Diagnosis of Helicobacter pylori: What should be the gold standard?

Tailored susceptibility-guided therapy via gastric juice PCR for the first-line H. pylori eradication, a randomized controlled trial

BACKGROUND/PURPOSE

Clarithromycin-based standard triple therapy is still commonly adopted by 81.4% of physicians in real-world practice but yields low eradication rates. Therefore, we conducted this study to compare the efficacy of gastric juice-guided therapy for first-line eradication with the standard triple therapy, in order to provide an alternative to real-world practice.

METHODS

A total of 182 treatment-naïve Hp-infected patients were included and randomly allocated to either susceptibility-guided therapy (SGT) with gastric juice PCR or Clarithromycin-based standard triple therapy (STT) for 7 days.

RESULTS

The intention-to-treat eradication rates were 89% (81/91) in SGT and 75.8% in STT (p < 0.031). The per-protocol eradication rates were 91.0% (81/89) in SGT and 79.3% (69/87) in STT (p < 0.034). Among the subgroups of different antibiotic resistance, patients with SGT demonstrated superior eradication rates (91.7% vs 45.5%, p < 0.027) in the subgroup of both clarithromycin resistance and levofloxacin resistance.

CONCLUSION

This prospective randomized controlled trial demonstrated the reliable efficacy of susceptibility-guided therapy via gastric juice PCR for the first-line Hp eradication. In Asia-Pacific area, where standard triple therapy is still adopted by the majority of the physicians, it is a recommended alternative to overcome the increasing antibiotic resistance.

DNA diagnostics for reliable and universal identification of Helicobacter pylori

Reliable diagnostics are a major challenge for the detection and treatment of Helicobacter pylori (H. pylori) infection. Currently at the forefront are non-invasive urea breath test (UBT) and stool antigen test (SAT). Polymerase chain reaction (PCR) is not endorsed due to nonspecific primers and the threat of false-positives. The specificity of DNA amplification can be achieved by nested PCR (NPCR), which involves two rounds of PCR. If the primers are properly designed for the variable regions of the 16S rRNA gene, it is not difficult to develop an NPCR assay for the unambiguous identification of H. pylori. Elaborate NPCR for a 454 bp amplicon was validated on 81 clinical biopsy, stool, and saliva samples, each from the same individuals, and compared with available H. pylori assays, namely histology, rapid urease test, SAT, and ¹³C-UBT. The assay was much more sensitive than simple PCR, and it was equally sensitive in biopsy samples as the ¹³C-UBT test, which is considered the gold standard. In addition, it is sufficiently specific because sequencing of the PCR products exclusively confirmed the presence of H. pylori-specific DNA. However, due to the threshold and lower abundance, the sensitivity was much lower in amplifications from stool or saliva. Reliable detection in saliva also complicates the ability of H. pylori to survive in the oral cavity aside from and independent of the stomach. The reason for the lower sensitivity in stool is DNA degradation; therefore, a new NPCR assay was developed to obtain a shorter 148 bp 16S rRNA amplicon. The assay was validated on stool samples from 208 gastroenterological patients and compared to SAT results. Surprisingly, this NPCR revealed the presence of H. pylori in twice the number of samples as SAT, indicating that many patients are misdiagnosed, not treated by antibiotics, and their problems are interpreted as chronic. Thus, it is unclear how to properly diagnose H. pylori in practice. In the first approach, SAT or UBT is sufficient. If samples are negative, the 148 bp amplicon NPCR assay should be performed. If problems persist, patients should not be considered negative, but due to threshold H. pylori abundance, they should be periodically tested. The advantage of NPCR over UBT is that it can be used universally, including questionable samples taken from patients with achlorhydria, receiving proton pump inhibitors, antibiotics, bismuth compound, intestinal metaplasia, or gastric ulcer bleeding.

Helicobacter pylori Infection in Geriatric Patients: Current Situation and Treatment Regimens

Helicobacter pylori (H. pylori) has so far infected more than half the global population. It is the most important and controllable risk factor for gastric cancer. The elderly, who are at a higher incidence of the infection, are also commonly found to develop antibiotic resistance. The symptoms, diagnosis, clinical features (of gastric or extra-digestive diseases), and treatment of H. pylori infection in the elderly, are different from that in the non-elderly. Health conditions, including comorbidities and combined medication have limited the use of regular therapies in elderly patients. However, they can still benefit from eradication therapy, thus preventing gastric mucosal lesions and gastric cancer. In addition, new approaches, such as dual therapy and complementary therapy, have the potential to treat older patients with H. pylori infection.

Overview of Helicobacter pylori Infection: Clinical Features, Treatment, and Nutritional Aspects

Helicobacter pylori (H. pylori) is a 0.5-1 µm wide, 2-4 µm long, short helical, S-shaped Gram-negative microorganism. It is mostly found in the pyloric region of the stomach and causes chronic gastric infection. It is estimated that these bacteria infect more than half of the world's population. The mode of transmission and infection of H. pylori is still not known exactly, but the faecal-oral and oral-oral routes via water or food consumption are thought to be a very common cause. In the last three decades, research interest has increased regarding the pathogenicity, microbial activity, genetic predisposition, and clinical treatments to understand the severity of gastric atrophy and gastric cancer caused by H. pylori. Studies have suggested a relationship between H. pylori infection and malabsorption of essential micronutrients, and noted that H. pylori infection may affect the prevalence of malnutrition in some risk groups. On the other hand, dietary factors may play a considerably important role in H. pylori infection, and it has been reported that an adequate and balanced diet, especially high fruit and vegetable consumption and low processed salty food consumption, has a protective effect against the outcomes of H. pylori infection. The present review provides an overview of all aspects of H. pylori infection, such as clinical features, treatment, and nutrition.

Assessment of the diagnostic accuracy and relevance of a novel ELISA system developed for seroepidemiologic surveys of Helicobacter pylori infection in African settings

Beside diagnostic uncertainties due to the lack of a perfect gold standard test for Helicobacter pylori infection, the diagnosis and the prevalence estimation for this infection encounter particular challenges in Africa including limited diagnostic tools and specific genetic background. We developed and evaluated the accuracy of an enzyme-linked immunosorbent assay (ELISA) system tailored for H. pylori genetics in Africa (HpAfr-ELISA). Strains belonging to main genetic populations infecting Africans were exploited as sources for whole-cell antigens to establish in-house the ELISA system. A phase II unmatched case-control study explored the diagnostic accuracy of the HpAfr-ELISA using a training set of samples collected from dyspeptic patients from Kinshasa, the Democratic Republic of Congo (DRC) who had been tested with invasive standard tests (i.e., histology, culture, and rapid urease test) in 2017. Then the assay was cross-validated through a community-based survey assessing the prevalence of H. pylori and associated factors in 425 adults from Mbujimayi, DRC in 2018. Bayesian inferences were used to deal with statistical uncertainties of estimates (true prevalence, sensitivity, and specificity) in the study population. At its optimal cut-off-value 20.2 U/mL, the assay achieved an estimated sensitivity of 97.6% (95% credible interval [95%CrI]: 89.2; 99.9%) and specificity of 90.5% (95%CrI: 78.6; 98.5). Consistent outcomes obtained at repeated tests attested the robustness of the assay (negative and positive agreements always > 70%). The true prevalence of H. pylori was estimated 53.8% [95%CrI: 42.8; 62.7%]. Increasing age (adjusted odds ratio [aOR] > 1.0 [95% confidence interval (CI): > 1.0; 1.1]; p<0.001), overcrowding households (aOR = 3.2 [95%CI: 2.0; 5.1]; p<0.001), and non-optimal hand hygiene (aOR = 4.5 [95%CI: 2.0; 11.4]; p = 0.001) were independently associated with the H. pylori-seropositivity. The novel ELISA system has demonstrated good diagnostic accuracy and potential usefulness for management and mitigation strategies for H. pylori infection in African settings.

Helicobacter pylori infection and antibiotic resistance - from biology to clinical implications

Helicobacter pylori is a major human pathogen for which increasing antibiotic resistance constitutes a serious threat to human health. Molecular mechanisms underlying this resistance have been intensively studied and are discussed in this Review. Three profiles of resistance - single drug resistance, multidrug resistance and heteroresistance - seem to occur, probably with overlapping fundamental mechanisms and clinical implications. The mechanisms that have been most studied are related to mutational changes encoded chromosomally and disrupt the cellular activity of antibiotics through target-mediated mechanisms. Other biological attributes driving drug resistance in H. pylori have been less explored and this could imply more complex physiological changes (such as impaired regulation of drug uptake and/or efflux, or biofilm and coccoid formation) that remain largely elusive. Resistance-related attributes deployed by the pathogen cause treatment failures, diagnostic difficulties and ambiguity in clinical interpretation of therapeutic outcomes. Subsequent to the increasing antibiotic resistance, a substantial drop in H. pylori treatment efficacy has been noted globally. In the absence of an efficient vaccine, enhanced efforts are needed for setting new treatment strategies and for a better understanding of the emergence and spread of drug-resistant bacteria, as well as for improving diagnostic tools that can help optimize current antimicrobial regimens.

