Diagnosis of Helicobacter pylori: Changes towards the Future

Helicobacter pylori Diagnosis and Treatment in Africa: The First Lagos Consensus Statement of the African Helicobacter and Microbiota Study Group

BACKGROUND

Helicobacter pylori (H. pylori) infection is the most prevalent type of bacterial infection. Current guidelines from different regions of the world neglect specific African conditions and requirements. The African Helicobacter and Microbiota Study Group (AHMSG), founded in 2022, aimed to create an Africa-specific consensus report reflecting Africa-specific issues.

SUMMARY

Eighteen experts from nine African countries and two European delegates supported by nine African collaborators from eight other countries prepared statements on the most important African issues in four working groups: (1) epidemiology, (2) diagnosis, (3) indications and prevention, and (4) treatment. Limited resources, restricted access to medical systems, and underdeveloped diagnostic facilities differ from those of other regions. The results of the individual working groups were presented for the final consensus voting, which included all board members.

KEY MESSAGES

There is a need for further studies on H. pylori prevalence in Africa, with diagnosis hinged on specific African situation. Treatment of H. pylori in the African setting should be based on accessibility and reimbursement, while indication and prevention should be defined in specific African countries.

Helicobacter pylori: A Contemporary Perspective on Pathogenesis, Diagnosis and Treatment Strategies

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the gastric mucosa and is associated with various gastrointestinal disorders. H. pylori is a pervasive pathogen, infecting nearly 50% of the world's population, and presents a substantial concern due to its link with gastric cancer, ranking as the third most common cause of global cancer-related mortality. This review article provides an updated and comprehensive overview of the current understanding of H. pylori infection, focusing on its pathogenesis, diagnosis, and treatment strategies. The intricate mechanisms underlying its pathogenesis, including the virulence factors and host interactions, are discussed in detail. The diagnostic methods, ranging from the traditional techniques to the advanced molecular approaches, are explored, highlighting their strengths and limitations. The evolving landscape of treatment strategies, including antibiotic regimens and emerging therapeutic approaches, is thoroughly examined. Through a critical synthesis of the recent research findings, this article offers valuable insights into the contemporary knowledge of Helicobacter pylori infection, guiding both clinicians and researchers toward effective management and future directions in combating this global health challenge.

In vitro anti-bactrical activity and its preliminary mechanism of action of the non-medicinal parts of Sanguisorba officinalis L. against Helicobacter pylori infection

ETHNOPHARMACOLOGICAL RELEVANCE

Sanguisorba officinalis L. (S. officinalis L.), known as Di Yu (DY) in Traditional Chinese Medicine (TCM), are used to treat burns, vomiting of blood, asthma, intestinal infections, and dermatitis. It has been reported that the root of DY has a significant inhibitory effect on Helicobacter pylori (H. pylori). However, there is currently little research on the composition analysis and anti-H. pylori infection properties of the non-medicinal parts of DY, such as its stems, leaves, and flowers.

AIM OF STUDY

The commonly used eradication therapies for H. pylori infection are antibiotic-based therapies. With the increasing antibiotic resistance of H. pylori, it is urgent to find effective alternative therapies. To find alternative therapies and increase the utilization of DY, this study aims to investigate the phytochemistry profile, in vitro anti-H. pylori activity, and preliminary antibacterial mechanism of the non-medicinal parts of DY.

MATERIALS AND METHODS

The non-medicinal parts of DY extracts were obtained by using hot water reflux method. The chemical composition of these extracts was analyzed using colorimetric method, high-performance liquid chromatography (HPLC), and ultra-high-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS). The in vitro anti-H. pylori activity was investigated using broth microdilution method, checkerboard dilution method, time-kill curve, time-inhibition curve, scanning electron microscopy, and transmission electron microscopy. Transcriptional sequencing technology was used to study the effect of DY stems and flowers on the gene expression of H. pylori and explore possible antibacterial mechanisms.

