title: Molecular identification of Helicobacter DNA present in human colorectal adenocarcinomas by 16S rDNA PCR amplification and pyrosequencing analysis.
abstract: Seroepidemiological studies have indicated that Helicobacter pylori infection might be a possible risk factor for colorectal adenocarcinoma (CRC) development. However, limited information is available as to whether or not Helicobacter species are present in CRC tissues. In this study the presence of Helicobacter DNA in 77 CRC biopsies was investigated by means of a Helicobacter species-specific 16S rDNA PCR assay and real-time DNA pyrosequencing of the 16S rDNA variable V3 region. Pyrosequencing revealed the presence of Helicobacter DNA sequences in 21 of 77 biopsy specimens (27%). 16S rDNA sequences corresponding to H. pylori 26695 and H. pylori J99 were most commonly found. Intriguingly, one sequence belonged to Helicobacter mustelae, previously identified in ferrets. No significant correlations were found in the prevalence of Helicobacter DNA between colon and rectum tumour biopsies (P = 0.815), nor between Dukes' classes A/B and C/D (P = 0.262). 16S rDNA PCR amplification combined with pyrosequencing analysis of 16S rDNA variable V3 regions provides a powerful molecular tool to identify Helicobacter species in human biopsy specimens.
authors.affiliation: Molecular Biology Laboratory - LMC, University Hospital, S-581 85 Linköping, Sweden 2Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden 3Laboratory of Human Molecular Genetics, Faculty of Medicine of Sfax, Tunisia.
authors.forename: Niclas
authors.initials: N
authors.lastname: Grahn
authors.affiliation: Molecular Biology Laboratory - LMC, University Hospital, S-581 85 Linköping, Sweden 2Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden 3Laboratory of Human Molecular Genetics, Faculty of Medicine of Sfax, Tunisia.
authors.forename: Mounira
authors.initials: M
authors.lastname: Hmani-Aifa
authors.affiliation: Molecular Biology Laboratory - LMC, University Hospital, S-581 85 Linköping, Sweden 2Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden 3Laboratory of Human Molecular Genetics, Faculty of Medicine of Sfax, Tunisia.
authors.forename: Karin
authors.initials: K
authors.lastname: Fransén
authors.affiliation: Molecular Biology Laboratory - LMC, University Hospital, S-581 85 Linköping, Sweden 2Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden 3Laboratory of Human Molecular Genetics, Faculty of Medicine of Sfax, Tunisia.
authors.forename: Peter
authors.initials: P
authors.lastname: Söderkvist
authors.affiliation: Molecular Biology Laboratory - LMC, University Hospital, S-581 85 Linköping, Sweden 2Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden 3Laboratory of Human Molecular Genetics, Faculty of Medicine of Sfax, Tunisia.
authors.forename: Hans-Jürg
authors.initials: HJ
authors.lastname: Monstein
mesh_terms: D000368:Aged; D001706:Biopsy; D015179:Colorectal Neoplasms / Q000209:etiology / Q000382:microbiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification*; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D005260:Female; D016998:Helicobacter / Q000235:genetics / Q000302:isolation & purification*; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S