Current Helicobacter pylori Diagnostics

The high prevalence of Helicobacter pylori and the variety of gastroduodenal diseases caused by this pathogen necessitate the use of only accurate methods both for the primary diagnosis and for monitoring the eradication effectiveness. There is a broad spectrum of diagnostic methods available for detecting H. pylori. All methods can be classified as invasive or non-invasive. The need for upper endoscopy, different clinical circumstances, sensitivity and specificity, and accessibility defines the method chosen. This article reviews the advantages and disadvantages of the current options and novel developments in diagnostic tests for H. pylori detection. The progress in endoscopic modalities has made it possible not only to diagnose precancerous lesions and early gastric cancer but also to predict H. pylori infection in real time. The contribution of novel endoscopic evaluation technologies in the diagnosis of H. pylori such as visual endoscopy using blue laser imaging (BLI), linked color imaging (LCI), and magnifying endoscopy is discussed. Recent studies have demonstrated the capability of artificial intelligence to predict H. pylori status based on endoscopic images. Non-invasive diagnostic tests such as the urea breathing test and stool antigen test are recommended for primary diagnosis of H. pylori infection. Serology can be used for initial screening and epidemiological studies. The histology showed its value in detecting H. pylori and provided more information about the degree of gastric mucosa inflammation and precancerous lesions. Molecular methods are mainly used in detecting antibiotic resistance of H. pylori. Cultures from gastric biopsies are the gold standard and recommended for antibiotic susceptibility tests.

Diagnosis of Helicobacter pylori Infection in a Routine Testing Workflow: Effect of Bacterial Load and Virulence Factors

Reliable diagnostic methods are mandatory for effective management of Helicobacter pylori infection. Histology and culture are the most common invasive methods in current practice, even if molecular methods are gaining in importance. The performance of these conventional methods varies significantly. We conducted a retrospective study of 1540 adults and 504 children with gastric biopsies taken during endoscopy to assess the impact of bacterial load and the cagA virulence factor on the performance of H. pylori infection testing. The association between virulence and histology findings was also investigated. With 23S rRNA qPCR confirmed by glmM amplification as the gold standard, culture and histology had lower sensitivity, 74.4% and 73.3%, respectively. However, their sensitivity was enhanced (>90%) in biopsies with high bacterial load (qPCR Ct < 30). Positive cagA status of the strain was associated with high bacterial load (94.9%), thus resulting in more frequent positive culture (94.3%) and H. pylori histology detection (91.7%) and more severe lesions on histology (p < 0.001). Conversely, the cagA status of the strains was negative in 110/119 (92.4%) of biopsies with low bacterial load (qPCR Ct < 30), 82/90 (91.1%) with negative H. pylori histology detection and 119/131 (90%) with negative culture findings (p < 0.001). This study highlights the low sensitivity of conventional culture and histology that may lead to false negative diagnosis if used alone. H. pylori quantification associated with cagA genotyping in routine workflow are essential for a sensitive and reliable diagnosis, to identify patients at high risk and to manage eradication therapies.

Vonoprazan vs lansoprazole for the treatment of artificial gastric ulcer after endoscopic submucosal dissection: a prospective randomized comparative study

Vonoprazan is a potent inhibitor of gastric acid secretion and may have better response than proton pump inhibitors (PPIs) in the treatment of endoscopic submucosal dissection induced artificial ulcers. However, reported outcomes remain controversial. In this study, we conducted a prospective, randomized comparative trial to evaluate healing effects of vonoprazan and lansoprazole on endoscopic submucosal dissection (ESD)-induced ulcers. We enrolled 216 patients who underwent endoscopic submucosal dissection for early gastric neoplasms. They were randomly divided into vonoprazan (20 mg/day) and lansoprazole (30 mg/day) groups. The primary endpoint was the reduction rate of ulcer and complete healing (scar) ratio of ESD-induced ulcers at 4 and 8 weeks. Finally, 101 patients of the vonoprazan group and 95 patients of the lansoprazole group were included in the analysis. There were no significant differences in the reduction rate between the vonoprazan and lansoprazole groups at either timepoint (4 weeks, 94.0 vs 93.4%; 8 weeks, 99.8 vs 99.9%, respectively). The complete healing ratio at 4 and 8 weeks did not differ significantly between the vonoprazan and lansoprazole groups (4 weeks, 11.9 vs 12.6%; 8 weeks, 87.1 vs 86.3%, respectively). In the anti-H. pylori-antibody negative or positive patients, there were no significant differences in the reduction rate and complete healing ratio between the vonoprazan and lansoprazole groups. Regardless of treatment choice, the overall complete healing ratio at 8 weeks was significantly higher in the anti-H. pylori-antibody negative patients than the positive patients (p = 0.006). The healing effects of vonoprazan on ESD-induced ulcers were comparative to those of lansoprazole.

Non-Invasive Colorimetric Magneto Loop-Mediated Isothermal Amplification (CM-LAMP) Method for Helicobacter pylori Detection

More than half the world's population is thought to be infected with Helicobacter pylori. Although the majority of infected people are asymptomatic, H. pylori infection may cause gastric ulcers and deadly gastric cancer. Owing to the difficulty and invasiveness of current routine culture and diagnostic methods, a highly sensitive and specific noninvasive assay for H. pylori is of interest. This study highlighted the design and performance of a colorimetric magneto loop-mediated isothermal amplification (CM-LAMP) assay to detect H. pylori in spiked saliva samples. LF primers were coated on magnetic nanoparticles by carbodiimide-induced immobilization and functionally used for solidphase amplification. During the LAMP reaction at 66°C, biotin-tagged FIPs were incorporated into LAMP amplicons. The colorimetric signal developed after the addition of NeutrAvidin horseradish peroxidase conjugate (NA-HRP) and ABTS. None of the tested microorganisms, including closely related bacteria, was shown positive by the CM-LAMP assay except H. pylori isolates. This novel platform was highly specific and 100-fold more sensitive (40 CFU/ml or 0.2 CFU per reaction) than the PCR and conventional LAMP assays for the detection of H. pylori in spiked saliva. Our results demonstrated the feasibility of using this noninvasive molecular diagnostic test to detect H. pylori in saliva samples.

Helicobacter pylori infection is correlated with the incidence of erosive oral lichen planus and the alteration of the oral microbiome composition

BACKGROUND

Oral lichen planus (OLP), a common clinical oral disease, is associated with an increased risk of malignant transformation. The mechanism underlying the pathogenesis of OLP is unknown. Oral dysbacteriosis is reported to be one of the aetiological factors of OLP. Although Helicobacter pylori infection is associated with various oral diseases, the correlation between H. pylori infection and OLP is unclear. This study aimed to investigate the effect of H. pylori infection on OLP pathogenesis and oral microbiome composition in the Chinese population, which has a high incidence of H. pylori infection.

RESULT

In this study, saliva samples of 30 patients with OLP (OLP group) and 21 negative controls (NC group) were collected. H. pylori infection was detected using the carbon-13-labeled urea breath test (UBT). The saliva samples were divided into the following four groups based on the H. pylori status: H. pylori-positive OLP (OLP+), H. pylori-positive NC (NC+), H. pylori-negative OLP (OLP-), and H. pylori-negative NC (NC-). Oral microbiome compositions were significantly different between the OLP and NC groups and between the OLP- and OLP+ groups. Compared with those in the OLP- group, those in the OLP+ group had a higher incidence of erosive OLP and higher levels of salivary cytokines. In contrast, the oral microbiome composition and cytokine levels were not significantly different between the NC- and NC+ groups.

CONCLUSIONS

This is the first report to demonstrate that H. pylori infection is significantly correlated with the pathogenesis of erosive OLP.

Unraveling antimicrobial resistance in Helicobacter pylori: Global resistome meets global phylogeny

BACKGROUND

Antimicrobial resistance (AMR) in Helicobacter pylori is increasing globally and can result in treatment failure and inappropriate antibiotic usage. This study used whole genome sequencing (WGS) to conduct an analysis of the H. pylori resistome and phylogeny.

