Molecular Cloning and Sequencing of Helicobacter pylori Urease Genes and Detection of H. pylori Using the Polymerase Chain Reaction Technique

1990 ◽  
pp. 74-80
Author(s):  
C. L. Clayton ◽  
M. J. Pallen ◽  
H. Kleanthous ◽  
B. W. Wren ◽  
S. Tabaqchali
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Molecular Cloning ◽  
Polymerase Chain Reaction Technique ◽  
Chain Reaction ◽  
Cloning And Sequencing ◽  
Polymerase Chain ◽  
H Pylori

scholarly journals Prevalence of the Helicobacter pylori babA2 Gene in Children Mainly Depends on the PCR Primer Set Used

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Anja Šterbenc ◽  
Maja M. Lunar ◽  
Matjaž Homan ◽  
Boštjan Luzar ◽  
Nina Zidar ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Diagnostic Tool ◽  
Clinical Relevance ◽  
Detection Methods ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Primer Sets ◽  
H Pylori ◽  
Pcr Primer

Various polymerase chain reaction- (PCR-) based methods with varying positivity rates were designed to detect the Helicobacter pylori babA2 gene. To compare different primer sets, babA2 prevalence was determined in 279 H. pylori-positive pediatric samples using the 832 bp, 139 bp, and 271 bp PCR primer sets, resulting in 34.0%, 51.3%, and 79.6% prevalence of the babA2 gene, respectively. The babA2 status determined using the 832 bp and 139 bp PCR primer sets significantly correlated with bacterial density and activity of inflammation, whereas no such correlations were found using the 271 bp PCR primer set. The 139 and 832 bp PCR primer sets concordantly detected the babA2 gene in 93 cases; however, in comparison to the 832 bp PCR primer set, the 139 bp PCR primer set detected additional 50 babA2 cases, whereas only two 832 bp positive cases were missed. The 271 bp PCR primer set missed 32 babA2 cases that were 832 bp and/or 139 bp PCR positive, but tested solely positive in 109 cases. Interestingly, cloning of a subset of 271 bp PCR positive samples revealed amplification of the babA/B gene chimera. Hence, in our opinion, the 271 bp PCR protocol is not a reliable diagnostic tool for detecting the babA2 gene in children. Our results reaffirm previous observations that the use of certain babA2 PCR primer sets can significantly impact estimation of the prevalence and clinical relevance of the H. pylori babA2 gene in children, suggesting babA2 detection methods should be carefully selected.

scholarly journals Clarithromycin-resistant Helicobacter pylori in Recife, Brazil, directly identified from gastric biopsies by polymerase chain reaction

2010 ◽  
Vol 47 (4) ◽  
pp. 379-382 ◽  
Author(s):  
Ana Kelly Lins ◽  
Roberto A Lima ◽  
Marcelo Magalhães
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Susceptibility Testing ◽  
Point Mutations ◽  
Chain Reaction ◽  
Clarithromycin Resistance ◽  
Polymerase Chain ◽  
Pre Treatment ◽  
H Pylori ◽  
Phenotypic Methods

CONTEXT: Clarithromycin is the most effective drug used in the eradication of infection by Helicobacter pylori. Due to worldwide increase in resistance, pre-treatment susceptibility testing for clarithromycin is recommended. OBJECTIVES: To evaluate the prevalence of clarithromycin resistance of H. pylori in Recife, a city in Northeast Brazil. METHODS: From January 2006 to December 2007, 114 gastric biopsy samples positive for H. pylori at culture were directly assayed by polymerase chain reaction (PCR) to detect the most frequent point mutations involved in clarithromycin resistance. Results were compared with those obtained by Etests. RESULT: Molecular and phenotypic methods showed 111 (97.4%) susceptible or resistant concordant results. PCR detected 3 (2.6%) biopsy specimens with H. pylori-resistant genotypes, which were misdiagnosed as susceptible by Etests. In Recife, based on PCR results, primary clarithromycin resistance was found in 15 (16.5%) patients, prevalence close to that observed in Southeast Brazil. Resistance increased to 52% among previously treated patients. The point mutation A2143G was present in 20 (71.4%) of specimens and A2142G, in 8 (28.6%) of specimens. A2142C was not found. CONCLUSION: In Recife, the prevalence of primary clarithromycin resistance, 16.5%, showed the need for pretreatment susceptibility testing in H. pylori infections.

