Torres-Rodríguez Josep M, Alvarado-Ramírez Eidi, Gutiérrez-Gallego Ricardo
Unidad de Investigación en Enfermedades Infecciosas y Micologia, Institut Municipal d' Investigació Mèdica, Unidad Docente del Instituto Municipal de Asistencia Sanitaria, Unversitat Autònoma de Barcelona, Spain.
Rev Iberoam Micol. 2008 Mar;25(1):27-31. doi: 10.1016/s1130-1406(08)70007-x.
Urease is an enzyme considered one of the main virulence factors in Cryptococcus neoformans. Quantitative differences in urease production between C. neoformans and the new species Cryptococcus gattii have not been so far documented. Using a standardized method, 25 isolates of C. neoformans and 19 of C. gattii were seeded in Christensen urea broth medium for urease activity detection. Approximately, the 50% of activity of one unit of commercial jack beans urease (A550=0.215) was considered as a reference to classified the Cryptococcus in two cathegories, low (A550<0.215) or high (A550=or>0.215) urease producers. After 72 hours of incubation, 76% of C. neoformans and 15.8% of C. gattii strains were high urease producers (p=0.016). Based on these results, the species C. neoformans appeared as the highest urease producer. Other virulence factors should also be investigated to explain C. gattii pathogenicity.
脲酶是一种酶，被认为是新型隐球菌的主要毒力因子之一。迄今为止，尚未有关于新型隐球菌和新物种格特隐球菌之间脲酶产生量的定量差异的记录。采用标准化方法，将25株新型隐球菌和19株格特隐球菌接种于克里斯滕森尿素肉汤培养基中进行脲酶活性检测。大约将一个单位的商业刀豆脲酶活性的50%（A550 = 0.215）作为参考，将隐球菌分为两类，即脲酶产生量低（A550 < 0.215）或高（A550 =或> 0.215）的生产者。培养72小时后，76%的新型隐球菌菌株和15.8%的格特隐球菌菌株是脲酶产生量高的生产者（p = 0.016）。基于这些结果，新型隐球菌似乎是脲酶产生量最高的物种。还应研究其他毒力因子以解释格特隐球菌的致病性。
