pylori and two types of point mutation causing clarithromycin resistance (A2142G and A2143G) on 127 gastric biopsies [42] in comparison with standard phenotypic tests and an in-house real-time fluorescence

resonance energy transfer (FRET)-PCR. The sensitivity of DPO-PCR and real-time FRET-PCR was 97.7 and 100%, and specificity was 83.1 and 80.7%, respectively, indicating the interest of this method. Miendje Deyi et al. [43] evaluated the performance and usefulness of a multiplex PCR followed by hybridization on a strip, the Genotype® HelicoDR kit (Hain LifeScience, Selleckchem Neratinib Nehren, Germany), for the detection of H. pylori and for the determination of resistance to clarithromycin and fluoroquinolones in gastric biopsies obtained from 128 patients. This kit proved to be promising for practical use because of its excellent sensitivity, speed, and ability to detect infections with multiple strains. Compared to the culture-based method, the performance of HelicoDR in detecting fluoroquinolone resistance was, however, lower LY294002 manufacturer than that of clarithromycin resistance. The authors emphasized the necessity of adapting the probes to the local prevalence of mutations, in particular in detecting new GyrA mutations that are not included in the kit. After the improvement of DNA extraction methods from stool samples, a stool real-time PCR assay (H. pylori ClariRes assay; Ingenetix, Vienna,

Austria) is now available as the only noninvasive test allowing H. pylori detection and clarithromycin susceptibility testing. In Brazil, H. pylori DNA from gastric biopsies and stool specimens from 217 dyspeptic children were extracted with the QIAampDNA stool mini kit (Qiagen, Valencia, CA, USA). The sensitivity and specificity of the test were 69 and 100% for the detection of H. pylori and 83.3 and 100% for the detection of clarithromycin resistance, respectively.

This assay proved to be appropriate for H. pylori clarithromycin susceptibility testing, particularly in populations with a high clarithromycin Montelukast Sodium resistance [44]. The same stool PCR assay was useful and effective as a noninvasive approach for H. pylori susceptibility testing in tailored treatments in children [45]. Results showed that it was as effective as culture. Another application of a stool PCR assay is as a noninvasive method for genotyping H. pylori. Several articles tackled this topic [46, 47]. Indian authors have developed a quantitative real-time PCR (Q-PCR) assay to determine the levels of the H. pylori DNA within human gastric mucosa [48]. They used the ureC gene (one copy per bacterium) as the target. This technique is easy to perform and allows for the rapid determination and quantification of H. pylori, which can be used for monitoring the treatment outcome. One of the presumed reasons why infection with H. pylori is persistent and difficult to eradicate is the colonization of individual hosts by multiple H. pylori genotypes. In the study of Ren et al.