scholarly journals Refluks Helicobacter pylori di mukosa hidung penderita rinosinusitis kronik disertai refluks laringofaring

2019 ◽  
Vol 48 (2) ◽  
pp. 148
Author(s):  
Sinta Sari Ratunanda ◽  
Billy Talakua ◽  
Teti Madiadipoera ◽  
Thaufiq Boesoirie ◽  
Ratna Anggraeni ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Real Time ◽  
Chronic Rhinosinusitis ◽  
Nasal Mucosa ◽  
Nasal Discharge ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Polymerase Chain ◽  
H Pylori

Latar belakang: Rinosinusitis kronik masih menjadi problema di seluruh dunia. Faktor yang berasosiasi dengan Rinosinusitis Kronik (RSK) diduga multifaktorial, salah satunya adalah refluks laringofaring (RLF). Isi refluks cairan lambung antara lain adalah bakteri Helicobacter pylori (H. pylori) yang dengan patomekanisme refluks, diduga dapat mencapai mukosa laringofaring bahkan sampai mukosa sinonasal, dan menyebabkan RSK. Tujuan: Mendeteksi  H. pylori di mukosa hidung akibat refluks pada penderita RSK disertai RLF. Bila terdeteksi H. pylori, tata laksana harus lebih komprehensif, sehingga diharapkan RSK menjadi terkontrol. Metode: Penelitian deskriptif untuk mengetahui ada tidaknya H. pylori di mukosa sinonasal penderita RSK dengan RLF. Deteksi H. pylori menggunakan teknik quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) dari bahan penyikatan mukosa hidung. Hasil: Didapatkan 86 orang penderita RSK disertai RLF, terdiri dari 30 (35%) pasien laki-laki dan 56 (65,0%) pasien wanita, dengan rerata usia 43,25±6,30 tahun. Keluhan RSK terbanyak adalah hidung tersumbat dengan skor VAS > 7 sebesar 76,8%. Skor nasoendoskopi RSK terbesar pada skor 2 untuk edema mukosa sebesar 65,3% dan skor 2 untuk sekret hidung sebesar 58,2%. Rata-rata skor gejala refluks (SGR) adalah 26,43±4,03 dan rata-rata total skor temuan refluks (STR) adalah 11,28±1,21. Hasil pemeriksaan deteksi H. pylori dengan qRT-PCR, 100% tidak menemukan H. pylori dari penyikatan mukosa hidung. Kesimpulan: Refluks berupa H. pylori tidak ditemukan pada mukosa hidung  penderita RSK disertai RLF. Penelitian lebih lanjut diperlukan dengan menggunakan gabungan beberapa metode pemeriksaan  bersamaan untuk deteksi H. pylori akibat refluks di mukosa sinonasal  penderita RSK disertai RLF.  Background: Chronic rhinosinusitis is presently still a worldwide problem. Assosiating factors  to chronic rhinosinusitis (CRS) are multifactorial, one of them is laryngopharyngeal reflux (LPR). The gastric juice contains Helicobacter pylori (H. pylori), which by pathologic reflux could reach laryngopharyngeal and sinonasal area causing CRS. Purpose: To detect H. pylori in nasal mucosa caused by reflux, which suspected of causing CRS with LPR disease. Should H. pylori be found in nasal mucosa, the management of the disease must be comprehensive to enable  controlling CRS. Methods: A descriptive study to detect H. pylori in nasal mucosa CRS with LPR patients, using Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) through nasal brushing. Results: Eighty-six CRS with LPR patients as study objects consisted of 30 (35%) male, and 56 (65%) female, the age mean was 43.25±6.3 years old. Visual Analoque Scale (VAS) score for nasal obstruction more than 7 was the highest complaint (76.8%). Nasal endoscopic score of mucosal edema (65.3%) and nasal discharge (58,2%) had score 2. The average total score reflux symptom index (RSI) was 26.43±4.03 and the total score reflux finding score (RFS) was 11.28±1.21. H. pylori detection found negative 100% in CRS with LPR specimens. Conclusion: This study did not find reflux containing H. pylori in nasal mucosa of CRS with LPR patients.    Suggesting further study using simultaneously several methods to detect H. pylori in nasal mucosa  CRS with LPR patients.

