中国医院和社区获得性感染革兰阳性球菌耐药性监测研究

目的　探讨我国不同地区医院获得性感染 (HAI)和社区获得性感染 (CAI)患者中革兰阳性球菌耐药情况。方法　按原设计方案对 13家医院从 2 0 0 0年 7月 1日至 2 0 0 1年 6月 30日年度内分离的 2 40 1株致病菌中的 80 5株革兰阳性球菌采用国际标准平皿二倍稀释法进行体外敏感试验 ,按2 0 0 1年美国临床实验标准委员会 (NCCLS)指导原则的标准 ,测得最低抑菌浓度 (MIC50 )、MIC90 表示抗菌药物的抗菌活性 ,并计算出所测细菌对抗菌药物的耐药率 (R % )、中介率 (I% )和敏感率 (S % )。结果　从住院感染患者中分离到 2 38株金黄色葡萄球菌 ,甲氧西林耐药金黄色葡萄球菌 (MRSA)与甲氧西林耐药表皮葡萄球菌 (MRSE)的检出率分别为 37 4% ( 89/ 2 38)和 33 8% ( 5 1/ 15 1)。其中从CAI患者与HAI患者中分离的金黄色葡萄球菌数分别为 139株和 37株 (另有 6 2株不明确是CAI还是HAI)。HAI患者中MRSA检出率为 89 2 % ( 33/ 37) ,显著高于CAI患者中MRSA检出率 30 2 % ( 42 / 139) (P <0 0 1)。青霉素耐药肺炎链球菌 (PRSP)的检出率 (R % +I% )为 3 3 % ( 1/ 30 ) +2 3 3% ( 7/ 30 ) ,总耐药率为 2 6 6 % ( 8/ 30 )。从研究病房分离到肠球菌 178株 ,非研究病房分离到 15 3株 ,共计 331株。其中粪肠球菌 2 86株、屎肠球

Surveillance on gram-positive bacteria isolated from patients with hospital acquired infections or community acquired infections

OBJECTIVE: To determine the drug-resistance rates of gram-positive cocci isolated from patients with hospital acquired infection (HAI) or community acquired infection (CAI) in 34 study wards of 13 hospitals located at different areas in China. METHODS: According to the previous protocol, from July 1(st) 2000 to June 30(th) 2001, a total of 2401 pathogenic strains were isolated from 13 hospitals. Among them, 805 strains of gram-positive cocci were collected for in vitro susceptibility test using international standard plate dilution method. According to the criteria of guidelines of NCCLS (2001), MIC(50) and MIC(90) were detected to represent the antibacterial activity of antimicrobial agents and R%, I%, and S%, were calculated to show the resistant, intermediate and susceptible rates of the bacteria to the compounds tested. RESULTS: The detectable rates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) were 37.4% (89/238) and 33.8% (51/151) respectively. Among a total of 238 strains of S. aureus, 139 were isolated from patients with CAI and 37 were from HAI patients, the rate of MRSA from HAI patients (89.2%, 33/37) was significantly higher than that of MRSA from CAI patients (30.2%, 42/139) (P < 0.01). The total resistant rate of penicillin resistant Streptococcus pneumoniae (PRSP) was 26.7% (8/30), including a R% of 3.3% (1/30) and an I% of 23.3% (7/30). 331 strains of Enterococcus were isolated, including 178 strains from the study wards and 153 strains from other wards. The ratio of number of strains of E. faecalis to E. faecium was 6.8:1 (286/42). The rate of ampicillin resistant E. faecium (AREF) was 73.8% (31/42), significantly higher than the rate of ampicillin resistant E. faecalis (16.4%, 47/286). Neither strains of S. aureus nor strains of coagulase negative Staphylococcus were found resistant to vancomycin. No strains of Enterococcus were found resistant to vancomycin, the intermediate rates of E. faecalis and E. faecium to vancomycin were 3.5% (10/286) and 9.5% (4/42) respectively. All strains of Enterococcus were found 100% susceptible to teicoplanin. CONCLUSION: The resistance patterns of Gram-positive cocci including MRSA, PRSP, and AREF are similar to the results of the 1998 - 1999 surveillance. No strain of vancomycin-resistant Staphylococcus aureus, including VRSA and VISA or vancomycin resistant enterococcus, VRE is found in this study.