scholarly journals Comparison of the Diagnostic Performance of qPCR, Sanger Sequencing, and Whole-Genome Sequencing in Determining Clarithromycin and Levofloxacin Resistance in Helicobacter pylori

2020 ◽  
Vol 10 ◽  
Author(s):  
Konrad Egli ◽  
Karoline Wagner ◽  
Peter M Keller ◽  
Lorenz Risch ◽  
Martin Risch ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Sanger Sequencing ◽  
Diagnostic Performance ◽  
Direct Detection ◽  
Resistance Testing ◽  
Whole Genome ◽  
Hybridization Probe ◽  
Gastric Biopsies ◽  
Probe Assay ◽  
H Pylori

Helicobacter pylori antibiotic resistance is increasing worldwide, emphasizing the urgent need for more rapid resistance detection prior to the administration of H. pylori eradication regimens. Macrolides and fluoroquinolones are widely used to treat H. pylori. In this study, we aimed to compare the diagnostic performance of A) 23SrDNA qPCR (with melting curve analysis) and an in-house developed gyrA qPCR followed by Sanger sequencing with a commercial IVD-marked hybridization probe assay (for 23SrDNA and gyrA) using 142 gastric biopsies (skipping culturing) and B) the same two qPCR for 23SrDNA and gyrA (including Sanger sequencing) with whole-genome sequencing (WGS) and phenotypic characterization of clarithromycin and levofloxacin resistance using 76 cultured isolates. The sensitivity of both qPCRs was 100% compared to that of the commercial IVD-marked hybridization probe assay for the detection of H. pylori in gastric biopsies (without resistance testing). The specificity of the qPCR gyrA followed by Sanger sequencing was 100%, indicating that the best sequence identity was always H. pylori. The results show good agreement between molecular tests, especially between qPCR (inclusive Sanger sequencing) and WGS. Discrepancies (concerning mutated or wild type of positive H. pylori gastric biopsies) were observed between Sanger sequencing of the gyrA gene and the corresponding commercial hybridization probe assay, mostly because the high sequence diversity of the gyrA gene even at positions adjacent to the relevant codons of 87 and 91 interfered with obtaining correct results from the hybridization probe assay. Interestingly, we found several mixed sequences, indicating mixed populations in the gastric biopsies (direct detection without culturing). There was a high percentage of both levofloxacin and clarithromycin resistance in gastric biopsies (both between 22% and 29%, direct detection in gastric biopsies). Therefore, we recommend analyzing both targets in parallel. We confirmed that phenotypic resistance is highly correlated with the associated mutations. We concluded that the two qPCR followed by Sanger sequencing of the gyrA gene is a fast, cost-effective and comprehensive method for resistance testing of H. pylori directly in gastric biopsies.

scholarly journals Efficacy of immunohistochemical staining in detecting Helicobacter pylori in Saudi patients with minimal and atypical infection

2021 ◽  
Vol 65 (3) ◽  
Author(s):  
Mohammed Akeel ◽  
Ahmed Elhafey ◽  
Atef Shehata ◽  
Erwa Elmakki ◽  
Thanaa Aboshouk ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Chronic Gastritis ◽  
Direct Detection ◽  
Giemsa Staining ◽  
Pcr Analysis ◽  
Qrt Pcr ◽  
Urease Test ◽  
Gastric Biopsies ◽  
Polymerase Chain ◽  
H Pylori

Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from patients with chronic gastritis and minimal or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H&E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H&E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The sensitivity of IHC staining (87.50%) was higher than that of H&E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H&E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H&E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. In contrast to routine H&E and modified Giemsa staining, IHC allows for the accurate H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

scholarly journals Efficacy of immunohistochemical staining in detecting Helicobacter pylori in Saudi patients with minimal and atypical infection

