Rapid increase in the prevalence of antimicrobial drug resistance among enterococcal blood isolates in southern Israel.

A prospective surveillance was conducted to monitor the prevalence and dynamics of antimicrobial resistance among enterococci isolated from blood cultures in southern Israel. A total of 242 organisms isolated between 1993 and 1996 were studied. The prevalence of Enterococcus faecalis significantly decreased during the study period, whereas that of Enterococcus faecium doubled. Antimicrobial drug resistance increased steadily among Enterococcus faecium isolates: resistance to ampicillin increased from 19% in 1993-1994 to 53% in 1995, and to 67% in 1996 (p = 0.005); during the same period, resistance to vancomycin increased from 0% to 20%, and to 50% (p = 0.002), and combined resistance to ampicillin and vancomycin and high-level resistance to gentamicin from 0% to 20% and to 38% (p < 0.02).