The resistance mechanisms of b-lactam antimicrobials in clinical isolates of Acinetobacter baumannii
The Korean Journal of Internal Medicine
;
: 94-99, 2002.
Artigo
em Inglês
| WPRIM
| ID: wpr-182207
ABSTRACT
BACKGROUND:
Despite increasing importance of Acinetobacter baumannii in nosocomial infections and rapid development of multi-antimicrobial resistance in this strain, the resistance mechanisms of beta-lactam antimicrobials in A. baumannii were not clearly defined. In order to observe the resistance mechanisms against beta-lactams and carbapenem, we characterized the production of beta-lactamases and outermembrane protein (OMP) profiles for the 44 clinical isolates of A. baumannii.METHODS:
The MICs of antimicrobials were determined by agar dilution test. The secondary beta-lactamases were characterized by isoelectric focusing, polymerase chain reactions and nucleotide sequencing, and the production of chromosomal beta-lactamases was quantitated by spectrophotometric method. For two strains with an elevated MIC of carbapenem, outermembrane protein (OMP) profile was analyzed by ultracentrifugation of the sonicated bacteral cells and SDS-PAGE. RESULTS ANDCONCLUSION:
Twenty two or 4 of 44 strains produced TEM-1-like beta-lactamase or PER-1 extended-spectrum beta-lactamase, respectively. However, when we analyzed the MICs of several beta-lactams with the beta-lactamase production, the resistance level of beta-lactam was mainly determined by the production of chromosomal beta-lactamase, not by the secondary beta-lactamases in the clinical isolates of A. baumannii. In two strains with an elevated MIC of imipenem, a decrease or loss of about 35 kDa and 22 kDa proteins in OMP was observed, which suggested that the change of OMP played a role in carbapenem resistance.
Texto completo:
DisponíveL
Índice:
WPRIM (Pacífico Ocidental)
Assunto principal:
Proteínas da Membrana Bacteriana Externa
/
Acinetobacter
/
Beta-Lactamases
/
Infecções por Acinetobacter
/
Carbapenêmicos
/
Infecção Hospitalar
/
Farmacorresistência Bacteriana
/
Lactamas
Limite:
Humanos
Idioma:
Inglês
Revista:
The Korean Journal of Internal Medicine
Ano de publicação:
2002
Tipo de documento:
Artigo
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