MATERIALS/METHODS

A total of 1040 H. pylori isolate sequences were retrieved. Analysis was conducted via an in-house bioinformatics pipeline targeting point mutations in selected genes frequently associated with AMR (pbp1A, 23S rRNA, gyrA, rdxA, frxA, and rpoB) and phylogenomic analyses using core genome multilocus sequence typing (cgMLST).

RESULTS

Phylogenomic analysis revealed a notable geographical clustering of H. pylori genomes across world regions, but large distances of more than 1000 loci between isolates on individual branches were observed. Resistome analysis revealed the prevalence of common mutations which have previously been found to correlate with phenotypic antibiotic resistance; the most common point mutations for each gene were S589G (pbp1A, 48.8% of perfect aligned sequences), A2143G (23S rRNA, 27.4% of perfectly aligned sequences), N87 K\I\Y (gyrA, 14.7% of perfectly aligned sequences), R131K (rdxA, 65.7% of perfectly aligned sequences), and C193S (frxA, 62.6% of perfectly aligned sequences).

CONCLUSIONS

This is the largest study to date featuring the global phylogeny of H. pylori in conjunction with a global snapshot of the H. pylori resistome based on >1000 genomes. Further analyses that combine WGS and phenotypic methods will provide further understanding of the association between the mutations and resistance.

Prevalence of Helicobacter pylori among residents and their environments in the Nara prefecture, Japan

BACKGROUND

Chronic infection with Helicobacter pylori, specifically cagA-positive strains, is associated with gastric cancer. Thus, measures to prevent H. pylori infection are required. This study was conducted to clarify the prevalence of H. pylori in the community to identify the infection source and comprehensively assess the risk of H. pylori infection.

METHODS

We collected 90 human faecal samples and 73 environmental samples (water, vegetable, and animal faecal samples) from the residents in an area with a high incidence of gastric cancer in Japan. Polymerase chain reaction assay was performed to detect the glmM housekeeping gene and the cagA virulence gene of H. pylori. A questionnaire survey was conducted, and the responses were analyzed statistically.

RESULTS

The glmM gene was detected in 18 of 90 (20%) faecal samples obtained from residents; among them, the cagA gene was detected in 33.3% (6/18), and in all who had undergone eradication therapy. H. pylori was not detected in environmental samples. However, contact with dogs (OR 3.89, 95% CI 1.15-13.15, P < 0.05) was associated with higher odds for glmM gene positivity in the questionnaire survey.

CONCLUSIONS

The prevalence of H. pylori and cagA-positive strains among the residents was low. However, the study results suggest a correlation between recurrent infection and cagA-positive H. pylori strains. Although H. pylori genes were not detected in living environments, an association between contact with dogs and a glmM positive status was revealed. Further investigations targeting community-dwelling healthy people and their living environments would be required for H. pylori infection control.

Prevalence of Helicobacter pylori Infection in Military Personnel from Northeast China: A Cross-Sectional Study

PURPOSE

Helicobacter pylori infection is an important cause of peptic ulcer disease and gastric cancer. Current knowledge regarding epidemiology of H. pylori infection in military personnel has insufficiently been updated. This cross-sectional study aimed to estimate the prevalence of H. pylori infection in military personnel and to compare the prevalences in military and civilian groups.

PATIENTS AND METHODS

We retrospectively enrolled the subjects who underwent ¹⁴C-urea breath tests at the Department of Gastroenterology of the General Hospital of Northern Theater Command between January 2017 and July 2020. Subjects were divided into military and civilian groups. H. pylori infection and major endoscopic findings were reviewed.

RESULTS

Overall, 23,496 subjects were eligible, including 2282 subjects in the military group and 21,214 subjects in the civilian group. In the overall analysis, the prevalence of H. pylori infection was not significantly different between military and civilian groups (33.9% versus 34.4%, P=0.592). In the population aged 17-25 years, the prevalence of H. pylori infection was significantly higher in the military group than in the civilian group (35.6% versus 25.9%, P=0.001). Both ¹⁴C-UBT and endoscopy were performed in 547 inpatients, including 83 military inpatients and 464 civilian inpatients. There was a significantly higher prevalence of H. pylori in inpatients with peptic ulcer and/or gastric cancer than in those without (65.5% versus 41.4%, P=0.001).

CONCLUSION

Among the adolescent population, H. pylori infection may be more common in military personnel as compared to the civilians. Well-designed prospective studies should be required to validate such a high prevalence and to explain its potential causes.

<p>Observation of Changes in <em>Helicobacter pylori</em> Antigen and Antibody Positivity According to Non-Invasive Tests Before and After <em>Helicobacter pylori</em> Eradication Therapy in Symptomatic Patients</p>

Background

Non-invasive tests can help with the diagnosis of Helicobacter pylori (H. pylori) infection and in determining patient prognosis following H. pylori eradication therapy. The aim of the study was to detect H. pylori antigens in the stool in symptomatic patients and to observe changes in the antigen test results following H. pylori eradication therapy.

Methods

A prospective study was conducted. Blood, urine and stool samples were collected from 62 dyspeptic patients. Anti-H. pylori IgM and IgG antibodies were detected in the serum by ELISA, anti-H. pylori IgG antibodies were detected in the urine by ICT and H. pylori antigens were detected in the stool by ELISA. Among the 62 patients, 39 (62.90%) were positive with all three methods. These 39 patients were asked to complete a 2-week course of medication and return after 6 weeks following completion of therapy to undergo repeated tests. In total, 3 dropped out of the study.

Results

Among the 62 dyspeptic patients, 41 (66.13%) were positive for serum IgG according to ELISA, 39 (62.90%) were positive for urine IgG according to ICT, 8 (12.90%) were positive for serum IgM according to ELISA, and 42 (67.74%) were positive for HpSA according to ELISA. After eradication therapy, 18 (50.00%) patients were positive for serum IgG, 19 (52.78%) were positive for urine IgG, 4 (11.11%) were positive for serum IgM and 5 (13.88%) were positive for HpSA. The difference in HpSA positivity before and after eradication therapy was statistically significant (P <0.05).

Conclusion

This study involved non-invasive procedures that can be used as first-line screening tools for the detection of active H. pylori infection to observe the role of HpSA test in diagnosis and assessment of prognosis following eradication therapy for H. pylori.

Evaluation of Better Staining Method among Hematoxylin and Eosin, Giemsa and Periodic Acid Schiff-Alcian Blue for the Detection of Helicobacter pylori in Gastric Biopsies

Background

This study was undertaken to evaluate the preferred method (Giemsa or periodic acid Schiff-Alcian blue [PAS-AB] stains) of detecting Helicobacter pylori (H. pylori) in gastric mucosal biopsies in terms of sensitivity, specificity and applicability. To the best of my knowledge, this is the first report comparing Giemsa and PAS-AB staining for the detection of H. pylori in such biopsies.

Methods

The formalin-fixed paraffin-embedded blocks of 49 gastric biopsies from different patients were collected from the archive of anatomical pathology at King Abdulaziz Medical City, National Guard, Riyadh, Saudi Arabia. From each block, three slides were prepared and analysed using the hematoxylin and eosin (H&E), Giemsa and PAS-AB stains to detect the presence/absence of H. pylori, and the results were compared in terms of sensitivity, specificity and applicability.

Results

The majority of the biopsies in this study showed antrum-type gastric mucosa. Only 15 biopsies showed active gastritis, whereas the rest showed chronic gastritis. Three biopsies showed intestinal metaplasia. All were detected by PAS-AB stain, but only two-thirds were detected by H&E stain. Fifteen gastric biopsies showed H. pylori infection in general and in 13 of them, active gastritis cases were discovered. Fourteen out of these 15 H. pylori infection cases were detected by Giemsa stain, whereas only 13 cases were detected by H&E stain. PAS-AB stain showed the worst results since it demonstrated only 40% sensitivity and 67.65% specificity in H. pylori detection.

Conclusion

Giemsa stain has better sensitivity and specificity in gastric H. pylori infection detection than PAS-AB. Therefore, using PAS-AB stain to detect H. pylori infection is not recommended.

Detection of Helicobacter pylori in gastric cancer tissue through histopathology, immunohistochemistry and real-time reverse transcription-PCR

Aim: Helicobacter pylori is usually detected based on hematoxylin-eosin (H-E) features, but, immunohistochemistry (IHC) and real-time PCR (RT-PCR) are more precise in chronic-gastritis. We evaluated the relevance of these tests in Peruvian gastric cancer samples. Materials & methods: We performed and evaluated H-E, IHC staining and RT-PCR in 288 gastric tumors. Slides were independently evaluated by three pathologists. Results: H. pylori was detected in 167/287 through H-E, 140/288 through IHC and 175/288 through RT-PCR, and positive-status were associated (p < 0.001). H. pylori detection by H-E had a good concordance with IHC (kappa index = 0.632) but poor with RT-PCR (kappa index = 0.317). Higher median gene-copies were found in high H. pylori density through H-E or IHC (p < 0.001). Conclusion: H-E evaluation is accurate in gastric cancer, and IHC and RT-PCR can complement its results.

