Antimicrobial resistance surveillance:: VIRA STUDY 2006

INTRODUCTION. The objective of this study was to determine the current antimicrobial susceptibility patterns of the most frequent multi-resistant bacteria and to analyze any possible changes with respect to the two VIRA studies carried out in 2001 and 2004. METHODS. In February 2006, the 40 participating hospitals sent the following microorganisms: non-penicillin-susceptible Streptococcus pneumoniae (92), methicillin-resistant Staphylococcus aureus (MRSA) (290), clinically significant coagulase-negative staphylococci (136), ampicillin-resistant Enterococcus faecium (89), ampicillin-resistant Haemophilus influenzae (67), ciprofloxacin-resistant Escherichia coli (365), Pseudomonas aeruginosa (181), and Acinetobacter baumannii (92). The hospitals provided epidemiological data on these microorganisms. Susceptibility was determined with a broth microdilution method. RESULTS. Among the non-penicillin-susceptible S. pneumoniae isolates, the proportion of those ones resistant to this antibiotic showed a significant (p < 0.001) decrease (59.8% in 2001, 30.2% in 2004 and 14.3% in 2006). Among MRSA, we detected one isolate nonsusceptible to linezolid, four resistant to quinupristin-dalfopristin and one strain with a vancomycin MIC of 4 mu g/mL. The prevalence of extended-spectrum beta-lactamase-producing E. coli was 12.1%. Resistance of A. baumannii to imipenem varied from 27% in the 2001-2004 period to 47.8% in 2006 (p < 0.005). CONCLUSION. These results again emphasize that resistance surveillance systems are an important tool for preventing the emergence and spread of multi-resistant pathogens.