Molecular Identification of Helicobacter pylori and IceA Genes Frequency from Dental Plaques Isolated from People Using PCR Method

2020 ◽  
Author(s):  
Zahra Salari ◽  
Atefeh Ranjkesh ◽  
Emad Behboudi
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Chain Reaction ◽  
Ulcer Disease ◽  
Two Samples ◽  
Pcr Method ◽  
Dental Plaques ◽  
Polymerase Chain ◽  
H Pylori ◽  
Development And Evolution

Background and Aims: Helicobacter pylori (H. pylori) is a gram-negative, microaerophilic, spiral-shaped flagellated bacterium that is urease, catalase and oxidase positive. One of its pathogenicity factors is the iceA gene. H. pylori has recently been recognized as a genetic indicator for the development and evolution of duodenal ulcer disease in the East. This study aimed to determine the presence of this bacterium in gingival plaques in non-endocrine patients in Bojnourd city, and the polymerase chain reaction technique examined the percentage of iceA gene. Materials and Methods: A total of 100 samples of dental plaque were taken and transferred to a tube that has been physiologically placed. After DNA extraction, primer design was performed, and then the polymerase chain reaction was performed for the whole sample. Results: Of 100 samples examined in this study, two samples of H. pylori were positive (2%), and the frequency of the iceA gene of two samples was positive (100%). Conclusion: In the Bojnord city, the frequency of iceA gene in people is high, and the frequency of H. pylori in tooth plaques is low. Also, iceA gene can be considered as an indicator for predicting the contamination and risk of H. pylori infection in the region. To confirm the results, more molecular studies are required in other populations.

Is the polymerase chain reaction or cure of Helicobacter pylori infection of help in the differential diagnosis of early gastric mucosa-associated lymphatic tissue lymphoma?

1997 ◽  
Vol 15 (3) ◽  
pp. 1104-1109 ◽  
Author(s):  
B Rudolph ◽  
E Bayerdörffer ◽  
M Ritter ◽  
S Müller ◽  
C Thiede ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Differential Diagnosis ◽  
Gastric Mucosa ◽  
Malt Lymphoma ◽  
Complete Regression ◽  
Lymphatic Tissue ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
H Pylori

PURPOSE The differential diagnosis of early gastric mucosa-associated lymphatic tissue (MALT) lymphoma based on Helicobacter pylori gastritis may be difficult when lymphoepithelial lesions are not detected. The aim of the present study was to investigate the question whether the polymerase chain reaction (PCR) or cure of H pylori infection may be of help in this respect. PATIENTS AND METHODS Twenty patients with suspected low-grade gastric MALT lymphomas were treated in a double-blinded, randomized, crossover trial with 2,250 mg of either amoxicillin or placebo, both in combination with omeprazole, for 14 days with the aim to cure H pylori infection. PCR was performed using primers specific for the CDR3 region to detect monoclonal B cells. RESULTS In five of 20 patients, MALT lymphomas were finally diagnosed. Three of these five patients went into complete remission, while two were referred to surgery. In the 15 patients with gastritis, complete regression was observed in all cases. With respect to PCR, monoclonal bands were detected in all four of the analyzed lymphoma patients before histology showed lymphoma. In addition, monoclonal bands were found in three patients with gastritis. In the patients with gastritis and monoclonal PCR, complete regression took longer as compared with the remaining 12 patients with polyclonal PCR and gastritis (P = .0209). Successful H pylori eradication was associated with earlier diagnosis of the MALT lymphoma (P = .0237). CONCLUSION CDR3-PCR may be of help in the differential diagnosis of early gastric MALT lymphoma. Furthermore, H pylori eradication may lead to earlier diagnosis.

scholarly journals HELICOBACTER PYLORI cagA VIRULENCE GENE AND SEVERE ESOGASTRODUODENAL DISEASES: IS THERE AN ASSOCIATION?