RESULTS

The non-medicinal parts of DY contain abundant phytochemicals, such as total phenols and total flavonoids, and possess strong inhibitory and bactericidal activity against both standard and clinical strains of H. pylori in vitro. The MIC was 80-1280 μg/mL and the MBC was 80-2560 μg/mL, and the strength of the antibacterial effects was dependent on the concentration of phytochemicals (total polyphenols, gallic acid and ellagic acid). In addition, the combination of non-medicinal parts of DY with antibiotics, such as amoxicillin, metronidazole, levofloxacin, and clarithromycin, did not result in any antagonistic effects. All of them could disrupt the morphology, internal microscopic and cell wall structures of H. pylori thereby acting as an inhibitor. The mechanism of action was found to be the disruption of H. pylori morphology, internal microstructure, and cell wall. Transcriptomic analysis showed that the non-medicinal parts of DY significantly regulated the gene expression of H. pylori, especially the metabolic pathway.

CONCLUSIONS

This study analyzed the chemical composition of the non-medicinal parts of DY and confirmed its inhibitory and bactericidal activities against H. pylori, both standard and clinical strains. Additional, the mechanism of inhibition involves disrupting the structure of H. pylori cells, altering gene expression, and interfering with bacterial metabolic pathways. This study provides a reference for further resource utilization and the development of H. pylori drugs using the non-medicinal parts of DY.

Helicobacter pylori infection in Xinjiang Uyghur Autonomous Region: Prevalence and analysis of related factors

BACKGROUND

14C urea breath test (14C UBT) and immunohistochemical staining (IHC) are widely used for detection Helicobacter pylori (H. pylori) infection with different sensitivity, and there is a difference in H. pylori infection rate in Uyghur and Han ethnic groups. Both need large cohort studies to evaluate the differences more accurately.

AIM

To analyze the difference between 14C UBT and IHC for H. pylori detection in Xinjiang Uyghur Autonomous Region and the difference between Uyghur and Han populations.

METHODS

There were 3944 cases of H. pylori infection detected by both IHC and 14C UBT at the same time (interval < 1 wk, with sampling site including gastric antrum, selected from 5747 patients). We compared the sensitivity of 14C UBT and IHC. We also compared 555 pairs of Han/Uyghur cases (completely matched for gender and age) for their H. pylori infection rates. The overall H. pylori infection rate of all 5747 cases and the correlation with other clinicopathological data were also further analyzed. SPSS V23.0 software was used for statistical analysis.

RESULTS

The sensitivity was 94.9% for 14C UBT and 65.1% for IHC, which was a significant difference (n = 3944, P < 0.001). However, among those cases negative for H. pylori by 14C UBT (detection value ≤ 100), 4.8% were positive by IHC. Combining both methods, the overall H. pylori infection rate was 48.6% (n = 5747), and differences in gender, age group, ethnicity and region of residence significantly affected the H. pylori positive rates. According to age group (Han/Uyghur), the positive rates were ≤ 30 years (62.2%/100.0%), 31-40 years (45.2%/85.7%), 41-50 years (47.2%/79.2%), 51-60 years (44.6%/76.1%), 61-70 years (40.9%/68.2%), 71-80 years (41.7%/54.1%) and ≥ 81 years (42.9%/NA). The H. pylori infection rates of Han/Uyghur paired cases were 41.4% and 73.3%, which was a significant difference (P < 0.001) (555 pairs). H. pylori positivity was significantly related to moderate-severe grade 2-3 chronic/active gastritis and intestinal metaplasia (all P < 0.05).

CONCLUSION

The sensitivity of 14C UBT was significantly higher, but combined application can still increase the accuracy. The prevention H. pylori should be emphasized for Uygur and young people.

Anthocyanin-rich black carrot (Daucus carota ssp. sativus var. atrorubens Alef.) and red cabbage (Brassica oleracea) extracts incorporated biosensor for colorimetric detection of Helicobacter pylori with color image processing

