Skip to main content
  • ASM
    • Antimicrobial Agents and Chemotherapy
    • Applied and Environmental Microbiology
    • Clinical Microbiology Reviews
    • Clinical and Vaccine Immunology
    • EcoSal Plus
    • Eukaryotic Cell
    • Infection and Immunity
    • Journal of Bacteriology
    • Journal of Clinical Microbiology
    • Journal of Microbiology & Biology Education
    • Journal of Virology
    • mBio
    • Microbiology and Molecular Biology Reviews
    • Microbiology Resource Announcements
    • Microbiology Spectrum
    • Molecular and Cellular Biology
    • mSphere
    • mSystems
  • Log in
  • My alerts
  • My Cart

Main menu

  • Home
  • Articles
    • Current Issue
    • Accepted Manuscripts
    • Archive
    • Minireviews
  • For Authors
    • Submit a Manuscript
    • Scope
    • Editorial Policy
    • Submission, Review, & Publication Processes
    • Organization and Format
    • Errata, Author Corrections, Retractions
    • Illustrations and Tables
    • Nomenclature
    • Abbreviations and Conventions
    • Publication Fees
    • Ethics Resources and Policies
  • About the Journal
    • About IAI
    • Editor in Chief
    • Editorial Board
    • For Reviewers
    • For the Media
    • For Librarians
    • For Advertisers
    • Alerts
    • RSS
    • FAQ
  • Subscribe
    • Members
    • Institutions
  • ASM
    • Antimicrobial Agents and Chemotherapy
    • Applied and Environmental Microbiology
    • Clinical Microbiology Reviews
    • Clinical and Vaccine Immunology
    • EcoSal Plus
    • Eukaryotic Cell
    • Infection and Immunity
    • Journal of Bacteriology
    • Journal of Clinical Microbiology
    • Journal of Microbiology & Biology Education
    • Journal of Virology
    • mBio
    • Microbiology and Molecular Biology Reviews
    • Microbiology Resource Announcements
    • Microbiology Spectrum
    • Molecular and Cellular Biology
    • mSphere
    • mSystems

User menu

  • Log in
  • My alerts
  • My Cart

Search

  • Advanced search
Infection and Immunity
publisher-logosite-logo

Advanced Search

  • Home
  • Articles
    • Current Issue
    • Accepted Manuscripts
    • Archive
    • Minireviews
  • For Authors
    • Submit a Manuscript
    • Scope
    • Editorial Policy
    • Submission, Review, & Publication Processes
    • Organization and Format
    • Errata, Author Corrections, Retractions
    • Illustrations and Tables
    • Nomenclature
    • Abbreviations and Conventions
    • Publication Fees
    • Ethics Resources and Policies
  • About the Journal
    • About IAI
    • Editor in Chief
    • Editorial Board
    • For Reviewers
    • For the Media
    • For Librarians
    • For Advertisers
    • Alerts
    • RSS
    • FAQ
  • Subscribe
    • Members
    • Institutions
Research Article

Pathological significance and molecular characterization of the vacuolating toxin gene of Helicobacter pylori.

S H Phadnis, D Ilver, L Janzon, S Normark, T U Westblom
S H Phadnis
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
D Ilver
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
L Janzon
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
S Normark
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
T U Westblom
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
DOI: 
  • Article
  • Info & Metrics
  • PDF
Loading

ABSTRACT

Some strains of Helicobacter pylori are known to produce an extracellular cytotoxin that causes vacuolization in various mammalian cells. In this study, we found that concentrated culture supernatants from four Helicobacter strains isolated from patients infected with the bacterium, but having normal gastric mucosa, lacked cytotoxic activity. We also show that a higher percentage of strains isolated from patients with polymorphonuclear leukocyte infiltration of gastric mucosa are toxin positive (78%) versus those isolated from patients lacking such infiltration (33%). In addition to examining the relationship between pathology and cytotoxic activity, we used the previously published N-terminal sequence of the protein to clone and characterize vacA, the structural gene encoding the cytotoxin. Briefly, three oligonucleotides capable of encoding the first nine amino acids corresponding to the sense strand and four oligonucleotides corresponding to the noncoding strand of the last seven known amino acids of the cytotoxin protein were made. They were used in all 12 possible combinations in 12 different PCR reactions, with DNA from a cytotoxin-positive strain as template. In four combinations, the expected 69-bp fragment was seen. The sequence of this 69-bp fragment confirmed that it encoded the known N-terminal sequence of the cytotoxin. This gene is capable of encoding a 136-kDa protein with a 33-amino-acid signal peptide, whereas the purified cytotoxin is only 87 kDa, suggesting processing in the C-terminal region of the protein. A single copy of the vacA gene encodes the cytotoxin in H. pylori. Consequently, the insertion of a kanamycin resistance marker in the vacA gene produced an isogenic mutant lacking the cytotoxic activity. This mutant provides genetic evidence that vacA encodes the cytotoxin. Sequence analysis of the DNA adjacent to the vacA gene demonstrated that this gene is next to a putative cysteinyl tRNA synthetase gene. From the sequence arrangement, we predict that there are no other genes transcribed together with vacA. We also show that five of seven cytotoxin-negative strains examined still carry the sequences encoding it whereas the other two have suffered a deletion of the vacA gene. We further show that in at least one cytotoxin-negative but vacA-positive strain (MO19), there are variations in the length of the vacA gene that could explain the cytotoxin-negative phenotype in this strain.

PreviousNext
Back to top
Download PDF
Citation Tools
Pathological significance and molecular characterization of the vacuolating toxin gene of Helicobacter pylori.
S H Phadnis, D Ilver, L Janzon, S Normark, T U Westblom
Infection and Immunity May 1994, 62 (5) 1557-1565; DOI:

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Print

Alerts
Sign In to Email Alerts with your Email Address
Email

Thank you for sharing this Infection and Immunity article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Pathological significance and molecular characterization of the vacuolating toxin gene of Helicobacter pylori.
(Your Name) has forwarded a page to you from Infection and Immunity
(Your Name) thought you would be interested in this article in Infection and Immunity.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Share
Pathological significance and molecular characterization of the vacuolating toxin gene of Helicobacter pylori.
S H Phadnis, D Ilver, L Janzon, S Normark, T U Westblom
Infection and Immunity May 1994, 62 (5) 1557-1565; DOI:
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Top
  • Article
  • Info & Metrics
  • PDF

Related Articles

Cited By...

About

  • About IAI
  • Editor in Chief
  • Editorial Board
  • Policies
  • For Reviewers
  • For the Media
  • For Librarians
  • For Advertisers
  • Alerts
  • RSS
  • FAQ
  • Permissions
  • Journal Announcements

Authors

  • ASM Author Center
  • Submit a Manuscript
  • Article Types
  • Ethics
  • Contact Us

Follow #IAIjournal

@ASMicrobiology

       

ASM Journals

ASM journals are the most prominent publications in the field, delivering up-to-date and authoritative coverage of both basic and clinical microbiology.

About ASM | Contact Us | Press Room

 

ASM is a member of

Scientific Society Publisher Alliance

 

American Society for Microbiology
1752 N St. NW
Washington, DC 20036
Phone: (202) 737-3600

Copyright © 2021 American Society for Microbiology | Privacy Policy | Website feedback

Print ISSN: 0019-9567; Online ISSN: 1098-5522