K. Venkateswarlu et al., FLUCONAZOLE TOLERANCE IN CLINICAL ISOLATES OF CRYPTOCOCCUS-NEOFORMANS, Antimicrobial agents and chemotherapy, 41(4), 1997, pp. 748-751
Eleven isolates of Cryptococcus neoformans were investigated to determ
ine the biochemical basis of their tolerance to fluconazole. The MICs
of fluconazole for three isolates with low-level resistance were 3- to
6-fold higher than those for sensitive isolates, while the MICs for f
our isolates with high-level resistance were 100- to 200-fold higher t
han those for sensitive isolates, The level of ergosterol present in t
he isolates varied, and those which had relatively low levels of ergos
terol were resistant to amphotericin B, Changes in the affinity of the
target enzyme (sterol 14 alpha-demethylase) and decreases in the cell
ular content of fluconazole seemed to be responsible for the resistanc
e in isolates with low-level and high-level resistance, respectively.