Improvement and optimization of the classical gastric biopsy culture technique for Helicobacter pylori diagnosis using trypsin

Evolution of Diagnostic Methods for Helicobacter pylori Infections: From Traditional Tests to High Technology, Advanced Sensitivity and Discrimination Tools

Rapid diagnosis and treatment application in the early stages of H. pylori infection plays an important part in inhibiting the transmission of this infection as this bacterium is involved in various gastric pathologies such as gastritis, gastro-duodenal ulcer, and even gastric neoplasia. This review is devoted to a quick overview of conventional and advanced detection techniques successfully applied to the detection of H. pylori in the context of a compelling need to upgrade the standards of the diagnostic methods which are currently being used. Selecting the best diagnostic method implies evaluating different features, the use of one or another test depending on accessibility, laboratories equipment, and the clinical conditions of patients. This paper aims to expose the diagnosis methods for H. pylori that are currently available, highlighting their assets and limitations. The perspectives and the advantages of nanotechnology along with the concept of nano(bio)sensors and the development of lab-on-chip devices as advanced tools for H. pylori detection, differentiation, and discrimination is also presented, by emphasizing multiple advantages: simple, fast, cost-effective, portable, miniaturized, small volume of samples required, highly sensitive, and selective. It is generally accepted that the development of intelligent sensors will completely revolutionize the acquisition procedure and medical decision in the framework of smart healthcare monitoring systems.

What Is New in Helicobacter pylori Diagnosis. An Overview

Helicobacter pylori infection remains one of the most prevalent infections worldwide, especially in low-resource countries, and the major risk factor for peptic ulcer and gastric cancer. The “test-and-treat” strategy is recommended by several guidelines and consensus. The choice of testing method is based on patient age, presence of alarm signs and/or symptoms, use of non-steroidal anti-inflammatory drugs, as well as local availability, test reliability, and cost. Culture is the gold standard to detect H. pylori and, possibly, to perform susceptibility testing, however, it requires upper endoscopy and dedicated labs. Recent advances in molecular biology have provided new strategies in detecting infection and antimicrobial resistance without invasive tests. In this review we attempt to offer a comprehensive panorama on the new diagnostic tools and their potential use in clinical settings, in order to accomplish specific recommendations.

Accuracy of invasive and noninvasive methods of Helicobacter pylori infection diagnosis in Saudi children

BACKGROUND/AIM

Helicobacter pylori (H. pylori) infection is one of the most common chronic infections in the world. The prevalence of H. pylori is high in Saudi Arabia, but there are no studies in children on the accuracy of invasive and noninvasive methods to diagnose H. pylori infection. The aim of this study was to evaluate the accuracy of six methods for diagnosis of H. pylori infection; four invasive [rapid urease test (RUT), histology, antral nodularity (AD), and biopsy culture (BC)] and two noninvasive methods [serologic test and stool antigen test (SAT)].

PATIENTS AND METHODS

A prospective cross-sectional study was performed among symptomatic children in National Guard hospitals who underwent esophagogastroduodenoscopy from 2010 to 2013. The gold standard diagnosis of H. pylori was positive tissue culture. If the culture was unsuccessful or not done, concordant-positive results for histology and RUT were considered to indicate a positive H. pylori. The variables analyzed as diagnostic methods included RUT, BC, histology, AD, serologic test, and SAT.

RESULTS

A total of 303 children were included in the study. The overall prevalence of H. pylori infection was 49.8%. Most diagnostic tests showed high specificity and moderate-to-low sensitivity when compared to the gold standard test. Sensitivity of AD, SAT, and RUT to detect H. pylori were 62% (95% CI: 0.51-0.74), 69% (95% CI: 0.58-0.79), and 87% (95% CI: 0.79-0.95), respectively (P value 0.040, 0.0023, and <0.0001, respectively). RUT showed the lowest specificity, 65% (95% CI: 0.58-0.71) in contrast to BC and histology which showed moderate-to-high specificities of 88% (95% CI: 0.82-0.95) and 89% (95% CI: 0.82-0.95), respectively (P <0.0001).

CONCLUSION

RUT is a valuable diagnostic method for identifying H. pylori with the highest sensitivity compared to AD and SAT. All diagnostic tests showed moderate-to-high specificities but BC and histology showed the highest specificity.

Diagnostic of Helicobacter pylori infection

There is progress in endoscopy techniques. While it is not yet possible to detect Helicobacter pylori directly in the stomach, it becomes easier to detect the mucosal changes induced by the bacteria. Some small changes can also increase the sensitivity of the invasive tests, for example culture or histology, but the wide use of proton-pump inhibitors has a negative impact on these tests. Only molecular methods are able to detect a limited load of bacteria, especially by using real-time PCR but also with new methods, for example dual-priming oligonucleotide-based PCR, loop-medicated isothermal amplification, droplet-digital PCR or a multiple genetic analysis system. Among the noninvasive tests, urea breath test remains a test of major interest, while there are attempts to develop an ammonia breath test and other nanosensor devices. A new antigen stool test, a chemoluminescence immunoassay using the LIAISON apparatus has also been tested for the first time with success. Despite its limitations, serology remains the most popular test to detect H. pylori antibodies. It also allows pepsinogen dosage which is of interest for detecting atrophy.