterogeneity in the same cosmopolitan urban area.

Efficacy of the standard quadruple therapy versus triple therapies containing proton pump inhibitor plus amoxicillin and clarithromycin or amoxicillin-clavulanic acid and metronidazole for Helicobacter pylori eradication in children

OBJECTIVES

Helicobacter pylori (H. pylori) cure rates vary in different geographical regions because of differences in hosts as well as in H. pylori strains. In this study we evaluated the efficacy of different treatment regimens for eradication of H. pylori infection in children, in order to select a treatment regimen that is most effective with the least adverse effects and cost.

METHOD

Through a randomized clinical trial study we enrolled 120 pediatric patients (age

RESULTS

A total of 117 patients with a mean age of 12 +/- 4 years completed the study. Eradication rate was 91.9% in group A, compared with 82.1% in group B, and 80.5% in group C (P = 0.33).

CONCLUSION

Considering these data we suggest quadruple therapy as the first line of therapy for eradication of H. pylori infection in children in our geographic area (Iran).

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MESH Headings

• Adolescent
• Amoxicillin/adverse effects
• Amoxicillin/therapeutic use
• Anti-Bacterial Agents/adverse effects
• Anti-Bacterial Agents/therapeutic use
• Breath Tests
• Child
• Child, Preschool
• Clarithromycin/adverse effects
• Clarithromycin/therapeutic use
• Clavulanic Acid/adverse effects
• Clavulanic Acid/therapeutic use
• Drug Therapy, Combination
• Female
• Helicobacter Infections/drug therapy
• Helicobacter Infections/ethnology
• Helicobacter Infections/metabolism
• Helicobacter pylori
• Humans
• Iran
• Male
• Metronidazole/adverse effects
• Metronidazole/therapeutic use
• Omeprazole/adverse effects
• Omeprazole/therapeutic use
• Organometallic Compounds/adverse effects
• Organometallic Compounds/therapeutic use
• Proton Pump Inhibitors/adverse effects
• Proton Pump Inhibitors/therapeutic use
• Single-Blind Method
• Treatment Outcome
• Urea/metabolism

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Affiliation(s)

Seyed Mohsen Dehghani Gastroenterohepatology Research Center, Pediatric Gastroenterology Department, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, 71937-11351, Iran.
Asma Erjaee
Mohammad Hadi Imanieh
Mahmood Haghighat

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Childhood hygienic practice and family education status determine the prevalence of Helicobacter pylori infection in Iran

BACKGROUND

Management of Helicobacter pylori, a causative agent of gastrointestinal diseases is an important health problem in most countries. The main reasons include poorly defined epidemiological status and unrecognized mode of bacterial transmission. Our objective was to investigate the prevalence of H. pylori infection in a representative population of Iran and to evaluate possible risk factors for the H. pylori infection.

MATERIALS AND METHODS

In this cross-sectional study, 2561 healthy individuals aged 18-65 years (mean age, 35.5 years) were selected out of 12,100,000 inhabitants of Tehran province by cluster sampling. Infection with H. pylori was evaluated by detection of anti-H. pylori IgG antibody in serum. Sociodemographic status of each subject was determined by filling up a questionnaire.

RESULTS

Prevalence of H. pylori infection was 69% and was correlated with increasing age. The highest infection rate (79.2%) was seen in individuals 46-55 years old. No association was detected between H. pylori positivity and gender. Low education of the study subjects; low father's and mother's education; poor tooth brushing habit; crowded families in childhood; and lack of household bath, hygienic drinking water, and swage disposal facility in childhood were determined as possible risk factors.

CONCLUSIONS

The rate of prevalence of H. pylori infection was higher than developed countries. Low socioeconomic status, poor sanitary indications, and crowded families in childhood were related to high prevalence of H. pylori infection in Iran. Accordingly, fecal-oral and oral-oral routes could be considered as the main pathways of transmission of H. pylori.