In this work, we developed novel colorimetric biosensors consisting of anthocyanin-rich either black carrot (Daucus carota ssp. sativus var. atrorubens Alef.) or red cabbage (Brassica oleracea) extracts for rapid, sensitive, and economic detection of Helicobacter pylori (H. pylori). We comparatively prepared two test solutions as biosensors including anthocyanin-rich black carrot extract (Anth@BCE) and red cabbage extract (Anth@RCE), both of which fixed to pH 2.5 and investigated their colorimetric responses based on electronic structure and electron density of anthocyanins. We successfully used anthocyanin-rich BCE and RCE as natural pH indicators in detection of H. pylori and introduced their advantages like non-toxicity, easy accessibility, and high stability compared to synthetic indicators. The BCE and RCE tests gave the best color change in the presence of 103 CFU/mL (at 60 min) and 104 CFU/mL (at 75 min) H. pylori suspensions prepared in an artificial gastric fluid. The limit of detection was down to 10 CFU/mL for RCE and BCE tests by increasing incubation time (≥ 5 h). We further made an additional study that color differences in the colorimetric responses observed by naked eyes were supported by digital image processing with RGB (Red Green Blue) and Delta-E (ΔE) analysis. It is confirmed that results evaluated by naked eyes and digital image processing are well consistent with each other. These findings proposed that these colorimetric tests can be implemented to pH dependent detection of various microorganisms and can be effectively transferred from laboratory work to clinics in the near future.

A Malaysian consensus report on the diagnosis and treatment of Helicobacter pylori infection

Helicobacter pylori is one of the most common chronic bacterial infections in humans and responsible for 90% of duodenal ulcers and 70-90% of gastric ulcers. Despite this, many misconceptions regarding the appropriate diagnostic method and treatment strategies still exist in the Malaysian clinical practice. Under the initiative of the steering committee, an expert panel consisting of nine key opinion leaders in the field of gastroenterology convened to develop a set of consensus statements that are relevant to the Malaysian healthcare practice. The panel members reviewed the current evidence on the management of H. pylori infection, focusing on the best practices that are relevant to the Malaysian population based on clinical experience and published clinical evidence. Using the modified Delphi method, the panel achieved consensus in three areas of H. pylori infection management: indications for testing, diagnosis, and treatment. The panel proposed a set of 19 consensus statements, which were synthesized via two rounds of blinded voting and group discussions. The recommendations provided are relevant to the Malaysian population and can be used as a guide by physicians across various healthcare settings to facilitate appropriate diagnostic testing and treatment of H. pylori infection.

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.

Novel Anthocyanin-Based Colorimetric Assay for the Rapid, Sensitive, and Quantitative Detection of Helicobacter pylori

Several different diagnostic tests have been reported for rapid, sensitive, and economical detection of bacterial pathogens, but most lack widespread and practical use in the clinic. In this study, we used anthocyanins from red cabbage (Brassica oleracea) as a natural pH indicator and, for the first time, incorporated this agent into a simple, rapid, and economical colorimetric strategy for the detection of Helicobacter pylori (H. pylori) (RCE@test). We prepared two sets of RCE@test solutions (test 1 is purple, and test 2 is blue) in different forms, including liquid, adsorbed filter paper, and agar, and investigated the performance of each RCE@test as a function of the test volume, H. pylori concentration, and reaction time. To elucidate the effect of the pathophysiological environment on these RCE@tests, H. pylori in an artificial gastric fluid was also detected. The 10 and 1 CFU/mL H. pylori suspensions were detected in 15 min and 3 h, respectively, and the limit of detection was determined down to 1 CFU/mL. We experimentally demonstrated the advantages of the RCE@test for detection of H. pylori by comparing it to a commercially available rapid urease test, the "CLO test (Campylobacter-like organism test)". In addition to colorimetric detection by the naked eyes, RGB (Red Green Blue) and Delta-E analysis in image-processing software was run to quantitatively monitor changes of color in the RCE@test using a smartphone application. Finally, we propose that this test provides simple, effective, rapid, and inexpensive detection and that it can be easily implemented for clinical use.

Evaluation of Hematological Parameters of Helicobacter pylori-Infected Adult Patients at Southern Ethiopia: A Comparative Cross-Sectional Study

BACKGROUND

Helicobacter pylori (H. pylori) infection is a global public health problem, a higher burden of the infection was reported in developing countries including Ethiopia. It has been associated with several gastrointestinal diseases, and recently implicated in some hematological abnormalities. Despite the high prevalence of H. pylori infection in Ethiopia, there was limited data regarding the relationship between hematological parameters with H. pylori infection. Therefore, this study aimed to evaluate selected hematological parameters of H. pylori-infected patients attending Wachemo University Nigist Eleni Mohammed Memorial Referral Hospital (WUNEMMRH), Hosanna, Southern, Ethiopia.

