Diagnosis and epidemiology of Helicobacter pylori infection

Molecular Characterization of Antimicrobial Resistance and Virulence Genotyping among Helicobacter pylori-Positive Dyspeptic Patients in North Iran

BACKGROUND

Iran has a relatively high prevalence of H. pylori, which correlates with high-risk areas for gastric cancer worldwide.

METHODS

Our study aimed to investigate the underlying genetic mechanisms associated with resistance to metronidazole (frxA, rdxA), clarithromycin (23S rRNA), tetracycline (16S rRNA), and fluoroquinolone (gyrA) in H. pylori-positive dyspeptic patients using PCR and sequencing. We further examined the potential correlation between resistance profiles and various virulence genotypes.

RESULTS

The rates of genetic mutations associated with resistance to metronidazole, fluoroquinolone, clarithromycin, and tetracycline were found to be 68%, 32.1%, 28.4%, and 11.1%, respectively. Well-documented multiple antibiotic resistance mutations were detected, such as rdxA and frxA (with missense and frameshift alterations), gyrA (Asp91, Asn87), 23S rRNA (A2142G, A2143G), and 16S rRNA (triple-base-pair substitutions AGA926-928→TTC). The cagA+ and vacA s1/m1 types were the predominant genotypes in our study. With the exception of metronidazole and tetracycline, no significant correlation was observed between the cagA+ and cagL+ genotypes and resistance-associated mutations.

CONCLUSION

The prevalence of antibiotic resistance-associated mutations in H. pylori was remarkably high in this region, particularly to metronidazole, ciprofloxacin, and clarithromycin. By conducting a simultaneous screening of virulence and resistance genotypes, clinicians can make informed decisions regarding the appropriate therapeutic regimen to prevent the escalation of antibiotic resistance against H. pylori infection in this specific geographical location.

Molecular, pathological and immunohistochemical investigation of Helicobacteraceae in the abomasum of dairy cattle and sheep in Northern Italy

Although several Helicobacter species have been associated with gastric disease in humans and animals, their role in domestic ruminants is still unclear. This study aimed to investigate the prevalence of H. pylori, "Candidatus H. bovis" and other Helicobacteraceae in the abomasum of dairy cattle and sheep reared in Northern Italy, to shed light on their role as potential reservoir of H. pylori for humans and to evaluate the involvement of Helicobacter spp. in the gastric pathology of these animal species. Abomasa from 25 dairy cows and 24 sheep were collected at slaughter. Following macroscopic examination, samples of fundic and pyloric mucosa were analysed by a screening PCR for Helicobacteraceae, followed by specific PCRs (H. pylori, "Candidatus H. bovis", and Wolinella spp.), histological examination, and immunohistochemistry for Helicobacter spp. Overall, 96 % of the bovine and 42 % of the ovine abomasa tested positive for Helicobacteraceae. No samples tested positive for H. pylori, while 68 % of bovine samples tested positive for "Candidatus H. bovis", mostly in the pyloric mucosa. Immunohistochemistry showed colonisation by Helicobacter spp. only in the pyloric glands of 11 bovine abomasa (44 %), while in ovine abomasa colonisation was not detected. Our results confirmed that "Candidatus H. bovis" is the most common Helicobacteraceae in the bovine abomasum and specifically colonises bovine pyloric glands. No association was found between Helicobacter spp. infection status and abomasal inflammation, suggesting a high degree of adaptation to the bovine host. The role of cattle and sheep as potential source of H. pylori for humans appears to be negligible.

Helicobacter pylori and oral-gut microbiome: clinical implications

More than half of the world's population are colonized with H. pylori; however, the prevalence varies geographically with the highest incidence in Africa. H. pylori is probably a commensal organism that has been associated with the development of gastritis, ulcers, and gastric cancer. H. pylori alone is most probably not enough for the development of gastric carcinoma, but evidence for its association with the disease is high and has, therefore, been classified by the International Agency for Research on Cancer as a Class 1 carcinogen. Bacteroidetes and Fusobacteria positively coexisted during H. pylori infection along the oral-gut axis. The eradication therapy required to treat H. pylori infection can also have detrimental consequences for the gut microbiota, leading to a decreased alpha diversity. Therefore, therapy regimens integrated with probiotics may abolish the negative effects of antibiotic therapy on the gut microbiota. These eradication therapies combined with probiotics have also higher rates of eradication, when compared to standard treatments, and are associated with reduced side effects, improving the patient's compliance. The eradication therapy not only affects gut microbiome but also affects the oral microbiome with robust predominance of harmful bacteria. However, there have been reports of a protective role of H. pylori in Barrett's esophagus, esophageal adenocarcinoma, eosinophilic esophagitis, IBD, asthma, and even multiple sclerosis. Therefore, eradication therapy should be carefully considered, and test to treat policy should be tailored to specific communities especially in highly endemic areas. Supplementation of probiotics, prebiotics, herbals, and microbial metabolites to reduce the negative effects of eradication therapy should be considered. After failure of many eradication attempts, the benefits of H. pylori eradication should be carefully balanced against the risk of adverse effects especially in the elderly, persons with frailty, and intolerance to antibiotics.

HELICOBACTER PYLORI OIPA VIRULENCE GENE AS A MOLECULAR MARKER OF SEVERE GASTROPATHIES

BACKGROUND

Helicobacter pylori is an etiologic agent of gastroduodenal diseases. The microorganism, considered a type I carcinogen, affects about 50% of the global population. H. pylori virulence factors are determinant for the clinical outcome of the infection. The outer inflammatory protein A (oipA) gene encodes an outer membrane adhesin and is related to severe gastropathies, such as gastric cancer.

OBJECTIVE

The aim of this study was to evaluate the association of the oipA gene with the severity of gastroduodenal diseases in dyspeptic patients in region Central Brazil.

METHODS

The polymerase chain reaction (PCR) was used to determine the presence of H. pylori. Samples positives were used for molecular screening of the oipA gene. Gastropathies were categorized as non-severe and severe diseases.

RESULTS

Approximately 68% of patients had H. pylori and 36% were infected with H. pylori oipA+ strains. Infection was significantly associated in patients aged over 44 years (P=0.004). However, there was no association between oipA and patients' age (P=0.89). Approximately 46% of patients infected with oipA+ strains had some severe illness. Gastric adenocarcinoma was the most frequent severe gastropathy. The H. pylori oipA genotype was inversely associated with the severity of gastroduodenal diseases (OR=0.247, 95%CI: 0.0804-0.7149 and P=0.007).

CONCLUSION

The characterization of possible molecular markers will contribute to personalized medicine, impacting the prognosis of patients.

The Anti-Oxidant Curcumin Solubilized as Oil-in-Water Nanoemulsions or Chitosan Nanocapsules Effectively Reduces Helicobacter pylori Growth, Bacterial Biofilm Formation, Gastric Cell Adhesion and Internalization

The bacterium Helicobacter pylori (H. pylori) represents a major risk factor associated with the development of gastric cancer. The anti-oxidant curcumin has been ascribed many benefits to human health, including bactericidal effects. However, these effects are poorly reproducible because the molecule is extremely unstable and water insoluble. Here we solubilized curcumin as either nanoemulsions or chitosan nanocapsules and tested the effects on H. pylori. The nanoemulsions were on average 200 nm in diameter with a PdI ≤ 0.16 and a negative zeta potential (-54 mV), while the nanocapsules were 305 nm in diameter with a PdI ≤ 0.29 and a positive zeta potential (+68 mV). Nanocapsules were safer than nanoemulsions when testing effects on the viability of GES-1 gastric cells. Also, nanocapsules were more efficient than nanoemulsions at inhibiting H. pylori growth (minimal inhibitory concentration: 50 and 75 μM, respectively), whereby chitosan contributed to this activity. Importantly, both formulations effectively diminished H. pylori's adherence to and internalization by GES-1 cells, as well as biofilm formation. In summary, the demonstrated activity of the curcumin nanoformulations described here against H. pylori posit them as having great potential to treat or complement other therapies currently in use against H. pylori infection.