Serum pepsinogen levels, Helicobacter pylori CagA Status, and cytokine gene polymorphisms associated with gastric premalignant lesions in Costa Rica

The detection of gastric premalignant lesions, atrophic gastritis, corpus atrophic gastritis, and intestinal metaplasia, using several potential markers was examined in Costa Rica. Depending on the lesion investigated, from a total of 223 dyspeptic patients, 58 (26.0%), 31 (13.9%), or 23 (10.3%) were histologically diagnosed with atrophic gastritis, corpus atrophic gastritis, or intestinal metaplasia, respectively. Sera were used for the measurement of pepsinogen (PG) and Helicobacter pylori CagA antibody (CagA-ab) levels by ELISA, and human genomic DNAs were used for the genotyping of interleukin (IL)-1beta (-511 and +3954), IL-10 (-1082 and -592), and IL-1RN intron 2 by PCR and RFLP. Multivariate analysis was done adjusting for sex, age, and H. pylori seropositivity. Low PG levels (L-PG; PG I < or = 70 microg/L + PG I/II < or = 3), very low PG levels (VL-PG; PG I < or = 30 microg/L + PG I/II < or = 2), and CagA-ab were individually associated with all premalignant lesions whereas IL-1beta +3954T-carrier and IL-1RN homozygous 2 allele were associated with intestinal metaplasia. VL-PG, for corpus atrophic gastritis detection, was the single marker with the highest combination of test characteristics, sensitivity (77.4%), specificity (80.7%), positive predictive value (39.3%), negative predictive value (95.7%), and seropositivity rate (27.4%), expected to improve after periodic measurements. Combined examinations of VL-PG and CagA-ab improved the specificity (92.7%) and positive predictive value (62.2%), with similar sensitivity (74.2%) and negative predictive value (95.7%). In conclusion, corpus atrophic gastritis detection with periodic measurements of serum PG, alone or in combination with CagA-ab status, to identify high gastric cancer risk, seems to be the method best suited for mass screening in Costa Rica.

A better method for confirming Helicobacter pylori infection in Mongolian gerbils

BACKGROUND

Our aim was to evaluate the accuracy of the stool antigen test and the optimal time point for detecting Helicobacter pylori infection in a Mongolian gerbil model.

METHODS

We inoculated 8-week-old Mongolian gerbils with H. pylori (Vac A (+)/CagA(+)). The gerbil-infected model was developed as follows: H. pylori was put into broth (about 10(9) CFU/ml), and 50 gerbils were then fed with 1 ml intragastrically twice within a 3-day interval. Another ten gerbils were fed broth only. Twenty-six weeks after the inoculation, the gerbils were killed. The gastric mucosa was sampled for a series of examinations including culture, histology, rapid urease test, and polymerase chain reaction. Stool samples for a stool antigen test, H. pylori-specific stool antigen assay (HpSA), were collected during weeks 4, 6, 8, 12, and 26 after inoculation. Of the 50 gerbils inoculated with H. pylori, the inoculation was successful in 88%. Severe active gastritis, ulceration, and intestinal metaplasia were obvious.

RESULTS

The HpSA test results were sensitivity, 88.6%; specificity, 100%; positive predictive value (PPV), 100%; negative predictive value (NPV), 54.5%, and accuracy, 90%. The HpSA test began to be more sensitive and accurate (P < 0.05) beginning during week 6 after inoculation. We also found that H. pylori could be detected earlier and more easily in the group with high H. pylori density.

CONCLUSIONS

HpSA seems to be suitable for confirming colonization of gerbils with H. pylori. The optimal testing time point is around 6 weeks after inoculation. This test is a good choice for long-term observation of H. pylori infection in Mongolian gerbils.

Adhesion of water stressed Helicobacter pylori to abiotic surfaces

AIM

The main aim of this work was to study and compare the adhesion of water exposed Helicobacter pylori to six different substrata and correlate any changes in morphology, physiology, ability to form aggregates and cultivability when in the planktonic or in the sessile phase.

METHODS AND RESULTS

The number of total cells adhered for different water exposure times and modifications in the cell shape were evaluated using epifluorescence and scanning electron microscopy, and physiology assessed using Syto9 and propidium iodide (PI) cellular uptake. All abiotic surfaces were rapidly colonized by H. pylori, and colonization appeared to reach a steady state after 96 h with levels ranging from 2.3 x 10(6) to 3.6 x 10(6) total cells cm(-2). Cell morphology was largely dependent on the support material, with spiral bacteria, associated with the infectious form of H. pylori, subsisting in a higher percentage on nonpolymeric substrata. Also, sessile bacteria were generally able to retain the spiral shape for longer when compared with planktonic bacteria, which became coccoid more quickly. The formation of large aggregates, which may act as a protection mechanism against the negative impact of the stressful external environmental conditions, was mostly observed on the surface of copper coupons. However, Syto9 and PI staining indicates that most of H. pylori attached to copper or SS304 have a compromised cell membrane after only 48 h. Cultivability methods were only able to detect the bacteria up to the 2 h exposure-time and at very low levels (up to 500 CFU cm(-2)).

