[Drug sensitivity and teicoplanin resistance of coagulase-negative Staphylococcus isolated from blood culture].

Drug sensitivity and teicoplanin (TEIC) resistance of coagulase-negative Staphylococcus spp (CNS) isolated from blood culture in 10 years between 1992 and 2001 were investigated, and epidemiological analysis was performed using the survey of clinical backgrounds. Regarding the resistance rates of CNS to various drugs, no isolate was resistant to vancomycin (VCM), arbekacin (ABK), and linezolid (LZD), but the minimum inhibitory concentration (MIC) of TEIC was 16 micrograms/ml or higher in 10.3% of isolates. The isolates include 56 S. epidermidis strains, 1 S. capitis strain and 4 S. haemolyticus strains. As for other drugs, the minocycline (MINO) resistance rate was relatively low (6.1%), and methicillin-resistant CNS (MRCNS) accounted for 67.1%. The resistance rate was high for many drugs between 1995 and 1997. MIC50/90 of drugs considered to be anti-Staphylococcus were 1/2 microgram/ml (VCM), 1/16 microgram/ml (TEIC), 0.25/1 microgram/ml (ABK) and 1/2 microgram/ml (LZD), showing that both MIC 50 and MIC90 of ABK were the lowest. Regarding cross-resistance to TEIC, the resistant group (MIC: 16 micrograms/ml or higher) exhibited cross-resistance to all drugs excluding MINO. Particularly, 90.2% of the TEIC resistant group was MRCNS. TEIC-resistant strain was most frequently (30.8%) detected in the pediatric ward. In comparison of clinical backgrounds of the TEIC-resistant and TEIC-sensitive groups, there were no significant differences in age, use of IVH, or prognosis, but a significant difference in detection of TEIC-resistant strains was noted in patients treated with the 4 th cepharosporins and carbapenems (p < 0.01). This survey clarified the presence of TEIC-resistant CNS strains. We will continue the survey to monitor resistance conversion. Investigation of the involvement of TEIC-resistant CNS strains in hospital infection and therapeutic course is also necessary.