Noninvasive Helicobacter pylori Diagnostic Methods in Indonesia

Although the prevalence of Helicobacter pylori infection in Indonesia is lower than that in other countries, H. pylori is still an essential pathogen associated with severe gastric mucosal damage and dyspeptic symptoms. Invasive diagnostic methods are not ideal due to the lack of endoscopic centers and high costs without full coverage by social insurance. Among the noninvasive methods, the urea breath test is widely available in Indonesia and has been suggested as the primary option to ensure the successful eradication of H. pylori. There has been no local validation for the urea breath test utilizing ¹³C or ¹⁴C. The stool antigen test is inexpensive and suitable for use in active infections before and after eradication; however, customs and habits are obstacles to delivering fresh stool on time. Only polyclonal antibodies and qualitative stool antigen test kits with low sensitivity are available. Serology is a widely validated method and has good accuracy, but it cannot distinguish between active and inactive infections. According to our observations, serology is the main choice of experts and patients, as it is simple, inexpensive and widely known. The urine test is an alternative for reducing costs and endoscopic workload, with high accuracy but low sensitivity. Further studies are necessary to prove the validity of the urine test to be used throughout Indonesia, especially in areas with a low prevalence of H. pylori infection. In conclusion, the validated urea breath test and the stool antigen test are considered noninvasive practical approaches for the detection of H. pylori infection in Indonesia, with serological and urine tests as alternatives.

Changes in Seroprevalence of Helicobacter pylori Infection over 20 Years in Jinju, Korea, from Newborns to the Elderly

BACKGROUND

The objective of this study was to examine changes in the prevalence of cytotoxic-associated gene A (CagA) positive Helicobacter pylori infection in Jinju, Korea, over the last 20 years.

METHODS

Three cross-sectional analyses were conducted concurrently. A total of 1,305 serum samples were collected from 1994-1995, 2004-2005, and 2014-2015, respectively. The presence of immunoglobulin (Ig) G, IgA, and IgM antibodies against H. pylori CagA protein was examined by western blotting.

RESULTS

Overall, seropositivity for anti-CagA IgG antibody was significantly decreased from 63.2% to 42.5% over the last 20 years (P < 0.001). Anti-CagA IgG seropositivities in children and young adults aged 10-29 years decreased from 1994 (60.0%-85.0%) to 2015 (12.5%-28.9%). The age when plateau of increasing IgG seropositivity was reached in each study period shifted from the 15-19 year-old group in 1994-1995 (85.0%) to the 40-49 year-old group in 2014-2015 (82.5%). Overall seropositive rates of anti-CagA IgA and IgM antibodies did not change significantly either over the last 20 years.

CONCLUSION

H. pylori infection rate in children and young adults declined over 20 years in Jinju, probably due to improved sanitation, housing, or economy.

Helicobacter pylori patient isolates from South Africa and Nigeria differ in virulence factor pathogenicity profile and associated gastric disease outcome

Helicobacter pylori is a gram-negative, spiral-shaped bacterial pathogen and the causative agent for gastritis, peptic ulcer disease and classified as a WHO class I carcinogen. While the prevalence of H. pylori infections in Africa is among the highest in the world, the incidence of gastric cancer is comparably low. Little is known about other symptoms related to the H. pylori infection in Africa and the association with certain phenotypes of bacterial virulence. We established a network of study sites in Nigeria (NG) and South Africa (ZA) to gain an overview on the epidemiological situation. In total 220 isolates from 114 patients were analyzed and 118 different patient isolates examined for the presence of the virulence factors cagA, vacA, dupA, their phylogenetic origin and their resistance against the commonly used antibiotics amoxicillin, clarithromycin, metronidazole and tetracycline. We report that H. pylori isolates from Nigeria and South Africa differ significantly in their phylogenetic profiles and in their expression of virulence factors. VacA mosaicism is intensive, resulting in m1-m2 vacA chimeras and frequent s1m1 and s1m2 vacA subtypes in hpAfrica2 strains. Gastric lesions were diagnosed more frequent in Nigerian versus South African patients and H. pylori isolates that are resistant against one or multiple antibiotics occur frequently in both countries.

Application of 16S rRNA gene sequencing in Helicobacter pylori detection

Helicobacter pylori is one of the major stomach microbiome components, promoting development of inflammation and gastric cancer in humans. H. pylori has a unique ability to transform into a coccoidal form which is difficult to detect by many diagnostic methods, such as urease activity detection, and even histopathological examination. Here we present a comparison of three methods for H. pylori identification: histological assessment (with eosin, hematoxylin, and Giemsa staining), polymerase chain reaction (PCR) detection of urease (ureA specific primers), and detection by 16S rRNA gene sequencing. The study employed biopsies from the antral part of the stomach (N = 40). All samples were assessed histologically which revealed H. pylori in eight patients. Bacterial DNA isolated from the bioptates was used as a template for PCR reaction and 16S rRNA gene sequencing that revealed H. pylori in 13 and in 20 patients, respectively. Thus, 16S rRNA gene sequencing was the most sensitive method for detection of H. pylori in stomach biopsy samples.

Diagnostic reliability of nested PCR depends on the primer design and threshold abundance of Helicobacter pylori in biopsy, stool, and saliva samples

BACKGROUND

The aim of this work was to find a reliable nested PCR for the detection of Helicobacter pylori in biopsy, stool, and saliva specimens.

MATERIALS AND METHODS

Novel nested PCR was elaborated and validated on 81 clinical biopsy, stool, and saliva samples from the same individual and compared to available H pylori assays: histology, rapid urease test (RUT), stool antigen test (SAT), ¹³ C-urea breath test (UBT).

RESULTS

The efficiency and selectivity of 17 published nested polymerase chain reactions (PCR) available for Helicobacter pylori detection were re-evaluated. Most of them had serious limitations and mistakes in primer design. Hence, we elaborated a nested PCR for the unambiguous identification of H pylori in biopsy, stool, and saliva, using primers targeted to variable regions of the 16S ribosomal RNA (rRNA) gene. Moreover, we determined the detection limit by adding a known number of cells. This number was as low as 0.5 cells in a PCR vial, but due to the DNA isolation procedures, it required 1-5 × 10³ cells/g or ml of specimen. The sensitivity for nested PCR from stomach biopsies was on the same scale as ¹³ C-UBT (93.8%), but it was much lower in amplifications from stool (31.3%). Sequencing of all obtained PCR products exclusively confirmed H pylori-specific DNA sequences.

CONCLUSIONS

Elaborated nested PCR assay can serve as an auxiliary method for controversial samples (patients with bleeding or taking proton-pump inhibitor) in laboratories with basic equipment. The sensitivity and specificity for the amplification from gastric biopsies was almost like ¹³ C-UBT. Despite the good sensitivity, the threshold occurrence and the ability to survive in the oral cavity aside from and independent of the stomach is the reason why H pylori DNA cannot be reliably detected in saliva, stool, and some biopsy samples.

Transformation of Helicobacter pylori into Coccoid Forms as a Challenge for Research Determining Activity of Antimicrobial Substances

Morphological variability is one of the phenotypic features related to adaptation of microorganisms to stressful environmental conditions and increased tolerance to antimicrobial substances. Helicobacter pylori, a gastric mucosal pathogen, is characterized by a high heterogeneity and an ability to transform from a spiral to a coccoid form. The presence of the coccoid form is associated with the capacity to avoid immune system detection and to promote therapeutic failures. For this reason, it seems that the investigation for new, alternative methods combating H. pylori should include research of coccoid forms of this pathogen. The current review aimed at collecting information about the activity of antibacterial substances against H. pylori in the context of the morphological variability of this bacterium. The collected data was discussed in terms of the type of substances used, applied research techniques, and interpretation of results. The review was extended by a polemic on the limitations in determining the viability of coccoid H. pylori forms. Finally, recommendations which can help in future research aiming to find new compounds with a potential to eradicate H. pylori have been formulated.

Community pharmacy-based H. pylori screening for patients with uninvestigated dyspepsia

BACKGROUND

Helicobacter pylori is identified by the World Health Organization as a major risk factor of gastritis, peptic ulcer disease and gastric carcinomas. As point-of-care screening technology becomes more widely available, pharmacists are ideally suited to use this tool to screen patients with H. pylori infection.