CONCLUSIONS

The fact that the pathogen is able to adhere, retain the spiral morphology for longer and form large aggregates when attached to different plumbing materials appeared to point to pipe materials in general, and copper plumbing in particular, as a possible reservoir of virulent H. pylori in water distribution systems. However, the Syto9/PI staining results and cultivability methods indicate that the attached H. pylori cells quickly enter in a nonviable physiological state.

SIGNIFICANCE AND IMPACT OF THE STUDY

This represents the first study of H. pylori behaviour in water-exposed abiotic surfaces. It suggests that co-aggregation with the autochthonous heterotrophic consortia present in water is necessary for a longer survival of the pathogen in biofilms associated to drinking water systems.

Inhibition of gastric H+, K+-ATPase and Helicobacter pylori growth by phenolic antioxidants of Zingiber officinale

Ulcer is a common global problem characterized by acute gastric irritability, bleeding, etc. due to either increased gastric cell proton potassium ATPase activity (PPA) or perturbation of mucosal defence. Helicobacter pylori has been identified as a major ulcerogen in addition to oxidative stress and nonsteroidal anti-inflammatory drugs. In this paper, we report ginger-free phenolic (GRFP) and ginger hydrolysed phenolic (GRHP) fractions of ginger (Zingiber officinale) as potent inhibitors of PPA and H. pylori growth. GRFP and GRHP inhibited PPA at an IC(50) of 2.9 +/- 0.18 and 1.5 +/- 0.12 microg/mL, exhibiting six- to eight-fold better potency over lansoprazole. GRFP is constituted by syringic (38%), gallic (18%) and cinnamic (14%) acids and GRHP by cinnamic (48%), p-coumaric (34%) and caffeic (6%) acids as major phenolic acids. GRFP and GRHP further exhibited free radical scavenging (IC(50) 1.7 +/- 0.07 and 2.5 +/- 0.16), inhibition of lipid peroxidation (IC(50) 3.6 +/- 0.21 and 5.2 +/- 0.46), DNA protection (80% at 4 microg) and reducing power abilities (80-338 U/g) indicating strong antioxidative properties. GRFP and GRHP may thus be potential in-expensive multistep blockers against ulcer.

Helicobacter pylori infection: further evidence for the role of feco-oral transmission

BACKGROUND

Helicobacter pylori infection is recognized as a major cause of chronic digestive diseases with a major public health impact, yet the knowledge of transmission pathways is limited. We studied the transmission in employees taking care of institutionalized persons with mental disabilities with a documented high prevalence of H. pylori.

MATERIALS AND METHODS

Six hundred and seventy-one health-care workers were screened for H. pylori serology. For each employee, information was collected on age, sex, father's and mother's education level, number of household members and number of children sleeping in the same bedroom during childhood, as well as lifestyle factors such as smoking and tropical journeys and occupational exposure data such as type of contact with inhabitants (changing napkins with stools, washing inhabitants, feeding inhabitants, personal contact) and seniority in the institution.

RESULTS

Seroprevalence for H. pylori increased significantly with age. In univariate analysis, risk factors for H. pylori positivity were (age-adjusted): father's education, mean length of employment, smoking, contact with fecal materials of inhabitants, washing and feeding of inhabitants. Controlling for confounders, in multiple logistic regression analysis, only fecal contact remained as a significant risk factor for H. pylori infection.

CONCLUSIONS

In health-care workers caring for a population with a high prevalence of H. pylori infection, there is an association with fecal transmission. This, however, does not rule out the possibility of other ways of transmission.

Factors associated with H. pylori epidemiology in symptomatic children in Buenos Aires, Argentina

AIM

To determine prevalence of H pylori infection in symptomatic children in Buenos Aires, Argentina, and to investigate factors associated with H pylori positivity.

METHODS

A total of 395 children with upper gastrointestinal symptoms referred to the Gastroenterology Unit of the Children Hospital "Sor Maria Ludovica" were evaluated for the presence of H pylori by the (13)C-Urea Breath Test ((13)C-UBT). A questionnaire was applied to the recruited population.

