Relationship between Candidas and melanin / 医学研究生学报

ABSTRACT

Objective Candidas rank as the second factor of deep fungal infection .This study aimed to investigate the rela-tionship between Candidas and melanin by screening clinically isolated melanin -producing Candidas . Methods We incubated 360 strains of clinically isolated Candidas with caffeic acid , DOPA agar , and minimal medium at a temperature of 35℃, with Cryptococcus neoformans as the positive control .We observed the changes in the culture media using transmission electron microscopy (TEM) and electron spin resonance ( ESR) spectroscopy . Results Cryptococcus neoforman produced pigmentation in all the three types of medi -um.At 5 days, a standard strain of Candida albicans SC 5314 turned dark brown in the DOPA agar and minimal medium and , at 10 days, 12 and 15 of the 360 Candida strains turned dark brown in the DOPA agar and minimal medium , respectively, which were not shown to be melanin by TEM and ESR spectroscopy . Conclusion Culture media are not reliable enough for the identification of mel-anin-producing Candidas , and the observations need to be further verified by TEM and ESR spectroscopy .