PURPOSE

The objective of this study was to evaluate the feasibility of implementing point-of-care screening technology for H. pylori into community pharmacy practice and to assess the number of patients who are positively identified as a result of testing.

METHODS

Three pharmacies in Toronto, Ontario, offered H. pylori screening as part of their clinical programs. Pharmacists enrolled patients with symptoms of dyspepsia and/or receiving acid suppressant therapy for >6 weeks. Decision to screen was based on the Canadian Helicobacter Study Group Consensus (CHSG). Patients were screened using the Rapid Response H. pylori test.

RESULTS

Seventy-one patients were recruited, with a mean age of 46.3 years. Patients were ethnically diverse, with a significant proportion (59.2%) identified as being born outside of North America, including Asia (26.8%), Africa (9.9%), the Middle East (7%), Europe (9.9%) and South and Central America (5.6%). Overall, the detection rate of H. pylori infection was 21%. North Americans had the lowest incidence of an undiagnosed H. pylori infection (6.9%). Europeans (28.6%), Middle Easterners (20%) and Asians (21.1%) had a moderate incidence, followed by the highest prevalence in those of African descent (71.4%).

CONCLUSION

These results highlight the readiness of community pharmacists to adopt H. pylori screening into practice and to leverage this novel technology to positively identify and treat undiagnosed H. pylori infection. Can Pharm J (Ott) 2020;153:xx-xx.

Eradication Treatment of Helicobacter pylori Infection Based on Molecular Pathologic Antibiotic Resistance

Background

Unfortunately, the eradication rate of Helicobacter pylori (H. pylori) treatment is markedly decreasing in recent years and the major reason is antibiotic resistance. Our study was designed to determine the effect and safety of H. pylori eradication treatment based on the molecular pathologic antibiotic resistance.

Methods

261 patients were analyzed retrospectively, including 111 patients who were treated for the first time (one group as First-treated) and 150 patients who failed at least once in bismuth quadruple therapy (another group as Re-treatment). Antibiotic resistance was examined by Real-time PCR detection and conventional PCR and sequencing method. The eradication rate (ER) was compared per intention to treat (ITT) and per protocol (PP) between the two groups.

Results

The resistance rates to amoxicillin, clarithromycin, fluoroquinolone and tetracycline were 5.5%, 42.1%, 41.7% and 12.9% in the 111 first-treated patients, and 11.7%, 79.7%, 70.7% and 30.0% in the 150 re-treatment patients. The ERs in the ITT and PP analyses were 92.79% (95% CI, 87.98–97.60%, n=111) and 98.10% (95% CI, 95.48–100%, n=105), respectively, in the first-treated patients and 90.67% (95% CI, 86.01–95.32%, n=150) and 95.10% (95% CI, 91.57–98.64%, n=143), respectively, in the re-treatment patients. No significant differences were shown in the ERs between two group patients, and no serious adverse events were found.

Conclusion

H. pylori eradication treatment based on molecular pathologic antibiotic resistance showed good effect and safety in both first and re-treated patients.

The association between chronic periodontitis and oral Helicobacter pylori: A meta-analysis

BACKGROUND

Epidemiological studies have shown that gastrointestinal Helicobacter pylori (H. pylori) infection is the main cause of chronic gastritis, but the relation between oral H. pylori and chronic periodontitis (CP) remains uncertain. A meta-analysis of published papers was performed to elucidate the correlation between oral H. pylori and CP.

METHOD

To perform this meta-analysis, we searched papers published from 2000 to 2018 on PubMed, OVID, Springer Link, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biology Medicine search engines. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the correlation between H. pylori and CP were estimated. Heterogeneity, publication bias and subgroup analyses were also conducted.

RESULTS

A total of 918 papers on oral H. pylori and CP were collected, and 11 papers were in accordance with the inclusion criteria. Oral H. pylori was suggested to be correlated with CP. The results indicated that a H. pylori-positive state significantly increased the risk of CP 3.42 times (OR = 3.42; 95% CI = 2.71-4.31). A diagnostic test using polymerase chain reaction (PCR) showed a higher prevalence of H. pylori (OR = 3.70; 95% CI = 2.66-5.14) than did that using the rapid urease test (RUT) (OR = 3.13; 95% CI = 2.26-4.34).

CONCLUSIONS

This paper demonstrated that CP was potentially correlated with oral H. pylori in adults and that oral H. pylori may be a possible risk factor for CP.

Signet ring cell carcinoma and poorly differentiated adenocarcinoma in a gastric hyperplastic polyp with lymphatic invasion: A case report

•

Gastric hyperplastic polyps can turn into adenocarcinoma.

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Very rarely they change into poorly differentiated adenocarcinoma.

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There have been no reports of these polyps transformed into poorly differentiated adenocarcinoma with lymphatic invasion.

Introduction

Gastric hyperplastic polyps are common stomach lesion and these polyps are generally benign. However, they can undergo malignant transformation. Most reported cases of malignant transformation of gastric hyperplastic polyps have been to well or moderately differentiated adenocarcinoma, and those transformed into poorly differentiated adenocarcinoma are extremely rare. No case has been reported that has changed to diffuse type adenocarcinoma with lymphatic invasion.

Presentation of case

A 48-year-old woman presented with worsening anemia. A polyp was seen in the gastric cardia seven years prior to presentation. Helicobacter pylori infection was also found at that time. She underwent upper gastrointestinal endoscopy and biopsy of the polyp revealed signet ring cell carcinoma. Total gastrectomy was performed due to concern about possible invasion into the submucosal layer and there was no evidence of distant metastases. Histologic examination revealed both poorly differentiated adenocarcinoma and signet ring cell carcinoma surrounded by hyperplastic epithelium at the head of the polyp. Lymphatic invasion was also found, and malignant cells were limited to the mucosa.

Discussion

Gastric hyperplastic polyps are commonly associated with chronic gastritis which is related to Helicobacter pylori infections. Gastric hyperplastic polyps are generally benign and rarely undergo malignant transformation to adenocarcinoma with differentiated histology. The gastric hyperplastic polyp in this patient transformed to poorly differentiated adenocarcinoma with lymphatic invasion.

Conclusion

Even small polyps may become poorly differentiated adenocarcinoma with invasion, so close follow-up or endoscopic resection are recommended as well as eradication of Helico Pylori infection when appropriate.

Value of CIM, CLO Test and Multiplex PCR for the Diagnosis of Helicobacter Pylori Infection Status in Patients with Gastritis and Gastric Ulcer

Objective:

To assess the value of Current Infection Marker (CIM) test, Campylobacter-Like Organism (CLO) test, and the multiplex polymerase chain reaction test (PCR) for the diagnosis of Helicobacter pylori (H. pylori) infection in a Vietnamese population.

Methods:

Targeted suitable patients were recruited. CIM test, CLO test and multiplex PCR were used to diagnose for H. pylori infection. Patients were considered positive for H. pylori when at least two of the three tests were positive. The performance of each of the three tests was compared to the H. pylori positive populations as defined.

Result:

Amongst 201 patients with a mean age of 40.5 (range, 18-74) years, there were 115 females and 86 males. Of the 201 patients, 107 (53.2%) were diagnosed as H. pylori positive according to the defined criteria. The positive patients obtained with CLO test, CIM test and multiplex PCR were 38.3%, 59.2% and 72.1%, correspondingly. The full performance of the three tests as highlighted in order as above were 85.07%, 83.08% and 81.09%, respectively. The positive rate of CLO test was the lowest, with 38.3% positive, but this method was the most accurate, with the accuracy of 85.07%. This suggested that CLO test has the highest specificity among the three. The sensitivity, specificity, positive, negative predictive values and accuracy of the CLO / CIM / multiplex PCR tests were 71.96% / 89.72% / 100%, 100% / 75.53% / 59.57%, 100% / 80.67% / 73.79%, 75.81% / 86.59% / 100%, and 85.07% / 83.08% / 81.09%, respectively.

Conclusion:

All the three methods have high accuracy for the diagnosis of H. pylori infection in the Vietnamese population with gastritis and gastric ulcers. These tests can be employed in the clinical settings for the Vietnamese population. CLO test should be used in combination with the other tests to reduce false-negative results.