RESULTS

Prevalence of H pylori infection was 40.0% in this population (mean age 9.97 +/- 3.1 years). The factors associated with H pylori positivity were number of siblings (P < 0.001), presence of pet cats (P = 0.03) and birds (P = 0.04) in the household, and antecedents of gastritis among family members (P = 0.01). After multivariate analysis, number of siblings [Odds ratio (OR) = 1.39; 95% CI, 1.20-1.61] and contact with pet cats (OR = 1.76; 95% CI, 1.00-3.09) remained as variables associated with H pylori infection.

CONCLUSION

The prevalence of H pylori infection in children with upper gastrointestinal symptoms in Argentina was similar to that reported in developed countries. Children from families with a higher crowding index and presence of pet cats have a higher risk of being colonized with H pylori.

Point-of-care Helicobacter pylori urine antibody detection in a multi-ethnic adult population in the United States

A need exists for accurate point-of-care tests for diagnosis of Helicobacter pylori (H. pylori) infection to evaluate a rapid urine-H. pylori antibody test device for detection of H. pylori infection in a point-of-care setting in the United States. A multi-center study in a multi-ethnic population compared the RAPIRUN urine antibody test with the (13)C-urea breath test (C-UBT) and a traditional serologic test, the high-molecular-weight cell-associated protein enzyme immunoassay (HM-CAP EIA). The primary comparator was with "definite positive" and "definite negative" patients defined as a concordance of combined results of the UBT and the HM-CAP IgG EIA. Overall, 188 eligible patients were enrolled (61 men, age range: 18-73 years, including 84 Hispanics, 73 Asian-Pacific Americans, 22 Black African-Americans, 6 non-Hispanic Caucasians, and 3 of "other" ethnicity). Compared with "definite positive" and "definite negative" results, the sensitivity and specificity of the urine antibody test were 0.9 and 1.0, respectively. The urine antibody test proved suitable for point-of-care rapid diagnosis of anti-H. pylori antibodies indicative of active or past H. pylori infection.

Shear stress, temperature, and inoculation concentration influence the adhesion of water-stressed Helicobacter pylori to stainless steel 304 and polypropylene

Although molecular techniques have identified Helicobacter pylori in drinking water-associated biofilms, there is a lack of studies reporting what factors affect the attachment of the bacterium to plumbing materials. Therefore, the adhesion of H. pylori suspended in distilled water to stainless steel 304 (SS304) coupons placed on tissue culture plates subjected to different environmental conditions was monitored. The extent of adhesion was evaluated for different water exposure times, using epifluorescence microscopy to count total cell numbers. High shear stresses-estimated through computational fluid dynamics-negatively influenced the adhesion of H. pylori to the substrata (P < 0.001), a result that was confirmed in similar experiments with polypropylene (P < 0.05). However, the temperature and inoculation concentration appeared to have no effect on adhesion (P > 0.05). After 2 hours, H. pylori cells appeared to be isolated on the surface of SS304 and were able to form small aggregates with longer exposure times. However, the formation of a three-dimensional structure was only very rarely observed. This study suggests that the detection of the pathogen in well water described by other authors can be related to the increased ability of H. pylori to integrate into biofilms under conditions of low shear stress. It will also allow a more rational selection of locations to perform molecular or plate culture analysis for the detection of H. pylori in drinking water-associated biofilms.

Comparison of three stool antigen assays with the 13C- urea breath test for the primary diagnosis of Helicobacter pylori infection and monitoring treatment outcome

BACKGROUND

The urea breath test (UBT) is the gold-standard non-invasive test for the detection of Helicobacter pylori infection, however, the lack of availability of the UBT due to the high cost of the test, and in particular the need for expensive analytical instrumentation, limits the usefulness of this method. Stool antigen assays may offer an alternative non-invasive method for the diagnosis of infection.

OBJECTIVE

To compare the accuracy of three stool antigen assays (HpSA, IDEIA HpStAR, and ImmunoCard STAT) against the UBT for the primary diagnosis of H. pylori infection and for monitoring treatment outcome.

METHODS

A total of 102 patients attending two gastroenterology day-case clinics for the investigation of dyspepsia were included. Each patient provided breath and stool samples for analysis. Patients who tested positive for H. pylori by the validated UBT were prescribed triple therapy and invited to return for repeat breath and stool sample analysis 6 weeks post-treatment.

RESULTS

Of the 102 patients tested, 48 were diagnosed with H. pylori infection by the UBT. The HpSA assay interpreted 38 of these as positive (79% sensitive). Of the 54 UBT-negative patients the HpSA assay interpreted all 54 as negative (100% specific). The IDEIA HpStAR assay correctly identified 44 patients as positive (92% sensitive) and 50 as negative (92.5% specific). The ImmunoCard STAT assay interpreted 38 patients as positive (79% sensitive) and 52 as negative (96.3% specific).

