Anaissie E, Paetznick V, Bodey G P
Section of Infectious Diseases, University of Texas, M. D. Anderson Cancer Center, Houston 77030.
Antimicrob Agents Chemother. 1991 Aug;35(8):1641-6. doi: 10.1128/AAC.35.8.1641.
In vitro antifungal susceptibility testing generally remains unstandardized and unreliable for directing therapy. When azoles are tested, this problem is further compounded by the lack of definite reading end points. We determined the in vitro susceptibility of 50 Candida albicans isolates (including 10 reference strains) to fluconazole by using a microbroth dilution method in which microtiter plates were agitated immediately before reading. Six fungal inoculum sizes (ranging from 2 x 10(2) to 4 x 10(5) CFU/ml), three different times of reading (24, 48, and 72 h), and two temperatures (30 and 35 degrees C) were tested. We also compared visual and spectrophotometric determinations of MIC end points. This agitation method resulted in clear-cut visual end points that were reproducible for different observers within the same laboratory, that were independent of inoculum size, temperature of incubation, and time of reading, and that correlated well with the degree of fungal inhibition as determined by spectrophotometry. Median MICs also correlated with usually achievable levels of fluconazole in serum and tissue of humans and experimental animals.
体外抗真菌药敏试验在指导治疗方面通常仍未标准化且不可靠。在检测唑类药物时，由于缺乏明确的读数终点，这个问题更加复杂。我们采用微量肉汤稀释法，在读取结果前立即振荡微量滴定板，测定了50株白色念珠菌分离株（包括10株参考菌株）对氟康唑的体外敏感性。测试了六种真菌接种量（范围从2×10²至4×10⁵CFU/ml）、三个不同的读数时间（24、48和72小时）以及两个温度（30和35摄氏度）。我们还比较了MIC终点的目视测定法和分光光度测定法。这种振荡方法产生了清晰的目视终点，在同一实验室内不同观察者之间具有可重复性，与接种量、培养温度和读数时间无关，并且与分光光度法测定的真菌抑制程度相关性良好。MIC中位数也与人和实验动物血清及组织中通常可达到的氟康唑水平相关。
