Guhad F A, Jensen H E, Aalbaek B, Csank C, Mohamed O, Harcus D, Thomas D Y, Whiteway M, Hau J
Department of Physiology, Uppsala University. Sweden.
FEMS Microbiol Lett. 1998 Sep 1;166(1):135-9. doi: 10.1111/j.1574-6968.1998.tb13194.x.
Candida albicans strains with a deletion of the mitogen-activated protein kinase CEK1 gene are defective in the yeast to hyphal transition on solid surfaces in vitro. The virulence of a cek1 delta/cek1 delta null mutant strain was compared with its wild-type parent strain (WT) in a novel model of localized candidiasis. The mammary glands of lactating mice (at day 5 postpartum) were infected for 2, 4 and 6 days with 50 microliter suspension containing 1 x 10(5), 1 x 10(6) and 1 x 10(7) blastopores before death. Infected and non-infected control glands were evaluated pathologically. All animals infected with cek1 delta/cek1 delta null mutant strains showed no lesions while 65% of animals infected with the WT strain had severe lesions characterized by widespread heterophilic infiltration, necrosis, and abscess formation. As an additional control, animals infected with the disrupted strain complemented with the WT CEK1, on a replicating plasmid, also showed severe pathological changes similar to the WT strain. These results clearly demonstrate that the CEK1 gene codes for a virulence determinant of C. albicans and that the mouse mastitis model is well suited for the discriminative study of the pathogenicity of different C. albicans strains.
丝裂原活化蛋白激酶CEK1基因缺失的白色念珠菌菌株在体外固体表面从酵母形态向菌丝形态转变方面存在缺陷。在一种新型局部念珠菌病模型中，将cek1 delta/cek1 delta基因敲除突变株的毒力与其野生型亲本菌株（WT）进行了比较。在死亡前，用含有1×10⁵、1×10⁶和1×10⁷芽生孢子的50微升悬液对哺乳期小鼠（产后第5天）的乳腺进行2天、4天和6天的感染。对感染和未感染的对照乳腺进行病理评估。所有感染cek1 delta/cek1 delta基因敲除突变株的动物均未出现病变，而感染WT菌株的动物中有65%出现了严重病变，其特征为广泛的嗜异性浸润、坏死和脓肿形成。作为额外对照，感染了携带野生型CEK1的复制质粒互补的缺失菌株的动物，也表现出与WT菌株相似的严重病理变化。这些结果清楚地表明，CEK1基因编码白色念珠菌的一种毒力决定因素，并且小鼠乳腺炎模型非常适合用于区分不同白色念珠菌菌株致病性的研究。
