Hawkins J E
J Clin Microbiol. 1986 May;23(5):934-7. doi: 10.1128/jcm.23.5.934-937.1986.
Determination of the drug susceptibility of Mycobacterium tuberculosis by conventional methods using an agar-based medium may take 3 weeks or more to complete. On the other hand, results on positive cultures are generally available in 4 to 7 days with the radiometric (BACTEC, Johnston Laboratories, Towson, Md.) procedure. One disadvantage to the latter is the requirement to determine the quantity of 14CO2 in each test vial on a daily basis from the day of inoculation. Growth index readings often must be made over weekends, adding to the work load of clinical laboratories during periods of reduced staff or necessitating compensatory pay or time. Susceptibility tests with streptomycin, isoniazid, ethambutol, and rifampin against 104 M. tuberculosis strains were performed by the submerged disk method, the recommended BACTEC method with daily growth index readings, and the radiometric procedure with readings delayed for 2 days after inoculation. Criteria for interpretation of "delayed" tests were established. Drug concentrations tested included some modifications of those available commercially. Overall agreement for the four drugs by the three methods was greater than 90%. We conclude that under our test conditions a schedule of inoculation of radiometric test vials on Friday with growth index readings commencing on Monday gives susceptibility results that correlate well with the daily BACTEC method and with a conventional 7H10 agar method.
采用基于琼脂培养基的传统方法来测定结核分枝杆菌的药敏性可能需要3周或更长时间才能完成。另一方面，使用放射测量法（BACTEC，约翰斯顿实验室，马里兰州陶森），阳性培养物的结果通常在4至7天内即可获得。后者的一个缺点是，从接种之日起，每天都需要测定每个测试瓶中的14CO2含量。生长指数读数常常必须在周末进行，这增加了临床实验室在人员减少期间的工作量，或者需要支付加班费或安排调休。采用浸盘法、推荐的每日读取生长指数的BACTEC法以及接种后延迟2天读取数据的放射测量法，对104株结核分枝杆菌进行了链霉素、异烟肼、乙胺丁醇和利福平的药敏试验。制定了“延迟”试验的判读标准。所测试的药物浓度包括对市售药物浓度的一些调整。三种方法对这四种药物的总体一致性超过90%。我们得出结论，在我们的测试条件下，周五接种放射测量测试瓶并于周一开始读取生长指数的方案所得到的药敏结果，与每日BACTEC法以及传统的7H10琼脂法的结果具有良好的相关性。