CONCLUSION

The findings indicate that the IDEIA HpStAR stool antigen kit is the most accurate assay of the three assays evaluated, and possibly represents a viable alternative to the UBT for the primary diagnosis of H. pylori infection and for monitoring treatment outcome.

Epidemiology of Helicobacter pylori infection in the Czech Republic

BACKGROUND

Prevalence of Helicobacter pylori infection has been estimated to range from 60 to 95% in the former communist countries of Central and Eastern Europe. The aim of this study was to evaluate H. pylori infection prevalence in a representative sample of the Czech population. The second objective was to describe difference of H. pylori prevalence between different social groups of children and adults.

MATERIALS AND METHODS

A total of 2509 persons aged 5-100 years, randomly selected out of 30,012 persons of the general population, took part in the study. H. pylori infection was investigated by means of 13C-urea breath test. Breath samples were analyzed by isotope ratio mass spectrometry. Social and demographic characteristics were based on data from self-completed questionnaires.

RESULTS

Using the total Czech population as a standard, we estimated the age-standardized prevalence of H. pylori in males aged 5+ years at 41.9% (95% CI 39.0%, 44.8%) and in females aged 5+ years at 41.4% (95% CI 38.6%, 44.3%) in 2001. Prevalence of H. pylori increased with age but was not related to gender. Children of mothers with basic or lower education, living in crowded accommodations, without access to running warm water, and residing in smaller towns appear to be at the highest risk. Low education and heavy smoking are most strongly associated with prevalence of H. pylori positivity in adults and adolescents.

CONCLUSIONS

This is a unique study based on a representative sample of the general population in a Central European country. The overall prevalence of H. pylori is lower than previously assumed and could partly reflect a substantial recent decrease in H. pylori prevalence in the Czech Republic. Consistent with earlier studies, H. pylori infection is strongly influenced by socioeconomic conditions and childhood poverty.

Diagnostic Utility of Invasive Tests and Serology for the Diagnosis of Helicobacter pylori Infection in Different Clinical Presentations

BACKGROUND

Invasive and noninvasive tests are used for the diagnosis of Helicobacter pylori infection. The aim of this study was to determine the diagnostic utility of rapid urease test (RUT), culture, histology and serology for the diagnosis of H. pylori in patients with different clinical presentations.

METHODS

We studied 527 consecutive patients (mean age, 52.5 years; F:M, 1.3; age range 15-89 years) enrolled at the Hospital Universitario, Universidad Autónoma de Nuevo León. Patients had gastric cancer (GC, 9.1%), non-ulcer dyspepsia (NUD, 81.4%), or peptic ulcer disease (PUD, 9.1%). The infection by H. pylori was determined by histology, rapid urease test, culture, and serology. Patients were determined as infected with H. pylori if at least a) two invasive tests were positive and b) two tests were positive (invasive or non-invasive). Diagnostic utility was calculated for each assay.

RESULTS

Prevalence of infection in the whole studied population was 50.9%. In NUD patients the prevalence was 51.3%, in PUD patients 58.3%, and in GC patients 39.6%. When we used the first diagnostic criteria, for the whole studied population, the RUT was the most reliable test, followed by the culture. Histology had the best sensitivity for the whole studied population and NUD patients and RUT had the best sensitivity value for the GC patients. In the whole studied population, NUD and GC patients, RUT and culture had the best specificity, accuracy and PPV. For PUD patients, serology had the best performance. When we used the second diagnostic criteria, histology and serology had a better performance compared with the results obtained with the first diagnostic criteria.

CONCLUSIONS

Diagnostic utility of the tests varies according to the clinical presentations, which should be considered in the selection of the diagnostic test for the detection of H. pylori.

Detection of Helicobacter species in liver and stomach tissues of patients with chronic liver diseases using polymerase chain reaction-denaturing gradient gel electrophoresis and immunohistochemistry

OBJECTIVE

Helicobacter DNA has been detected in the hepatobiliary tree of patients with chronic liver diseases (CLD). The presence of H. pylori in the stomach compared with in the liver of the same patients with CLD has not been studied, therefore to the aim of this study was to investigate the presence of Helicobacter DNA and antigens in the liver and stomach of Polish patients with chronic liver diseases using molecular and immunological methods.