Single-capsule bismuth-based quadruple therapy as a rescue therapy for Helicobacter pylori eradication

INTRODUCTION

Helicobacter pylori (H. pylori) infection is highly prevalent in Portugal and its eradication is formally recommended. However, the indiscriminate use of antimicrobials has led to a drastic rise in antibiotic resistance, with the failure of traditional eradication schemes. A single-capsule bismuth-based quadruple therapy became recently available in Portugal. This study aims to evaluate the efficacy and safety of a bismuth-based quadruple therapy as a second-line or rescue therapy.

PATIENTS AND METHODS

This was a multicentric study. All consecutive patients that were treated with bismuth-based quadruple therapy, as second-line or salvage treatment between July 2017 and April 2019 were enrolled. Their medical records were reviewed and clinical and laboratorial parameters, as well as data on treatment efficacy and adverse events were retrieved. Patients were also contacted by phone after treatment to confirm compliance, adverse events, and global satisfaction with this specific therapy.

RESULTS

A total of 151 subjects were included (female-68.9%; mean age-56 ± 13.5 years). Patients were previously submitted to 212 eradication schemes (Median-1; 1-5; IQR:4): 33.5% triple clarithromycin-based, 25% sequential, 7.5% concomitant, 5.2% others, and in 28.8% it was not possible to know the previous eradication scheme(s) followed by the patient. The PPI of choice was esomeprazole (39.7%), followed by omeprazole (27.8%). Compliance was achieved in 93.4% and the overall eradication rate was 90.1% (95% CI: 84.6-94.2). Treatment-related adverse effects were experienced by 63 patients (41.7%; 95% CI: 34-49.7), being mild in 29, moderate in 19, and severe in 15. The main drawbacks of the treatment, from the patient's perspective, were the high price (47%) and the adverse effects (16.6%). Failure to eradicate H. pylori was correlated with the following: previous rifabutin-based scheme (0 vs. 100%; p = 0.010) and a higher number of previous treatment schemes (1.5 ± 0.7 vs. 2.3 ± 1.2; p < 0.001).

CONCLUSION

In this South-European country a single-capsule bismuth-based quadruple therapy is an excellent option as a second-line or rescue therapy, with acceptable compliance and side effects.

Comparison of the diagnostic accuracy of the updated Sydney system and single biopsy

BACKGROUND

Updated Sydney system (USS) recommends taking biopsies from certain areas of the stomach for the diagnosis of precancerous lesions associated with Helicobacter pylori. Our aim was to evaluate the contribution of each of the biopsy sites to the diagnosis.

METHODS

This prospective study included 97 patients aged 40 and over with dyspeptic complaints. Biopsies were taken from five regions: the lesser curvature of the antrum (LCA), the lesser curvature of the corpus (LCC), incisura angularis (IA), the greater curvature of the antrum (GCA), and the greater curvature of the corpus (GCC). Biopsy specimens were stained with hematoxylin-eosin stain, periodic acid Schiff-alcian blue, and Giemsa histochemical stain and evaluated according to the Sydney classification.

RESULTS

Thirty-seven (38%) patients were positive for H. pylori in at least one biopsy site. Atrophic gastritis without intestinal metaplasia (IM) was found in 17 (17.5%) of the patients (6.2% in IA, 5.2% in each of LCA, GCA, and LCC, and 2% in GCC). The prevalence of atrophic gastritis with IM was 42.3% (21.6% in LCA, 20.6% in GCA, 20.6% in IA, 14.4% in LCC, and 5.2% in GCC). Endoscopic follow-up was planned in 21 (22%) patients due to the presence of extensive atrophy or incomplete IM. If a single biopsy of the LCA or a biopsy of both LCA and GCA was taken, endoscopic follow-up would have been missed in 12 (57%) or 6 (29%) patients, respectively.

CONCLUSION

Taking biopsies in accordance with the USS had higher sensitivity in detecting atrophic gastritis with or without IM compared to single biopsy. One or two biopsies is not sufficient to identify patients for whom endoscopic follow-up is recommended.

Heteroresistance to clarithromycin and metronidazole in patients with a Helicobacter pylori infection: a systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance of H. pylori can lead to treatment failure. Importantly, several studies have reported on heteroresistance, i.e. the presence of resistant and susceptible H. pylori populations in the same sample and/or a difference in the susceptibility patterns between biopsy samples. This meta-analysis aims to provide comprehensive data on the prevalence of metronidazole and clarithromycin heteroresistance and the approaches to their detection.

MATERIAL AND METHODS

A systematic review was performed after the search of MEDLINE, Scopus and Web of Science. The study outcomes were the weighted pooled prevalence of heteroresistance to clarithromycin and metronidazole in H. pylori positive samples and/or isolates with a subanalysis by continent.

RESULTS

A total of 22 studies that had investigated 3852 H. pylori positive patients were included in the meta-analysis. Heteroresistance to clarithromycin was reported in 20 studies, with a weighted pooled prevalence of 6.8% (95% CI 5.1-8.6; 3654 H. pylori positive patients; the substantial heterogeneity I² = 55.6%). Heteroresistance to metronidazole was reported in 12 studies, with a weighted pooled prevalence of 13.8% (95% CI 8.9-18.6; 1670 H. pylori positive patients; the substantial heterogeneity I² = 60.9%). The weighted pooled prevalence of clarithromycin heteroresistance was similar in Asia and Europe (p = 0.174584), however, metronidazole heteroresistance was detected more often in Europe (p < 0.00001). Clarithromycin heteroresistance was detected more often by phenotype rather than by using genotyping methods (12 vs 8 studies), whereas heteroresistance to metronidazole was detected only by phenotype.

CONCLUSION

The prevalence of heteroresistance to clarithromycin and/or metronidazole is not negligible and can be detected in approximately 7 and 14% of H. pylori positive samples, respectively. These findings highlight the need to raise the awareness of gastroenterologists and microbiologists to the heteroresistance to clarithromycin and metronidazole in patients with a H. pylori infection.

Gossypol from Gossypium spp. Inhibits Helicobacter pylori Clinical Strains and Urease Enzyme Activity: Bioactivity and Safety Assessments

This study investigates the inhibitory activities of gossypol, a natural polyphenolic compound from Gossypium spp., against Helicobacter pylori (HP) clinical strains and a urease enzyme that plays a key role in the pathogenesis of HP. Gossypol was detected to exhibit a bacteriostatic action against all the HP strains tested with minimum inhibitory concentration (MIC) values ranging from 3.51 to 4.14 µg/mL. The activity of HP urease (HPU) was efficiently impeded by gossypol with a 50% inhibitory concentration (IC50) value of 3.3 µM using an Electrospray Ionization–Mass Spectrometry (ESI-MS)-based method. The in vitro cytotoxicity assay showed no significant cytotoxic properties of gossypol against human gastric epithelial cells. Additionally, molecular docking studies were performed to assess the binding mode and the molecular interactions of gossypol with HPU with a binding affinity value of −8.1 kcal/mol compared with an HPU–acetohydroxamic acid (a standard urease inhibitor) docking complex (–6.1 kcal/mol). The overall results reveal that gossypol might help fight against HP infection by two mechanisms of action: inhibition of the growth of HP and inhibition of urease.

Lower Incidence of Hepatobiliary Cancer in Helicobacter pylori-Infected Persons: A Cohort Study of 53.633 Persons

BACKGROUND AND AIMS

Helicobacter pylori (HP) is known to be involved in intestinal carcinogenesis. As regards hepatobiliary cancers, there are few and inconsistent reports. We investigated HP infection and its association with the incidence of hepatobiliary cancers in a large cohort study. The cohort's appropriateness for the purpose was gauged by its ability to identify the established risk relation to gastric cancer.

