Review: Diagnosis of Helicobacter pylori infection

Development and application of an artificial intelligence-assisted endoscopy system for diagnosis of Helicobacter pylori infection: a multicenter randomized controlled study

BACKGROUND

The early diagnosis and treatment of Heliobacter pylori (H.pylori) gastrointestinal infection provide significant benefits to patients. We constructed a convolutional neural network (CNN) model based on an endoscopic system to diagnose H. pylori infection, and then examined the potential benefit of this model to endoscopists in their diagnosis of H. pylori infection.

MATERIALS AND METHODS

A CNN neural network system for endoscopic diagnosis of H.pylori infection was established by collecting 7377 endoscopic images from 639 patients. The accuracy, sensitivity, and specificity were determined. Then, a randomized controlled study was used to compare the accuracy of diagnosis of H. pylori infection by endoscopists who were assisted or unassisted by this CNN model.

RESULTS

The deep CNN model for diagnosis of H. pylori infection had an accuracy of 89.6%, a sensitivity of 90.9%, and a specificity of 88.9%. Relative to the group of endoscopists unassisted by AI, the AI-assisted group had better accuracy (92.8% [194/209; 95%CI: 89.3%, 96.4%] vs. 75.6% [158/209; 95%CI: 69.7%, 81.5%]), sensitivity (91.8% [67/73; 95%CI: 85.3%, 98.2%] vs. 78.6% [44/56; 95%CI: 67.5%, 89.7%]), and specificity (93.4% [127/136; 95%CI: 89.2%, 97.6%] vs. 74.5% [114/153; 95%CI: 67.5%, 81.5%]). All of these differences were statistically significant (P < 0.05).

CONCLUSION

Our AI-assisted system for diagnosis of H. pylori infection has significant ability for diagnostic, and can improve the accuracy of endoscopists in gastroscopic diagnosis.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Daping Hospital (10/07/2020) (No.89,2020) and was registered with the Chinese Clinical Trial Registration Center (02/09/2020)   ( www.chictr.org.cn ; registration number: ChiCTR2000037801).

ACG Clinical Guideline: Treatment of Helicobacter pylori Infection

ABSTRACT

Helicobacter pylori is a prevalent, global infectious disease that causes dyspepsia, peptic ulcer disease, and gastric cancer. The American College of Gastroenterology commissioned this clinical practice guideline (CPG) to inform the evidence-based management of patients with H. pylori infection in North America. This CPG used Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to systematically analyze 11 Population, Intervention, Comparison, and Outcome questions and generate recommendations. Where evidence was insufficient or the topic did not lend itself to GRADE, expert consensus was used to create 6 key concepts. For treatment-naive patients with H. pylori infection, bismuth quadruple therapy (BQT) for 14 days is the preferred regimen when antibiotic susceptibility is unknown. Rifabutin triple therapy or potassium-competitive acid blocker dual therapy for 14 days is a suitable empiric alternative in patients without penicillin allergy. In treatment-experienced patients with persistent H. pylori infection, "optimized" BQT for 14 days is preferred for those who have not been treated with optimized BQT previously and for whom antibiotic susceptibility is unknown. In patients previously treated with optimized BQT, rifabutin triple therapy for 14 days is a suitable empiric alternative. Salvage regimens containing clarithromycin or levofloxacin should only be used if antibiotic susceptibility is confirmed. The CPG also addresses who to test, the need for universal post-treatment test-of-cure, and the current evidence regarding antibiotic susceptibility testing and its role in guiding the choice of initial and salvage treatment. The CPG concludes with a discussion of proposed research priorities to address knowledge gaps and inform future management recommendations in patients with H. pylori infection from North America.

Assessment of the quality, diagnosis, and therapeutic recommendations of clinical practice guidelines on patients with Helicobacter pylori infection: A systematic review

We conducted this study to systematically review and assess the current clinical practice guidelines (CPGs) related to the diagnosis and treatment of Helicobacter pylori (H. pylori) infection. The aim was to evaluate the quality of these included CPGs and provide clinicians with a convenient and comprehensive reference for updating their own CPGs. We searched four databases to identify eligible CPGs focusing on H. pylori diagnosis and treatment recommendations. The results were presented using evidence mappings. Quality and clinical applicability were assessed comprehensively using AGREE-II and AGREE-REX. Statistical tests, specifically Bonferroni tests, were employed to compare the quality between evidence-based guidelines and consensus. A total of 30 eligible CPGs were included, comprising 17 consensuses and 13 guidelines. The quality showed no statistical significance between consensuses and guidelines, mainly within the moderate to low range. Notably, recommendations across CPGs exhibited inconsistency. Nevertheless, concerning diagnosis, the urea breath test emerged as the most frequently recommended method for testing H. pylori. Regarding treatment, bismuth quadruple therapy stood out as the predominantly recommended eradication strategy, with high-dose dual therapy being a newly recommended option. Our findings suggest the need for specific organizations to update their CPGs on H. pylori or refer to recently published CPGs. Specifically, CPGs for pediatric cases require improvement and updating, while a notable absence of CPGs for the elderly was observed. Furthermore, there is a pressing need to improve the overall quality of CPGs related to H. pylori. Regarding recommendations, additional evidence is essential to elucidate the relationship between H. pylori infection and other diseases and refine test indications. Clinicians are encouraged to consider bismuth quadruple or high-dose dual therapy, incorporating locally sensitive antibiotics, as empirical radical therapy. .

