Differences in response in vivo to amphotericin B among Candida albicans strains.
A group of ten Candida albicans strains previously determined to be resistant or susceptible to topical amphotericin B in vivo and in vitro were exposed to treatment with different concentrations of the drug in a quantitative model of candidal keratitis in Dutch-belted rabbits. After 5 days of topical treatment with amphotericin B eye drops in concentrations of 0.3%, 0.03%, or 0.003%, quantitative isolate recovery in treated animals was compared with that of untreated controls. A dose response was observed for all five susceptible strains. The two strains that were most sensitive to amphotericin B in vitro also were the most susceptible in vivo. At each dose level there was a two- to eightfold reduction in isolate recovery among highly susceptible strains compared with less susceptible strains (P less than 0.05). The five resistant strains remained so even when the 0.3% concentration was used. Among strains of C. albicans susceptible to amphotericin B, there appeared to be a variation in degree of susceptibility in vivo that correlated with the minimum inhibitory concentration.
O'Day
D M
DM
Department of Ophthalmology, Vanderbilt University School of Medicine, Nashville, Tennessee.
Ray
W A
WA
Robinson
R D
RD
Head
W S
WS
Williams
T E
TE
D000287:Administration, Topical; D000666:Amphotericin B / Q000494:pharmacology*; D000818:Animals; D002176:Candida albicans / Q000187:drug effects* / Q000302:isolation & purification; D002177:Candidiasis / Q000188:drug therapy / Q000382:microbiology*; D015169:Colony Count, Microbial; D003315:Cornea / Q000187:drug effects / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial; D015821:Eye Infections, Fungal / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D007634:Keratitis / Q000188:drug therapy / Q000382:microbiology*; D011817:Rabbits
D000666:Amphotericin B