Horizontal transfer of penicillin-binding protein genes in penicillin-resistant clinical isolates of Streptococcus pneumoniae
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Resistance to penicillin in clinical isolates of
Streptococcus pneumoniae has occurred by the development of
altered penicillin-binding proteins (PBPs) that have greatly
decreased affinity for the antibiotic. We have investigated the
origins of penicillin-resistant strains by comparing the sequences
of the transpeptidase domain of PBP2B from 6 penicillin-sensitive
and 14 penicillin-resistant strains. In addition
we have sequenced part of the amylomaltase gene from 2 of the
sensitive and 6 of the resistant strains. The sequences of the
amylomaltase gene of all of the strains and of the PBP2B gene
of the penicillin-sensitive strains show that S. pneumoniae is
genetically very uniform. In contrast the PBP2B genes of the
penicillin-resistant strains show -14% sequence divergence
from those of the penicillin-sensitive strains and the development
of penicillin resistance has involved the replacement,
presumably by transformation, of the original PBP2B gene by
a homologous gene from an unknown source. This genetic event
has occurred on at least two occasions, involving different
sources, to produce the two classes of altered PBP2B genes
found in penicillin-resistant strains of S. pneumoniae. There is
considerable variation among the PBP2B genes of the resistant
strains that may have arisen by secondary transformation
events accompanied by nismatch repair subsequent to their
original introductions into S. pneumoniae.
Streptococcus pneumoniae has occurred by the development of
altered penicillin-binding proteins (PBPs) that have greatly
decreased affinity for the antibiotic. We have investigated the
origins of penicillin-resistant strains by comparing the sequences
of the transpeptidase domain of PBP2B from 6 penicillin-sensitive
and 14 penicillin-resistant strains. In addition
we have sequenced part of the amylomaltase gene from 2 of the
sensitive and 6 of the resistant strains. The sequences of the
amylomaltase gene of all of the strains and of the PBP2B gene
of the penicillin-sensitive strains show that S. pneumoniae is
genetically very uniform. In contrast the PBP2B genes of the
penicillin-resistant strains show -14% sequence divergence
from those of the penicillin-sensitive strains and the development
of penicillin resistance has involved the replacement,
presumably by transformation, of the original PBP2B gene by
a homologous gene from an unknown source. This genetic event
has occurred on at least two occasions, involving different
sources, to produce the two classes of altered PBP2B genes
found in penicillin-resistant strains of S. pneumoniae. There is
considerable variation among the PBP2B genes of the resistant
strains that may have arisen by secondary transformation
events accompanied by nismatch repair subsequent to their
original introductions into S. pneumoniae.
Date Issued
1989-11-01
Date Acceptance
1989-07-21
Citation
Proceedings of the National Academy of Sciences of the United States of America, 1989, 86 (22), pp.8842-8846
ISSN
1091-6490
Publisher
National Academy of Sciences
Start Page
8842
End Page
8846
Journal / Book Title
Proceedings of the National Academy of Sciences of the United States of America
Volume
86
Issue
22
Copyright Statement
The author(s) retains copyright to individual articles published prior to 1992, and the author has given permission for this article to be posted here. Proc. Nati. Acad. Sci. USA
Vol. 86, pp. 8842-8846, November 1989
Vol. 86, pp. 8842-8846, November 1989
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
MULTIDISCIPLINARY SCIENCES
Publication Status
Published