Helicobacter pylori infection in Africa: comprehensive insight into its pathogenesis, management, and future perspectives

Helicobacter pylori is a widespread bacterium that has effectively colonized half of the global population, with Africa having over 70% of the total burden of H. pylori infections (HPI). Considering its acknowledged classification of as bacterial carcinogens and their significant contribution to the development of gastrointestinal disorders such as gastritis, peptic ulcers, and gastric neoplasia, together with their growing resistance to antibiotics. Gaining insight into the etiology of this organism is crucial in order to investigate and develop appropriate treatment strategies. Furthermore, the rise of bacteria that are resistant to antibiotics presents an extra danger in managing this detrimental bacterium. Our review focuses on investigating the presence of H. pylori in Africa and analyzing the various factors that contribute to its extensive prevalence. We simplified the complex mechanisms that H. pylori utilizes to flourish in the human body, with a specific emphasis on its virulence factors and antibiotic resistance. These variables pose significant challenges to conventional treatment strategies. In addition, we analyze both conventional and developing diagnostic methods, as well as the current treatment approaches implemented in various African nations. In addition, we tackle the distinct healthcare obstacles of the region and put-up practical remedies. The main goal of this review is to improve the formulation of more efficient methods for the management and treatment of HPI in Africa.

Detection Rate of Helicobacter Pylori Infection and Atrophic Gastritis Using Serological Markers “GastroPanel®” Among Employees of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation

Aim: to evaluate, using the “GastroPanel®”, the frequency of detection of H. pylori infection and associated gastric diseases among doctors and medical staff of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Moscow.

Materials and methods. Employees of three branches of the National Medical Research Radiological Centre (n = 434, mean age — 48.5 ± 0.6 years) were examined using laboratory tests “GastroPanel®” (Biohit Oyj, Finland). The test results make it possible to identify infection of the stomach with H. pylori, hypo- and hyperacid conditions, as well as atrophic gastritis of the antrum and body of the stomach, as its precancerous conditions. Esophagogastroduodenoscopy (EGDS) for suspected atrophic gastritis was performed with an Olympus GIF-HQ190 video endoscope (Japan) in a narrow-spectrum mode with close focus (NBI Dual Focus).

Results. The absence of pathological signs detected by “GastroPanel®” was established in 23.3 % of cases, hyperacid state — in 18.4 %, and hypoacid state — in 5.2 %. These disorders are classified as functional. Consequently, the conditional norm in total was identified in 46.9 % of observations. An increased level of antibodies to H. pylori was found in 43.3 % of those examined. Atrophic gastritis in the body of the stomach according to the results of the “GastroPanel®” was detected in 4.8 % of cases (median age — 59 years), in the antrum (or increased secretion of hydrochloric acid) — also in 4.8 % of cases (median age — 52 years). Within two months after laboratory diagnostics, EGDS was performed for 10 out of 15 patients examined at the P. Hertsen Moscow Oncology Research Institute in whom, based on the results of the “GastroPanel®”, the presence of atrophic gastritis in the antrum (or increased secretion of hydrochloric acid) was suspected. In 6 out of 10 cases, atrophic gastritis of the antrum was confirmed (in two of them, the atrophy extended to the body of the stomach and was assessed as severe). Of the 11 people with the “GastroPanel®” conclusion “Atrophic gastritis of the body of the stomach,” an endoscopic examination was carried out in 7 persons, and in all these cases the diagnosis was confirmed, and in two people the conclusion was made of severe atrophic pangastritis.

Conclusion. “GastroPanel®” confirmed its high significance in identifying H. pylori infection and precancerous atrophic changes in the gastric mucosa. Regarding the occupational risks of infection among medical workers, we consider it advisable to conduct such screening without selecting an asymptomatic population.

An investigative study on the zoonotic potential of Helicobacter pylori

BACKGROUND

Helicobacter pylori is one of the most common bacterial infections and is widespread globally. It causes a variety of gastrointestinal disorders, though a great proportion of infections are asymptomatic. A total of 143 fresh stool samples were collected from apparently healthy farm and pet animals (43 cattle, 50 buffaloes, 50 sheep, 50 dogs, and 50 cats), in addition to 768 human stool samples. The samples were examined using stool antigen and rapid antibody tests, and further confirmation of glmM "human antigen-positive samples and animal milk samples" was conducted by polymerase chain reaction (PCR).

