PCR Detection of Helicobacter pylori in Clinical Samples

Rimbara, Emiko; Sasatsu, Masanori; Graham, David Y.

doi:10.1007/978-1-60327-353-4_19

Cited by 74 publications

(54 citation statements)

References 12 publications

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“…Tumor and normal tissues were investigated for the presence of H. pylori DNA using H. pylori-specific primers for 16S rRNA and UreC (Table 1) [29]. The PCR conditions were as follows: initial denaturation at 95°C for 5 min, followed by 40 cycles at 92°C for 30 s, 55°C for 40 s, and 72°C for 40 s. The final extension step was at 72°C for 5 min.…”

Section: Pcr Amplification Of H Pylori Genesmentioning

confidence: 99%

Evaluation of thymic stromal lymphopoietin (TSLP) and its correlation with lymphatic metastasis in human gastric cancer

et al. 2015

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Thymic stromal lymphopoietin (TSLP) is an IL-7-like type 1 inflammatory cytokine that is mainly produced by epithelial cells in the skin, lungs, thymus, and gastrointestinal tract. This cytokine is a master regulator involved in T helper 2 cell-type inflammation immune responses. Various cell types, including T, B, mast, dendritic, and cancer or cancer-associated cells, are activated via TSLP. TSLP expression is also associated with various human cancers and produced by Helicobacter pylori-infected human gastric epithelial cells. TSLP is a multi-functional protein that can act as both an oncogene and a tumor suppressor. The aim of this study was to examine the role of TSLP in the progression of gastric cancer (GC) and its correlation with clinicopathological features in GC patients. Because of the relationship between H. p ylori infection and GC, we also examined gastric tissue specimens for H. p ylori DNA. In this study, fresh tumoral tissues and distant tumor-free samples from 50 GC patients were assessed for TSLP mRNA expression by quantitative real-time PCR. The GC samples were also assessed for H. p ylori DNA using primers specific for H. p ylori 16S rRNA and the UreC genes by PCR. TSLP mRNA was overexpressed in 20 of the 50 (40%) GC samples relative to their corresponding normal tissues. TSLP overexpression was significantly correlated with tumor cell metastasis to lymph nodes. Of the 20 patients with TSLP overexpression, 17 (85.0%) had metastasis to lymph nodes (p = 0.023). In addition, the presence of H. p ylori was confirmed by PCR in 22 of the 50 (44%) cases and 10 (50%) of the 20 TSLP overexpressors. We show that human GC cells produce TSLP and a significant correlation was seen between TSLP overexpression and GC metastasis to lymph nodes. This is the first report to indicate that TSLP may play a role in lymph node involvement in GC patients.

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Section: Pcr Amplification Of H Pylori Genesmentioning

confidence: 99%

Evaluation of thymic stromal lymphopoietin (TSLP) and its correlation with lymphatic metastasis in human gastric cancer

et al. 2015

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“…Molecular characterization of sensitive and resistant strains has yielded information that could be useful in assessing the genotypic association with Mtz resistance, phylogenetic evolution, and epidemiological study. Some of the molecular techniques used to study genotypic variations include sequencing, rapid amplified polymorphic DNA (RAPD), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), real-time-PCR, denaturing gel gradient electrophoresis, ribotyping, and pulse field gel electrophoresis; however, these methods are sophisticated (requiring high-end instrumentation), time-consuming, and expensive (Kansau et al, 1996;Tee, 1997;Sjunnesson et al, 2003;Rimbara et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Analysis of allelic variants of rdxA associated with metronidazole resistance in Helicobacter pylori: detection of common genotypes in rdxA by multiplex allele-specific polymerase chain reaction

Butlop¹,

Mungkote²,

Chaichanawongsaroj³

2016

Genet. Mol. Res.

