Analysis on clinical distribution and antimicrobial resistance of common gram-positive cocci

Objective To investigate the clinical distribution and antimicrobial resistance of common gram-positive cocci in author's hospital.Methods Identification of these bacteria were done with API analysis system,disc diffusion tests were employed to study the antimicrobial resistance.Results A total of 25 052 clinical isolates were collected in 8 years,of gram-positive cocci accounted for 7907(31.9%).Staphylococcus aureus(3549 strains,44.9%),enterococcus(1760 strains,22.3%)and coagulase-negative staphylococcus(1558 strains,19.7%)were the most common isolates.The prevalence of MRSA increased from 59.6% in 2001 to 76.3% in 2008,and MRSCoN increased from 64.2% to 77.0%.The resistant rate of MRSA to gentamicin,clindamycin,erythromycin and levofloxacin were over 90%,to trimethoprim/sulfamethoxazole and chloramphenicol were less than 20%.The resistant rate of MSSA to gentamicin,levofloxacin,trimethoprim/sulfamethoxazole and chloramphenicol were low 20%,and to beta-lactamase antibacterial agents except penicillin were 0.The resistant rates of MRSCoN to all antimicrobial agents were lower than MRSA,but to trimethoprim/sulfamethoxazole(71.2%)was higher than MRSA(21.2%).No staphylococcus strains were resistant to vancomycin,teicoplanin and linezolid.2.1% enterococcus feacium and 4.4% other enterococcus were resistant to vancomycin.No strains of enterococcus were found resistant to teicoplanin and linezolid.Conclusion The resistant rate of gram-positive cocci were increasing obviously,the prevalence of MRS was high.Vancomycin,teicoplanin and linezolid were the most active agents against severe infection induced by multidrug-resistant gram-positive cocci.