RESULTS

The prevalence rates of H. pylori infection in animals were 22.2% and 16% in antibody and stool antigen tests, respectively. The detection rates were 28%, 24%, 12%, 10%, and 4.7% in cats, dogs, buffaloes, sheep, and cattle, respectively. On the other hand, the prevalence rate of H. pylori infection in human stool samples was 74.8%, and a statistically significant association was observed between prevalence and several factors, such as sex, age, and locality. PCR was performed to detect the glmM gene of H. pylori, and this gene was found in 21 of 27 human antigen-positive samples and 5 of 13 animal milk samples.

CONCLUSIONS

H. pylori was detected in both human and animal samples. Furthermore, glmM was found in milk and human samples. Our findings suggest that pet and farm animals could transmit H. pylori infection to humans.

Kyoto classification of gastritis, virtual chromoendoscopy and artificial intelligence: Where are we going? What do we need?

Chronic gastritis (CG) is a widespread and frequent disease, mainly caused by Helicobacter pylori infection, which is associated with an increased risk of gastric cancer. Virtual chromoendoscopy improves the endoscopic diagnostic efficacy, which is essential to establish the most appropriate therapy and to enable cancer prevention. Artificial intelligence provides algorithms for the diagnosis of gastritis and, in particular, early gastric cancer, but it is not yet used in practice. Thus, technological innovation, through image resolution and processing, optimizes the diagnosis and management of CG and gastric cancer. The endoscopic Kyoto classification of gastritis improves the diagnosis and management of this disease, but through the analysis of the most recent literature, new algorithms can be proposed.

Value of Serological Biomarker Panel in Diagnosis of Atrophic Gastritis and Helicobacter pylori Infection

Background: Gastric cancer is one of the most common types of cancer worldwide. Helicobacter pylori infection is clearly correlated with gastric carcinogenesis. Therefore, the use of a new non-invasive test, known as the GastroPanel test, can be very helpful to identify patients at a high risk, including those with atrophic gastritis, intestinal metaplasia, and dysplasia. This study aimed to compare the results of GastroPanel test with the pathological findings of patients with gastric atrophy to find a safe and simple alternative for endoscopy and biopsy as invasive methods. Methods: This cross-sectional study was performed on patients with indigestion, who were referred to Motahari Clinic and Shahid Faghihi Hospital of Shiraz, Iran, since April 2017 until August 2017 for endoscopy of the upper gastrointestinal tract. The serum levels of gastrin-17 (G17), pepsinogen I (PGI), and pepsinogen II (PGII), as well as H. pylori antibody IgG, were determined by ELISA assays. Two biopsy specimens from the antrum and gastric body were taken for standard histological analyses and rapid urease test. A pathologist examined the biopsy specimens of patients blindly. Results: A total of 153 patients with indigestion (62.7% female; mean age, 63.7 years; 37.3% male; mean age, 64.9 years) were included in this study. The G17 levels significantly increased in patients with chronic atrophic gastritis (CAG) of the body (9.7 vs. 32.8 pmol/L; P = 0.04) and reduced in patients with antral CAG (1.8 vs. 29.1 pmol/L; P = 0.01). The results were acceptable for all three types of CAG, including the antral, body, and multifocal CAG (AUCs of 97%, 91%, and 88% for body, antral, and multifocal CAG, respectively). The difference in PGII level was not significant. Also, the PGI and PGI/PGII ratio did not show a significant difference (unacceptably low AUCs for all). The H. pylori antibody levels were higher in patients infected with H. pylori (251 EIU vs. 109 EIU, AUC = 70, P = 0.01). There was a significant relationship between antibody tests and histopathology. Conclusion: Contrary to Biohit's claims, the GastroPanel kit is not accurate enough to detect CAG; therefore, it cannot be used for establishing a clinical diagnosis.

Usefulness of Molecular Methods for Helicobacter pylori Detection in Pediatric Patients and Their Correlation with Histopathological Sydney Classification

Helicobacter pylori infections, as one of the most prevalent among humans, are generally acquired during childhood, and are one of the main causes of chronic gastritis and peptic ulcer disease. A bacterial culture from a gastric biopsy is the gold standard and is the only method that has 100% specificity. However, its sensitivity varies, depending on experience of the laboratory staff, applied culture media, specimen transport conditions, biopsy site, and quality of the sample. The same factors compromise all invasive methods and a culture-based H. pylori infection diagnostic, as well as a recent intake of antibiotics, bismuth-containing compounds, and proton pump inhibitors. Molecular methods have been used for clinical microbiology investigation since the beginning of the 21st century. However, their usefulness for H. pylori infections diagnosis remains unclear, especially in pediatric patients. The aim of the study was to assess the incidence of H. pylori infections in a group of 104 pediatric patients and to compare the results of the PCR test with the corresponding histopathological investigation effects. Among the biopsy samples collected from 104 children, 44 (42.3%) were positive in PCR, while 43 (41.3%) and 39 (37.5%) presented histologically-confirmed signs of inflammation and H. pylori colonization, respectively. Moreover, the mean grades of the parameters of the histopathological examination were higher in the group of PCR-positive samples. The compatibility of both research methods was confirmed, emphasizing the usefulness of molecular methods for detecting H. pylori infections in pediatric patients. Considering that the PCR-based method gives reliable results and is less time-consuming and costly, it is worth discussing this method as a new standard in the diagnosis of H. pylori infections, at least among pediatric patients, for which culture-based diagnostics is not sufficient or histopathological examination is negative, while inflammation signs are observed macroscopically.

