Archer G L, Pennell E
Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0049.
Antimicrob Agents Chemother. 1990 Sep;34(9):1720-4. doi: 10.1128/AAC.34.9.1720.
A DNA probe derived from the PBP 2a gene of the methicillin-resistant Staphylococcus aureus COL was compared with phenotypic microbiologic tests for its ability to identify methicillin-resistant and -susceptible staphylococci. Lysates were applied to nitrocellulose with a dot blot apparatus. Isolates tested were both S. aureus and coagulase-negative staphylococci that had been recovered from a variety of geographic and clinical sources. When compared with a spread plate phenotypic test, the DNA probe gave sensitivity, specificity, and predictive values for both positive and negative tests of 100% for 204 S. aureus isolates (103 positive, 101 negative) and 99, 95, 99, and 95%, respectively, for 249 coagulase-negative staphylococci (210 positive, 39 negative). The probe was more sensitive than broth microdilution and more specific than agar dilution in identifying methicillin-resistant and -susceptible coagulase-negative staphylococci; all tests were equally accurate in identifying the methicillin susceptibility of S. aureus. DNA probe analysis for determining the methicillin susceptibility of staphylococci was rapid, easily interpretable, and equally accurate with radioactive and nonradioactive probes, and it gave results equivalent to the most sensitive microbiologic test for all staphylococcus species studied.
将源自耐甲氧西林金黄色葡萄球菌COL的PBP 2a基因的DNA探针与表型微生物学检测法进行比较，以评估其鉴定耐甲氧西林和甲氧西林敏感葡萄球菌的能力。使用斑点印迹仪将裂解物点样于硝酸纤维素膜上。所检测的菌株包括从各种地理区域和临床来源分离出的金黄色葡萄球菌和凝固酶阴性葡萄球菌。与平板涂布表型检测法相比，对于204株金黄色葡萄球菌分离株（103株阳性，101株阴性），DNA探针的阳性和阴性检测的敏感性、特异性及预测值均为100%；对于249株凝固酶阴性葡萄球菌（210株阳性，39株阴性），其敏感性、特异性及预测值分别为99%、95%、99%和95%。在鉴定耐甲氧西林和甲氧西林敏感的凝固酶阴性葡萄球菌方面，该探针比肉汤微量稀释法更敏感，比琼脂稀释法更具特异性；在鉴定金黄色葡萄球菌的甲氧西林敏感性方面，所有检测方法的准确性相当。用于确定葡萄球菌甲氧西林敏感性的DNA探针分析快速、易于解读，放射性和非放射性探针的准确性相同，并且对于所有研究的葡萄球菌种类，其结果与最敏感的微生物学检测方法相当。