METHODS

This historical study was performed in the Central Denmark Region. Patients were included from primary healthcare after being tested for HP infection with a urea breath test. Patients' diagnoses, age, gender, and country of birth were obtained from Danish national administrative registries. Cox regression was used to compare incidences of hepatobiliary and gastric cancer between HP-positive and HP-negative persons, adjusting for confounding variables.

RESULTS

A total of 53,633 persons were included and 10,553 were tested HP-positive. They were followed for a median of 4.6 years (total 250,515 person-years). We found 64 hepatobiliary cancers, with a markedly lower incidence in HP-positive persons; HR = 0.27 (95% CI 0.11-0.68). A higher incidence of gastric cancer in HP-positive persons was confirmed (HR = 1.99 (95% CI 1.35-2.94)).

CONCLUSION

The incidence of hepatobiliary cancers was remarkably lower in HP-infected persons after adjusting for age, gender, cirrhosis, alcohol-related diagnoses, chronic viral hepatitis, and country of origin. We found no methodological cause for this unexpected finding, and the pathogenic links between the infection and cancer remain to be identified. Our results must be confirmed in a similar cohort.

Genome-scale protein interaction network construction and topology analysis of functional hypothetical proteins in Helicobacter pylori divulges novel therapeutic targets

The emergence and spread of multi-drug resistance among Helicobacter pylori (H. pylori) strain raise more stakes for genetic research for discovering new drugs. The quantity of uncharacterized hypothetical proteins in the genome may provide an opportunity to explore their property and promulgation could act as a platform for designing the drugs, making them an intriguing genetic target. In this context, the present study aims to identify the key hypothetical proteins (HPs) and their biological regulatory processes in H. pylori. This investigation could provide a foundation to establish the molecular connectivity among the pathways using topological analysis of the protein interaction networks (PINs). The giant network derived from the extended network has 374 nodes connected via 925 edges. A total of 43 proteins with high betweenness centrality (BC), 54 proteins with a large degree, and 23 proteins with high BC and large degrees have been identified. HP 1479, HP 0056, HP 1481, HP 1021, HP 0043, HP 1019, gmd, flgA, HP 0472, HP 1486, HP 1478, and HP 1473 are categorized as hub nodes because they have a higher number of direct connections and are potentially more important in understanding HP's molecular interactions. The pathway enrichment analysis of the network clusters revealed significant involvement of HPs in pathways such as flagellar assembly, bacterial chemotaxis and lipopolysaccharide biosynthesis. This comprehensive computational study revealed HP's functional role and its druggability characteristics, which could be useful in the development of drugs to combat H. pylori infections.

Optimization of pre- treatments with Propidium Monoazide and PEMAX™ before real-time quantitative PCR for detection and quantification of viable Helicobacter pylori cells

Accurate detection of H. pylori in different environmental and clinical samples is essential for public health strtdudies. Now, a big effort is being made to design PCR methodologies that allow for the detection of viable and viable but non-culturable (VBNC) H. pylori cells, by achieving complete exclusion of dead cells amplification signals. The use of DNA intercalating dyes has been proposed. However, its efficacy is still not well determined. In this study, we aimed to test the suitability of PMA and PEMAX™ dyes used prior to qPCR for only detecting viable cells of H. pylori. Their efficiency was evaluated with cells submitted to different disinfection treatments and confirmed by the absence of growth on culture media and by LIVE/DEAD counts. Our results indicated that an incubation period of 5 min for both, PMA and PEMAX™, did not affect viable cells. Our study also demonstrated that results obtained by using intercalating dyes may vary depending on the cell stress conditions. In all dead cell's samples, both PMA and PEMAX™ pre-qPCR treatments decreased the amplification signal (>10³ Genomic Units (GU)), although none of them allowed for its disappearance confirming that intercalating dyes, although useful for screening purposes, cannot be considered as universal viability markers. To investigate the applicability of the method specifically to detect H. pylori cells in environmental samples, PMA-qPCR was performed on samples containing the different morphological and viability states that H. pylori can acquire in environment. The optimized PMA-qPCR methodology showed to be useful to detect mostly (but not only) viable forms, regardless the morphological state of the cell.

Helicobacter pylori: Commensal, symbiont or pathogen?

This review considers the data on Helicobacter pylori (H. pylori), which have been accumulated over 40 years since its description as an etiological factor in gastrointestinal diseases. The majority of modern publications are devoted to the study of the pathogenic properties of the microorganism in the development of chronic gastritis, peptic ulcer disease, and gastric cancer, as well as methods for its eradication. However, in recent years, there have been more and more studies which have suggested that H. pylori has a beneficial, or potentially positive, effect on the human body. The authors have attempted to objectively analyze the information accumulated in the literature on H. pylori. Some studies consider it as one of the recently identified human bacterial pathogens, and special attention is paid to the evidence suggesting that it is probably part of the composition of the human microbiome as a commensal (commensal from French to English is a table companion) or even a symbiont. The presented data discussing the presence or absence of the effect of H. pylori on human health suggest that there is an apparent ambiguity of the problem. The re-assessment of the data available on H. pylori infection is important in order to answer the question of whether it is necessary to create a program of mass H. pylori eradication or to apply a more personalized approach to treating patients with H. pylori-associated gastrointestinal diseases and to perform eradication therapy.

The increasing antimicrobial resistance of Helicobacter pylori in Iran: A systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance of Helicobacter pylori can result in eradication failure. Metadata on the antimicrobial resistance of H pylori in Iran could help to formulate H pylori eradication strategies in Iran.

METHODS

A systematic review was performed after searching in MEDLINE, Scopus, Embase, Web of Science, and the Cochrane Library. A meta-analysis was performed, and a comparison of the rates between children and adults; time periods (1999-2010, 2011-2016, 2017-2019); and the methods used was carried out.

RESULTS

A total of 66 studies investigating 5936 H pylori isolates were analyzed. The weighted pooled resistance (WPR) rates were as follows: clarithromycin 21% (95% CI 16-26), metronidazole 62% (95% 57-67), clarithromycin in combination with metronidazole 16% (95% CI 10-23), ciprofloxacin 24% (95% CI 15-33), levofloxacin 18% (95% CI 9-30), erythromycin 29% (95% CI 12-50), furazolidone 13% (95% CI 4-27), tetracycline 8% (95% CI 5-13), and amoxicillin 15% (95% CI 9-22). During the three time periods, there was an increased resistance to amoxicillin, clarithromycin, ciprofloxacin, furazolidone, and tetracycline (P ˂ .05). Furazolidone and a clarithromycin/metronidazole combination had the higher resistance rates in children (P ˂ .05).

CONCLUSION

An increasing rate of resistance to amoxicillin, clarithromycin, ciprofloxacin, furazolidone, and tetracycline in Iranian H pylori isolates was identified. In children, the resistance to furazolidone and a combination of clarithromycin and metronidazole is higher compared to adults. As a stable, high resistance to metronidazole was found in children and adults in all Iranian provinces, we suggest that metronidazole should not be included in the Iranian H pylori eradication scheme.

Evaluation of miR-21 Expression Level in Helicobacter pylori-Infected Gastric Mucosa

Background: Gastric cancer is one of the main causes of death worldwide. In this regard, Helicobacter pylori infection is considered as the main risk factor for gastric cancer. MicroRNA (mirNA) can interface with mRNA molecules as well as blocking their translation into proteins or inducing degradation. Objectives: The aim of this study was to compare the expression of mir-21 in biopsy samples of gastritis and healthy adjacent tissues. Methods: Between Feb-Dec 2017, 70 patients with dyspeptic symptoms from Taleghani Hospital were enrolled in this study. Accordingly, the expression level of mir-21 was evaluated using semi-quantitative RT-PCR in mucosal biopsy samples from those well-characterized patients. Moreover, the U6 gene was used as an internal control. Results: Our data indicated that mir-21 expression was significantly up-regulated in the infected samples with H. pylori compared to healthy samples. Conclusions: Our results confirm that H. pylori infection can alter the expression of mir-21 in gastric epithelial cells and gastric mucosal tissues. However, the exact role of the miRNA changes in H. pylori infection will require further experiments.