Helicobacter pylori infection and risk of multiple sclerosis: An updated meta-analysis

BACKGROUND

There is considerable controversy around the question as to whether Helicobacter pylori (H. pylori) infection has a protective or causative role in the development of multiple sclerosis (MS). This study evaluated published information to assess the association between H. pylori infection and MS.

METHODS

We conducted a comprehensive systematic review of relevant observational studies in international databases. A random-effects model was used to calculate pooled odds ratio (OR) and 95% confidence interval (CI). I² statistic was used to assess the between-study heterogeneity. Subgroup and meta-regression analyses were applied to identify the source of heterogeneity.

RESULTS

In total, 22 studies (25 datasets) were eligible for the meta-analysis: 17 datasets had prevalence data and eight datasets had data on the mean titer of anti-H. pylori IgG. The pooled prevalence of H. pylori was 44.1% (908/2606) in the MS patients and 46.1% (1016/2200) in the controls, indicating a non-significant protective effect of H. pylori on MS (OR, 0.82; 95%CI, 0.58-1.17). In the subgroup analysis, studies that used ELISA yielded a significant protective association (OR, 0.59; 95%CI, 0.46-0.77), while a positive non-significant association (OR, 1.33; 95%CI, 0.83-2.15) was found from studies that used other serological methods; interestingly, a significant positive association (OR, 6.64; 95%CI, 2.40-13.76) was found from studies that used histological methods to detect H. pylori infection.

CONCLUSIONS

Our findings do not support the hypothesis that H. pylori infection represents a protective factor against the development of MS; however, the results varied depending on the diagnostic method(s). Particularly, a significant positive association was identified when studies introduced results based on histological examination, suggesting that active H. pylori infection might be a risk factor for development of MS. Thus, further studies are needed utilizing accurate diagnostic methods to elucidate the association between active H. pylori infection and MS.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Evaluation of Anti-Helicobacter pylori IgG Antibodies for the Detection of Helicobacter pylori Infection in Different Populations

Serological testing (immunoassay) for Helicobacter pylori (H. pylori) is widely available and inexpensive, and does not require medication modifications before testing. It can also determine the type of infection, which helps with clinical diagnosis and treatment, and guides the use of medication. However, the performance of immunoblotting for the detection of H. pylori infections in different populations has still not been fully evaluated. We performed a retrospective analysis of patients in the Health Examination Center and Outpatient Department, from November 2017 to September 2020, at Peking Union Medical College Hospital. All the subjects were tested with the 13C-urea breath test (13C-UBT) and for IgG antibodies. A total of 1678 participants, including 1377 individuals who had undergone physical examinations, were recruited. The results of the immunoassay were significantly different from those of the 13C-UBT for all the subjects and outpatients (p < 0.001). For the physical examinations of individuals, the agreement between the immunoassay and the 13C-UBT was 0.64 (95%CI: 0.59−0.68; p < 0.001), and the H. pylori immunoassay demonstrated a sensitivity and specificity of 74.24% and 90.45%, respectively, with a positive predictive value of 71.01% and negative predictive value of 91.76%. In addition, in patients with gastric mucosal atrophy or early gastric cancer, antibody typing tests can also detect infected patients with missed UBT. The prevalence of H. pylori in Beijing was 26.8%, and the serological positivity rate for H. pylori in the population of Beijing was about 31.7% (25.1% in the physical examination population). The rate of H. pylori antibody positivity among patients with allergic diseases was 73.5%, which is significantly higher than that of the non-allergic disease population (29.3%, p < 0.001). In conclusion, H. pylori antibody typing testing can be applied as a specific test in the healthy physical examination population, and the test can be performed with the remaining serum during the physical examination.