DETECTION OF HELICOBACTER PYLORI INFECTION IN CHRONIC GASTRITIS BIOPSY SPECIMEN USING WARTHIN-STARRY AND MODIFIED GIEMSA STAIN IN DR SOETOMO HOSPITAL SURABAYA

Helicobacter pylori is a bacteria that commonly cause chronic gastritis. Identification of its infection is essential for eradication treatment. Detection of H.pylori bacteria in gastric biopsy specimen by histology method is a diagnostic tool that widely accepted because it is superior to serology examination. Although the bacteria can be seen in routinely Hematoxylin-Eosin staining, Modified Giemsa and Whartin Starry stain was commonly used to see the bacteria more clearly. Whartin Starry stain gives more contrast to the bacteria but modified Giemsa stain is preferable at many centres because it is a cheaper and simpler method. This study want to find out whether there is difference result in detection of H.pylori using these two stains. Material and methods. Paraffin blocks from gastric biopsy patients with chronic gastritis were retrieved from Anatomic Pathology Laboratory Dr.Soetomo Hospital Surabaya in the year 2017. Thirty paraffin blocks were taken randomly and were made into microscopic slides for staining with Warthin-starry and modified Giemsa stain concomitantly. Results. Specimen with Whartin starry stain show 19 out of 30 were positive for H.pylori while modified-Giemsa stain found 16 out of 30 specimen were positive for H.pylori. Whartin Starry stain use silver reagent to coat the bacteria so it become more clearly visible. Conclusion. Detection of H.pylori Warthin-starry stain give more chance to obtain positive result because it use silver technique that coat the bacteria making it is more clearly visible in microscopic examination.   

Pathogenesis and clinical management of Helicobacter pylori gastric infection

Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. However, its prevalence varies among different geographic areas, and is influenced by several factors. The infection can be acquired by means of oral-oral or fecal-oral transmission, and the pathogen possesses various mechanisms that improve its capacity of mobility, adherence and manipulation of the gastric microenvironment, making possible the colonization of an organ with a highly acidic lumen. In addition, H. pylori presents a large variety of virulence factors that improve its pathogenicity, of which we highlight cytotoxin associated antigen A, vacuolating cytotoxin, duodenal ulcer promoting gene A protein, outer inflammatory protein and gamma-glutamyl transpeptidase. The host immune system, mainly by means of a Th1-polarized response, also plays a crucial role in the infection course. Although most H. pylori-positive individuals remain asymptomatic, the infection predisposes the development of various clinical conditions as peptic ulcers, gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. Invasive and non-invasive diagnostic methods, each of them with their related advantages and limitations, have been applied in H. pylori detection. Moreover, bacterial resistance to antimicrobial therapy is a major challenge in the treatment of this infection, and new therapy alternatives are being tested to improve H. pylori eradication. Last but not least, the development of effective vaccines against H. pylori infection have been the aim of several research studies.

E-Cadherin Protein as a Potential Marker for Gastric Cancer and Its Association with Helicobacter Pylori- Induced Gastritis and Gastric Ulcer

BACKGROUND

Gastric cancer is still the main health threat being the third leading cause of deaths from cancers in the world. The major risk behind the gastric cancer is that it remains asymptomatic in the early stages and in (97%) cases it metastasizes to other organs. Gastric cancer is a multifactorial disease in which Helicobacter pylori (H. pylori) has been known as a risk factor. However, patients with gastritis, especially atrophic gastritis and gastric ulcer have been shown to be at an increased risk for developing gastric cancer.

METHODS

This study included measuring the serum levels of E-Cadherin protein, carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) in 30 patients diagnosed with gastritis, 20 gastric ulcer patients, 20 gastric cancer patients and in 20 healthy volunteers serving as the control group.

RESULTS

Infection with H. pylori was diagnosed by serology (IgA and IgG antibodies) as well as by rapid urease test (RUT) and histology. The results showed that 50 (71.4%) of the patients were positive for H. pylori. Levels of E-Cadherin were increased significantly in all patients in comparison to the control group with a large significant increase in the gastric cancer group. The levels of E-Cadherin were also significantly increased in H. pylori infected patients compared to H. pylori negative patients. A non-significant difference in the levels of CA19-9 and CEA was observed in all patients in comparison to healthy controls.

CONCLUSION

This study concluded that serum E-Cadherin could be considered as a potential marker in diagnosis of gastric cancer.

Helicobacter pylori Infection and Psoriasis: A Systematic Review and Meta-Analysis

Background and Objectives: To perform a systematic review and meta-analysis with the aim of determining the relationship between H. pylori infection and psoriasis. Methods: Pubmed, Embase, China National Knowledge Infrastructure (CNKI), and Web of Science were searched for articles published up to July, 2019. Review Manager 5.3 and Stata 12.0 were used for statistical analyses. Results: The initial database search resulted in 204 articles. Through exclusion and screening, 11 studies involving a total of 1741 participants were finally included in this meta-analysis. The odds ratio (OR) of H. pylori infection rate in the psoriasis group was significantly higher than that in the control group (OR = 1.19, 95% CI 1.15–2.52, P = 0.008). Subgroup analysis showed that no significant difference was detected between the Asia group and the Europe group. As for the methods of H. pylori detection, a statistically significant increase of H. pylori infection in the IgG ELISA test group was detected, compared with the urea breath test group. In addition, analysis based on the severity of psoriasis showed a statistically significant increase of H. pylori infection in moderate and severe psoriasis patients (OR = 2.27; 95% CI: 1.42–3.63, I² = 27%), but not in the mild psoriasis patients (OR = 1.10; 95% CI: 0.79–1.54, I² = 0%). Conclusion: H. pylori infection is associated with psoriasis, and psoriasis patients with H. pylori infection have higher Psoriasis Area and Severity Index (PASI) scores. The findings are of considerable significance for the clinical practices.

Helicobacter pylori is associated with poor prognosis of laryngeal precancerous lesion

OBJECTIVES

Previous evidence suggested Helicobacter pylori (H. pylori) promoted tumorigenesis by inducing inflammation in gastric premalignant disease. Whether this organism affected the development of head and neck precancerous lesion remains unknown. We performed this study to assess the prognostic impact of H. pylori infection on patients with laryngeal precancerous lesion.

METHODS

In this prospective study, 41 enrolled patients with laryngeal precancerous lesion were arranged into H. pylori-positive group (n=16) and H. pylori-negative group (n=25). Two poor outcomes were recurrence and malignant transformation. Prognostic impact of H. pylori infection was analyzed using the Univariate Cox proportional hazard model and Cochran-Mantel-Haenszel test. We also analyzed the prognostic value of systemic inflammation-based markers.

RESULTS

During a median follow-up of 32.9 months, recurrence developed in 8 patients in the H. pylori positive group and 5 patients in the H. pylori negative group (50.0% vs. 20.0%, P=0.026, Log-rank test). Malignant transformation developed in 4 patients in the H. pylori positive group and no patients in the H. pylori negative group (25.0% vs. 0.0%, P=0.005, Log-rank test). H. pylori positive group had a significant higher malignant transformation rate after stratifying on the observed covariates. There was no significant difference of recurrence rate in two groups stratified with laryngopharyngeal reflux, size of lesion, and pathological type (Cochran-Mantel-Haenszel test). The basal levels of lymphocyte counts and neutrophils to lymphocytes ratio were significantly different in patients with H. pylori infection. Moreover, the receiver operating characteristic curve analysis revealed a predictive value of lymphocyte counts and neutrophils to lymphocytes ratio for poor outcomes (areas under the curve, 0.658 and 0.651, respectively).

CONCLUSION

The data demonstrate a malignant transformation-relevant role of H. pylori in laryngeal precancerous lesion. H. pylori infection combined with laryngopharyngeal reflux, size of lesion, and pathological type might relate to recurrence of laryngeal precancerous lesion. And changes of lymphocyte counts and neutrophils to lymphocytes ratio associated with H. pylori infection might deserve as predictive indicators for poor prognosis of laryngeal precancerous lesion.

Mutations in the Helicobacter pylori 23S rRNA gene associated with clarithromycin resistance in patients at an endoscopy unit in Medellín, Colombia

Introduction: Clarithromycin is the first-line antibiotic for the treatment of Helicobacter pylori infection. Bacterial resistance is mainly due to the presence of specific mutations in the 23S ribosomal RNA (rRNA) gene. Objective: To determine the frequency of A2143G and A2142G specific mutations in the 23S rRNA gene associated with clarithromycin resistance of H. pylori in samples from patients with dyspeptic manifestations in Medellín, northwestern Colombia. Materials and methods: DNA was extracted from gastric biopsy samples of patients with dyspeptic manifestations seen at an endoscopy unit in Medellín between 2016 and 2017. PCR was performed to amplify the bacterial s and m vacA regions, and a region in the 23S rRNA gene. The presence of the A2142G and A2143G mutations was determined using the restriction fragment length polymorphism (RFLP) technique with the BbsI and BsaI enzymes, respectively. Results: The prevalence of infection was 44.2% (175/396), according to the histopathology report. The positive samples were analyzed and the three regions of the bacterial genome were amplified in 143 of the 175 samples. The A2143G and A2142G mutations were identified in 27 samples (18.8%, 27/143). The most frequent mutation was A2143G (81.5%, 22/27). Conclusions: We found a high prevalence of H. pylori mutations associated with clarithromycin resistance in the study population. Further studies are required to determine the bacterial resistance in the Colombian population in order to define first line and rescue treatments.