Optimizing the MIC breakpoints of amoxicillin and tetracycline for antibiotic selection in the rescue therapy of H. pylori with bismuth quadruple regimen

PURPOSE

H. pylori with triple-drug resistance (TR) to clarithromycin, metronidazole, and levofloxacin limits the success of rescue therapy. We aimed to identify the optimal breakpoints of antibiotic minimal inhibitory concentration (MIC) to predict the success of rescue therapy for TR H. pylori infection.

METHODS

We consecutively enrolled 430 patients with at least one course of failed H. pylori eradications to receive an H. pylori culture for antibiotic MIC test. Seventy-three (17%) had TR H. pylori infection (MIC of clarithromycin > 0.5, levofloxacin > 1, and metronidazole > 8 mg/L, respectively). Sixty-nine cases with TR H. pylori infection received rescue therapy with either ATBP (amoxicillin, tetracycline, bismuth, and PPI) or MTBP (metronidazole, tetracycline, bismuth and PPI) for 7-14 days. Fourteen patients with positive ¹³C-urea breath test after the first rescue therapy were retreated with a crossover second rescue therapy.

RESULTS

The MTBP regimen had higher eradication success than the ATBP regimen as the first rescue therapy for TR H. pylori (intent-to-treat (ITT) analysis, 70.3 vs. 46.9%, p = 0.048; per protocol (PP) analysis, 78.8% vs. 51.7%, p = 0.025). For MTBP regimen, tetracycline MIC ≤ 0.094 mg/L (p < 0.001) with a 14-day treatment duration (p = 0.037) could predict eradication success with 100% accuracy. For the ATBP regimen, amoxicillin MIC selected as ≤ 0.032 mg/L could optimally determine eradication success (72.2 vs. 33.3%, p = 0.025).

CONCLUSION

Optimizing the MIC breakpoints of amoxicillin and tetracycline resistance better predicts the outcome of bismuth quadruple therapy. Further prospective studies using the revised MIC breakpoints to select antibiotics are warranted.

Helicobacter pylori seroprevalence in Spain: influence of adult and childhood sociodemographic factors

Helicobacter pylori (H. pylori) chronic infection causes severe digestive diseases, including gastric cancer, and certain strains entail a higher risk. Risk factors for this infection are still not fully understood. The aim of this study was to describe the association of adult and childhood sociodemographic factors with the seroprevalence of H. pylori, and with CagA and VacA antigen-specific seropositivity among H. pylori-seropositive individuals in the Spanish adult population. Serum antibody reactivity to H. pylori proteins was evaluated using multiplex serology in 2555 population-based controls enrolled in the MCC-Spain study, a multicase-control study recruiting participants from 2008 to 2013 in different areas of Spain. H. pylori seroprevalence was defined as seropositivity against at least four bacterial proteins. Information on sociodemographics, lifestyles, and environmental exposures was collected through personal interviews. Prevalence ratios and 95% confidence intervals were estimated using Poisson regression models to assess the association of lifetime sociodemographic factors with H. pylori seroprevalence and with seropositivity for CagA and VacA. H. pylori seroprevalence was 87.2%. Seropositivity was statistically significantly higher in men, increased with age, BMI, and number of siblings, and decreased with education and socioeconomic family level at birth. Among H. pylori-seropositive individuals, seropositivity was 53.3% for CagA, 61.4% for VacA, and 38.8% for both CagA and VacA. Ever smokers had lower seroprevalence for CagA and VacA than never smokers. H. pylori seroprevalence among this Spanish adult population was high and one third of the population was seropositive for two well-known markers of gastric cancer risk: CagA and VacA. Sex, age, education, and BMI were associated with H. pylori seroprevalence.

Sex differences in the relationship among alcohol, smoking, and Helicobacter pylori infection in asymptomatic individuals

OBJECTIVE

We aimed to investigate the relationship of Helicobacter pylori infection with alcohol and smoking.

METHODS

We conducted a cross-sectional study among participants who underwent health check-ups for H. pylori infection between January 2013 and March 2017. We subsequently investigated the relationship of H. pylori infection with alcohol and smoking.

RESULTS

A total of 7169 participants were enrolled in this study. The overall prevalence of H. pylori infection was 55.2%. Participants with H. pylori infection were more likely to be older than those without H. pylori infection. For male participants with H. pylori infection, multivariable logistic regression analysis indicated that both smoking (odds ratio (OR): 1.61; 95% confidence interval (CI): 1.41-1.83) and alcohol consumption (OR: 1.30; 95% CI: 1.10-1.52) were independently positively associated with H. pylori infection. For female participants, multivariable logistic regression analysis indicated that both smoking (OR: 0.03; 95% CI: 0.02-0.07) and alcohol consumption (OR: 0.20; 95% CI: 0.12-0.33) were inversely significantly associated with H. pylori infection after adjustment for age.

CONCLUSIONS

Smoking and alcohol consumption were risk factors for male participants but these were protective factors for female individuals with H. pylori infection.

Is the Utilization of Helicobacter pylori Stool Antigen Tests Appropriate in an Urban Canadian Population?

OBJECTIVES

Helicobacter pylori stool antigen test (HpSAT) appropriateness was investigated by assessing its testing and positivity rates in Calgary, Canada.

METHODS

The laboratory information system was accessed for all patients who received an HpSAT in 2018. Testing volume, test results, age, and sex of patients were collected. Sociodemographic risk factors and geospatial analysis were performed by matching laboratory data to the 2016 census data. Testing appropriateness was defined as a concordance between testing and positivity rates for each sociodemographic variable.

RESULTS

In 2018, 25,518 H pylori stool antigen tests were performed in Calgary, with an overall positivity rate of 14.7%. Geospatial mapping demonstrated significant distribution variations of testing and positivity rates of HpSAT in the city. Certain sociodemographic groups studied (eg, recent immigrants) appeared to be appropriately tested (testing rate relative risk [RR] = 2.26, positivity rate RR = 4.32; P < .0001), while other groups (eg, male) may have been undertested (testing rate RR = 0.85, positivity rate RR = 1.14; P < .0001).

CONCLUSIONS

Determining concordance of testing and positivity rate of a laboratory test can be used for assessing testing appropriateness for other diseases in other jurisdictions. This study demonstrated some at-risk patients may be missed for H pylori testing.

Clinical Performance of the Automated LIAISON® Meridian H. pylori SA Stool Antigen Test

Background

Antigens derived from Helicobacter pylori can be used as stool biomarkers to assist in the diagnosis of H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Methods

This prospective multisite study enrolled patients undergoing an esophagogastroduodenoscopy with collection of biopsy and stool specimens. Adult patients (≥22 years) participated in the study from February 2017 to August 2018. Specimens of the stomach were tested by three methods, known as the Composite Reference Method: (1) histological evaluation, (2) culture of the organism, and (3) rapid urease detection test. H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Results

277 patients (63% female) were included in the study. The prevalence of infected subjects was 24.2% in this study cohort. Clinical performance assessed against the Composite Reference Method showed very good agreement (Cohen′s kappa = 0.922), with good sensitivity (95.5%) and specificity (97.6%). Reproducibility study results showed total imprecision ranging from 3.1% to 13.9% CV.

