Surveillance on antibiotic resistance of gram-positive cocci

  Objective   To investigate the drug-resistance of gram-positive cocciislated from patients in the First Affiliated Hospital, China Medical University.

  Methods   Antimicrobial susceptibility of 2104 clinical isolated from 1999-2003 was tested by K-B method and Broth microdilution method.

  Results   Of 2104 clinical isolates, staphylococcus aureus accounted for 20.5%, coagulase-negative staphylococci 42.8%, enterococci 32.9%.The detectable rates of methicillin-resistant staphylococcus aureus and methicillin-resistant coagulase-negative staphylococci in 2003 were 19.4% and 81.1%, which were higher than those in 1999 (17.1% and 65.4%). The difference in methicillin-resistant coagulase-negative staphylococci was significantly during 1999-2003 (P < 0.05).Neither strains of staphylococcus aureus norstrains of coagulase-negative staphylococci were found resistant to vancomycin.4 strains of coagulase-negative staphylococci showed resistance to teicoplanin. No significant changes in vancomycin-resistant entrococci were found from 1999 to 2003.The prevalence of vancomycin-resistant enterococci (1999-2003) were 9.8%, 7.7%, 5.0%, 4.1%, and 6.7% respectively.67.1-76.7 percent of E. faecalis isolates were sensitive to ampicillin, but ampicillin-resistant E. faecium were higher (66.7%-89.7%). The prevalence of teicoplaninr-esistant enterococci was 2.1%, 2.5% and 5.5% respectively.

  Conclusion   Multidrug-resistant gram-positive cocci including methicillin-resistant staphylococcus aureus and methicillin-resistant coag ulasenegative staphylococci and ampicillin-resistant E. faecium are increasing.