Helicobacter pylori Infection: Conventional and Molecular Strategies for Bacterial Diagnosis and Antibiotic Resistance Testing

Helicobacter pylori infection is a common health problem, which can cause gastric and extragastric diseases. Accurate detection of H. pylori is critical for appropriate patient management and bacterial eradication. In this regard, there are several methods for the diagnosis of H. pylori infection, which are classically divided into two major groups of invasive and non-invasive methods. Invasive methods, such as endoscopy, histology, and relative culture are less preferred due to their operational difficulties. By contrast, non-invasive methods, such as urea breath test, (UBT) are clinically preferred. Moreover, molecular methods, including polymerase chain reaction (PCR)-based methods, next-generation sequencing (NGS), and DNA microarray, have shown good sensitivity and specificity, and are considered helpful in H. pylori diagnosis. These methods have also increasingly concentrated on the detection of bacterial antibiotic resistance patterns. Besides, point of care (POC) devices play an important role in H. pylori diagnosis, mainly by shortening the time to the result and by making the test available at the bedside or at remote care centres. Biosensors, including aptasensors, have shown to be more appropriate tools because of their low limit of detection, high selectivity, fast response, and ease of handling. Finally, new emerging techniques, like MALDI-TOF MS, have been considered as fast methods with high degree of accuracy and sensitivity to identify and differentiate new species of H. pylori. The current article reviews the most recent developments in invasive, noninvasive, and molecular approaches for the diagnosis of H. pylori infections. Moreover, the application of emerging techniques, including MALDI-TOF MS and recently developed POCs, and biomarker-based methods, is discussed.