Previous Article | Next Article ![]()
Journal of Clinical Microbiology, August 1998, p. 2240-2247, Vol. 36, No. 8
Microbiology Unit, Catholic University of
Louvain, 1200 Brussels, Belgium1;
Department of Biology, University of Ljubljana, 1000 Ljubljana, Slovenia2; and
Institute of
Medical Microbiology, Johanes-Gutenberg-University, 55101 Mainz,
Germany3
Received 17 November 1997/Returned for modification 23 February
1998/Accepted 14 April 1998
Two hundred nineteen Clostridium difficile isolates
from 22 serogroups were screened for changes in the genes coding for
toxin B (tcdB) and toxin A (tcdA). Parts of the
toxin genes were amplified, and the PCR fragments were checked for
length polymorphisms and cut with several restriction enzymes to
monitor restriction fragment length polymorphisms (RFLPs). For 47 strains (21%), differences in the toxin genes were found compared to
the toxin genes of reference strain VPI 10463. Polymorphisms were
usually observed in both toxin genes. RFLPs were more commonly found in
the tcdB gene, in which a single restriction enzyme could
give up to five different patterns. Restriction sites seemed to be less
heterogeneous in the tcdA gene, in which for most enzymes
only two different RFLPs were recognized. However, deletions were
observed in tcdA, and four new types of shortened
tcdA genes are described. According to the changes in their
toxin genes, variant strains could be divided into 10 groups
(toxinotypes I to X). A toxinotype was characterized by similar
patterns of changes in the toxin genes and in other regions of the
pathogenicity locus and also similar pulsed-field gel electrophoresis
patterns. Variant toxinotypes were found in 9 of the 22 serogroups
studied, and some toxinotypes were clearly associated with specific
serogroups. Toxinotype VIII is characteristic for all strains of
serogroup F. Other serogroups in which variant toxinotypes were
commonly found are A1, A15, E, and X. Testing of variability in
C. difficile toxin genes not only might be useful as a
molecular typing system but also could have implications in diagnostics
and pathogenesis.
0095-1137/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
A Novel Toxinotyping Scheme and Correlation of
Toxinotypes with Serogroups of Clostridium difficile
Isolates
*
Corresponding author. Mailing address: Microbiology
Unit, Catholic University of Louvain, Avenue Hippocrate 54.90, B1200
Brussels, Belgium. Phone: 32 2 764 94 41. Fax: 32 2 764 94 40. E-mail:
delmee{at}mblg.ucl.ac.be.
This article has been cited by other articles:
| Antimicrob. Agents Chemother. | Clin. Microbiol. Rev. |
|---|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|