FIG 4 .

Pyruvate kinase mutants exhibit enhanced persistence in the lung without disease production. A/Jcr inbred mice were infected per nasally with the WT, pyk1∆, pyk1∆/mig1∆, or hxk1∆/hxk2∆ strain of C. neoformans in order to assess the persistence of these strains in vivo. (A) Fungal burden in lung tissues was assessed for three mice per strain every 3 weeks following infection as described elsewhere (70). Brain tissues from these mice showed no fungal burden over the course of the experiment. (B) The mice in the fungal burden assay were also observed over the course of the experiment for clinical signs correlating with eventual mortality (≥15% loss of body weight, lack of grooming, etc.). The survival of mice not sampled at the predetermined endpoints was assessed for similarity to the WT level. All mutant strains showed statistically significant differences from the WT (P < 0.0001; log rank test).