2021 ◽  
Vol 58 (4) ◽  
pp. 468-475
Author(s):  
Ana Karoline Silva OLIVEIRA ◽  
Lucas Luiz de Lima SILVA ◽  
Marina Pacheco MIGUEL ◽  
Angel José Vieira BLANCO ◽  
Lilian Carla CARNEIRO ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Clinical Outcomes ◽  
Gastric Adenocarcinoma ◽  
Gastric Lymphoma ◽  
Caga Gene ◽  
Chain Reaction ◽  
Increased Risk ◽  
Polymerase Chain ◽  
H Pylori

ABSTRACT BACKGROUND: Helicobacter pylori colonizes approximately half of the world’s human population. Its presence in the gastric mucosa is associated with an increased risk of gastric adenocarcinoma, gastric lymphoma, and peptic ulcer disease. In Brazil, the high prevalence of H. pylori infection is a serious health problem. H. pylori virulence factors are associated with an increased risk of serious gastrointestinal disorders. The cagA gene encodes a cytotoxin-A-associated antigen (CagA) that is involved in bacterial pathogenicity. H. pylori strains carrying the cag pathogenicity island (cag-PAI) are significantly associated with severe clinical outcomes and histopathological changes. OBJECTIVE: The present study aims to investigate the prevalence of the cagA gene among H. pylori isolates from patients with different gastric pathologies. Further, the study hopes to verify its association with clinical outcomes. In addition, phylogenetic analysis was performed on cagA-positive H. pylori strains from patients with severe and non-severe diseases. METHODS: Gastric specimens were collected through a biopsy from 117 patients with different esogastroduodenal diseases. DNA was extracted from these gastric specimens and the polymerase chain reaction was performed to amplify the gene fragments corresponding to the 16S ribosomal RNA and cagA genes using specific primers. The polymerase chain reaction products of selected samples positive for cagA were sequenced. The sequences were aligned with reference sequences from the National Center for Biotechnology Information (NCBI) (Bethesda/USA), and a phylogenetic tree was constructed. RESULTS: H. pylori was detected in 65.9% (77/117) of Brazilian patients with different gastroduodenal disorders. Overall, 80.5% (62/77) of the strains were cagA-positive. The ages of patients with cagA-positive strains (15 males and 47 females) ranged from 18 to 74 years. The lesions were categorized as non-severe and severe according to the endoscopic and histopathological reports the most prevalent non-severe esogastroduodenal lesion was gastritis 54/77 (70.12%), followed by esophagitis 12/77 (15.58%) and duodenitis 12/77 (15.58%). In contrast, the most prevalent severe lesions were atrophy 7/77 (9.09%), followed by metaplasia 3/77 (3.86%) and gastric adenocarcinoma 2/77 (2.59%). Phylogenetic analyses performed with the partial sequences of the cagA gene obtained from local strains were grouped in the same clade. No differences in phylogenetic distribution was detected between severe and non-severe diseases. CONCLUSION: The cagA gene is highly prevalent among H. pylori isolates from gastric lesions in Brazilian patients. The presence of the cagA gene was not considered a marker of the severity of esogastroduodenal lesions in the present study. This is the first study to investigate the phylogenetic population structure of H. pylori strains in a Brazilian capital, which may improve our understanding of the clinical outcome of H. pylori infection.

scholarly journals Current Prevalence of Oral Helicobacter pylori among Japanese Adults Determined Using a Nested Polymerase Chain Reaction Assay

Pathogens ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Ryoko Nagata ◽  
Tatsuya Ohsumi ◽  
Shoji Takenaka ◽  
Yuichiro Noiri
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Infection Prevalence ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Lower Incisor ◽  
Characteristic Distribution ◽  
Japanese Adults ◽  
Polymerase Chain ◽  
H Pylori

In Japan, gastric Helicobacter pylori infection prevalence has markedly decreased with socioeconomic development. We aimed to investigate the prevalence of oral H. pylori in Japanese adults in 2020 by sex, age, sampling site, and medical history. Unstimulated saliva, supragingival biofilm, and tongue coating were obtained from 88 subjects–with no complaints of upper digestive symptoms–attending a dentist’s office for dental check-up or disorders. Supragingival biofilm was collected from the upper incisors, lower incisors, upper right molars and lower left molars to analyze the characteristic distribution. Oral H. pylori was detected using nested polymerase chain reaction. Oral H. pylori prevalence did not statistically differ by sex or age. Supragingival biofilm (30.7%) was the most common oral H. pylori niche; it was also detected in 4.5% of saliva and 2.3% of tongue samples. The lower incisor was the most common site among the supragingival biofilm samples, followed by the upper incisors, lower left molars, and upper right molars. Oral H. pylori DNA was frequently detected in patients with a history of gastric H. pylori infection. Oral H. pylori has a characteristic distribution independent of sex and age, suggesting that it is part of the normal microflora in the adult oral cavity.

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