RESUMEN
20 antimicrobial agents were determined by Kirby-Bauer methods by the participating institutions.RESULTS A total of 428 strains were isolated,Gram-positive cocci and Gram-negative bacilli accounted for 49.8% and 50.2%,respectively.The Gram-positive bacteria increased from 44.6% to 51.2% from 1995-1996 through 2003-2004 and Gram negative bacteria decreased from 55.4% to 48.2% in the meantime.The most frequent Gram-positive isolates were coagulase negative staphylococci,Staphylococcus aureus,Enterococcus spp and Streptococcus pneumoniae;the most frequent Gram-negative isolates were Acinetobacter spp,Klebsiella spp,Escherichia coli,Pseudomonas aeruginosa and Enterobacter spp;Neisseria meningitidis,Haemophilus influenzae,Flavobacterium spp and Citrobacter spp were relative less common.No strains resistant to vancomycin were found in staphylococci and enterococci.Gram-negative bacilli were highly susceptible to carbapenem.CONCLUSIONS Gram-positive cocci play an increasing role in central nervous sysytem infections,especilly coagulase negative staphylococci,and Gram-positive cocci have been increasing from 1995-1996 through 2003-2004,resistance to the first line antibiotics is common among all cerebrospinal fluids isolates.