Gastric Wash-Based Molecular Testing for Antibiotic Resistance in Helicobacter pylori

Abstract

Background: A number of noninvasive tests have been developed to establish the presence of Helicobacter pylori infection. However, thus far these tests have only been capable of detecting its presence. An increasing number of antibiotic-resistant H. pylori infections have been reported and they are known to be correlated with 23S rRNA single nucleotide polymorphisms (SNPs). We hypothesized that genomic analysis of H. pylori recovered from gastric washes could not only be less invasive, but also useful as a screening test and for assessing the outcome of eradication therapy. Methods: Biopsy specimens and gastric washes were collected from 100 patients during endoscopic examination. Then we analyzed 23S rRNA, ureA, and cagA genes using PCR and high-throughput pyrosequencing analysis. Results: Forty-five percent (44/97) of patients tested positive for ureA and 42.3% (41/97) tested positive by a rapid urease test. One hundred percent (35/35) of patients who tested positive by both methods were observed to have the cagA gene. Among these 35 patients, 23S rRNA SNPs were present in 34.3% (12/35). Conclusions: Gastric wash-based PCR and a pyrosequencing assay were used to rapidly detect and estimate the number of 23S rRNA SNPs in clinical isolates of H. pylori. Not only is this a less invasive technique, but it can also diagnose drug resistance.

BARHL2 Methylation Using Gastric Wash DNA or Gastric Juice Exosomal DNA is a Useful Marker For Early Detection of Gastric Cancer in an H. pylori -Independent Manner

“…However, discovery of tumor-specific hypermethylated genes using this strategy is challenging, because chronic inflammation of the gastric mucosae (mainly due to H. pylori infection and aging) also induces aberrant methylation. 9 , 10 , 11 , 12 , 13 , 14 Moreover, the process relies on endoscopic biopsy, which is a topical procedure that only samples a small portion of tissue. 15 As a result of the uneven distribution of the atrophy or intestinal metaplasia, this restricted biopsy can lead to flawed evaluation of methylation status.…”

Detection of DNA methylation of gastric juice-derived exosomes in gastric cancer

“…Indeed, the use of gastric juice DNA for molecular diagnostics has been deemed unfeasible because the DNA is easily degraded by gastric acidity [13]. One alternative to gastric juice is the use of gastric washes, for which we have developed a method for early GC detection by DNA methylation analysis of genes such as MINT25 and sex determining region Y-Box 17 (SOX17) [13][14][15].…”

Gastric Microenvironment Enables Persistence of Helicobacter pylori: a Physician's Combat Towards Eradication and Directions for the Future

“…For example, 23Sr RNA sequencing is done to assess clarithromycin susceptibility (Versalovic et al, 1996;Taylor et al, 1997). Molecular diagnostics can be run on traditional biopsy specimens and even on samples obtained by oro-gastric brush and gastric wash which are minimally invasive or stool samples, which are noninvasive (Kawai et al, 2008;Graham et al, 2005;Baba et al, 2011;Lottspeich et al, 2007). Moreover, these methods are time-saving when compared to conventional culture-sensitivity that consumes almost 10-14 days (7-10 days for culture, 2-4 days for sensitivity testing) and are more accurate.…”