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 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.

Detection of Helicobacter pylori cagA gene by polymerase chain reaction in faecal samples

1999 ◽  
Vol 11 (3) ◽  
pp. 251-256 ◽  
Author(s):  
Francesco Russo ◽  
Maria Notarnicola ◽  
Giovanni Di Matteo ◽  
Claudio Leoci ◽  
Maria Lucia Caruso ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Helicobacter Pylori ◽  
Caga Gene ◽  
Chain Reaction ◽  
Faecal Samples ◽  
Polymerase Chain

scholarly journals Helicobacter pylori and cagA gene detected by polymerase chain reaction in gastric biopsies: correlation with histological findings, proliferation and apoptosis

2005 ◽  
Vol 123 (3) ◽  
pp. 113-118 ◽  
Author(s):  
Katia Ramos Moreira Leite ◽  
Elaine Darini ◽  
Flavio Canelas Canavez ◽  
Claudia Muraro de Carvalho ◽  
Cristina Aparecida Troquez da Silveira Mitteldorf ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Cell Proliferation ◽  
Helicobacter Pylori ◽  
Epithelial Cell Proliferation ◽  
Caga Gene ◽  
Histological Findings ◽  
Chain Reaction ◽  
Proliferation And Apoptosis ◽  
Gastric Biopsies ◽  
Polymerase Chain

CONTEXT AND OBJECTIVE: The virulence of Helicobacter pylori (HP) in gastroduodenal disease is related to pathogenicity islands (cagPAI) present in some strains. Infection with cagPAI induces IL-8 secretion, increases epithelial cell proliferation and may be important in carcinogenesis. Our objective was to detect HP and the cagA gene (cagPAI marker) by polymerase chain reaction (PCR) and to correlate these results to histological findings, epithelial cell proliferation and apoptosis. DESIGN AND SETTING: Retrospective, at the Surgical and Molecular Pathology Laboratory, Hospital Sírio-Libanês. METHODS: DNA samples isolated from 164 gastric biopsies were used for HP detection by PCR. cagPAI+ was identified in HP+ cases by cagA gene amplification. All cases were submitted to immunohistochemistry to evaluate cell proliferation, and TUNEL to detect apoptosis. Statistical analysis was performed to compare results. RESULTS: HP was detected in 67.7% of the patients, with good correlation between HP infection and moderate to severe gastritis, gastric ulcer and MALT lymphoma. There was a correlation between cagPAI+ strains and severe gastric diseases including cancer. The risk of gastric ulcer, adenocarcinoma and MALT lymphoma was 8.8 times higher for cagPAI+ patients. cagPAI+ infection was related to higher proliferation rates. The proliferation/apoptosis index was significantly higher for cagPAI+ patients. CONCLUSION: Cell growth deregulation in cagPAI+ patients could be demonstrated by the difference in the proliferation index. We believe that this explains the carcinogenic role of Helicobacter pylori.

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 Analysis of Helicobacter pylori Genotypes in Afghani and Iranian Isolates

2010 ◽  
Vol 59 (1) ◽  
pp. 61-66 ◽  
Author(s):  
HOSSEIN DABIRI ◽  
MEHDI BOLFION ◽  
AKBAR MIRSALEHIAN ◽  
MARYAM REZADEHBASHI ◽  
FERESHTEH JAFARI ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Clinical Outcomes ◽  
Positive Culture ◽  
Chain Reaction ◽  
Vacuolating Cytotoxin ◽  
Ulcer Disease ◽  
Polymerase Chain ◽  
H Pylori ◽  
Iranian Patients

The geographical variation in Helicobacter pylori genotypes is an observed phenomenon. Cytotoxin associated genes A (cagA) and E (cagE), and vacuolating cytotoxin (vacA) genotypes of H. pylori are associated with peptic ulcer disease (PUD). This study compared the distribution of these genotypes in Iranian and Afghani isolates and their association with clinical outcomes. H. pylori infected patients, as proven by positive culture, were recruited prospectively. A total of 70 patients, 55 Iranian (26 men and 29 women, mean age 48 +/- 18 years) and 15 Afghani immigrants (13 men and 2 women, mean age 34.8 +/- 11 years) living in Tehran, Iran were enrolled in this study. DNA was extracted from isolated H. pylori and polymerase chain reaction was carried out to determine the cagA and cagE status and vacA alleles. The number of gastric cancer, peptic ulcer and gastritis cases was 11, 23 and 36, respectively. The cagA positive isolates were more common in Iranian (67%) than Afghani isolates (60%). cagE was positive in 53% of Afghani compared to 51% of Iranian isolates. The most common vacA s-region genotype was s1; 80% in Afghani and 67% in Iranian. The slml was a frequently observed genotype in Afghani strains (53%) while s1m2 (47%) was more common in strains isolated from Iranian patients. There is a difference in the H. pylori strains between Iranian and Afghani groups, for instance Iranian isolates were similar to European isolates while Afghani isolates were similar to isolates from India. However, there was no significant association between cagA, cagE and vacA genotypes and clinical outcomes in Iranian and Afghani patients.