2020 ◽  
Author(s):  
Mohammed Abdulraheem Akeel ◽  
Ahmed Elhafey ◽  
Atef Shehata ◽  
Erwa Elmakki ◽  
Thanaa Aboshouk ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Diagnostic Accuracy ◽  
False Positive ◽  
Direct Detection ◽  
Giemsa Staining ◽  
Pcr Analysis ◽  
Qrt Pcr ◽  
Urease Test ◽  
Gastric Biopsies ◽  
H Pylori

Abstract Background Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from dyspeptic patients with minimal and/or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H&E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). Results The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H&E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The false-positive rates of H&E and modified Giemsa staining were 16% and 14%, respectively. The sensitivity of IHC staining (87.50%) was higher than that of H&E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H&E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H&E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. Conclusions H. pylori can be detected using routine H&E or modified Giemsa staining. However, the high sensitivity, specificity, and diagnostic accuracy of IHC staining minimise the false-positive/negative results and enable H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

Molecular Resistance Testing of Helicobacter pylori in Gastric Biopsies

2001 ◽  
Vol 125 (4) ◽  
pp. 493-497
Author(s):  
Jeremy Andrew Peña ◽  
James G. Fox ◽  
Mary Jane Ferraro ◽  
James Versalovic
Keyword(s):  
Helicobacter Pylori ◽  
Target Genes ◽  
Point Mutations ◽  
Resistance Testing ◽  
Biopsy Specimens ◽  
Gastric Biopsies ◽  
Initiation Of Therapy ◽  
H Pylori ◽  
Rdna Amplification ◽  
Diagnosis Of Infection

Abstract Objective.—To evaluate simultaneous diagnosis of infection and molecular resistance testing of Helicobacter pylori. Methods.—Gastric biopsies were obtained from 26 rapid urease-positive and 51 rapid urease-negative test kits used to diagnose H pylori infection. Following glass bead–assisted DNA isolation, amplification of H pylori 16S ribosomal DNA (rDNA), glmM, and 23S rDNA target genes was performed. Results.—Helicobacter pylori DNA was successfully amplified from 100% (26/26) of urease-positive and 3.9% (2/51) of urease-negative gastric biopsies. Subsequent restriction enzyme–mediated digestion of 23S rDNA amplification products revealed that 17% (4/24) of urease-positive and H pylori DNA–positive biopsy specimens contained point mutations (A2142G or A2143G) associated with clarithromycin resistance. Helicobacter pylori DNA from gastric biopsies was successfully amplified 8 weeks following rapid urease testing. Conclusion.—Helicobacter pylori genotyping may be used to detect macrolide-resistant H pylori in individuals prior to initiation of therapy or in patients refractory to anti-H pylori therapy. Two urease-negative specimens yielded Helicobacter DNA distinct from that of H pylori and indicated the need for further investigations of Helicobacter species present in the human stomach.

Analysis of babA, cagE and cagA Genes in Helicobacter pylori from Upper Gastric Patients in the North of Iran

2019 ◽  
Vol 19 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Saba Fakhrieh Asl ◽  
Mehrnaz Pourvahedi ◽  
Ali Mojtahedi ◽  
Mohammad Shenagari
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Diseases ◽  
Specific Primers ◽  
The North ◽  
Different Types ◽  
North Of Iran ◽  
Gastric Biopsies ◽  
Pcr Method ◽  
Non Ulcer Dyspepsia ◽  
H Pylori

Objective:Helicobacter pylori is a Gram-negative bacterium which has a serious effect on up to half of the world’s population and has been related to different gastric diseases. The goal of this study was to assess the frequency of babA, cagE and cagA genotypes among H. pylori strains isolated from gastric biopsies of endoscopic patients in the north of Iran.Methods:The present study was performed on 90 strains of H. pylori isolated from patients with gastric diseases (Gastric ulcer (GU), Duodenal ulcer (DU), Gastritis (G), Non-ulcer dyspepsia (NUD) and Gastric adenocarcinoma (GC)). DNA was extracted from all isolated strains and PCR method was performed to detect the prevalence of babA2, cagE and cagA genes using specific primers.Results:Among 90 samples of H. pylori, babA2, cagE, and cagA genes were detected in 42.2%, 30% and 82.2% of strains respectively. The statistical analysis showed that the prevalence of cagA gene in GU, G, DU, and NUD was significantly higher than other genes. Moreover, cagA, and babA2 genes were significantly more prevalent in GC patients compared to cagE gene. Our isolates exhibited 8 distinct arrangements of virulence patterns. The occurrence of cagA (35.6%) was the most prevalent pattern followed by cagA/babA2 (20%) and cagA/babA2/cagE (14.4%).Conclusion:In summary, as first report from Guilan province in the north of Iran, we showed significant association between the presence of babA2, cagE, and cagA genes in different types of gastric disorders.

