Author(s)

Takuya Kuraoka¹, Takayoshi Yamada², Akito Ishiyama³, Hiroko Oyamada¹, Yukiko Ogawa⁴, Hidemitsu Kobayashi^1*

¹Divisions of Microbiology, Nagasaki International University, Huis Ten Bosch, Sasebo, Nagasaki, Japan.
²Sanko Medical Tomato Pharmacy Co. Ltd., Shimogumigo, Kawatanacho, Nagasaki, Japan.
³Sasebo City General Hospital, Hirasecho, Sasebo, Nagasaki, Japan.
⁴Divisions of Infection Control and Prevention, Department of Pharmaceutical Science, Nagasaki International University, Huis Ten Bosch, Sasebo, Nagasaki, Japan.

To investigate the chemical structure of cell wall mannan obtained from pathogenic yeast, Candida tropicalis NBRC 1400 (former antigenic standard strain, IFO 1400). As a result of two-dimensional NMR analysis, it was shown that the mannan of this strain is composed of α-1,6-, α-1,3-, α-1,2- and β-1,2-linked mannose residues. In this research, the mannan was subjected to three degradation procedures, acid-treatment, α-mannosidase, and acetolysis under two conditions in order to determine the chemical structure of the antigenic oligomannosyl side chains in this molecule. The ¹H-nuclear magnetic resonance spectra of resultant oligosaccharides, pentaose and hexaose, demonstrated the existence of the oligomannosyl side chains corresponding to Manα1-3Manα1-2Manα1-2Manα1-2Man and Manα1-3Manα1-2Manα1-2Manα1-2Manα1-2Man, respectively, which have previously also been found in Candida albicans serotype A strain mannans. These findings indicate that C. tropicalis and C. albicans serotype A have no significant difference in the chemical structure of these cell wall mannans. Therefore, it can be interpreted that it is extremely difficult to distinguish both species by targeting the antigenic group in these mannans.

Candida tropicalis, Pathogenic Yeast, Cell Wall Mannan, Antigenic Oligomannosyl Side Chain, Acetolysis, α-1, 3-Linked Mannose Residue

Kuraoka, T. , Yamada, T. , Ishiyama, A. , Oyamada, H. , Ogawa, Y. and Kobayashi, H. (2020) Determination of α-1,3-Linked Mannose Residue in the Cell Wall Mannan of Candida tropicalis NBRC 1400 Strain. Advances in Microbiology, 10, 14-26. doi: 10.4236/aim.2020.101002.