Hepatoma-derived growth factor participates in Helicobacter Pylori-induced neutrophils recruitment, gastritis and gastric carcinogenesis

Helicobacter pylori (Hp) infection and overexpression of hepatoma-derived growth factor (HDGF) are involved in gastric carcinogenesis. However, the relationship between Hp-induced gastric diseases and HDGF upregulation is not yet completely clear. This study aimed to elucidate the role of HDGF in Hp-induced gastric inflammation and carcinogenesis. HDGF expression in gastric biopsy and serum from patients was analyzed by immunohistochemical and ELISA analysis, respectively. Hp and gastric cells coculture system was employed to delineate the mechanism underlying HDGF overexpression during Hp infection. The gastric pathologies of wild type and HDGF knockout mice after Hp infection were investigated by immunohistochemical, immunoblot, and immunofluorescence analyses. HDGF level was significantly elevated in patients with Hp infection or intestinal metaplasia (IM, a precancerous lesion), and HDGF overexpression was positively correlated with Hp load, IM, and neutrophil infiltration in gastric biopsy. Consistently, patients with Hp infection or IM had significantly higher serum HDGF level. By using coculture assay, Hp infection led to HDGF upregulation and secretion in gastric cells. In mice model, HDGF ablation significantly suppressed the Hp-induced neutrophil infiltration and inflammatory TNF-α/COX-2 signaling, thereby relieving the tissue damage in stomach. This was further supported by that recombinant HDGF (rHDGF) stimulated the differentiation/chemotaxis of cultured neutrophils and oncogenic behaviors of gastric cells. Time series studies showed that Hp infection elicited an inflammatory TNF-α/HDGF/COX-2 cascade in stomach. HDGF secretion by Hp infection promotes the neutrophils infiltration and relays Hp-induced inflammatory signaling. Thus, HDGF may constitute a novel diagnostic marker and therapeutic target for Hp-induced gastritis and carcinogenesis.

Antibiotic Resistance and Genotypes of Helicobacter pylori Strains in Patients with Gastroduodenal Disease in Southeast Poland

The aim of this study was to investigate genetic diversity of Helicobacter pylori virulence markers to predict clinical outcome as well as to determine an antibiotic susceptibility of H. pylori strains in Poland. Gastric biopsies from 132 patients with gastrointestinal disorders were tested for presence of H. pylori with the use of rapid urease test, microbial culture, and polymerase chain reaction (PCR) detection. The genetic diversity of 62 H. pylori positive samples was evaluated by detection of cagA and PCR-typing of vacA and iceA virulence-associated genes. Most common H. pylori genotypes were cagA(+)vacAs1m2 (27.4%) and cagA(−)vacAs2m2 (24.2%). In logistic regression analysis, we recognized the subsequent significant associations: gastritis with ureC, i.e., H. pylori infection (p = 0.006), BMI index (p = 0.032); and negatively with iceA1 (p = 0.049) and peptic ulcer with cagA (p = 0.018). Thirty-five H. pylori strains were cultured and tested by E-test method showing that 49% of strains were resistant to at least one of the tested antibiotics. This is the first study that reports the high incidence and diversity of allelic combination of virulence genes in gastroduodenitis patients in Poland. Genotyping of H. pylori strains confirmed the involvement of cagA gene and vacAs1m1 genotype in development and severity of gastric disorder.

Development of a loop-mediated isothermal amplification assay for rapid Helicobacter pylori detection

Infection with cagA-positive Helicobacter pylori is associated with gastric cancer. Molecular techniques are vital for accurate H. pylori diagnosis. We developed a loop-mediated isothermal amplification (LAMP) for detecting the H. pylori cagA gene and evaluated its use for clinical diagnosis. A LAMP primer set was designed to recognize the homologous regions of cagA gene sequences of 6 H. pylori strains. LAMP sensitivity was evaluated with serial dilutions of H. pylori ATCC 43504 and fecal specimens; specificity was evaluated with H. pylori ATCC 49396 and CIP 104086. The LAMP sensitivity for H. pylori specimens was 10^-1 cfu/tube (reaction time, 37 min), which was 10-fold more sensitive than polymerase chain reaction. LAMP was also highly sensitive and rapid for fecal specimens. It detected cagA gene from ATCC 49396 and CIP 104086. The findings suggest LAMP can be used for diagnosing and screening of H. pylori infections to decrease gastric cancer incidence.

High Efficacy of Rapid Urine Test for Diagnosis of Helicobacter pylori Infection in Thai People

Background:

Accurate diagnosis of Helicobacter pylori (H. pylori) infection plays an important role in further effective treatment. Rapid urine test (RAPIRUN) is a test developed for qualitative detection of urine H. Pylori antibody and use for determine the sensitivity, specificity and accuracy. However, the test needs validation in Thai population before using in clinical practice.

Objective:

This study aimed to compare performance of different diagnostic tests on H. pylori detection in Thai population.

Methods:

Total of 94 patients with dyspepsia who referred to Thammasat University Hospital, Pathumthani, Thailand, between December 2012 and April 2013 were enrolled in this study. All patients underwent gastroscopy. Then, 3 biopsies at antrum were taken for H. pylori diagnosis. including rapid urease test (Pronto Dry, Eisai, Thailand), H. pylori culture, and histopathology. Urine samples were also collected at the same time for rapid urine test (RAPIRUN H. pylori Antibody, Otsuka Pharmaceutical Co., Ltd.). Patients were diagnosed with H. pylori-positive if their culture or rapid urease tests plus histopathology yielded positive results.

Results:

Total of 29 patients (30.9%) were infected with H. pylori. Prevalence of H. pylori infection by rapid urease test, histopathology, culture and rapid urine test were 25.5%, 28.7%, 29.8%, and 32.9% respectively. We observed that rapid urease test, histopathology, culture, and rapid urine test had sensitivity of 82.8%, 93.1%, 93.1% and 86.2%; specificity of 100%, 100%, 100%, and 90.8%; and accuracy of 95.7%, 97.9%, 97.9%, and 89.4%, respectively.

Conclusion:

Rapid urine test (RAPIRUN) provided a reliable result for diagnosis of H. pylori infection. Furthermore, this rapid urine test demonstrated high accuracy, reliable, safe handle and easy to use. We suggested rapid urine test for diagnosis of H. pylori infection in Thai population since we found it less invasive and with higher reliable efficacy.

Detection of Helicobacter pylori and its virulence genes (cagA, dupA, and vacA) among patients with gastroduodenal diseases in Chris Hani Baragwanath Academic Hospital, South Africa

BACKGROUND

The global prevalence of H. pylori approaches 50%, with prevalence rates between 20 and 40% in developed countries and up to 90% in Africa and other developing nations of the world. Development of H. pylori-associated diseases is determined by a number of virulence factors. This study aimed at determining the prevalence of H. pylori infections and virulence genes (cagA, dupA, and vacA); the relationship between virulence factors and gastroduodenal diseases among patients.

METHODS

Gastric biopsies were obtained from patients and cultured, DNA was extracted from cultured isolates and biopsies for PCR assay after which samples were investigated using standard laboratory procedures. Data of associated risk factors were obtained with the aid of questionnaires.

RESULTS

Of the 444 participants, H. pylori was detected in 115 (25.9%) from culture analysis and 217 (48.9%) by direct PCR method. Ninety-eight (85.2%) of the culture-positive patients were also detected by PCR giving an overall prevalence of 52.7% (234/444). The highest number of H. pylori isolates 76.9% (180/234) was obtained from patients suffering from pangastritis. The CagA virulence gene was found in 62% (145/234), dupA in 53.4% (125/234) and vacA in 90.6% (212/234). VacA genotype s1 m1 was the most prevalent [56.4% (132)] followed by s2 m2 [11.5% (27)], s2 m1 [10.3% (24)] and [s1 m2 9.4% (22)]. There was a significant association observed in vacA s1 and peptic ulcer disease, as well as vacA s1/m2 and gastric erosion (P < 0.05).

CONCLUSION

The study revealed a significant association between virulence genes and the development of certain forms of gastric infections while the variations in H. pylori detection and the associated risk factors investigated in the study were not significantly related.