Conclusion

The automated LIAISON® Meridian H. pylori SA assay brings reliable noninvasive testing for H. pylori to the laboratory that is in very good agreement with the current, more invasive biopsy-based methods such as histology, culture, or rapid urease test. The clinical trial identifiers are NCT03060746 (pretherapy) and NCT03060733 (posttherapy).H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

A positive Helicobacter pylori test is associated with low spondylarthritis incidence in a Danish historical cohort study

Ankylosing spondylitis (AS) and undifferentiated spondylarthritis (uSpA) are related inflammatory diseases affecting the spine and joints with infections among possible etiological factors. Helicobacter pylori (H. pylori) may affect the development of inflammatory diseases. Thus, we hypothesized that H. pylori infection affects AS and uSpA development. This cohort study was performed in Denmark with 56,000 patients from primary health care centers who were enrolled when a UBT was performed. They were followed for a median time of 8 years. From nationwide administrative registries, we extracted personal, diagnostic, and treatment information. Prevalence at time of UBT was studied on enrollment using logistic regression and incidence in the follow-up time of 8 years after UBT was studied using Cox regression, comparing H. pylori positive and H. pylori negative patients and adjusting for confounding variables. The prevalence of AS at the time of the UBT was higher among H. pylori positive individuals (OR = 2.00, CI 1.17-3.41), but likely to be linked to confounding as trends disappeared when stratifying for country of birth. The incidence of AS after UBT was lower for individuals who were previously H. pylori positive (OR = 0.23, CI 0.06-0.93). A similar phenomenon was observed for uSpA. As a novel finding, after UBT, the previously H. pylori infected individuals had lower risk of developing AS and uSpA compared to non-infected. This finding may be caused by etiological effects of previous H. pylori infection or unknown confounders. This suggests that H. pylori may somehow be positively involved in the pathogenesis of AS and uSpA.

Are Histopathological Changes of H. pylori Infection in Young Dyspeptic Patients Necessitate Endoscopy?

BACKGROUND:

Helicobacter pylori is an important gastrointestinal infective bacteria with many serious complications including gastric erosions and ulceration, duodenal ulcer, gastric carcinoma and MALT gastric lymphoma. The gastric biopsy is commonly performed in H. pylori-positive dyspeptic individuals, and many previous researchers studied the histopathological features of infected gastric biopsies however little previous studies focused on the histopathological findings in young population in comparison to the older one.

AIM:

To make a focus on the histopathological effects of H. pylori infection in young patients compared with the older one and predicts the need for endoscopy in this population, also to estimates the prevalence of infection in Iraqi patients.

MATERIAL AND METHODS:

the sample for this study is 180 patients in total, they attended Marjan medical city in Iraq for dyspepsia of more than 3 months and prepared for OGD. Patients asked for their permission to do immunological tests for H. pylori. Both serology for H. pylori antibodies and stool for antigen tests are used, and the case is included in the study only if both tests were positive, after OGD, the gastric biopsies are processed and examined histopathologically.

RESULTS:

Normal gastric biopsy is the most common histopathological finding in young (< 25 years) patients (75%) while chronic atrophic gastritis is the most common one in patients > 25 years age (57%). The prevalence of Helicobacter pylori infection in dyspeptic patients was 73.3%, the correlation between infection and sex was insignificant (p-value 0.06), and no significant correlation between infection and age (p-value 0.07) was concluded.

CONCLUSION:

H. pylori-related histopathological changes of gastric mucosa in young (< 25 years) are commonly mild and does not necessitate endoscopy at this age unless there are alarming signs.

Challenges of Accurate Diagnosis of Helicobacter pylori in Iran

Background: Helicobacter pylori-associated gastritis is regarded as the most prevalent gastrointestinal infection, as well as the major cause of several other diseases. Despite being discovered over 30 years ago, no golden diagnostic method has yet been suggested for this microorganism. Objective: The present study aimed to compare two common diagnostic methods of histology and serology. Materials and Methods: This cross-sectional study began in July, 2016, and was conducted at Imam Jafar Sadegh Hospital (a university hospital) in Maybod, Yazd, Iran, on 70 patients. All the patients underwent endoscopy, and biopsy samples were taken for histology, as well as blood samples for ELISA test. Finally, sensitivity, specificity, NPV (negative predictive values), and PPV (positive predictive values) were calculated and analyzed. Results: The sensitivity, specificity, accuracy, PPV, and NPV of the ELISA method with histology as the gold standard were 87.5%, 36.9%, 54.2%, 42%, and 85%, respectively. Still, the histology method appears to be the most reliable test for the diagnosis of H. pylori in Iran. Conclusion: Regarding the high prevalence of H. pylori in Iran, the present study recommends the use of histology as a diagnostic method in combination with other diagnostic methods for detecting H. pylori infection.

N-acetylcysteine as an adjuvant therapy for Helicobacter pylori eradication

BACKGROUND

Helicobacter pylori (H pylori) is one of the most common pathogens to establish and cause infection in human beings, affecting about 50% of the world's population. Prevalence may be as high as 83% in Latin American countries and as low as 17% in North America. Approximately 20% of infected people will manifest disease; people at high risk include those who live in low- and middle-income countries with poor sanitary conditions, since the mechanism of transmission seems to be oral-oral or faecal-oral (mostly during infancy). There are several antibiotic regimens to treat the infection, but antibiotic resistance is growing around the world. New adjuvant drugs - such as probiotics, statins, curcumin, and N-acetylcysteine (NAC) - are being tested to enhance eradication rates.N-acetylcysteine can destabilise the biofilm structure; it also has synergic action with antibiotics, and bactericidal effects. In addition, NAC has antioxidant properties, and has a primary mucolytic effect by reducing the thickness of the gastric mucus layer, both of which may exert beneficial adjuvant effects on H pylori eradication.

OBJECTIVES

To assess the efficacy and safety of N-acetylcysteine as an adjuvant therapy to antibiotics for Helicobacter pylori eradication.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1966 to April 2018), Embase (1988 to April 2018), CINAHL (1982 to April 2018), LILACS (1982 to April 2018), grey literature databases and trials registries. We handsearched the reference lists of relevant studies. We screened 726 articles and assessed 18 for eligibility.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of any antibiotic regimen plus NAC, in adults infected with H pylori. To be included, trials had to use a control consisting of the same antibiotic regimen with or without placebo. Outcomes of interest were eradication rates, and gastrointestinal, toxic, and allergic adverse events. Reporting of the primary outcomes listed here was not an inclusion criterion for the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed and extracted data and completed the 'Risk of bias' assessments. A third review author independently confirmed the 'Risk of bias' assessments. We used Review Manager 5 software for data analysis. We contacted study authors if there was missing information.

MAIN RESULTS

We included eight RCTs (with a total of 559 participants) in this review. The studies recruited outpatients aged between 17 and 76 years who were referred to endoscopy centres in several different countries. The certainty of evidence was reduced for most outcomes due to the poor methodological quality of included studies; issues mainly related to the generation of allocation sequence, allocation concealment, and blinding (this last domain related specifically to adverse outcomes).We are uncertain whether the addition of NAC to antibiotics improves H pylori eradication rates, compared with the addition of placebo or no NAC (38.8% versus 49.1%, risk ratio (RR) 0.74, 95% confidence interval (CI) 0.51 to 1.08; participants = 559; studies = eight; very low-certainty evidence). A post-hoc sensitivity analysis, in which we removed studies that tested antibiotic regimens no longer recommended in clinical practice, showed that the addition of NAC may improve eradication rates compared to control (27.2% versus 37.6%, RR 0.71, 95% CI 0.53 to 0.94; participants = 397; published studies = five).We are uncertain whether NAC is associated with a higher risk of gastrointestinal adverse events compared to control (23.9% versus 18.9%, RR 1.25, 95% CI 0.85 to 1.85; participants = 336; studies = five; very low-certaintyevidence), or allergic adverse events (2% versus 0%, RR 2.98, 95% CI 0.32 to 27.74; participants = 336; studies = five; very low-certainty evidence). There were no reports of toxic adverse events amongst included studies.

