Coagulase-negative staphylococci(CNS) once considered nonpathogenic contaminants, recently represent the leading organisms of hospital-acquire bacteremia in catheter-associated infections, immunocompromised patients and neonates. patients and neonates.
We reviewed 141 caews of CNS isolated from blood in Ehwa Womans University Dongdaemoon Hospital, from March 1993 to February 1994 and deagnosed as pathogens or contaminants by clinical data and performed species identification and antimicrobial susceptibility test.
The results were as follows:
1) 46.8% of isolated CNS from blood was diagnosed as pathogens and most common age of CNS bacteremia was less than 1 month(39.0%). The most frequent underlying desease was respiratory tract infection(28.1%) followed by neonatal desorder(17.2%), malignancy(12.5%) and urinary tract infection(6.3%).
2) The most common identified species of CNS bacteremia was S.epidermidis(34.4%) folloewd by S. hominis(9.4%), S.auricularis(9.4%), S.haemolyticus(6.3%), S.dimulans(6.3%), S.capitis(3.1%), S.cohnii(1.5%) and S.warneri(1.5%). S.epidermidis, S.haemolyticus and S.simlans were more common identified as pathogens than contaminants(p<0.05) but S.auriculares, S. hominis, S.capitis, S.cohnii and S.ciuri were more common identified as contaminants than pathogens(p<0.05).
3) The antimicrobial susceptibility results of CNS bacteremia showed multi-drug resistance to penicillin(96.9%), cephalothin(75.0%), ampicillin/sulbactam(70.3%), oxacillin(70.3%), tetracycline(67.1%) and erythromycin(48.4%). But vancomycin resistance showed 1.6% of CNS bacteremia. Among CNS species, S.haemolyticus showed the highest resistance to multiple antibiotics. The resistance retes to penicillin, oxacillin among CNS species were S.haemolyticus, S.epidermidis and S.simulans higher than S.auricularis, S.hominis(p<0.05).
These results that species identification and antimicrobial susceptibility test of CNS isolated from blood will be useful diagnostic tool of CNS bacteremia.
