St-Germain G, Dion C
Laboratoire de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Canada.
Mycoses. 1996 May-Jun;39(5-6):201-6. doi: 10.1111/j.1439-0507.1996.tb00125.x.
The effect of four media or media combinations on the growth and the in vitro susceptibility to amphotericin B, 5-fluorocytosine, fluconazole and itraconazole of 51 isolates of Cr. neoformans was studied. The drug concentration producing a 50% decrease in OD405 (IC50) was determined in microtiter format. The following MOPS buffered media or media combinations (antifungal drug diluent/inoculum diluent) were used: RPMI 1640 (RPMI)/RPMI, Yeast nitrogen base (YNB)/YNB, RPMI/YNB and RPMI/High resolution broth. Amphotericin B was further tested in M3 broth in the microdilution format and on RPMI agar with the E-test. Growth rates (OD405) were higher in YNB, RPMI/YNB, RPMI/HR and M3 as compared to RPMI alone. After 48 h of incubation, IC50 values obtained with RPMI alone and with RPMI/YNB correlated within two dilutions for 98, 95, 95 and 100% of test strains with amphotericin B, 5-fluorocytosine,fluconazole and itraconazole respectively. The E-test provided the widest range of IC values with amphotericin B. Growth of Cr. neoformans can be enhanced in susceptibility tests using microtiter plates with drugs diluted in RPMI by preparing the inoculum in YNB. However, when using spectrophotometric endpoint determinations, sufficient growth is obtainable with most isolates for test interpretation at 48 h in RPMI alone.
研究了四种培养基或培养基组合对51株新型隐球菌生长及对两性霉素B、5-氟胞嘧啶、氟康唑和伊曲康唑体外敏感性的影响。采用微量滴定法测定使OD405降低50%的药物浓度（IC50）。使用了以下MOPS缓冲培养基或培养基组合（抗真菌药物稀释液/接种物稀释液）：RPMI 1640（RPMI）/RPMI、酵母氮源（YNB）/YNB、RPMI/YNB和RPMI/高分辨率肉汤。两性霉素B进一步在M3肉汤中采用微量稀释法进行测试，并在RPMI琼脂上使用E-test法进行测试。与单独使用RPMI相比，YNB、RPMI/YNB、RPMI/HR和M3中的生长速率（OD405）更高。孵育48小时后，单独使用RPMI和使用RPMI/YNB获得的IC50值，对于两性霉素B、5-氟胞嘧啶、氟康唑和伊曲康唑的测试菌株，分别在两个稀释度范围内相关性为98%、95%、95%和100%。E-test法测定两性霉素B时提供的IC值范围最宽。在使用微量滴定板进行敏感性测试时，通过在YNB中制备接种物，可增强新型隐球菌在以RPMI稀释药物的培养基中的生长。然而，当使用分光光度终点测定法时，仅在RPMI中，大多数菌株在48小时时就有足够的生长用于测试解读。