AUTHORS' CONCLUSIONS

We are uncertain whether the addition of NAC to antibiotics improves H pylori eradication rates compared with the addition of placebo or no NAC. Due to the clinical, statistical and methodological heterogeneity found in included studies, and the uncertainty observed when analysing therapy subgroups, any possible beneficial effect of NAC should be regarded cautiously.We are uncertain whether NAC is associated with a higher risk of gastrointestinal or allergic adverse events compared with placebo or no NAC. There were no reports of toxic adverse events amongst the included studies.Further large, well-designed, randomised clinical studies should be conducted, with good reporting standards and appropriate collection of efficacy and safety outcomes, especially for current recommended antibiotic regimens.

Helicobacter pylori eradication: influence of interleukin-1beta -31 C/T polymorphism

Aim

To analyze the influence of the –31 C/T polymorphism of the interleukin-1β gene on Helicobacter pylori eradication therapy success in patients with functional dyspepsia.

Methods

Functional dyspepsia was diagnosed according to the Rome III criteria. All patients underwent upper gastrointestinal endoscopy, and gastric biopsies were obtained at screening and 12 months after randomization (last follow-up visit). Urease test and histological examination were performed to define the H. pylori status. Patients received twice-daily amoxicillin, clarithromycin and omeprazole for 10 days. Genotyping of the interleukin-1beta –31 C/T polymorphism (rs1143627) was performed using polymerase chain reaction-restriction fragment length polymorphism.

Results

One hundred forty-nine patients received treatment with triple therapy for H. pylori eradication. Only one patient was lost to follow-up, and adherence to study medication was 94.6%. A total of 148 patients (mean age 46.08 ± 12.24 years; 81.8% women) were evaluated for the influence of the interleukin-1beta –31 C/T polymorphism on the outcome of H. pylori eradication therapy. After treatment, bacteria were eradicated in 87% of patients (129/148). Genotype frequencies of the polymorphism were as follows: CC, 38/148 (25.7%); CT, 71/148 (47.9%); and TT, 39/148 (26.4%). Successful eradication rate was 78.9%, 94.4% and 82.1% for the CC, CT and TT genotypes, respectively. The CT genotype was significantly associated with successful H. pylori eradication (p = 0.039).

Conclusion

This study suggests that the CT genotype of the interleukin-1beta –31 C/T polymorphism plays a role in the successful eradication of H. pylori among patients with functional dyspepsia.

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.

Systematic review of the relationship of Helicobacter pylori infection with geographical latitude, average annual temperature and average daily sunshine

BACKGROUND

Helicobacter pylori (H. pylori) infection is a worldwide threat to human health with high prevalence. In this study, we analyzed the relationship between latitude, average annual temperature, average daily sunshine time and H. pylori infection.

METHODS

The PubMed, ClinicalTrials.gov , EBSCO and Web of Science databases were searched to identify studies reporting H. pylori infection. Latitude 30° was the cut-off level for low and mid-latitude areas. We obtained information for latitude, average annual temperature, average daily sunshine, and Human Development Index (HDI) from reports of studies of the relationships with H. pylori infection.

RESULTS

Of the 51 studies included, there was significant difference in H. pylori infection between the low- and mid-latitude areas (P = 0.05). There was no significant difference in the prevalence of H. pylori infection in each 15°-latitude zone analyzed (P = 0.061). Subgroup analysis revealed the highest and lowest H. pylori infection rates in the developing regions at > 30° latitude subgroup and the developed regions at < 30° latitude subgroup, respectively (P < 0.001). Multivariate analysis showed that average annual temperature, average daily sunshine time and HDI were significantly correlated with H. pylori infection (P = 0.009, P < 0.001, P < 0.001), while there was no correlation between H. pylori infection and latitude.

CONCLUSIONS

Our analysis showed that higher average annual temperature was associated with lower H. pylori infection rates, while average daily sunshine time correlated positively with H. pylori infection. HDI was also found to be a significant factor, with higher HDI associated with lower infection rates. These findings provide evidence that can be used to devise strategies for the prevention and control of H. pylori.

Dietary habits and Helicobacter pylori infection: a cross sectional study at a Lebanese hospital

BACKGROUND

To examine the association between dietary habits and Helicobacter pylori (H. pylori) infection among patients at a tertiary healthcare center in Lebanon.

METHODS

This cross-sectional study was conducted on 294 patients in 2016, at a hospital in Northern Lebanon. Participants were interviewed using a structured questionnaire to collect information on socio-demographic and lifestyle characteristics; dietary habits were ascertained via a short food frequency questionnaire (FFQ). H. pylori status (positive vs. negative) was determined after upper GI endoscopy where gastric biopsy specimens from the antrum, body, and fundus region were collected and then sent for pathology analysis. Multivariable logistic regression was conducted to identify the association between socio-demographic, lifestyle, dietary and other health-related variables with H pylori infection.

RESULTS

The prevalence of H. pylori infection was found to be 52.4% in this sample. Results of the multivariable analysis showed that H. pylori infection risk was higher among participants with a university education or above (OR = 2.74; CI = 1.17-6.44), those with a history of peptic ulcers (OR = 3.80; CI = 1.80-8.01), gastric adenocarcinoma (OR = 3.99; CI = 1.35-11.83) and vitamin D level below normal (OR = 29.14; CI = 11.77-72.13). In contrast, hyperglycemia was protective against H. pylori (OR = 0.18; CI = 0.03-0.89). No relationship between dietary habits and H. pylori infection was found in the adjusted analysis.

CONCLUSIONS

Socio-demographic and clinical variables are found to be associated with H. pylori, but not with dietary factors. Further studies are needed to investigate the effect of diet on H. pylori risk.

Functional gastrointestinal disorders in children from low socio-economic status and Helicobacter pylori infection

BACKGROUND

Most studies on functional gastrointestinal disorders (FGIDs) in children are based on data from the northern hemisphere. Scientific reports are arising in South American population, but little is still known about children from low socio-economic status (SES), where Helicobacter pylori infection is endemic. Our objective was to evaluate the prevalence of FGIDs in school children from low SES and its relationship with H. pylori infection.

METHODS

Children from 3 public schools of low SES from Santiago de Chile were included. Students completed the Rome III Questionnaire and a survey about other symptoms. Also, the ¹³ C urea breath test determined the presence of H. pylori infection.

RESULTS

Five hundred six children were included, where 48% were male, with a median age of 15.7 years (range 7.1-19.6). Forty-two percent had some FGID, aerophagia and functional constipation being the most frequent. Females (adjusted OR 1.5, 95% CI [1.1, 2.2]), those children with parents within the lowest level of education (adjusted OR 1.6, 95% CI: 1.1-2.4), and family history of gastric cancer (adjusted OR 1.9, 95% CI: 1.2-3.1) were related to FGIDs. The prevalence of H. pylori infection was 55.9% (95% CI [50.7, 60.9]). In multivariable analysis, the presence of abdominal pain (OR 1.55, 95% CI [1.02, 2.36]), but not FGIDs, was related to H. pylori infection.

CONCLUSIONS

FGIDs are common in low SES students. A low educational level of the household head, family history of gastric cancer. and being female are related to the development of FGIDs. In this study, no relationship between the presence of H. pylori and FGIDs was found.

Systematic identification of immunodominant CD4+ T cell responses to HpaA in Helicobacter pylori infected individuals

In mice, antigen-specific CD4⁺ T cell response is indispensible for the protective immunity against Helicobacter pylori (H. pylori). It has been demonstrated that neuraminyllactose-binding hemagglutinin (HpaA) immunization protected mice from H. pylori infection in a CD4⁺ T cell dependent manner. However, much remains unclear concerning the human CD4⁺ T cell responses to HpaA. We conducted a systematic study here to explore the immunodominant, HpaA-specific CD4⁺ T cell responses in H. pylori infected individuals. We found that HpaA-specific CD4⁺ T cell responses varied remarkably in their magnitude and had broad epitope-specificity. Importantly, the main responses focused on two regions: HpaA76-105 and HpaA130-159. The HLA-DRB1*0901 restricted HpaA142-159 specific CD4⁺ T cell response was the most immunodominant response at a population level. The immunodominant epitope HpaA142-159 was naturally presented and highly conserved. We also demonstrated that it was not the broad peptide specificity, but the strength of HpaA specific CD4⁺ T cell responses associated with gastric diseases potentially caused by H. pylori infection. Such investigation will aid development of novel vaccines against H. pylori infection.