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.

scholarly journals Evaluation of the Pattern of EPIYA Motifs in the Helicobacter pylori cagA Gene of Patients with Gastritis and Gastric Adenocarcinoma from the Brazilian Amazon Region

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Adenielson Vilar e Silva ◽  
Mario Ribeiro da Silva Junior ◽  
Ruth Maria Dias Ferreira Vinagre ◽  
Kemper Nunes Santos ◽  
Renata Aparecida Andrade da Costa ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Intestinal Metaplasia ◽  
Gastric Adenocarcinoma ◽  
Brazilian Amazon ◽  
Caga Gene ◽  
Neutrophil Activity ◽  
Increased Risk ◽  
Brazilian Amazon Region ◽  
H Pylori ◽  
Epiya Motifs

The Helicobacter pylori is associated with the development of different diseases. The clinical outcome of infection may be associated with the cagA bacterial genotype. The aim of this study was to determine the EPIYA patterns of strains isolated from patients with gastritis and gastric adenocarcinoma and correlate these patterns with the histopathological features. Gastric biopsy samples were selected from 384 patients infected with H. pylori, including 194 with chronic gastritis and 190 with gastric adenocarcinoma. The presence of the cagA gene and the EPIYA motif was determined by PCR. The cagA gene was more prevalent in patients with gastric cancer and was associated with a higher degree of inflammation, neutrophil activity, and development of intestinal metaplasia. The number of EPIYA-C repeats showed a significant association with an increased risk of gastric carcinoma (OR = 3.79, 95% CI = 1.92–7.46, and P=0.002). A larger number of EPIYA-C motifs were also associated with intestinal metaplasia. In the present study, infection with H. pylori strains harboring more than one EPIYA-C motif in the cagA gene was associated with the development of intestinal metaplasia and gastric adenocarcinoma but not with neutrophil activity or degree of inflammation.

scholarly journals Diagnosis and posttreatment follow-up of Helicobacter pylori-positive gastric lymphoma of mucosa-associated lymphoid tissue: histology, polymerase chain reaction, or both?

Blood ◽  
1996 ◽  
Vol 87 (4) ◽  
pp. 1255-1260 ◽  
Author(s):  
A Savio ◽  
G Franzin ◽  
AC Wotherspoon ◽  
G Zamboni ◽  
R Negrini ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
B Cell ◽  
Lymphoid Tissue ◽  
Gastric Lymphoma ◽  
Cell Populations ◽  
Chain Reaction ◽  
Clonal Population ◽  
Biopsy Specimens ◽  
Polymerase Chain ◽  
H Pylori

The differential diagnosis between Helicobacter pylori (H pylori- associated chronic gastritis and low-grade B-cell gastric lymphoma of mucosa-associated lymphoid tissue (MALT) and the assessment of endoscopic biopsy specimens after treatment of lymphoma can be problematic. Although immunocytochemistry can be used to identify clonal B-cell populations, which are characteristic of MALT lymphoma, its application to small biopsy specimens and the subsequent interpretation can be difficult. The polymerase chain reaction (PCR) can detect clonal B-cell populations by analysis of the Ig heavy chain gene in routinely fixed paraffin-embedded material and might provide a useful tool in the assessment of these specimens. We have investigated the value of histology and PCR in the diagnosis of lymphoma and its followup in formalin-fixed paraffin-embedded gastric endoscopy biopsy specimens from 69 sequential patients selected on the basis of a dense mucosal lymphoid infiltrate associated with H pylori infection. Histologic evidence of MALT lymphoma was identified in 13 cases, 9 of which showed PCR-detected monoclonality. In 12 of 13 cases, H pylori was eradicated, and in 11 of 12 cases, histologic regression of the lymphoma followed. PCR evidence of monoclonality disappeared in 6 of 9 originally monoclonal cases. This was synchronous with histologic remission in 1 case, but lagged in the remaining 5 cases by up to 28 months. Two of the 3 of the 9 cases originally monoclonal by PCR that have not shown molecular regression have monoclonal-amplified products 17 and 24 months after negative histology. In 3 cases, the histology of the biopsies was considered indeterminate or discordant. In 1 of these cases, the histologic features were obscured by crush artefact. In a second case, there was molecular evidence of monoclonality in the absence of histologic features suggestive of lymphoma; this persisted after H pylori eradication. An additional single case originally diagnosed as reactive developed a PCR detectable clonal population 29 months after original evaluation in the absence of histologic features of lymphoma but in the presence of persistent H pylori infection. These findings suggest that the histologic assessment of gastric biopsies remains the method of choice for the diagnosis of lymphoma in gastric endoscopic biopsies with a dense mucosal lymphoid infiltrate. PCR provides a useful technique to support the diagnosis if clonal amplification products are found. The significance of PCR detected clonality in the absence of histologic evidence of lymphoma in uncertain but may represent a stage of tumor progression/regression when the clonal population is insufficient to be detected by conventional histology. This is supported by the evidence that PCR- detectable monoclonality can persist after treatment and the disappearance of histologically detectable lymphoma.

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