scholarly journals Evaluation of the Novel Helicobacter pylori ClariRes Real-Time PCR Assay for Detection and Clarithromycin Susceptibility Testing of H. pylori in Stool Specimens from Symptomatic Children

2007 ◽  
Vol 45 (6) ◽  
pp. 1718-1722 ◽  
Author(s):  
C. Lottspeich ◽  
A. Schwarzer ◽  
K. Panthel ◽  
S. Koletzko ◽  
H. Russmann
Keyword(s):  
Helicobacter Pylori ◽  
Real Time ◽  
Real Time Pcr ◽  
Susceptibility Testing ◽  
The Novel ◽  
Pcr Assay ◽  
Stool Specimens ◽  
H Pylori

scholarly journals Clinical Evaluation of a Real-Time PCR Assay for Simultaneous Detection of Helicobacter pylori and Genotypic Markers of Clarithromycin Resistance Directly from Stool

2021 ◽  
Author(s):  
Rebecca Marrero Rolon ◽  
Scott A Cunningham ◽  
Jayawant N Mandrekar ◽  
Erin T Polo ◽  
Robin Patel
Keyword(s):  
Helicobacter Pylori ◽  
Real Time ◽  
Triple Therapy ◽  
Real Time Pcr ◽  
Simultaneous Detection ◽  
Pcr Assay ◽  
Clarithromycin Resistance ◽  
Treatment Naïve ◽  
Stool Samples ◽  
H Pylori

Helicobacter pylori infection is mainly diagnosed non-invasively, with susceptibility testing traditionally requiring endoscopy. Treatment is empiric, with clarithromycin triple therapy recommended where resistance rates are below 15%. Rising clarithromycin resistance resulting in high therapy failure rates is seen worldwide but United States data is limited. We developed a real-time PCR assay for simultaneous detection of H. pylori and genotypic markers of clarithromycin resistance directly from stool specimens. The assay was validated by testing 524 stool samples using an H. pylori stool antigen test as the reference method for detection accuracy and Sanger sequencing to confirm genotypic susceptibility results. A separate set of 223 antigen positive stool samples was tested and retrospective medical record review conducted to define clinical utility. PCR resulted in 88.6% and 92.8% sensitivity in the validation and clinical study sets, respectively. Sequencing confirmed correct detection of clarithromycin resistance-associated mutations in all positive validation samples. The PCR predicted clarithromycin resistance rate was 39% in the clinical data set overall and 28% in treatment naïve patients; the clarithromycin triple therapy eradication rate in treatment naïve patients was 62%. The clarithromycin triple therapy success was lower when resistance was predicted by PCR (41%) than when no resistance was predicted (70%, p=0.03). PCR was positive in 98% of antigen positive stools from patients tested for eradication. The described PCR assay can accurately and non-invasively diagnose H. pylori, provide genotypic susceptibility, and test for eradication. Our findings support the need for susceptibility-guided therapy in our region if a clarithromycin-based regimen is considered.

scholarly journals Evaluation of DNA extraction methods for quantifying Helicobacter pylori in water with PCR inhibitors

2021 ◽  
Author(s):  
Eun-Sook Lee ◽  
So-Yang Cha ◽  
Jong-Soon Jung
Keyword(s):  
Helicobacter Pylori ◽  
Real Time ◽  
Dna Extraction ◽  
Water Samples ◽  
Real Time Pcr ◽  
Heavy Rain ◽  
Extraction Methods ◽  
Pcr Inhibitors ◽  
H Pylori ◽  
Dna Extraction Methods

Abstract DNA extraction methods were evaluated to reduce PCR inhibitors and quantify Helicobacter pylori directly from water samples using real-time PCR. Three nucleic acid extraction methods were evaluated for different types of water samples. While the QIAamp DNA mini kit for tissue was suitable for DNA extraction from treated water, the QIAamp DNA stool mini kit was still efficient in analyzing samples from river water after heavy rain and with high concentration of PCR inhibitors. The FastDNA SPIN Kit for Soil could extract DNA effectively from microbes in river and stream waters without heavy rain. Immunomagnetic separation (IMS) was used prior to DNA extraction and was a useful tool for reducing PCR inhibitors in influent and stream samples. H. pylori in various waters could be quantified directly by real-time PCR while minimizing the effect of PCR inhibitors by an appropriate method through the evaluation of DNA extraction methods considering the characteristics of the matrix water. The findings of the present study suggest that the types or characteristics of water sample by source and precipitation are an important factor in detecting H. pylori and they can be applied when detecting and monitoring of other pathogens in water.

scholarly journals Evaluation of a stool antigen test using a mAb for native catalase for diagnosis of Helicobacter pylori infection in children and adults

2014 ◽  
Vol 63 (12) ◽  
pp. 1621-1625 ◽  
Author(s):  
Masumi Okuda ◽  
Takako Osaki ◽  
Shogo Kikuchi ◽  
Junko Ueda ◽  
Yingsong Lin ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Real Time ◽  
Real Time Pcr ◽  
High Specificity ◽  
Antigen Test ◽  
Stool Antigen Test ◽  
Non Invasive ◽  
Significant Difference ◽  
Stool Antigen ◽  
H Pylori

Non-invasive diagnosis of Helicobacter pylori infection is important not only for screening of infection but also for epidemiological studies. Stool antigen tests are non-invasive and are convenient to identify H. pylori infection, particularly in children. We evaluated the stool antigen test, which uses a mAb for native catalase of H. pylori developed in Japan. A total of 151 stool samples were collected from participants (52 children and 99 adults) of the Sasayama Cohort Study and stored between −30 and −80 °C. The stool antigen test used was Testmate pylori antigen (TPAg), and was performed according to the manufacturer’s instructions. Furthermore, we conducted a quantitative real-time PCR test and compared the PCR results with those of the TPAg test. When compared with the results in real-time PCR, the sensitivity of TPAg was 89.5 % overall, 82.7 % for children and 92.4 % for adults, and the specificity was 100 %. The accuracy was 93.4 % overall, 90.4 % for children and 94.9 % for adults, and there was no significant difference in the accuracy of TPAg between children and adults. Five of 28 children (18 %) and five of 38 adults (13 %) were PCR positive with negative TPAg results. Four of five children with positive PCR and negative TPAg results were given a 13C-urea breath test and all four children tested negative. No significant correlation was observed between the TPAg results and DNA numbers of H. pylori in faeces among children or adults. A stool antigen test (TPAg) using a mAb for native catalase is useful for diagnosis of H. pylori in children and adults. Additionally, this test has particularly high specificity.

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