Reversibility of atrophic gastritis and intestinal metaplasia after Helicobacter pylori eradication - a prospective study for up to 10 years

BACKGROUND

Atrophic gastritis and intestinal metaplasia are premalignant conditions for gastric cancer. Their reversibility by Helicobacter pylori eradication remains controversial.

AIM

To evaluate the reversibility of atrophic gastritis and intestinal metaplasia by H. pylori eradication with long-term follow-up.

METHODS

598 subjects were prospectively enrolled and followed for up to 10 years. They were categorised as H. pylori-negative (n = 65), H. pylori non-eradicated (n = 91), and H. pylori-eradicated (n = 442). Histological assessment was performed for antrum and corpus by Sydney classification.

RESULTS

Histological follow-up was performed regularly at 1, 2, 3-4 and ≥5 years, with mean follow-up of 1.07 ± 0.21, 2.29 ± 0.83, 3.93 ± 1.02, and 6.45 ± 1.28 years, respectively. Atrophic gastritis in antrum and corpus gradually and significantly (both P < .05 for all timepoints) improved only in the H. pylori-eradicated group compared to that at baseline. Significant difference in atrophic gastritis between H. pylori-eradicated and H. pylori-negative groups disappeared from 1-year follow-up. Similarly, intestinal metaplasia in antrum and corpus improved significantly (both P < .05 for all timepoints) only in the H. pylori-eradicated group in comparison with that at baseline. Significant difference in intestinal metaplasia between H. pylori-eradicated and H. pylori-negative groups disappeared from ≥5 years of follow-up in the antrum and from 3 years of follow-up in the corpus.

CONCLUSION

H. pylori eradication may be a preventative strategy for intestinal-type gastric cancer by regression of atrophic gastritis and intestinal metaplasia.

Seroprevalence of Helicobacter pylori in Hispanics living in Puerto Rico: A population-based study

BACKGROUND

Helicobacter pylori is an important etiologic factor for peptic ulcers and gastric cancer, one of the top ten leading causes of cancer death in Puerto Rico. However, the prevalence of H. pylori infections in this population was previously unknown. The aim of this study was to examine the seroprevalence of H. pylori and its associated risk factors in Puerto Rico.

MATERIALS AND METHODS

A cross-sectional study was designed using an existing population-based biorepository. Seropositivity was determined using the Premier^™ H. pylori immunoassay. Helicobacter pylori seroprevalence was estimated with 95% confidence using marginal standardization following logistic regression. To assess the risk factors associated with H. pylori seropositivity, a multivariable log-binomial model was fitted to estimate the prevalence ratio (PR) and its 95% confidence interval (95% CI).

RESULTS

A total of 528 population-based serum samples were analyzed. The mean age of the study population was 41 ± 12 years, of whom 55.3% were females. The overall seroprevalence of H. pylori was 33.0% (95% CI = 28.3%-38.1%). Increasing age and having <12 years of education were significantly (P < .05) associated with H. pylori seropositivity in the multivariable model; however, residing in counties with low population density reached marginal significance (P = .085).

CONCLUSIONS

We report that H. pylori infection is common among Hispanics living in Puerto Rico. The H. pylori seroprevalence observed in Puerto Rico is similar to the seroprevalence reported in the overall population of the United States. The association between H. pylori seroprevalence and the risk factors analyzed offers insight into the epidemiology of gastric cancer in Puerto Rico and warrants further investigation.

Resistance mechanisms of Helicobacter pylori and its dual target precise therapy

Helicobacter pylori drug resistance presents a significant challenge to the successful eradication of this pathogen. To find strategies to improve the eradication efficacy of H. pylori, it is necessary to clarify the resistance mechanisms involved. The mechanisms of H. pylori drug resistance can be investigated from two angles: the pathogen and the host. A comprehensive understanding of the molecular mechanisms of H. pylori resistance based on both pathogen and host would aid the implementation of precise therapy, or ideally "dual target precise therapy" (bacteria and host-specific target therapy). In recent years, with increased understanding of the mechanisms of H. pylori resistance, the focus of eradication has shifted from disease-specific to patient-specific treatment. The implementation of "precision medicine" has also provided a new perspective on the treatment of infectious diseases. In this article, we systematically review current research on H. pylori drug resistance from the perspective of both the pathogen and the host. We also review therapeutic strategies targeted to pathogen and host factors that are aimed at achieving precise treatment of H. pylori.

GenoType® HelicoDR test in comparison with histology and culture for Helicobacter pylori detection and identification of resistance mutations to clarithromycin and fluoroquinolones

BACKGROUND

There are several methods for Helicobacter pylori infection diagnosis.

AIM

The efficacies of three methods for H. pylori identification directly from a biopsy were compared: histology, culture, and molecular GenoType® HelicoDR test.

MATERIALS & METHODS

Eighty-five triplicates of stomach antrum biopsies were obtained during gastroscopy procedures for culture, histology, and molecular assay. In addition, we performed molecular identification of genes encoding resistance to clarithromycin and fluoroquinolones.

RESULTS

The results have shown that the most specific method with the highest number of positive specimens was by molecular kit, compared to culture and histology (94.3%, 77.1%, and 71.4%, respectively). There was a higher rate of resistance mutations to clarithromycin than to fluoroquinolones (68.26% vs 20%). The most common mutations for clarithromycin and fluoroquinolones resistance were found in alleles A2143G and N87K, respectively. The highest rate of positive specimens was identified by the molecular.

DISCUSSION

GenoType HelicoDR kit (94.3%), which has several advantages: direct identification, strain resistance characterization, mixture of genotypes detection, and no transport or storage limitations; thus, it is an excellent epidemiological screening tool. This work has demonstrated a lower resistance rate to fluoroquinolones; it is possible that in the investigated geographic area treatment with fluoroquinolones may be preferable to clarithromycin. GenoType® HelicoDR test eliminates the need for culture performance and susceptibility tests for several common antibiotic agents and enables optimal and specific antibiotic treatment adjustment.

CONCLUSION

We recommend a combination of PCR assay and bacterial culture for a quick method of screening and more efficient identification of H. pylori strains and resistance patterns.

Gastric TFF1 Expression from Acute to Chronic Helicobacter Infection

TFF1, a mucin-associated secreted peptide of gastric mucous cells, is known as a protective agent for stomach epithelium under different stimuli, but its role upon Helicobacter infection is still not clear. In this paper we characterized TFFs expression, with particular attention to TFF1, under Helicobacter infection in gastric cell lines. A mouse model was used to distinguish TFF1 mRNA expression between acute and chronic stages of Helicobacter infection. Our results show that TFF1 expression is induced in infected cells; in addition, the inflammatory response upon Helicobacter infection is inversely associated to pre-existing TFF1 protein levels. In infected mice, TFF1 is initially upregulated in gastric antrum in the acute phase of infection, along with IL-1β and IL-6. Then, expression of TFF1 is gradually silenced when the infection becomes chronic and IFN-γ, CXCL5, and CXCL15 reach higher levels. Our data suggest that TFF1 might help cells to counteract bacteria colonization and the development of a chronic inflammation.

Helicobacter pylori infection is associated with reduced prevalence of colonic diverticular disease

BACKGROUND

Colonic diverticular disease is a common disorder with increasing incidence in Western societies. The intestinal microbiome may be among etiological factors. Helicobacter pylori may protect against some intestinal diseases, and incidence of H. pylori is decreasing in Western societies. Thus, we aimed to determine whether H. pylori is associated to decreased prevalence of registered colonic diverticular disease.

