Cryptococcus neoformans is an opportunistic pathogen which attacks individuals with weakened immune systems. Two C. neoformans isolates, 184A and NU-2, were examined to determine characteristics that contribute to their difference in virulence. Both isolates were grown under tissue culture conditions, and different characteristics were tested at timed intervals. Isolate 184A was found to grow at a faster rate than isolate NU-2, with doubling times of 4 and 12 hours respectively. The polysaccharide capsule of isolate NU-2 doubled in size in four hours, while that of isolate 184A stayed approximately the same. The NU-2 yeast cell diameter without the polysaccharide capsule was initially bigger than 184A at 3.62 pm and continued to increase although the diameter of isolate 184A stayed approximately the same at 2.41 pm. Isolate NU-2 shed excessive capsular material into the media, but isolate 184A shed little. These findings highlight some major differences in the characteristics of the two isolates which may contribute to the differing degrees of virulence.
Jones, Kristy L. and Murphy, Juneann W.
"In vitro Growth Characteristics of Two Cryptococcus neoformans Isolates,"
Journal of the Arkansas Academy of Science: Vol. 52
, Article 14.
Available at: http://scholarworks.uark.edu/jaas/vol52/iss1/14