Modern knowledge on pathogenesis, diagnosis and treatment of helicobacter infection

Since its discovery, H. pylori infection is known as one of the risk factor for the development of gastritis, peptic ulcer, GIT tumors and numerous other diseases such as psoriasis. Infection caused by H. pylori is posed as the top oncogene in the risk of the development of gastrocarcinoma (First class oncogene by Classification of International Agency for Research of Cancer). That is why the elaboration of fast and accurate methods of diagnosis (non-invasive methods especially) and proper treatment of Helicobacter infection is still very important. Throughout the time, knowledge about pathogenesis of Helicobacter infection have been expanded with the detection of adhesins, chemotaxins and multiple virulence factors related to invasion, adhesion and cytotoxicity of H. pylori. Invasive and non-invasive methods of diagnostics are currently being improved in effectiveness and accuracy. But still, due to different factors (e. g., dramatically increasing drug resistance), eradication of H. pylori remains big problem world-wide. Our review represents modern data on pathogenesis, diagnostics and treatment of Helicobacter infection.

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.

Helicobacter pylori Infection in Africa: Update of the Current Situation and Challenges

BACKGROUND

The burden of Helicobacter pylori infection (HPI) in Africa remains high with varying levels of prevalence among children and adults reported in different regions of the continent. Persistent and uneradicated HPI could result in gastric cancer, although less severe pathological outcomes have been reported among Africans - the so-called "African enigma."

SUMMARY

Analysis of endoscopic findings of the upper gastrointestinal tract demonstrates similarities with that of patients from the West. Thus, it could be asserted that the true picture of HPI in Africa is yet to be unveiled due to several challenges including inadequate health-care system, lack of treatment guidelines and standardized protocol for diagnosis, and lack of data. This review explores the prevalence, diagnosis, treatment, and health-care system in Africa as it relates to HPI, thus providing an update and highlighting the need for an African HPI guideline.

KEY MESSAGES

There is high prevalence of Helicobacter pylori infection (HPI) in Africa with an increasing burden of antibiotic resistance. Various methods including invasive and noninvasive methods are deployed in the diagnosis of HPI in Africa. There is a need for consensus on diagnosis and treatment of HPI in Africa.

Current situation and prospect of artificial intelligence application in endoscopic diagnosis of Helicobacter pylori infection

With the appearance and prevalence of deep learning, artificial intelligence (AI) has been broadly studied and made great progress in various fields of medicine, including gastroenterology. Helicobacter pylori (H. pylori), closely associated with various digestive and extradigestive diseases, has a high infection rate worldwide. Endoscopic surveillance can evaluate H. pylori infection situations and predict the risk of gastric cancer, but there is no objective diagnostic criteria to eliminate the differences between operators. The computer-aided diagnosis system based on AI technology has demonstrated excellent performance for the diagnosis of H. pylori infection, which is superior to novice endoscopists and similar to skilled. Compared with the visual diagnosis of H. pylori infection by endoscopists, AI possesses voluminous advantages: High accuracy, high efficiency, high quality control, high objectivity, and high-effect teaching. This review summarizes the previous and recent studies on AI-assisted diagnosis of H. pylori infection, points out the limitations, and puts forward prospect for future research.

Clinical performance of the H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ assays, novel stool antigen tests for diagnosis of Helicobacter pylori

Infection with Helicobacter pylori is a global health issue, and rapid and accurate testing is a key to diagnosis. We aimed to assess the performance of two novel enzyme immunoassays (EIA), the H. PYLORI QUIK CHEK™ and the H. PYLORI CHEK™ assays, for the detection of H. pylori antigen in stool. Patients from five geographically diverse sites across the USA, Germany, and in Bangladesh were tested for infection with Helicobacter pylori with the two novel stool antigen tests and two commercially available stool antigen assays. All patients provided a stool sample and underwent esophagogastroduodenoscopy for biopsy. Results were compared to a clinical diagnosis using a composite reference method consisting of histological analysis and rapid urease testing of the biopsy. A total of 271 patients, 68.2% female and mean age of 46 years, were included. The overall prevalence of H. pylori infection was 24.1%. The sensitivity of the H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ was 92% and 91%, respectively. The specificity of H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ was 91% and 100%, respectively. No significant cross-reactivity against other gut pathogens was observed. The H. PYLORI QUIK CHEK™ and H. PYLORI CHEK™ assays demonstrate excellent clinical performance compared the composite reference method.