METHODS AND MATERIALS

A comparative cross-sectional study was conducted from January to May 2019 among 374 (187 H. pylori-infected patients and 187controls) study participants. Data on socio-demographic characteristics were collected using a structured questionnaire. A five-milliliter venous blood sample was collected for hematological parameter analysis. Approximately two gram of stool specimen was collected to assess the presence of H. pylori antigen. Data were entered and analyzed by using SPSS version 21. Pearson correlation analysis and independent sample T-test was performed, and P-value < 0.05 was considered statistically significant.

RESULTS

Mean value of Hgb (p<0.001), RBC count (p<0.001), HCT (p<0.001), MCV (p=0.003), MCH (p=0.008), and MCHC (p=0.006) of H. pylori-infected patients were significantly lower than control group. However, the mean value of RDW (p=0.003) in H. pylori-infected patients was significantly higher than in the control group. About 13.3%, 7%, 6.4%, and 18.2% of H. pylori-infected patients showed reduced Hgb concentration, RBC count, HCT, and MCV values, respectively.

CONCLUSION

The study showed a statistically significant difference in the mean value of Hgb, RBC count, HCT, MCV, MCH, MCHC, and RDW of H. pylori-infected patients and controls. Thus, hematological parameters should be considered for proper diagnosis and management of H. pylori-infected patients and eradication of this microorganism from infected patients, determination of hematological parameters for H. pylori-infected patients were recommended.

Anemia and its association with Helicobacter pylori infection among adult dyspeptic patients attending Wachemo University Nigist Eleni Mohammad Memorial Referral Hospital, Southwest Ethiopia: A cross-sectional study

BACKGROUND

Anemia is a worldwide public health problem and also associated with Helicobacter pylori (H. pylori) infection. Determining the association of anemia with H. pylori infection is important to develop evidence-based decision and intervention strategies, which is not well known in Ethiopia. Thus, this study aimed to determine the association between anemia and H. pylori infection among adult dyspeptic patients attending Wachemo University Nigist Eleni Mohammad Memorial Referral Hospital in Southwest Ethiopia.

METHODS

A cross-sectional study was conducted from January to April 2019 involving 362 consecutive adult dyspeptic patients who came to the hospital during the study period. Socio-demographic, clinical and other related data were collected by structured questionnaires. Four milliliters of the venous blood sample was collected for hematological parameters analysis and blood film preparation. A stool sample was collected to detect H. pylori antigen and intestinal parasites. Data were analyzed by SPSS version 21. Logistic regression analyses were performed and p-value <0.05 was considered as statistically significant.

RESULTS

The overall prevalence of anemia among dyspeptic patients was 24.3% (95%CI: 19.9-28.7). Among H.pylori infected participants 29.2% were anemic, of which 69.2% had mild anemia and 63.5% had normocytic normochromic anemia. Rural residence (AOR: 1.9, 95%CI: 1.1-3.3), H. pylori infection (AOR: 1.77, 95%CI: 1.05-2.98) and intestinal parasitic infection (AOR: 2.14, 95%CI: 1.14-4.03) were significantly associated with anemia.

CONCLUSION

The prevalence of anemia in this study indicated that it is a moderate public health problem. Rural residence, H. pylori and intestinal parasitic infection were significantly associated with anemia. The findings of this study should be taken into account for the prevention and control of anemia among dyspeptic adults.

Helicobacter pylori Infection and Predictors Among Dyspeptic Adult Patients in Southwest Ethiopia: Cross-Sectional Study

Background

Globally, H. pylori infection affects approximately 4.4 billion people. The burden of the infection varies within and between countries, with a higher prevalence reported from developing countries including Ethiopia. Thus, this study aimed to determine the magnitude and predictors of H. pylori infection among dyspeptic patients who visited Wachemo University Nigist Eleni Mohammed Memorial Referral Hospital, Southwest Ethiopia.