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ABSTRACT. Resistance to metronidazole (Mtz) in Helicobacter pylori is a major problem worldwide, especially in developing countries. Alterations in Mtz nitroreductase enzymes, such as oxygen-insensitive NADPH nitroreductase (RdxA) and NADPH flavin oxidoreductase (FrxA), are the major contributing factors for this resistance. In this study, rdxA and frxA were amplified, sequenced, and analyzed in 34 Mtz-resistant H. pylori isolates (MIC ≥ 8 µg/mL) using multiple allelespecific polymerase chain reaction (MAS-PCR); this method was developed to target the most common genotypes of rdxA in H. pylori. In this study, the rdxA and frxA genes in Mtz-resistant H. pylori strains displayed a large number of point mutations. The rdxA and frxA genes of Mtz-resistant clinical isolates showed a higher percentage of missense mutations (97.1 and 78.6%, respectively) compared to 26695 reference strains; additionally, missense mutations were more common than frameshift (20.6 and 32.1%) and nonsense mutations (8.8 and 10.7%, respectively) in these genes. The most common missense mutations in rdxA were D 59 N (94.1%), T 31 E (88.2%), and R 131 K (85.3%). The most common missense mutations in frxA were F 72 S (57.1%), G 73 S (57.1%), and C 193 S (53.6%). The developed MAS primers, specific to position 175 and 392 of rdxA, successfully amplified the common alleles and distinguished the variants. MAS-PCR could be a useful tool for epidemiological studies of H. pylori, associated with Mtz resistance. rdxA variants must be screened in order to ensure the effectiveness of Mtz-based H. pylori therapies in developing countries.

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“…Due to poor correlation between symptoms and disease, many of gastric cancer cases are detected lately when the disease is rooted and become incurable. Direct PCR methods performed on H. pylori DNA isolated from biopsy specimens have been evaluated previously [4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Prevalence of H. pylori strains harbouring cagA and iceA virulence genes in saudi patients with gastritis and peptic ulcer disease

Kadi¹,

Halawani²,

Abdelkader³

2014

Microbiol Discov

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Aim: The study is aimed to detect the presence of cagA, iceA1, and iceA2 virulence genes in H. pylori from gastric biopsies, and to deduce the correlation between these genotypes and the two clinical outcomes peptic ulcer disease (PUD), and gastritis. Materials and methods: Thirty three Saudi patients 15 males and 18 females, 20 to 90 years were assigned into two groups PUD and gastritis. Genomic DNAs were extracted from biopsy specimens and used to detect the presence of cagA, and iceA genes by PCR typing system. Fisher's and Phi coefficient association tests were used for statistical analysis. Results: Genotyping show that both cagA and iceA genes were amplified from 27 specimens (81.7%). The prevalence of cagA+ and cagA-genotypes or iceA+ and iceA-genotypes did not differ significantly between males and females (p=0.070). Within the PUD and gastritis groups, the percentages of specimens positive for cagA gene were 76.9 % and 85 %, while those positive for iceA+ were 92.3% and 75% respectively. All cagA+/iceA+ combined genotypes was statically correlated with peptic ulcer (77%). This correlation was not observed within H. pylori specimens typed from gastritis. Patients with either PUD or gastritis were most likely infected by several strains of H. pylori. Conclusion: Different strains of H. pylori have virulent genotypes evidenced by PCR-based genotyping from biopsy specimens at a reasonable cost and time. These virulence strains spread at Taif province, may result in sever clinical outcomes such as ulcers which may be developed to cancer, the situation which necessitates further studies.

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PCR Detection of Helicobacter pylori in Clinical Samples

Cited by 74 publications

References 12 publications

Evaluation of thymic stromal lymphopoietin (TSLP) and its correlation with lymphatic metastasis in human gastric cancer

Evaluation of thymic stromal lymphopoietin (TSLP) and its correlation with lymphatic metastasis in human gastric cancer

Analysis of allelic variants of rdxA associated with metronidazole resistance in Helicobacter pylori: detection of common genotypes in rdxA by multiplex allele-specific polymerase chain reaction

Prevalence of H. pylori strains harbouring cagA and iceA virulence genes in saudi patients with gastritis and peptic ulcer disease

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