Use of a Commercial Reagent Leads to Reduced Germ Tube Production by Candida dubliniensis

Abstract

ABSTRACT The goal of this study was to determine the factor(s) explaining our inability to detect Candida dubliniensis . When germ tube-positive yeasts were tested for C. dubliniensis , no C. dubliniensis was detected; however, 58 C. dubliniensis strains were detected when germ tube-negative Candida albicans strains were tested further. Since all 58 C. dubliniensis strains detected were germ tube negative, these data implied that false-negative germ tube tests occurred with germ tube solution (GTS; Remel, Lenexa, KS). All 41 known C. dubliniensis strains tested were negative with GTS, whereas 40 were positive with rabbit serum (RS; Sigma-Aldrich, St. Louis, MO). Results for C. albicans were equivalent in GTS and RS. In conclusion, GTS cannot be used for the detection of C. dubliniensis , and switching from yeast to hyphae in C. dubliniensis is more restricted than in C. albicans .