Epidemiologia della meticillino-resistenza negli Stafilococchi isolati in reparti a rischio ed effetti della vancomicina sulla espressione della meticillino-resistenza

Translated title of the contribution: Epidemiology of methicillin-resistance among Staphylococci strains isolated in risk units and effects of the vancomycin on the expression of methicillin-resistance

S. Roveta, E. Tonoli, A. Marchese, G. C. Schito

Research output: Contribution to journalArticle

Abstract

Four hundred Staphylococci strains, isolated from different in intensive care unit hospitalized patients, were analyzed. 53% of all strains were resistant to methicillin. Against methicillin-resistant S. aureus (MRSA), teicoplanin and vancomycin (100% of susceptibility), rifampin (76.3%) and co-trimoxazole (73%) emerged as the most potent drugs tested; the 15% of the strains were susceptible to ciprofloxacin, erythromycin, clindamycin and genta micin. Only one MRSA strain (0.8%) resulted hetero-resistant to vancomycin. Among 100 strains exposed to serial concentration of vancomycin (0.25-32 mg/L for 30 days), 57 were selected with intermediate-level of resistance to the glycopeptides; the MRSA strains have shown to acquire resistance in vitro more easily than methicillin-susceptible. These results indicate that in the clones of Staphylococci circulating in our region, the evolution of glycopeptides-resistance is not a rapid process and the loss of effectiveness of these antibiotics cannot be predicted to short term. In particular, the restriction profile analysis of chromosomal DNA from MRSA strains, selected in vitro with intermediate -level of vancomycin resistance, demonstrated that at the moment in the hospital departments studied, the diffusion of a clone able to acquire resistance more easily than others is not present.

Translated title of the contributionEpidemiology of methicillin-resistance among Staphylococci strains isolated in risk units and effects of the vancomycin on the expression of methicillin-resistance
Original languageItalian
Pages (from-to)82-89
Number of pages8
JournalInfezioni in Medicina
Volume9
Issue number2
Publication statusPublished - 2001

ASJC Scopus subject areas

  • Microbiology (medical)

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