MATERIAL AND METHODS

Gastric mucosa and liver tissue samples and sera were collected from 97 Polish patients with CLD. Anti-H. pylori antibodies were detected by enzyme immunoassay (EIA), and H. pylori-like antigens detected by immunohistochemistry. Helicobacter DNA was detected in stomach and liver samples using a semi-nested Helicobacter genus-specific polymerase chain reaction (PCR) assay, and Helicobacter species identified by denaturing gradient gel electrophoresis (DGGE) and sequencing analysis of amplified PCR products.

RESULTS

H. pylori was identified by DGGE and sequence analysis in 60/62 (97%) and 25/25 (100%) of the gastric and liver Helicobacter genus-positive samples, respectively, whereas DNA of H. heilmannii was detected in 2/62 (3%) of the Helicobacter genus-positive gastric samples. H. pylori cagA gene was detected in 23/62 (36%) and 3/25 (12%) gastric and liver tissue samples, respectively. H. pylori-like antigens were detected in 61/97 (63%) gastric mucosa and in 40/97 (41%) liver tissue samples.

CONCLUSIONS

H. pylori-like organisms appeared to dominate the gastric mucosa and liver tissue of Polish patients with CLD. The prevalence of the cagA gene was higher in stomach compared with liver samples, which suggests a possible role of cagA negative H. pylori-like organisms in CLD. On the other hand, no significant correlation was found between the presence of H. pylori-like DNA and antigens in the liver and liver function tests.

A genetic locus of Helicobacter pylori inversely associated with gastric intestinal metaplasia

The genomic contents of Helicobacter pylori strain C1 from a patient with gastric cancer and strain 98587 from a patient with duodenal ulcer disease were compared using a rapid subtractive hybridisation approach. A total of 11 tester-specific sequences representing gene specificity, DNA rearrangement and sequence variation were identified. This included two novel sequences, clone P32 and clone F5, which have no significant homologue in the database. H. pylori strains positive for clone P32 were less prevalent in patients with gastric intestinal metaplasia (12.5%) than in duodenal ulcer (39.1%) (p=0.036), or chronic gastritis (38.1%) (p=0.036). The results suggest that H. pylori clone P32 is potentially a useful marker for distinguishing intestinal metaplasia associated strains from others.

Is Helicobacter pylori seropositivity related to body mass index in the United States?

BACKGROUND

Helicobacter pylori infection may decrease serum ghrelin and increase gastric leptin levels, which may, in turn, decrease body mass index.

AIM

To determine whether H. pylori seropositivity is associated with body mass index.

METHODS

Serum H. pylori and cytotoxin-associated gene product A (CagA) antibody levels were measured on 6724 adult participants of the third National Health and Nutrition Examination Survey (1988-91). We evaluated the association between H. pylori/CagA antibody status [both negative (-/-), H. pylori-positive/CagA-negative (+/-), or both positive (+/+)] and body mass index, adjusting for sociodemographic factors. We also investigated whether H. pylori/cytotoxin-associated gene product A antibody status was associated with fasting serum leptin levels.

RESULTS

H. pylori/CagA antibody status was not associated with obesity (body mass index > or = 30 kg/m(2)) [adjusted odds ratio (OR) 1.2, 95% CI: 0.9-1.6 comparing (+/+) to (-/-) and adjusted OR 1.1, 95% CI: 0.8-1.5 comparing (+/-) to (-/-)], overweight (body mass index 25 to <30 kg/m(2)) [adjusted OR 1.0, 95% CI: 0.7-1.2 comparing (+/+) to (-/-) and adjusted OR 1.0, 95% CI: 0.8-1.3 comparing (+/-) to (-/-)], or fasting serum leptin level in the USA population.

CONCLUSIONS

H. pylori seropositivity and CagA antibody status are not associated with body mass index or fasting serum leptin level.

Evaluation of the stool antigen test for Helicobacter pylori in children and adolescents