40 Years of Helicobacter pylori: A Revolution in Biomedical Thought

Background: Various microorganisms such as bacteria, virus, and fungi can infect humans and cause not just a simple infection but septic conditions, organ dysfunction, and precancerous conditions or cancer involving various organ systems. After the discovery of the microscope, it was easier to discover and study such microorganisms, as in the case of Helicobacter pylori, a pathogen that was seen in the distant era of the nineteenth century but without being recognized as such. It took 100 years to later discover the pathogenesis and the cancer that this bacterium can cause. Since it was discovered, until today, there has been a continuous search for the understanding of its pathogenetic mechanisms, and the therapeutic approach is continuously updated. Methods: We investigated how diagnosis and therapy were dealt with in the past and how researchers sought to understand, exactly, the pathogenetic biomolecular mechanisms of H. pylori, from the genesis of the infection to the current knowledge, with an analysis of carcinogenic mechanisms in the stomach. We have examined the scientific evolution of the knowledge of the disease over these 40 years in the gastroenterological and pharmacological fields. This was possible through a search in the databases of Medline, the WHO website, the Centers for Disease Control and Prevention (CDC) website, PubMed, and Web of Science to analyze the earlier and the latest data regarding H. pylori. Results: With the scientific discoveries over time, thanks to an increasing number of progressions in scientific research in the analysis of the gastric mucosa, the role of Helicobacter pylori in peptic ulcer, carcinogenesis, and in some forms of gastric lymphoma was revealed. Furthermore, over the years, the biomolecular mechanism involvement in some diseases has also been noted (such as cardiovascular ones), which could affect patients positive for H. pylori. Conclusions: Thanks to scientific and technological advances, the role of the bacterium H. pylori in carcinogenesis has been discovered and demonstrated, and new prospective research is currently attempting to investigate the role of other factors in the stomach and other organs. Cancer from H. pylori infection had a high incidence rate compared to various types of cancer, but in recent years, it is improving thanks to the techniques developed in the detection of the bacterium and the evolution of therapies. Thus, although it has become an increasingly treatable disease, there is still continuous ongoing research in the field of treatment for resistance and pharma compliance. Furthermore, in this field, probiotic therapy is considered a valid adjuvant.

Amoxicillin and Clarithromycin Mucoadhesive Delivery System for Helicobacter pylori Infection in a Mouse Model: Characterization, Pharmacokinetics, and Efficacy

Helicobacter pylori is the main pathogen responsible for gastric ulcers and a predisposing factor of stomach cancer. Although current treatment is usually successful, it requires high doses and frequent administration. An innovative mucoadhesive system (Mucolast^®) loaded with amoxicillin and clarithromycin is proposed to improve the efficacy of treatment against H. pylori. The drug product was optimized based on its viscoelastic properties to obtain long-term stability of the vehicle. The drug release mechanisms were different for both antibiotics based on their solubilization status. A systemic and stomach pharmacokinetic profile was obtained after three different doses were administered to mice, obtaining similar systemic exposure levels but an increase in drug concentration in the stomach. The efficacy results in mice infected with H. pylori also demonstrated the superiority of the antibiotics when administered in Mucolast^®, as shown by the bacterial count in stomach tissue and under histopathological and biochemical evaluation. The proposed treatment was efficacious and safe and is presented as a realistic alternative to current treatment options to improve patient compliance and to reduce bacterial resistance.

Screening for gastric cancer in China: Advances, challenges and visions

Gastric cancer (GC) is one of the major cancers in China and all over the world. Most GCs are diagnosed at an advanced stage with unfavorable prognosis. Along with some other countries, China has developed the government-funded national screening programs for GC and other major cancers. GC screening has been shown to effectively decrease the incidence of and mortality from GC in countries adopting nationwide screening programs (Japan and Korea) and in studies based on selected Chinese populations. The screening of GC relies mostly on gastroendoscopy, the accuracy, reliability and safety of which have been indicated by previous studies. However, considering its invasive screening approach, requirements on skilled endoscopists and pathologists, and a high cost, developing noninvasive methods to amend endoscopic screening would be highly needed. Numerous studies have examined biomarkers for GC screening and the combination of biomarkers involving pepsinogen, gastrin, and Helicobacter pylori antibodies has been proposed for risk stratification, seeking to narrow down the high-risk populations for further endoscopy. Despite all the achievements of endoscopic screening, evidence on appropriate screening age, intervals for repeated screening, novel biomarkers promoting precision prevention, and health economics need to be accumulated to inform policymakers on endoscopic screening in China. With the guide of Health China 2030 Planning Outline, we have golden opportunities to promote prevention and control of GC. In this review, we summarize the characteristics of screening programs in China and other East Asian countries and introduce the past and current approaches and strategies for GC screening, aiming for featuring the latest advances and key challenges, and illustrating future visions of GC screening.

Comparison of the Diagnostic Performance of qPCR, Sanger Sequencing, and Whole-Genome Sequencing in Determining Clarithromycin and Levofloxacin Resistance in Helicobacter pylori

