Coagulase-negative staphylcocci(CNS) once considered nonpathogenic contaminants, recently represent the leading organisms of hospital-acquired bacteremia in catheter-associate infections, immunocompromised patients and neonates.
We reviewed 141 cases of CNS isolated from blood in Ehwa Womans University Dongdaemoon Hospital, from March 1993 to February 1994 and diagnosed as pathogens or contaminants by clinical data and performed species identification and antimicrobial
susceptibility test.
@ES The results were as follows:
@EN 1) 46.8% of isolated CNS from blood was diagnosed as pathogens and most common age of CNS bacteremia was less than l month (39.0%). The most frequent underlying disease was respiratory tract infection(28.1%) followed by neonatal disorder
(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%) followed by S.heminis(9.4%), S.auricularis(9.4%), S.haemolyticus(6.3%), S.simulans(6.3%), S. captitis(3.1%), S.cohnii(1.5%) and S.warneri(1.5%). S.epidermidis,
S.haemolyticus and s.simlans were common identified as pathogens than contaminants (P<0.05) but S.auricularis, 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 rates to penicillin, oxacillin among CNS species were s.haemoyticus, S.epidermidis land S.simulans higher than
S.auricularis, S.hominis(P<0.05).
There results suggest that species identification and antimicrobial susceptibility test of CNS isolated from blood will be useful diagnostic tool of CNS bacteremia.
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