scholarly journals Whole-Genome Sequencing and Comparative Genomics of Three Helicobacter pylori Strains Isolated from the Stomach of a Patient with Adenocarcinoma

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 331
Author(s):  
Montserrat Palau ◽  
Núria Piqué ◽  
M. José Ramírez-Lázaro ◽  
Sergio Lario ◽  
Xavier Calvet ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Virulence Factors ◽  
Outer Membrane Proteins ◽  
Whole Genome ◽  
Flagellar Biosynthesis ◽  
H Pylori ◽  
Restriction Modification

Helicobacter pylori is a common pathogen associated with several severe digestive diseases. Although multiple virulence factors have been described, it is still unclear the role of virulence factors on H. pylori pathogenesis and disease progression. Whole genome sequencing could help to find genetic markers of virulence strains. In this work, we analyzed three complete genomes from isolates obtained at the same point in time from a stomach of a patient with adenocarcinoma, using multiple available bioinformatics tools. The genome analysis of the strains B508A-S1, B508A-T2A and B508A-T4 revealed that they were cagA, babA and sabB/hopO negative. The differences among the three genomes were mainly related to outer membrane proteins, methylases, restriction modification systems and flagellar biosynthesis proteins. The strain B508A-T2A was the only one presenting the genotype vacA s1, and had the most distinct genome as it exhibited fewer shared genes, higher number of unique genes, and more polymorphisms were found in this genome. With all the accumulated information, no significant differences were found among the isolates regarding virulence and origin of the isolates. Nevertheless, some B508A-T2A genome characteristics could be linked to the pathogenicity of H. pylori.

Frequency of rdx A Deletion Mutation Conferring Metronidazole Resistance in Helicobacter pylori

2020 ◽  
Vol 29 (3) ◽  
pp. 59-64
Author(s):  
Hanaa M. El Maghraby ◽  
Samar Mohaseb
Keyword(s):  
Helicobacter Pylori ◽  
Epigastric Pain ◽  
Deletion Mutation ◽  
Rapid Urease Test ◽  
Rrna Gene ◽  
University Hospitals ◽  
Metronidazole Resistance ◽  
Urease Test ◽  
Gastric Biopsies ◽  
H Pylori

Background: Metronidazole is one of the antimicrobial drugs that can be used in combination with other drugs for eradication of Helicobacter pylori (H. pylori).Unfortunately, metronidazole resistance in H. plori is an increasing health problem which may be attributed to inactivation of many genes as rdx A gene. Objective: To determine the frequency of rdx A deletion mutation in H. pylori detected in infected patients attending at the Gastroenterology Unit, Zagazig University Hospitals. Methodology: Two gastric biopsies were taken from each enrolled patient by endoscopy. H.pylori detection was done by rapid urease test and polymerase chain reaction (PCR) amplification of 16S rRNA gene. Deletion mutation in rdx A gene was detected by conventional PCR. Results: Out of 134 doubled gastric biopsies obtained from 134 patients, 52.2% were positive for H. pylori. Epigastric pain, vomiting and gastritis were significantly associated with detection of H. pylori infection (p˂ 0.05). Deletion mutation of rdx A gene was detected in 28.6% of H. pylori positive specimens obtained from infected patients. Conclusion: Deletion mutation of rdx A gene is a frequent determinant of rdx A inactivation conferring metronidazole resistance among H. pylori.