Helicobacter pylori antibiotic resistance is increasing worldwide, emphasizing the urgent need for more rapid resistance detection prior to the administration of H. pylori eradication regimens. Macrolides and fluoroquinolones are widely used to treat H. pylori. In this study, we aimed to compare the diagnostic performance of A) 23SrDNA qPCR (with melting curve analysis) and an in-house developed gyrA qPCR followed by Sanger sequencing with a commercial IVD-marked hybridization probe assay (for 23SrDNA and gyrA) using 142 gastric biopsies (skipping culturing) and B) the same two qPCR for 23SrDNA and gyrA (including Sanger sequencing) with whole-genome sequencing (WGS) and phenotypic characterization of clarithromycin and levofloxacin resistance using 76 cultured isolates. The sensitivity of both qPCRs was 100% compared to that of the commercial IVD-marked hybridization probe assay for the detection of H. pylori in gastric biopsies (without resistance testing). The specificity of the qPCR gyrA followed by Sanger sequencing was 100%, indicating that the best sequence identity was always H. pylori. The results show good agreement between molecular tests, especially between qPCR (inclusive Sanger sequencing) and WGS. Discrepancies (concerning mutated or wild type of positive H. pylori gastric biopsies) were observed between Sanger sequencing of the gyrA gene and the corresponding commercial hybridization probe assay, mostly because the high sequence diversity of the gyrA gene even at positions adjacent to the relevant codons of 87 and 91 interfered with obtaining correct results from the hybridization probe assay. Interestingly, we found several mixed sequences, indicating mixed populations in the gastric biopsies (direct detection without culturing). There was a high percentage of both levofloxacin and clarithromycin resistance in gastric biopsies (both between 22% and 29%, direct detection in gastric biopsies). Therefore, we recommend analyzing both targets in parallel. We confirmed that phenotypic resistance is highly correlated with the associated mutations. We concluded that the two qPCR followed by Sanger sequencing of the gyrA gene is a fast, cost-effective and comprehensive method for resistance testing of H. pylori directly in gastric biopsies.

Accuracy of Endoscopic Diagnosis of Helicobacter pylori Based on the Kyoto Classification of Gastritis: A Multicenter Study

Background

There is lack of clinical evidence supporting the value of the Kyoto classification of gastritis for the diagnosis of Helicobacter pylori (H. pylori) infection in Chinese patients, and there aren’t enough specific features for the endoscopic diagnosis of past infections, which is of special significance for the prevention of early gastric cancer (GC).

Methods

This was a prospective and multicenter study with 650 Chinese patients. The H. pylori status and gastric mucosal features, including 17 characteristics based on the Kyoto classification and two newly-defined features unclear atrophy boundary (UAB) and RAC reappearance in atrophic mucosa (RAC reappearance) were recorded in a blind fashion. The clinical characteristics of the subjects were analyzed, and the diagnostic odds ratio (DOR), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under the receiver operating characteristics curve (ROC/AUC), and 95% confidence intervals were calculated for the different features, individually, and in combination.

Results

For past infection, the DOR of UAB was 7.69 (95%CI:3.11−19.1), second only to map-like redness (7.78 (95%CI: 3.43−17.7)). RAC reappearance showed the highest ROC/AUC (0.583). In cases in which at least one of these three specific features of past infection was considered positive, the ROC/AUC reached 0.643. For current infection, nodularity showed the highest DOR (11.7 (95%CI: 2.65−51.2)), followed by diffuse redness (10.5 (95%CI: 4.87−22.6)). Mucosal swelling showed the highest ROC/AUC (0.726). Regular arrangement of collecting venules (RAC) was specific for no infection.

Conclusions

This study provides evidence of the clinical accuracy and robustness of the Kyoto classification of gastritis for the diagnosis of H. pylori in Chinese patients, and confirms UAB and RAC reappearance partly supplement it for the diagnosis of past infections, which is of great benefit to the early prevention of GC.

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.

First report of PCR-based detection of Helicobacter species DNA in Camelus dromedarius in Egypt

Background and Aim:

Helicobacter species infections have epidemiological and zoonotic impacts, and different species of Helicobacter have been implicated in infecting humans and animals. The aim of this study was to investigate Helicobacter species infections in Camelus dromedarius.

Materials and Methods:

Fecal samples were collected from 32 camels from 9 camel farms located at Ismailia Governorate, Egypt. The collected samples were investigated by bacteriological isolation and conventional polymerase chain reaction (PCR) assays targeting the 16S ribosomal RNA gene.

Results:

Although Helicobacter species could not be isolated from all the examined samples, Helicobacter DNA was detected in 2 (22.22%) of the 9 camel farms. Of the 32 camel fecal samples examined, 4 (12.5%) were positive for Helicobacter species as analyzed by the PCR assay.

Conclusion:

To the best of our knowledge, this is the first report of PCR-based detection of Helicobacter species infections in C. dromedarius. Further epidemiological studies are required to clarify Helicobacter species infections in camels.

Application of gene chip technology in the diagnostic and drug resistance detection of Helicobacter pylori in children

BACKGROUND AND AIMS

Helicobacter pylori (HP) culture for diagnosing HP infection is time-consuming and technologically complex. This study evaluated the clinical significance of gastric mucosal gene chip technology in the rapid diagnosis of HP infection and detection of drug resistance in children.

METHODS

Patients (between the age of 2.5 and 16.0 years old) manifesting gastrointestinal symptoms were enrolled in this study. HP culture of gastric mucosa and drug sensitivity test were performed. A gene chip of gastric mucosa was used to detect the presence of HP infection, some single nucleotide polymorphisms in HP drug resistance genes, or associated gene mutation. DNA sequencing was investigated and compared with the gene chip test results.

