TABLE 1.

Correlation analysis for virulence factors and C. neoformans strains

C. neoformans strain or parameteraTime to death (days)Ordinal melaninb (day 7)Laccase (OD, 420 nm)Capsule size (μm3)Doubling time (h)Phospholipase indexcUrease (OD, 560 nm)Phagocytosis index in J774.16 cellsdMacrophage killingeGXM released in vitro (μg/ml)
In vitroLiverBrain
D14140.2870NANA2.60.50.11.12.35.1
H993900.21,200NANA3.00.60.20.99.01.9
F13940.21,9003903603.20.60.10.72.88.1
B13220.22707601,2003.70.60.11.51326
K23120.35201,6006603.10.60.11.11.011
F22600.26303203203.20.50.20.85.315
B22500.26806207803.20.60.11.31810
K12430.28501,3002,2002.80.70.21.01.011
Q22200.23804405603.00.50.01.42.00.1
Balb11530.32406306403.20.60.01.11.81.7
Alt d/q1400.33503604603.60.60.20.62.846
Q11320.26601,3001,2003.40.60.11.11.56.0
D2700.27501,1001,4002.60.60.11.33.516
Balb2720.22502207303.30.60.20.84.33.8
Alt het600.24309708403.30.60.10.72.512
Control strains
    H99D1400.21,0001,6009802.90.50.11.21126
    H99ENAf20.32,700NANA2.40.60.12.9192.0
    24067NA30.21,300NANA2.71.00.03.1194.1
R2 with time to death0.170.01 0.28 g 0.010.030.030.030.040.010.020.04
P value0.110.80 0.03 0.810.580.520.530.480.670.570.45
  • a Strain names reflect the major histocompatibility complex genotypes or strains of mice in which C. neoformans was passaged (19). Strains H99Duke (H99D), H99Einstein (H99E), and 24067 are controls. AH d/q indicates C. neoformans passaged in alternating d/d and g/g MHC genotypes. Alt het indicates C. neoformans passaged in alternating heterozygote MHC genotypes. H99 is the nonpassaged C. neoformans strain.

  • b 0, no color; 1, absence or presence of color; 2, some color; 3, moderate amount of color; 4, a lot of color.

  • c Ratio of the colony diameter to the diameter of the colony plus the precipitation zone.

  • d Ratio of macrophages associated with C. neoformans to the total number of macrophages counted.

  • e Number of dead macrophages at 18 h.

  • f NA, not available.

  • g Boldface indicates significant correlation.