84株肺炎链球菌的耐药性测定

Antimicrobial Resistance of 84 Strains of Streptococcus pneumoniae in Wuhan

目的 调查武汉地区肺炎链球菌对青霉素等抗生素的耐药率及防治对策。方法 用琼脂稀释法测定临床分离的 84株肺炎链球菌对 19种抗生素的最低抑菌浓度 (MIC) ,同时用E test法测定其中 30株菌对青霉素、头孢噻肟、头孢曲松的MIC。结果 E test法和琼脂稀释法的一致性≥ 90 % ,无高度耐青霉素菌株 (MIC≥ 2 μg/ml) ,35株 (41.6 % )低耐青霉素 (MIC 0 .12 5～ 1μg/ml) ;青霉素敏感株对头孢噻肟、头孢吡肟、头孢曲松均敏感 ,对头孢呋辛、头孢克洛、头孢丙烯的耐药率分别为 16 .3%、34.7%、6 .1% ;青霉素不敏感株对以上 6种药的耐药率为2 0 %～ 77.1% ;氯霉素、四环素、红霉素、阿奇霉素的耐药率分别为 10 .7%、73.8%、6 9.0 %、6 7.8% ;所有菌株对万古霉素、利福平、左氧氟沙星、阿莫西林、阿莫西林 /克拉维酸、哌拉西林敏感 ;儿童分离株对青霉素的不敏感率高于成人 (P <0 .0 1) ;入院 >4 8h患者分离株对青霉素的不敏感率高于门诊及入院 <4 8h患者分离株 (P <0 .0 5 )。结论 武汉地区 4 1.6 %的肺炎链球菌对青霉素不敏感 ,青霉素不敏感株对抗生素的抗菌活性依次为阿莫西林、氯霉素、头孢噻肟、头孢呋辛及头孢丙烯。

OBJECTIVE To investigate antimicrobial resistance of Streptococcus pneumoniae and make guidelines in Wuhan. METHODS The resistance to 19 antibiotics of the 84 clinical strains of S. pneumoniae was studied by agar dilution method. Among them 30 isolates were performed by E-test for penicillin, cefotaxime and ceftriaxone as well. RESULTS The consistency between the MICs obtained by E-test and agar dilution was ≥90%. Overall, no fully resistant strain was detected, but 35 strains (41.6% of the total) were in the penicillin-intermediate range. Penicillin-susceptible isolates were also sensitive to the tested third generation cephalosporins, such as cefotaxime, cefepime and ceftriaxone and their resistant rates to cefuroxime, cefaclor, cefprozil were 16.3%, 34.7%, 6.1%, respectively. Whereas, the percentage range of resistance to the above 6 antibiotics of the penicillin-nonsusceptible isolates was 20.0-77.1%. The overall percentage of resistance to chloramphenicol, tetracycline,erythromycin and azithromycin were 10.7%, 73.8%, 69.0% and 67.8%, respectively. All strains were sensitive to vancomycin, rifampicin, levofloxacin, amoxicillin, amoxicillin/clavulanic acid and piperacillin. The proportion of penicillin-nonsusceptible isolates was significantly higher for children than for adults (P<0.01). So were the patients in hospital surpassed 48 hours than that of those in hospital within 48 hours and outpatients (P<0.05). CONCLUSIONS In Wuhan, the prevalence of penicillin-nonsusceptible pneumococci was high to 41.6%. To penicillin-nonsusceptible strains, active antibiotics were amoxicillin, chloramphenicol, cefotaxime, cefuroxime and cefprozil.