MATERIALS AND METHODS

In a historical cohort study, patients were enrolled from primary health care centers after urea breath test for H. pylori and then followed for a median of 6 years. The patient's diagnostic codes and country of birth were acquired from nationwide Danish administrative registries. We used logistic regression to compare prevalence and Cox regression to compare incidence of diverticular disease between H. pylori-positive and H. pylori-negative patients, adjusting for confounding variables.

RESULTS

Patients infected with H. pylori had lower prevalence of colonic diverticular disease (0.87% vs 1.14%, OR=0.62, 95% CI: 0.50-0.78). This phenomenon was observed whether we studied all registered diagnoses or only cases registered as primary diagnoses at discharge. After urea breath test, we observed no statistical difference in incidence rates of diverticular disease.

CONCLUSION

H. pylori is associated with reduced prevalence of colonic diverticular disease. The inverse association was absent after the urea breath test. Thus, we speculate that H. pylori may provide protection from colonic diverticular disease. Alternatively, H. pylori is a marker for other factors affecting disease development.

Targeting the Mucosal Barrier: How Pathogens Modulate the Cellular Polarity Network

The mucosal barrier is composed of polarized epithelial cells with distinct apical and basolateral surfaces separated by tight junctions and serves as both a physical and immunological barrier to incoming pathogens. Specialized polarity proteins are critical for establishment and maintenance of polarity. Many human pathogens have evolved virulence mechanisms that target the polarity network to enhance binding, create replication niches, move through the barrier by transcytosis, or bypass the barrier by disrupting cell-cell junctions. This review summarizes recent advances and compares and contrasts how three important human pathogens that colonize mucosal surfaces, Pseudomonas aeruginosa, Helicobacter pylori, and Neisseria meningitidis, subvert the host cell polarization machinery during infection.

Prevalence of Helicobacter pylori Infection in Samples of Gastric Biopsies

BACKGROUND

Helicobacter pylori (H. pylori) infection affects about 50% of the world population and its association with environmental factors and host properties is involved in gastric carcinogenesis. The study aimed to estimate the prevalence of H. pylori in samples of gastric mucosa biopsies, correlate the presence of the bacteria in the sample with the variables age, sex and origin, to identify the types of lesions found in patients with H. pylori, and to evaluate the association of the lesions with the region of the gastric mucosa.

METHODS

A cross-sectional, retrospective study was carried out in Aracaju, Sergipe, Brazil, from January 2013 to December 2015. A total of 45,206 gastric mucosal biopsies were obtained from patients submitted to upper gastrointestinal endoscopy. Of the reports evaluated, 12,909 met the inclusion criteria since they presented the patient's demographic data as well as the histopathological characteristics of gastric mucosal regions and positivity for H. pylori. Data were analyzed by IBM SPSS Statistic 20 and subjected to descriptive analyses (categorical variables) and inferential (Pearson's Qui-square and linear association tests) and multiple correspondence analyses. Significance level adopted 5%.

RESULTS

Of the total of 12,909 (28.6%) reports evaluated, 67% (8,647) came from urban areas and 64.5% (8,320) were female. The mean age (standard deviation (SD)) was 43 years, ranging from 8 to 100 years, prevailing between 21 and 60 years. Among the types of gastric mucosa analyzed, 95.5% (12,322) were of the antral mucosa. The absence of glandular atrophy, the mild infection intensity for H. pylori, the absence of metaplasia, the presence of foveolar hyperplasia and lymphoid follicles were statistically significant (P < 0.001) in this region. In the fundic region, the evidence of fibrinoleucocytic crust and lymphoid follicles was significant (P < 0.001). There was no evidence of associated ulcerated lesions or significant relationship with intestinal metaplasia in the antral mucosa, whereas the fundic mucosa had a strong association with lymphoid follicles. The prevalence of active H. pylori infection in this study was 30.93%.

CONCLUSION

Detection rate of H. pylori and its association with acute and chronic inflammation should be taken into account. The antral region has shown higher incidence and the presence of H. pylori was strongly associated with foveolar hyperplasia and lymphoid follicles.

The internalization of Helicobacter pylori plays a role in the failure of H. pylori eradication

BACKGROUND

Helicobacter pylori (H. pylori) internalization involves invasion of cells by the bacterium. Several studies have shown that H. pylori can invade human gastric epithelial cells, immune cells, and Candida yeast in vivo and in vitro. Whether bacterial invasion plays a role in eradication failure is unclear.

AIM

To investigate the relationship between H. pylori invasion of GES-1 cells and H. pylori eradication failure.

MATERIALS AND METHODS

Forty-two clinical strains isolated from H. pylori-positive patients with different outcomes after treatment with furazolidone-based therapy were examined (17 failures and 25 successes). The H. pylori strains were shown to be susceptible to amoxicillin and furazolidone, and the patients also exhibited good compliance. Genotyping was performed for cagA and vacA (s and m). The antibiotic susceptibility of the strains to amoxicillin, furazolidone, clarithromycin, metronidazole, and levofloxacin was determined by E-tests. The levels of H. pylori invasion of GES-1 cells were detected by gentamicin colony-forming unit assays.

RESULTS

The internalization level in the eradication success group was 5.40±5.78 × 10^-3  cfu/cell, and the median was 6.194 × 10^-3  cfu/cell; the internalization level in the eradication failure group was 8.98±5.40 × 10^-3  cfu/cell, and the median was 10.28 × 10^-3  cfu/cell. The eradication failure group showed a greater invasion level than the eradication success group (P<.05). No significant difference was observed between the susceptible strains and the resistant strains when the internalization levels were compared (P>.05).

CONCLUSIONS

The results showed that H. pylori invasion of the gastric epithelia might play a role in eradication failure.

Detection of Helicobacter pylori DNA in Formalin-Fixed Paraffin-Embedded Gastric Biopsies Using Laser Microdissection and qPCR

Molecular detection and analysis of virulence factors of Helicobacter pylori depends on the specificity of cell selection in the gastric biopsies. The laser microdissection (LM) instruments combine microscopy with laser cut sectioning. This combination allows one to choose only the bacteria that are in direct contact with epithelial cells in the gastric biopsy sample, avoiding those microorganisms attached to the mucus layer in the sample. The average concentration of DNA isolated from 25 cuts with selected bacteria is around 1.94 ng/μL, which is enough DNA to perform a qPCR protocol using real-time instruments to amplify 16sDNA or virulence factors like cagA or vacA. Consequently, the application of these technologies in the molecular analysis of Helicobacter pylori directly in contact with the surface of gastric epithelial cells is more precise and could yield better insights about the complex mechanisms of interactions between pathogen and host. Insights derived from research using the techniques described herein may in future facilitate prevention of infection or improved therapeutic options.

Structure-Activity Relationship for Sulfonamide Inhibition of Helicobacter pylori α-Carbonic Anhydrase

α-Carbonic anhydrase of Helicobacter pylori (HpαCA) plays an important role in the acclimation of this oncobacterium to the acidic pH of the stomach. Sulfonamide inhibitors of HpαCA possess anti-H. pylori activity. The crystal structures of complexes of HpαCA with a family of acetazolamide-related sulfonamides have been determined. Analysis of the structures revealed that the mode of sulfonamide binding correlates well with their inhibitory activities. In addition, comparisons with the corresponding inhibitor complexes of human carbonic anhydrase II (HCAII) indicated that HpαCA possesses an additional, alternative binding site for sulfonamides that is not present in HCAII. Furthermore, the hydrophobic pocket in HCAII that stabilizes the apolar moiety of sulfonamide inhibitors is replaced with a more open, hydrophilic pocket in HpαCA. Thus, our analysis identified major structural features can be exploited in the design of selective and more potent inhibitors of HpαCA that may lead to novel antimicrobials.