Development of high-level ceftazidime resistance via single-base substitutions of blaCTX-M-3 in hyper-mutable Escherichia coli.
Clin Microbiol Infect
; 12(8): 803-6, 2006 Aug.
Article
em En
| MEDLINE
| ID: mdl-16842579
ABSTRACT
Mutations can increase the ceftazidimase activity of CTX-M-3 beta-lactamase, as seen with its widespread variant CTX-M-15. This study compared the frequencies of emerging ceftazidime resistance in isogenic wild-type and hyper-mutable mutS CTX-M-3-producing Escherichia coli strains, and sequenced the mutant bla(CTX-M) alleles selected. Ceftazidime resistance emerged more readily in the hyper-mutable background than in the wild-type strain. All selected CTX-M mutants, in both the wild-type and the mutS derivatives, had single amino-acid changes at position 167, including a novel Pro167Gln substitution. These data emphasise the potential for further diversification of CTX-M enzymes.
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Base de dados:
MEDLINE
Assunto principal:
Beta-Lactamases
/
Ceftazidima
/
Escherichia coli
/
Antibacterianos
/
Mutação
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article