Methods

Consecutive willing dyspeptic adult patients (n=405) were enrolled in a cross-sectional study done from September to December 18, 2019. Socio-demographic and behavioral characteristics of the study participants were gathered by a pretested structured questionnaire. Stool samples were examined for H. pylori antigens using Wondfo one step H. pylori feces test kit. SPSS version 20 was utilized to compute descriptive statistics, binary and multivariate logistic regression. A p-value of <0.05 was considered statistically significant.

Results

Mean age of patients was 30 (± 7.4 SD) years, and 56.8% of participants were females. About 51.4% (208/405) of adult dyspeptic patients were infected with H. pylori. Being female gender (AOR꞊ 2.56, CI 95% ꞊1.61-4.07, p꞊0.001), consumption of alcohol (AOR꞊1.95, CI 95% ꞊1.02-3.73, p꞊ 0.019) and being undernourished (underweighted) (AOR꞊ 4.59, CI 95%꞊ 1.28-16.45, p꞊0.019) were independent predictors of H. pylori infection.

Conclusion

In the study area, high (51.4%) magnitude of H. pylori infection was observed in dyspeptic patients and significantly associated with female gender, alcohol consumption, and undernourishment.

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.

Evaluating Diagnostic Tests for Helicobacter pylori Infection Without a Reference Standard: Use of Latent Class Analysis

Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.

A label-free fluorescence method for detection of ureC gene and diagnosis of Helicobacter pylori infection

The feasibility of using a polymerase chain reaction (PCR)-based label-free DNA sensor for the detection of Helicobacter pylori is investigated. In particular, H. pylori ureC gene, a specific H. pylori nucleic acid sequence, was selected as the target sequence. In the presence of ureC gene, the target DNA could be amplified to dsDNA with much higher detectable levels. After added the SYBR green I (SGI), the sensing system could show high fluorescence. Thus, the target DNA can be detected by monitoring the change of fluorescence intensity of sensing system. The clinical performance of this method was determined by comparing it with another conventional technique urea breath test (UBT). The result also showed good distinguishing ability between negative and positive patient, which was in good agreement with that obtained by the UBT. It suggests that the label-free fluorescence-based method is more suitable for infection confirmation test of H. pylori. This approach offers great potential for simple, sensitive and cost-effective identification of H. pylori infection.

Sensitivity of Helicobacter pylori detection by Giemsa staining is poor in comparison with immunohistochemistry and fluorescent in situ hybridization and strongly depends on inflammatory activity

BACKGROUND

Conventional stainings (including H&E and special stains like Giemsa) are the most widely applied histopathologic detection methods of Helicobacter pylori (HP).

MATERIALS AND METHODS

We aimed to compare the diagnostic performance of Giemsa staining with immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) on a monocentric cohort of 2896 gastric biopsies and relate results to histologic alterations in order to find such histopathologic subgroups in which these methods underperform. All cases were categorized regarding presence or absence of chronic gastritis, inflammatory activity, and mucosal structural alterations.

RESULTS

Giemsa revealed 687 cases (23.7%), IHC 795 cases (27.5%), and FISH 788 cases (27.2%) as being HP positive. Giemsa showed significantly lower overall sensitivity (83.3%) compared to IHC (98.8%) and FISH (98.0%). Moreover, the sensitivity of Giemsa dramatically dropped to 33.6% in the nonactive cases. We found that sensitivity of Giemsa strongly depends on HP density and, accordingly, on the presence of activity. Structural alterations (intestinal metaplasia, atrophy, etc.) had only no or weak effect on sensitivity of the three stainings. Both IHC and FISH proved to be equally reliable HP detecting techniques whose diagnostic performance is minimally influenced by mucosal inflammatory and structural alterations contrary to conventional stainings.

CONCLUSIONS

We highly recommend immunohistochemistry for clinically susceptible, nonactive chronic gastritis cases, if the conventional stain-based HP detection is negative. Moreover, we recommend to use IHC more widely as basic HP stain. Helicobacter pylori FISH technique is primarily recommended to determine bacterial clarithromycin resistance. Furthermore, it is another accurate diagnostic tool for HP.