Alcaide F, Carratala J, Liñares J, Gudiol F, Martin R
Department of Microbiology, Hospital Prínceps d'Espanya, Ciutot Sanitària i Universitària de Bellvitge, Barcelona, Spain.
Antimicrob Agents Chemother. 1996 Sep;40(9):2117-20. doi: 10.1128/AAC.40.9.2117.
From January 1988 to December 1994, 66 consecutive blood culture isolates of viridans group streptococci collected from febrile neutropenic cancer patients were tested for antimicrobial susceptibilities by the agar dilution method. The antibiotics studied were erythromycin, clarithromycin, roxithromycin, dirithromycin, azithromycin, josamycin, diacetyl-midecamycin, spiramycin, and quinupristin-dalfopristin. A total of 26 (39.4%) strains were resistant to erythromycin with an MIC range of 0.5 to > 128 micrograms/ml. The strains were classified into three groups according to their penicillin susceptibility: 42 (63.6%) were susceptible, 8 (12.1%) were intermediately resistant, and 16 (24.3%) were highly resistant. The percentages of erythromycin-resistant strains in each group were 23.8, 62.5, and 68.8%, respectively. Streptococcus mitis was the species most frequently isolated (83.3%) and showed the highest rates of penicillin (40%) and erythromycin (43.6%) resistance. MICs of all macrolide antibiotics tested and of quinupristin-dalfopristin were higher for penicillin-resistant strains than for penicillin-susceptible strains. All macrolide antibiotics tested had cross-resistance to erythromycin, which was not observed with quinupristin-dalfopristin. Our study shows a high rate of macrolide resistance among viridans group streptococci isolated from blood samples of neutropenic cancer patients, especially those infected with penicillin-resistant strains. These findings make macrolides unsuitable prophylactic agents against viridans group streptococcal bacteremia in this patient population.
1988年1月至1994年12月，采用琼脂稀释法对66株从发热性中性粒细胞减少症癌症患者中连续分离出的草绿色链球菌血培养菌株进行了药敏试验。所研究的抗生素有红霉素、克拉霉素、罗红霉素、地红霉素、阿奇霉素、交沙霉素、麦迪霉素二乙酸酯、螺旋霉素和奎奴普丁-达福普汀。共有26株（39.4%）菌株对红霉素耐药，其MIC范围为0.5至>128微克/毫升。根据青霉素敏感性将这些菌株分为三组：42株（63.6%）敏感，8株（12.1%）中度耐药，16株（24.3%）高度耐药。每组中红霉素耐药菌株的百分比分别为23.8%、62.5%和68.8%。缓症链球菌是最常分离出的菌种（83.3%），对青霉素（40%）和红霉素（43.6%）的耐药率最高。所有测试的大环内酯类抗生素和奎奴普丁-达福普汀对青霉素耐药菌株的MIC高于青霉素敏感菌株。所有测试的大环内酯类抗生素对红霉素均有交叉耐药性，而奎奴普丁-达福普汀未观察到这种情况。我们的研究表明，从中性粒细胞减少症癌症患者血样中分离出的草绿色链球菌中大环内酯类耐药率很高，尤其是那些感染了青霉素耐药菌株的患者。这些发现表明大环内酯类不适用于该患者群体预防草绿色链球菌菌血症。