RESULTS

Out of 267 cases, HP culture was positive in 169 cases and negative in 98 cases. HP detection by the gene chip method was positive in 208 cases and negative in 59 cases. The sensitivity, specificity, and accuracy of the gene chip technology for diagnosing HP infection were 96.1, 85.0, and 93.6%, respectively. HP resistance gene locus using the gene chip showed the main mutation locus of clarithromycin to be 2143A/G, levofloxacin at locus GyrA 91 and GyrA 87, and amoxicillin at PBP1 556ser. Concordance rates between gene chip and DNA sequencing for VacA-S/M, 16S rRNA, 23S rRNA, and GyrA were greater than 95%, and that of PBP1 was greater than 82%.

CONCLUSION

Gastric mucosal gene chip technology can be used for rapid diagnosis and drug resistance detection of HP infection in children.

Diagnosis of Helicobacter pylori infection in the elderly using an immunochromatographic assay-based stool antigen test

The diagnostic value of Helicobacter pylori stool antigen (HpSA) tests in elderly subjects remains unclear. The objective of this study was to assess the diagnostic accuracy of the immunochromatographic assay‐based HpSA test in a male elderly cohort and identify factors affecting the accuracy. Data for asymptomatic elderly male citizens (≥65 years old) who received health checkups at the Chinese PLA General Hospital between July 2007 and November 2018 were collected. The diagnostic accuracy of the HpSA test was determined using the ¹³C‐urea breath test as a reference standard. Associations between baseline comorbidities and the accuracy of the HpSA test were analyzed. In total, 316 participants were enrolled, including 193 in the pre‐treatment group (77.2 ± 7.8 years old) and 123 in the post‐treatment group (78.7 ± 8.3 years old). The accuracy (91.5%, 91.2%, and 91.9%) and specificity (97.6%, 98.7%, and 96.0%) were high in all participants, pre‐ and post‐treatment groups, respectively. However, sensitivities were only 68.7%, 65.1%, and 75.0%, respectively. In the pre‐treatment group, constipation was associated with decreased sensitivity (p = 0.039), while colorectal polyps were associated with increased sensitivity (p = 0.010). Multivariate analysis indicated that constipation and colorectal polyps are independent factors for the sensitivity of HpSA in the pre‐treatment group. The immunochromatographic assay‐based HpSA test achieved high accuracy with high specificity but suboptimal sensitivity in the elderly male cohort. Constipation and colorectal polyps were negatively and positively associated with HpSA sensitivity, respectively, in the pre‐treatment group.

Helicobacter pylori CagA Protein Attenuates 5-Fu Sensitivity of Gastric Cancer Cells Through Upregulating Cellular Glucose Metabolism

Introduction

Gastric cancer (GC) is one of the most malignancies leading to human mortality due to its development, progress, metastasis and poor prognosis, despite the development of remarkable chemotherapy and surgery. The 5-fluorouracil (5-Fu) is an effective anti-gastric cancer agent. However, a fraction of GC patients acquire 5-Fu chemoresistance.

Methods

In this study, the CagA protein was detected from CagA-positive gastric cancer patients by qRT-PCR and immunohistochemistry. The 5-Fu resistant gastric cancer cell line was generated from MKN45-CagA cells which was transfected with CagA overexpression vector. Cellular glucose metabolism was determined by measurements of glucose uptake, lactate product and glycolysis enzymes.

Results

We report that the Helicobacter pylori (H. pylori)-secreted Cytotoxin-associated gene A (CagA) oncoprotein is positively correlated with 5-Fu resistance of gastric cancer. From totally 72 CagA-positive gastric cancer patients, CagA high-expressed patients showed more resistance to 5-Fu than CagA low-expressed patients. Moreover, statistical analysis revealed that CagA mRNA and protein expressions were significantly upregulated in 5-Fu resistant gastric cancer patients. We observed that CagA protein is upregulated in 5-Fu resistant gastric cancer cells compared with sensitive cells. Interestingly, cellular glucose metabolism was upregulated; the glucose uptake and lactate production were significantly higher in 5-Fu resistant gastric cancer cells. The Akt phosphorylation and expressions of glycolysis key enzymes, Hexokinase 2 and LDHA, were significantly upregulated in 5-Fu resistant gastric cancer cells. On the other way, inhibition of glycolysis or Akt pathway effectively overcame 5-Fu resistance from both in vitro and in vivo models. Finally, we report that the combination of Akt or glycolysis inhibitor with 5-Fu could synergistically enhance the cytotoxicity of 5-Fu to CagA-overexpressed gastric cancer cells.

Discussion

In summary, our study demonstrated a CagA-Akt-glycolysis-5-Fu resistance axis, contributing to the development of new therapeutic agents against chemoresistant human gastric cancer.

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.