Introduction: The objective of the study was to know the current situation of the antimicrobial sensitivity patterns of the main multi-resistant bacteria and to analyze any possible changes with respect to the VIRA study carried out in 2001.
Methods: The 40 participating hospitals sent a total of 1,425 microorganisms isolated in February 2004, distributed as follows: penicillin-resistant Streptococcus pneumoniae (139), methicillin-resistant Staphylococcus aureus (289), clinically significant coagulase-negative staphylococci (158), ampicillin-resistant Enterococcus faecium (89) and Enterococcus faecalis (2), ampicillin-resistant Haemophilus influenzae (85), ciprofloxacin-resistant Escherichia coli (346), Pseudomonas aeruginosa (187), and Acinetobacter baumannii (130). The hospitals provided epidemiological data on these microorganisms. Sensitivity was determined by the broth microdilution method.
Results: The number of highly penicillin-resistant pneumococci fell significantly (p < 0.0001) compared with the previous study (from 59.8% to 30.2%). Global methicillin-resistance in S. aureus was 31.2%, which represents a significant increase (p < 0.001) compared with the year 2001 (24.8%). 11.3% of the E. coli strains were extended-spectrum beta -lactamase-producers and came from 24 hospitals. One P. aeruginosa isolate gave a positive result in the E-test MBL assay, suggesting the presence of metallo-beta -lactamases. The strains of imipenem-resistant A. baumannii presented cross-resistance with several antibiotics.
Conclusion: These results show how the multi-resistant bacteria included in the study represent a growing problem in our hospitals. This emphasizes the importance of resistance surveillance systems and the correct use of antimicrobial agents.