Effects of hypoxia on the capsule size of Cryptococcus neoformans / 医学研究生学报

ABSTRACT

Objective Little is known about the role of low oxygen concentration in the formation of the capsule of Cryptococ -cus neoformans .This study was to investigate the effect of hypoxic condition on the capsule size of Cryptococcus neoformans . Methods We cultured 39 Cryptococcus neoformans strains in liquid Sabouraud medium and then incubated them at the normoxic (21%) and hypoxic concentration (1%), respectively.After 72 hours of incubation, we observed the capsules formed at different ox-ygen conditions under the Olympus microscope and the measured their sizes using the Axiovision software . Results Of the total number of Cryptococcus neoformans strains , 30 showed larger capsules in the normoxic than in the hypoxic condition , 17 with statisti-cally significant differences in their diameters (P<0.05), while the other 9 strains exhibited just the opposite results , 4 with statisti-cally significant differences in their diameters ( P<0.05). Conclusion Hypoxia might inhibit the growth of the Cryptococcus neoformans capsule.However, further studies are needed on its correlation with the serum or gene types of the Cryptococcus neofor-mans strain.