scholarly journals Evaluation of Better Staining Method among Hematoxylin and Eosin, Giemsa and Periodic Acid Schiff-Alcian Blue for the Detection of Helicobacter pylori in Gastric Biopsies

2020 ◽  
Vol 27 (5) ◽  
pp. 53-61
Author(s):  
Abdullah Saleh Alkhamiss
Keyword(s):  
Helicobacter Pylori ◽  
Alcian Blue ◽  
National Guard ◽  
Periodic Acid ◽  
Giemsa Stain ◽  
Periodic Acid Schiff ◽  
Gastric Biopsies ◽  
Hematoxylin And Eosin ◽  
H Pylori ◽  
Sensitivity Specificity

Background: This study was undertaken to evaluate the preferred method (Giemsa or periodic acid Schiff-Alcian blue [PAS-AB] stains) of detecting Helicobacter pylori (H. pylori) in gastric mucosal biopsies in terms of sensitivity, specificity and applicability. To the best of my knowledge, this is the first report comparing Giemsa and PAS-AB staining for the detection of H. pylori in such biopsies. Methods: The formalin-fixed paraffin-embedded blocks of 49 gastric biopsies from different patients were collected from the archive of anatomical pathology at King Abdulaziz Medical City, National Guard, Riyadh, Saudi Arabia. From each block, three slides were prepared and analysed using the hematoxylin and eosin (H&E), Giemsa and PAS-AB stains to detect the presence/absence of H. pylori, and the results were compared in terms of sensitivity, specificity and applicability. Results: The majority of the biopsies in this study showed antrum-type gastric mucosa. Only 15 biopsies showed active gastritis, whereas the rest showed chronic gastritis. Three biopsies showed intestinal metaplasia. All were detected by PAS-AB stain, but only two-thirds were detected by H&E stain. Fifteen gastric biopsies showed H. pylori infection in general and in 13 of them, active gastritis cases were discovered. Fourteen out of these 15 H. pylori infection cases were detected by Giemsa stain, whereas only 13 cases were detected by H&E stain. PAS-AB stain showed the worst results since it demonstrated only 40% sensitivity and 67.65% specificity in H. pylori detection. Conclusion: Giemsa stain has better sensitivity and specificity in gastric H. pylori infection detection than PAS-AB. Therefore, using PAS-AB stain to detect H. pylori infection is not recommended.

Primary antibiotic resistance of Helicobacter pylori among a Chinese Tibetan population

2020 ◽  
Vol 15 (14) ◽  
pp. 1353-1361
Author(s):  
Xiaoqiong Tang ◽  
Xiaohong Chen ◽  
Yalin Shen ◽  
Tiankuo Yang ◽  
Renwei Hu ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Primary Resistance ◽  
Tibetan Population ◽  
Disk Diffusion Assay ◽  
Treatment Naïve ◽  
Gastric Biopsies ◽  
H Pylori ◽  
Resistance Rates ◽  
Diffusion Assay

Aim: To evaluate the primary antibiotic resistance in Helicobacter pylori strains isolated from a Chinese Tibetan population. Methods & materials: Gastric biopsies from 400 H. pylori treatment-naive Tibetan patients were collected for H. pylori isolation. Susceptibility to amoxicillin (AML)/clarithromycin (CLR)/levofloxacin (LEV)/metronidazole (MTZ)/tetracycline (TET)/rifampicin (RIF)/furazolidone (FZD) was determined by E-test or a disk diffusion assay. Results: Biopsies from 117 patients were H. pylori culture positive (29.3%). The primary resistance rates to MTZ, CLR, LEV, RIF, AML, TET and FZD were 90.6, 44.4, 28.2, 69.2, 7.7, 0.8 and 0.8%, respectively. Interestingly, 42.7% of the strains had simultaneous resistance to CLR and MTZ. Conclusion: Among Tibetan strains, primary resistance rates were high for CLR/MTZ/LEV, whereas primary resistance rates to AML/TET/FZD were low. The high resistance to RIF is a concerning finding.

