2-PERCENT SODIUM-CHLORIDE IS REQUIRED FOR SUSCEPTIBILITY TESTING OF STAPHYLOCOCCI WITH OXACILLIN WHEN USING AGAR-BASED DILUTION METHODS
2-PERCENT SODIUM-CHLORIDE IS REQUIRED FOR SUSCEPTIBILITY TESTING OF STAPHYLOCOCCI WITH OXACILLIN WHEN USING AGAR-BASED DILUTION METHODS
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DOI：
10.1128/jcm.31.10.2683-2688.1993
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发表时间：
1993-10-01
影响因子：
9.4
通讯作者：
TENOVER, FC
中科院分区：
文献类型：
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作者：
HUANG, MB;GAY, TE;TENOVER, FC
研究了在用苯唑西林检测葡萄球菌时，向琼脂培养基中加入NaCl以确保结果准确性的必要性。四个抗菌药物敏感性测试方法（琼脂和肉汤稀释，E测试，和磁盘扩散），其中生长培养基中含有0，2，4，或5%的NaCl的结果进行了比较，使用mec基因探针的杂交试验的结果。我们检测了223株葡萄球菌，其中128株mec基因阳性。128株阳性菌株中共有7株为凝固酶阴性葡萄球菌，24小时苯唑西林MIC小于或等于2 μ g/ml。95株分离株为mec基因阴性，包括7株苯唑西林MIC大于或等于4 μ g/ml的金黄色葡萄球菌。在试验培养基中加入NaCl后，mec基因阳性、苯唑西林耐药葡萄球菌菌株的苯唑西林MIC增加了2 - 4倍，而mec基因阴性菌株的MIC在加入盐的情况下没有变化。在不加盐的情况下，琼脂稀释和E测试方法的非常重大错误率范围为18.2%至20.2%。mec基因阴性S.当将4或5%NaCl加入到试验培养基中时，所有试验方法的金黄色葡萄球菌分离株均>17%。在Mueller-Hinton琼脂中加入2% NaCl检测苯唑西林，
The need to add NaCl to agar media to ensure accuracy of results when testing staphylococci with oxacillin was investigated. The results of four antimicrobial susceptibility testing methods (agar and broth dilution, E test, and disk diffusion) in which the growth medium contained 0, 2, 4, or 5% NaCl were compared with the results of a hybridization assay using a mec gene probe. We tested 223 strains of staphylococci, 128 of which were mec gene positive. A total of 7 of the 128 positive strains were coagulase-negative staphylococci with 24-h oxacillin MICs of less-than-or-equal-to 2 mug/ml. Ninety-five isolates were mec gene negative, including seven strains of Staphylococcus aureus with oxacillin MICs of greater-than-or-equal-to 4 mug/ml. The oxacillin MICs for mec gene-positive, oxacillin-resistant strains of staphylococci increased two- to fourfold with the addition of NaCl to the test medium, while the MICs for mec gene-negative strains did not change in the presence of added salt. Very major error rates for the agar dilution and E test methods in the absence of salt ranged from 18.2 to 20.2%. Major error rates for mec gene-negative S. aureus isolates were >17% for all test methods when 4 or 5% NaCl was added to the test medium. The addition of 2% NaCl to Mueller-Hinton agar for testing of oxacillin resulted in very major error rates of