Department of Oral Biology, University of Malaya, Kuala Lumpur, Malaysia.
FEMS Yeast Res. 2012 May;12(3):351-8. doi: 10.1111/j.1567-1364.2011.00786.x. Epub 2012 Jan 24.
Phenotypic switching is characterized as a virulence factor of Candida spp. This study was carried out to evaluate the phenotypic switching ability of C. krusei ATCC 14243 and to determine its effect on the biological properties, adherence capacity and susceptibility towards chlorhexidine digluconate (CHX). To induce switched generations C. krusei was cultured under nitrogen-depleted growth conditions by adding phloxine B. These phenotypically switched colonies were designated as the 1st generation. Subsequent sub-culturing was performed to produce the 2nd, 3rd and 4th switched generations. The recovery of the 3rd generation was the highest at 85.7% while that of the 4th generation was lower at 70.8%, and the recovery of the 1st and 2nd generations gradually reduced to 46.6% and 36.4%, respectively. All generations of C. krusei were susceptible towards CHX. The unswitched C. krusei was the most susceptible but the least adherent to coated hard surfaces. The 2nd generation was the least susceptible, but with the highest adherent ability. The minimum inhibition concentration and minimal fungicidal concentration of C. krusei of all generations were determined at 0.4 mg mL(-1) . These observations suggest that the switching activity of C. krusei induces changes to its biological properties and susceptibility towards CHX.
表型转换是念珠菌属的一种毒力因子。本研究旨在评估克柔假丝酵母菌 ATCC 14243 的表型转换能力，并确定其对生物特性、黏附能力和对洗必泰葡萄糖酸盐（CHX）敏感性的影响。为了诱导表型转换世代，在氮饥饿生长条件下通过添加 phloxine B 培养克柔假丝酵母菌。这些表型转换的菌落被指定为第一代。随后进行连续传代培养以产生第二代、第三代和第四代转换世代。第三代的恢复率最高，为 85.7%，而第四代的恢复率较低，为 70.8%，第一代和第二代的恢复率逐渐降低至 46.6%和 36.4%。所有克柔假丝酵母菌世代均对 CHX 敏感。未转换的克柔假丝酵母菌最敏感，但对涂覆硬表面的黏附性最低。第二代最不敏感，但黏附能力最高。所有世代的克柔假丝酵母菌的最低抑菌浓度和最低杀菌浓度均为 0.4 mg mL(-1)。这些观察结果表明，克柔假丝酵母菌的转换活性诱导其生物特性和对 CHX 的敏感性发生变化。