The stool antigen test for Helicobacter pylori is a noninvasive immunoassay to diagnose active infection with Helicobacter pylori in human fecal samples. Its performance in children and teenagers has been tested in some developed countries, showing a sensitivity and specificity above 90%, however, its accuracy in developing countries and in children under 6 years is not well established. To determine the accuracy of the test for diagnosing Helicobacter pylori infection in children and teenagers, we evaluated 133 patients (4 months to 17 years old). The gold standard was a positive culture or positive histology and rapid urease test. The test was done according to the manufacturer's instructions. However, modifications were introduced for better reproducibility. Samples were analyzed twice and results are expressed as optical density (OD) determined spectrophotometrically at 450 nm. HpSA was considered positive at OD > or =0.160 and negative at OD <0.140. One hundred twenty-seven of the 133 (95.5%) patients were included. There were no infected infants. The test showed a 94.6% sensitivity (95% CI: 90.6-98.5) and a 96.5% specificity (95% CI: 93.3-99.7). At ages 2 to 6 years the specificity was 96.4% (95% CI: 85.1-99.2) and the sensitivity was 80.0% (95% CI: 64.8-89.7), at ages 6 to 10 years the sensitivity was 100.0% and the specificity 95.7%, and above 10 years the sensitivity and specificity were 100.0%. We conclude that the test is efficient in adolescents and children, however there is a need for further studies with a greater number of patients for evaluation of its accuracy in infants.

Helicobacter pylori seroprevalence in patients with lung cancer

AIM: To assess Helicobacter pylori (H pylori) seroprevalence in a cohort of Greek patients with lung cancer.

METHODS: Seventy-two lung cancer patients (55 males and 17 females, aged 58.2 ± 11.7 years) and 68, age and gender-matched, control subjects were enrolled. All subjects underwent an enzyme-linked immunosorbent assay IgG serologic test for H pylori diagnosis.

RESULTS: A correlation between age and H pylori IgG level was detected for both lung cancer patients (r = 0.42, P = 0.004) and controls (r = 0.44, P = 0.004). Seropositivity for H pylori did not differ significantly between patients with lung cancer and controls (61.1% vs 55.9%, P > 0.05). Concerning the mean serum concentration of IgG antibodies against H pylori, no significant difference between the two groups was detected (32.6 ± 19.1 vs 27.4 ± 18.3 U/mL, P > 0.05).

CONCLUSION: No significant association between H pylori infection and lung cancer was found.

Nutrient shock and incubation atmosphere influence recovery of culturable Helicobacter pylori from water

Three different media-Columbia agar, Wilkins-Chalgren agar, and Helicobacter pylori special peptone agar-were prepared in a diluted version and compared to the standard medium formulation in order to study a possible nutrient shock effect observed when recovering H. pylori from water by counting the number of CFU. This same parameter was subsequently used to evaluate the influence of the incubation atmosphere by using a modular atmosphere-controlled system to provide different atmospheres and by employing an established gas generation kit as a control. Both a low nutrient content of the media and a rapidly achieved microaerophilic incubation atmosphere proved to increase the numbers of environment-stressed H. pylori organisms recovered. An atmosphere of 5% CO(2), 5% O(2), and 3% H(2) is recommended, although other atmospheres with a low oxygen concentration are also acceptable. Besides highlighting and assessing the importance of several factors in the culturability of H. pylori, this paper demonstrates the potential ability to develop an optimized technique for recovery of this pathogen from water.

Beta-lactamase inhibitor enhances Helicobacter pylori eradication rate

OBJECTIVES

One-week triple therapy, a combination of acid suppression with two antibiotics, is the gold standard for anti-Helicobacter pylori treatment. There is increasing evidence of H. pylori resistance to classical triple therapy. Recently, it was reported that the amoxicillin-clavulanate combination had a slightly higher activity than amoxicillin alone against H. pylori, and that beta-lactamase inhibitors had 'in-vitro' antibacterial activity against H. pylori.

SETTING

To evaluate the efficacy of 1 week triple therapy omeprazole, clarithromycin and amoxicillin plus clavulanate compared with omeprazole, clarithromycin and amoxicillin for H. pylori eradication. The study was open randomized.

SUBJECTS

Sixty dyspeptic patients (36 male, 24 female; mean age 53 +/- 9 years) with Helicobacter pylori infection never treated before, were enrolled and randomly assigned to two different 7-day triple therapies: (i) (n = 30) amoxicillin 875 mg plus clavulanic acid 125 mg b.i.d., clarithromycin 500 mg b.i.d., omeprazole 20 mg b.i.d. (ACCO); (ii) (n = 30) amoxicillin 1 g b.i.d., clarithromycin 500 mg b.i.d., omeprazole 20 mg b.i.d. (ACO). Bacterial eradication was assessed by 13C-urea breath test 4-6 weeks after therapy. Information on gastrointestinal symptoms and antibiotic-related side-effects were recorded using a questionnaire.

