[Urease activity in Cryptococcus neoformans and Cryptococcus gattii].
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.
Torres-Rodríguez
Josep M
JM
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. jmtorres@imim.es
Alvarado-Ramírez
Eidi
E
Gutiérrez-Gallego
Ricardo
R
D000818:Animals; D003453:Cryptococcosis / Q000382:microbiology / Q000662:veterinary; D003454:Cryptococcus / Q000201:enzymology* / Q000472:pathogenicity; D003455:Cryptococcus neoformans / Q000201:enzymology* / Q000472:pathogenicity; D004783:Environmental Microbiology; D005656:Fungal Proteins / Q000032:analysis*; D006801:Humans; D013045:Species Specificity; D014510:Urease / Q000032:analysis*; D014774:Virulence
D005656:Fungal Proteins; D014510:Urease