Prevalence, resistance mechanisms, and susceptibility of multidrug-resistant bloodstream isolates of Pseudomonas aeruginosa.
Antimicrob Agents Chemother
; 54(3): 1160-4, 2010 Mar.
Article
em En
| MEDLINE
| ID: mdl-20086165
ABSTRACT
Pseudomonas aeruginosa is an important pathogen commonly implicated in nosocomial infections. The occurrence of multidrug-resistant (MDR) P. aeruginosa strains is increasing worldwide and limiting our therapeutic options. The MDR phenotype can be mediated by a variety of resistance mechanisms, and the corresponding relative biofitness is not well established. We examined the prevalence, resistance mechanisms, and susceptibility of MDR P. aeruginosa isolates (resistant to > or =3 classes of antipseudomonal agents [penicillins/cephalosporins, carbapenems, quinolones, and aminoglycosides]) obtained from a large, university-affiliated hospital. Among 235 nonrepeat bloodstream isolates screened between 2005 and 2007, 33 isolates (from 20 unique patients) were found to be MDR (crude prevalence rate, 14%). All isolates were resistant to carbapenems and quinolones, 91% were resistant to penicillins/cephalosporins, and 21% were resistant to the aminoglycosides. By using the first available isolate for each bacteremia episode (n = 18), 13 distinct clones were revealed by repetitive-element-based PCR. Western blotting revealed eight isolates (44%) to have MexB overexpression. Production of a carbapenemase (VIM-2) was found in one isolate, and mutations in gyrA (T83I) and parC (S87L) were commonly found. Growth rates of most MDR isolates were similar to that of the wild type, and two isolates (11%) were found to be hypermutable. All available isolates were susceptible to polymyxin B, and only one isolate was nonsusceptible to colistin (MIC, 3 mg/liter), but all isolates were nonsusceptible to doripenem (MIC, >2 mg/liter). Understanding and continuous monitoring of the prevalence and resistance mechanisms of MDR P. aeruginosa would enable us to formulate rational treatment strategies to combat nosocomial infections.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Pseudomonas aeruginosa
/
Infecções por Pseudomonas
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Infecção Hospitalar
/
Bacteriemia
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Farmacorresistência Bacteriana Múltipla
/
Antibacterianos
Tipo de estudo:
Prevalence_studies
/
Risk_factors_studies
Limite:
Humans
País/Região como assunto:
America do norte
Idioma:
En
Revista:
Antimicrob Agents Chemother
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos