The drug resistance analysis and distribution of coagulase negative staphylococcus

Objective:To investigate the distribution and the drug-resistance of coagulase negative staphylococcus(CNS) isolated from the clinical department in our hospital, and provide the reference for therapy of bacterial infection. Methods:Coagulase negative staphylococcus from clinical samples were isolated, cultured and identified as per the standard routine procedures from January of 2005 to December of 2007. Susceptibility was measured by K-B antibacterial disk susceptibility test, as recommended by the National Committee for Clinical Laboratory Standards (CLSI/NCCLS) of 2004. Results:There are 13 species in the 426 strains of the CNS isolated,Staphylococcus epidermidis,staphylococcus haemolyticus and staphylococcus hominis accounte for the majority, they are 218 strains (51.17%), 103 strains (24.18%) and 46 strains (10.80%). Drug susceptibility tests revealed that they were relatively sensitive to chloramphenicol, amikacin (drug resistance5%), and very sensitive to vancomycin and teicoplanin (drug resistance =0 %),but the resistance rate of 1penicillin,oxacillin, erythromycin, cefoxintin, piperacillin, gentamicin and ciprofloxacin are higber than 50%.In all 426 strains of CNS, meticillin-resistant coagulase negative staphylococcus (MRCNS) and meticillin-susceptible coagulase negative staphylococcus(MSCNS) each account for 350 strains(82.16%) and 76 strains(17.84%). MRCNS is relatively resistant to many kinds of antibiotics, and there is a significant difference between MRCNS and MSCNS (P0.01). Conclusion:Drug-resistance of CNS,especially MRCNS in nosocomial infections become prevalent in recently years. To provide clinical doctors the referdnce for therapy of bacterial infection, Strengthen the surveillance of the antimicriobial resistance of CNS to investigate the distribution, and inform clinical department on time are needed.