The 5th year KONSAR surveillance in 2001 was based on routine test data at 30 participating hospitals. It was of particular interest to find a trend in the resistances of enterococci to vancomycin, of Enterobacteriaceae to the 3rd generation cephalosporin and fluoroquinolone, and of Pseudomonas aeruginosa and acinetobacters to carbapenem. Resistance rates of Gram-positive cocci were: 70% of Staphylococcus aureus to oxacillin; 88% and 16% of Enterococcus faecium to ampicillin and vancomycin, respectively. Seventy-two percent of pneumococci were nonsusceptible to penicillin. The resistance rates of Enterobacteriaceae were: Escherichia coli, 28% to fluoroquinolone; Klebsiella pneumoniae, 27% to ceftazidime, and 20% to cefoxitin; and Enterobacter cloacae, > or =40% to cefotaxime and ceftazidime. The resistance rates of P. aeruginosa were 21% to ceftazidime, 17% to imipenem, and those of the acinetobacters were > or =61% to ceftazidime, aminoglycosides, fluoroquinolone and cotrimoxazole. Thirty-five percent of non-typhoidal salmonellae were ampicillin resistant, and 66% of Haemophilus influenzae were -lactamase producers. Notable changes over the 1997-2001 period were: increases in vancomycin-resistant E. faecium, and amikacin- and fluoroquinolone-resistant acinetobacters. With the increasing prevalence of resistant bacteria, nationwide surveillance has become more important for optimal patient management, for the control of nosocomial infection, and for the conservation of the newer antimicrobial agents.
Anti-Bacterial Agents/*pharmacology ; Cephalosporins/pharmacology ; *Drug Resistance, Microbial ; Enterococcus faecium/metabolism ; Human ; Imipenem/pharmacology ; Klebsiella pneumoniae/metabolism ; Korea ; Pseudomonas aeruginosa/metabolism ; Time Factors ; Vancomycin/*pharmacology

The presence of hyl gene in 364 PFGE clones of Enterococcus faecium was detected by colony hybridization under conditions of high stringency. The isogenic hyl-deficient mutant (* hyl) was constructed with suicide pTX4577 and screened by allelic replacement. Moreover, an in vitro study was made on the effect of hyl gene detection on the growth ability of hylgene detection on the mutant, and an in vivo study was made on the decrease of virulence in the mouse peritonitis model. The results showed, in the clinical isolates, the positive percentage of hyl gene was 32.8%, which was significantly higher than that (5.3%) in the non-clinical isolates. The * hyl was selected by kanamycin and identified by PCR, pulsed field gel electrophoresis (PFGE) and Southern blot. The experimental evidence indicated that the growth ability of * hyl was remarkably reduced in comparison with that of the wild-type strain. The percentage survival of mice in TX2466 groups was 0, while that of * hyl groups was 50% at the same inoculum in mouse peritonitis. The differences were significant. These data suggest that hyl gene in specific E. faecium strains may be enriched in determinants that make them more likely to cause clinical infections. Being important in the pathogenesis, hyl gene is probably a major virulence factor of Enterococcus faecium.
Animals ; Enterococcus faecium ; genetics ; pathogenicity ; Genes, Bacterial ; Gram-Positive Bacterial Infections ; microbiology ; Hyaluronoglucosaminidase ; genetics ; Male ; Mice ; Mice, Inbred ICR ; Mutation ; Peritonitis ; microbiology ; Virulence ; Virulence Factors ; genetics ; metabolism

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacteremia/blood/*diagnosis/microbiology ; C-Reactive Protein/analysis ; Cholecystitis/blood/cerebrospinal fluid/microbiology ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecium/drug effects/isolation & purification/metabolism ; Humans ; Male ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning ; Ochrobactrum/drug effects/isolation & purification/*metabolism ; RNA, Ribosomal, 16S/analysis/genetics/metabolism ; Sequence Analysis, DNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization