Mokaddas Eiman M, Salako Nathaneal O, Philip Leeba, Rotimi Vincent O
Department of Microbiology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
J Clin Microbiol. 2007 Jul;45(7):2162-5. doi: 10.1128/JCM.00063-07. Epub 2007 May 2.
A total of 270 viridans group streptococci (VS) isolated from healthy children, identified to the species level, were tested for their susceptibilities to penicillin, imipenem, erythromycin, and vancomycin. A total of 270 isolates and 1,080 organism-antibiotic combinations were evaluated. The overall susceptibility rates of all isolates obtained by the Etest (ET) versus agar dilution (AD) were 60.4% versus 61.8% for penicillin, 63.8% versus 63.9% for erythromycin, 90.6% versus 96% for vancomycin, and 99.1% versus 96.0% for imipenem, respectively. Major discrepancies occurred in the testing of the susceptibility of Streptococcus mutans to vancomycin, with 59.5% (ET) versus 100% (AD), followed by S. salivarius, with 84.1% versus 100%; S. oralis, with 82.1% versus 96.4%; and S. mitis, with 90% versus 100%, respectively. There were also differences in the rates of susceptibility of S. mutans, 66.5% (ET) versus 85.1% (AD), and S. intermedius, 82.9% versus 72.1%, respectively, to penicillin. General agreement between the results of ET and AD was obtained for 973 organism-antibiotic combinations out of 1,080 antibiotic combinations, i.e., 90.1%. Very major errors were found for 6.8% of isolates, and major errors were found for 3.2% of isolates; the minor errors were negligible. Agreement between the results of the two methods was 98.7% for penicillin, 94.6% for vancomycin, 96.9% for imipenem, and 99.9% for erythromycin. The highest rate of very major errors was for vancomycin, at 5.4%. The ET appears to be as efficient as AD for susceptibility testing of VS, except for vancomycin, where very major errors in the results were relatively high.
对从健康儿童中分离出的270株经种水平鉴定的草绿色链球菌（VS）进行了青霉素、亚胺培南、红霉素和万古霉素敏感性测试。共评估了270株分离菌和1080种菌株-抗生素组合。Etest（ET）法与琼脂稀释法（AD）测得的所有分离菌对青霉素的总体敏感率分别为60.4%和61.8%，对红霉素的敏感率分别为63.8%和63.9%，对万古霉素的敏感率分别为90.6%和96%，对亚胺培南的敏感率分别为99.1%和96.0%。变形链球菌对万古霉素敏感性测试中出现主要差异，ET法为59.5%，AD法为100%，其次是唾液链球菌，分别为84.1%和100%；口腔链球菌，分别为82.1%和96.4%；缓症链球菌，分别为90%和100%。变形链球菌对青霉素的敏感率分别为66.5%（ET法）和85.1%（AD法），中间链球菌对青霉素的敏感率分别为82.9%和72.1%，也存在差异。在1080种抗生素组合中，973种菌株-抗生素组合的ET法和AD法结果总体一致，即90.1%。发现6.8%的分离菌存在非常大的误差，3.2%的分离菌存在大误差；小误差可忽略不计。两种方法结果的一致性在青霉素方面为98.7%，万古霉素方面为94.6%，亚胺培南方面为96.9%，红霉素方面为99.9%。万古霉素的非常大误差率最高，为5.4%。除万古霉素结果的非常大误差相对较高外，ET法在VS敏感性测试中似乎与AD法一样有效。