scholarly journals Antibiotic Resistance and Genotypes of Helicobacter pylori Strains in Patients with Gastroduodenal Disease in Southeast Poland

2019 ◽  
Vol 8 (7) ◽  
pp. 1071 ◽  
Author(s):  
Izabela Korona-Glowniak ◽  
Halina Cichoz-Lach ◽  
Radoslaw Siwiec ◽  
Sylwia Andrzejczuk ◽  
Andrzej Glowniak ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Test Method ◽  
Rapid Urease Test ◽  
Microbial Culture ◽  
Virulence Markers ◽  
Gastroduodenal Disease ◽  
Urease Test ◽  
Gastric Biopsies ◽  
H Pylori

The aim of this study was to investigate genetic diversity of Helicobacter pylori virulence markers to predict clinical outcome as well as to determine an antibiotic susceptibility of H. pylori strains in Poland. Gastric biopsies from 132 patients with gastrointestinal disorders were tested for presence of H. pylori with the use of rapid urease test, microbial culture, and polymerase chain reaction (PCR) detection. The genetic diversity of 62 H. pylori positive samples was evaluated by detection of cagA and PCR-typing of vacA and iceA virulence-associated genes. Most common H. pylori genotypes were cagA(+)vacAs1m2 (27.4%) and cagA(−)vacAs2m2 (24.2%). In logistic regression analysis, we recognized the subsequent significant associations: gastritis with ureC, i.e., H. pylori infection (p = 0.006), BMI index (p = 0.032); and negatively with iceA1 (p = 0.049) and peptic ulcer with cagA (p = 0.018). Thirty-five H. pylori strains were cultured and tested by E-test method showing that 49% of strains were resistant to at least one of the tested antibiotics. This is the first study that reports the high incidence and diversity of allelic combination of virulence genes in gastroduodenitis patients in Poland. Genotyping of H. pylori strains confirmed the involvement of cagA gene and vacAs1m1 genotype in development and severity of gastric disorder.

scholarly journals Deep learning for sensitive detection of Helicobacter Pylori in gastric biopsies

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Sebastian Klein ◽  
Jacob Gildenblat ◽  
Michaele Angelika Ihle ◽  
Sabine Merkelbach-Bruse ◽  
Ka-Won Noh ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Deep Learning ◽  
Decision Support ◽  
Ground Truth ◽  
Novel Technologies ◽  
Therapeutic Decisions ◽  
Gastric Biopsies ◽  
H Pylori ◽  
Microscopic Diagnosis ◽  
Whole Slide Images

Abstract Background Helicobacter pylori, a 2 × 1 μm spiral-shaped bacterium, is the most common risk factor for gastric cancer worldwide. Clinically, patients presenting with symptoms of gastritis, routinely undergo gastric biopsies. The following histo-morphological evaluation dictates therapeutic decisions, where antibiotics are used for H. pylori eradication. There is a strong rational to accelerate the detection process of H. pylori on histological specimens, using novel technologies, such as deep learning. Methods We designed a deep-learning-based decision support algorithm that can be applied on regular whole slide images of gastric biopsies. In detail, we can detect H. pylori both on Giemsa- and regular H&E stained whole slide images. Results With the help of our decision support algorithm, we show an increased sensitivity in a subset of 87 cases that underwent additional PCR- and immunohistochemical testing to define a sensitive ground truth of HP presence. For Giemsa stained sections, the decision support algorithm achieved a sensitivity of 100% compared to 68.4% (microscopic diagnosis), with a tolerable specificity of 66.2% for the decision support algorithm compared to 92.6 (microscopic diagnosis). Conclusion Together, we provide the first evidence of a decision support algorithm proving as a sensitive screening option for H. pylori that can potentially aid pathologists to accurately diagnose H. pylori presence on gastric biopsies.

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