Previous Article | Next Article ![]()
Clinical and Diagnostic Laboratory Immunology, March 1998, p. 139-145, Vol. 5, No. 2
Department of Medical Microbiology, Johannes
Gutenberg University, D-55101 Mainz, Germany
Received 14 April 1997/Returned for modification 26 June
1997/Accepted 15 December 1997
Genetic diversity in Helicobacter pylori strains may
affect the function and antigenicity of virulence factors associated with bacterial infection and, ultimately, disease outcome. In this
study, DNA diversity of H. pylori isolates was examined by analysis of vacA genotypes and by restriction fragment
length polymorphism (RFLP) analysis of H. pylori-associated
genes (vacA, cagA, flaA,
ureAB, and ureCD). Thirty-seven H. pylori isolates from 26 patients were successfully classified
into distinct vacA allelic genotypes. The signal sequence
allele s1 (31 of 37) predominated over the s2 allele (6 of 37) and was
significantly associated with the occurrence (past or present) of
gastric ulcers. A novel midregion allele, designated as m3, has been
identified in two H. pylori isolates which could not be
typed with midregion allele m1- or m2-specific primers. Additionally,
significant nucleotide diversity yielding different amino acid
sequences was demonstrated by DNA sequencing of vacA
fragments from clinical isolates of H. pylori. Furthermore,
RFLP analysis of 45 H. pylori isolates (including 15 paired
isolates) obtained from antrum and corpus biopsy specimens from 30 individual patients showed remarkably high interhost diversity (one
patient, one H. pylori strain) and intrahost identity in
gene sequences coding for VacA, CagA, flagellin, and urease. Only in a
single patient was a minor genotypic variation at different anatomic
sites within the stomach identified. These data warrant the detailed
analysis of the effect of genetic diversity on the function and
antigenicity of H. pylori-associated virulence factors.
1071-412X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
vacA Genotypes and Genetic Diversity in
Clinical Isolates of Helicobacter pylori
*
Corresponding author. Mailing address: Department of
Medical Microbiology, Johannes Gutenberg University,
Hochhaus/Augustusplatz, D-55101 Mainz, Germany. Phone: (49)
6131-177341. Fax: (49) 6131-173439. E-mail:
maeurer{at}omalley.zdv.uni-mainz.de.
This article has been cited by other articles:
| Antimicrob. Agents Chemother. | Clin. Microbiol. Rev. | Infect. Immun. |
|---|---|---|
| J. Clin. Microbiol. | J. Virol. | ALL ASM JOURNALS |