RESULTS

All patients completed the study. A significantly higher H. pylori eradication rate with ACCO compared with ACO: (26/30) 86.6 vs. (20/30) 66.6%, respectively (P < 0.05) were observed. No major side-effects were reported, whilst 8% patients complained of mild side-effects; no significant differences were noted between the two groups.

CONCLUSIONS

Our results suggest that amoxicillin and clavulanate in combination achieve a higher H. pylori eradication rate than amoxicillin alone, without any increase in side-effects. The combination of amoxicillin and clavulanate may represent an alternative therapeutic scheme for the treatment of H. pylori infection.

Prevalence of Helicobacter pylori infection in Warao lineage communities of Delta Amacuro State, Venezuela

The purpose of this study was the evaluation of Helicobacter pylori infections in children and adults from two indigenous communities of Delta Amacuro State, Venezuela, that differ in hygienic conditions of the housing. The evaluation was performed in 98 children (mean age 7 +/- 3.37 years) and their mothers (33.96 +/- 13.77 years) from two communities of Warao lineage. Anti-H. pylori serum IgG and secretory anti-H. pylori IgA antibodies were determined, as well as total secretory IgA and H. pylori antigens in feces. Serological prevalence of H. pylori infection was 38% in children and 84% their in mothers. Children from the community that had the most deficient sanitary and hygienic conditions had significantly lower titers of specific IgG antibodies and total secretory IgA (P<0.0001) and a high percentage of them had H. pylori antigens in their feces (P<0.0001). The levels of specific IgA were similar in both groups. The results indicate that in these populations there is a high prevalence of H. pylori infection and that poor hygienic conditions can increase the risk of infection and damage to the gastrointestinal tract.

Comparison of diagnostic techniques for Helicobacter cetorum infection in wild Atlantic bottlenose dolphins (Tursiops truncatus)

Helicobacter cetorum sp. nov. has been cultured from the stomach of Atlantic white-sided dolphins (Lagenorhynchus acutus) and the feces of Pacific white-sided (L. obliquidens) and Atlantic bottlenose (Tursiops truncatus) dolphins and a beluga whale (Delphinapterus leucas). H. cetorum has high homology to Helicobacter pylori as shown by 16S rRNA sequencing, and H. cetorum infection has been associated with gastritis and clinical signs in cetaceans. Because the prevalence of H. cetorum in wild populations is unknown, minimally invasive techniques for detecting H. cetorum were compared for 20 wild bottlenose dolphins sampled as part of a long-term health study. Fecal samples were tested for helicobacter by culture, Southern blotting, and PCR using genus-specific and H. cetorum-specific primers. An enzyme-linked immunosorbent assay (ELISA) was developed to measure H. cetorum immunoglobulin G (IgG). H. cetorum was cultured from 4 of 20 fecal samples, 7 samples were positive using Helicobacter sp. PCR, and 8 samples were positive for H. cetorum using species-specific primers. Two additional fecal samples were positive by Helicobacter sp. Southern blotting, suggesting infection with another helicobacter. All 20 sera contained high levels of IgG antibodies to H. cetorum that were significantly lowered by preabsorption of the sera with whole-cell suspensions of H. cetorum (P < 0.02). Until the specificity of the serum ELISA can be determined by testing sera from dolphins confirmed to be uninfected, PCR and Southern blot screenings of feces are the most sensitive techniques for detection of H. cetorum, and results indicate there is at least a 50% prevalence of H. cetorum infection in these dolphins.

Helicobacter in the developing world

Helicobacter pylori in the developing world is associated with many unique challenges not encountered in an industrialized setting. The 20% prevalence of infection with H. pylori among adolescents in the United States pales in comparison to infection rates exceeding 90% by 5 years of age in parts of the developing world. While H. pylori within the developed world is associated with gastritis, which may lead to peptic ulcer and gastric carcinoma, the infection in the developing world appears to also be linked with chronic diarrhea, malnutrition and growth faltering as well as predisposition to other enteric infections, including typhoid fever and cholera. Once identified, treatment of H. pylori within the developing world presents increased difficulties due to the frequency of antibiotic resistance as well as the frequency of recurrence after successful treatment. Control, and possibly eradication, of H. pylori could likely be achieved through increased standards of living and improved public health, as it has in the industrialized world. However, these measures are distant objectives for most developing countries, making long-term control of the organism dependent on the development and administration of an effective vaccine.