Gastric juice-based PCR assay: An alternative testing method to aid in the management of previously treated Helicobacter pylori infection

BACKGROUND

Culture of Helicobacter pylori with previous eradication failure has been emphasized in clinical guidelines. The current unmet need to manage previously treated H pylori is one tool with diagnostic accuracy and ability for antibiotics susceptibility. Gastric juice PCR can provide diagnosis and antibiotics susceptibility; however, whether treatment failure affects its accuracy remains uninvestigated. Our study aimed to investigate diagnostic accuracy and antibiotics susceptibility of juice PCR in previously treated H pylori and to compare with the current standard of culture.

METHODS

We categorized all 547 patients into treatment-naïve, post-1st treatment, post-2nd treatment, and post-3rd treatment. Helicobacter pylori infection was confirmed using gold standards. Sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve and area under ROC curve (AUC) of juice PCR and culture were calculated. Intra-gastric H pylori density was evaluated. Lastly, the antibiotics susceptibility results of gastric juice and culture were compared.

RESULTS

Our findings demonstrated AUC was higher in juice PCR than culture in all patients (96.7% vs 91.3%, P < 0.0001). The superiority of juice PCR was statistically significant in previously treated patients (P < 0.0001) but not in treatment-naïve patients (P = 0.13). Antral H pylori density was less marked in previously treated patients (P = 0.014). The comparisons of PCR-RFLP and E-test for Clarithromycin resistance showed reliable AUC = 89.8%.

CONCLUSION

Compared with the current standard of culture, the gastric juice PCR contains the strengths of performing the antibiotics susceptibility and overcomes the shortcomings of low accuracy. Consequently, gastric juice PCR suits the unmet need to manage previously treated H pylori.

Application of PCR and Microscopy to Detect Helicobacter pylori in Gastric Biopsy Specimen among Acid Peptic Disorders at Tertiary Care Centre in Eastern Nepal

BACKGROUND

Helicobacter pylori infection is most prevalent in developing countries. It is an etiological agent of peptic ulcer, gastric adenocarcinoma, and mucosal-associated lymphoid tissue (MALT) lymphoma. Despite the development of different assays to confirm H. pylori infection, the diagnosis of infection is challenged by precision of the applied assay. Hence, the aim of this study was to understand the diagnostic accuracy of PCR and microscopy to detect the H. pylori in the gastric antrum biopsy specimen from gastric disorder patients.

METHODS

A total of 52 patients with gastric disorders underwent upper gastrointestinal endoscopy with biopsy. The H. pylori infection in gastric biopsies was identified after examination by microscopy and 23S rRNA specific PCR. The agreement between two test results were analysed by McNemar's test and Kappa coefficient.

RESULT

H. pylori infection was confirmed in 9 (17.30%) patients by both assays, 6.25% in antral gastritis, 22.22% in gastric ulcer, 100% in gastric ulcer with duodenitis, 50% in gastric ulcer with duodenal ulcer, and 33.33% in severe erosive duodenitis with antral gastritis. Out of nine H. pylori infection confirmed patients, 3 patients were confirmed by microscopy and 8 patients by PCR. In case of two patients, both microscopy and PCR assay confirmed the H. pylori infection. The agreement between two test results was 86.54% and disagreed by 13.46% (p value > 0.05).

CONCLUSION

We found that PCR assay to detect H. pylori is more sensitive than microscopy. However, we advocate for the combination of both assays to increase the strength of diagnostic accuracy due to the absence of the gold standard assay for H. pylori infection.

Ultrasensitive detection of H. pylori in human feces based on immunomagnetic bead capture and fluorescent quantum dots

A novel fecal test was developed to detect H. pylori based on immunomagnetic beads (IMBs) with monoclonal antibodies sensitively recognizing and capturing the H. pylori, coupled with a polyclonal antibody-conjugating quantum dot probe.

Helicobacter pylori: History and facts in Peru

Helicobacter pylori (H. pylori) is a cosmopolite bacteria and the main responsible for the high burden of gastric cancer in developing countries, such as Peru. In this review, we describe some historical facts in the H. Pylori discovery, the first researches of this bacterium in Peru, as well as its epidemiology, clinical characteristics, diagnosis, treatments, and outcomes. Our literature and review of real-life data suggest that several efforts should be conducted in our country to deal with antibiotic-resistance and lack of adherence to treatment in order to reduce our incidence of gastric cancer.

A comparison of techniques to address the frequency of Helicobacter pylori positive dyspeptic patient

Objectives

The study was aimed to compare the diagnostic techniques, for the detection of Helicobacter pylori infection, available in low-income countries, where molecular testing is not available or inaccessible to anyone.

Results

Of total enrolled patient, with the mean age of 41.4 ± 13.33 years, 24 (14 female; 10 male) were diagnosed to have been infected. The diagnosis was established based upon the gold standard test [either two of three tests: Rapid Urease Test (RUT), culture and histological examinations]. Of clinical presentation, the epigastric pain (75%) was the commonest; nevertheless, the endoscopic findings had shown an equivocal specificity since the larger percentile (58.3%) reported as normal findings, in a presumed dyspepsia. Based on the premise—with calculated sensitivity, specificity, and predictive values; the accuracy order observed as histology > RUT > serology > stool antigen test, in H. pylori detection from the clinical samples. The accuracy order of the diagnostic test may vary depending upon the laboratory settings and study population. Therefore, in reference to low-income countries, the clinicians must resort any available positive test so that the supporting positive rudiments would be an ancillary in augmenting the diagnostic accuracy.

HIV related hypochlorhydria does not appear to respond to anti-retroviral therapy in Zambian adults: a case control study

INTRODUCTION

Human Immunodeficiency Virus (HIV) infection is associated with hypochlorhydria but the mechanism is unknown. The objective of this study was to determine effects of anti-retroviral therapy (ART) on gastric physiology as measured by validated markers.

METHODS

We studied HIV infected individuals who were either ART-naïve or on treatment with undetectable viral loads. We measured H.pylori IgG antibodies, pepsinogen (PG) 1 and 2 levels and fasting gastrin-17 using Biohit GastroPanel®. Gastric antral biopsies and juice were obtained for histology and pH respectively. Also included were historical data from HIV negative participants (n = 72) in a previous study, for reference.

RESULTS

We enrolled 84 HIV positive individuals with a median age 42 years (IQR 37-40 years). 55(66%) were female, 32(38%) were ART naïve, and 52(62%) were on ART. Hypochlorhydria (pH>4) was present in 48(57%) of the HIV positive and 18(25%) of the HIV negative individuals (OR 4: 95% CI 1.9-8.5, P<0.001) with no significant effect of ART (OR 0.9: 95% CI 0.3-2.3, P = 0.82). Hypochlorhydria was not associated with the serological detection of corpus atrophy using low PG 1:2 ratio (OR 2.1: 95% CI 0.5-10.2, P = 0.37) or GastroPanel® algorithm, (OR 0.7: 95% CI 0.01-60.1, P = 1.0). ART reduced the frequency of low PG 1:2 ratio (P = 0.001), but not the histological detection in the antrum of atrophy or non-atrophic gastritis.

CONCLUSION

ART use is associated with reduced serological evidence of corpus atrophy but has no effect on fasting pH, supporting earlier data that suggest that the mechanism of HIV-associated hypochlorhydria is multifactorial.

Contribution of genetic amplification by PCR for the diagnosis of Helicobacter pylori infection in patients receiving proton pump inhibitors

Background

Helicobacter pylori detection by standard methods may be altered by proton pump inhibitor (PPI) use. However, some patients cannot or should not interrupt PPI use before undergoing testing for H. pylori. Polymerase chain reaction (PCR) could allow more reliable H. pylori detection even in patients taking PPIs.

Objective

The aim of our study is to compare the H. pylori infection diagnostic value of histological examination without and with immunohistochemical staining, bacterial culture and PCR, in PPI-treated vs untreated patients.

Methods

Patients undergoing a gastric endoscopy for upper digestive symptoms were included. Gastric biopsy samples were obtained. The impact of taking PPI on the diagnostic performance of the different methods was studied. PCR results were confirmed by sequencing the glmM gene.

Results

A total of 497 patients were included, of whom 192 were H. pylori positive. Fifty-two patients received PPIs during the 14 days preceding the endoscopy while 140 did not. All methods had lower sensitivity than PCR, in all cases (PPI treatment or not). PPI use did not change significantly the methods' sensitivities.

Conclusion

The PCR method showed the best performance for the detection of H. pylori in gastric samples, whether or not patients received previous PPI treatment. This diagnosis test could become a new gold-standard test, especially in patients undergoing PPI treatment.