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|Title: ||Some effects of steroids on candida albicans|
|Authors: ||Wulkau, Susan E.|
|Issue Date: ||1984|
|Publisher: ||© S.E. Wulkau|
|Abstract: ||The effect of several bile salts and hydrocortisone,
on Candida albicans was investigated. Deoxycholic acid
salt, cholic acid salt and glycodeoxycholic acid salt were
found to suppress growth at concentrations of 0.1% and
above. 3-0-hemisuccinoyldeoxycholic acid salt and
hydrocortisone were only slightly inhibitory and
glycocholic acid salt and 3-0-hemisuccinoylcholic acid
salt had no effect on growth rate.
No zones of inhibition were caused by several bile
salt derivates - 3 α -succinoy- 7α - hydroxy- 5β -cholan-24-oic
acid disodium salt, disodium-3α -sulphoxy-5 β -cholan-24-oic
acid, disodium-3α---succinoy-5β -cholan-24-oate, lithocholic
acetate sodium salt or methyl-3α-succinoy-5β cholan-24-
oate sodium salt.
Several of the bile salts were found to cause
alterations in morphology which included swelling of some
cells, pinching off of portions of hyphae to form chains
of cells, and wrinkling of the cell surface. Transmission
electron microscopy revealed that cholic acid salt caused
more vacuoles in the cytoplasm, and convolutions of some
portions of cell membrane.
Growth in 0.2% cholic acid salt caused an alteration
in sterol content, for example an increase in calciferol,
24,28, dehydroergosterol and 4,4,dimethylzymosterol, and
a decrease in ergosterol, lanosterol and squalene.
Cholic acid salt caused alterations in fatty acid composition which included an increase in palmitoleate,
stearate, and oleate, and a decrease in linoleate and
linolenate. The changes in composition were presumed to
be in order to maintain the fluidity of the membrane.
Cholic acid salt did not damage the cell membrane
resulting in leakage, or have any effect on oxygen
The incorporation of sugars into the cell walls of
C. albicans was affected by cholic acid salt. The
uptake of glucose into cells was unaffected, but its
incorporation into cell walls was suppressed. The
uptake and incorporation of glucosamine was enhanced at
0.4% cholic acid salt, and mannose incoporation was
osuppressed at 0.2% and at 0.4% both mannose uptake and
incorporation was suppressed.
C. albicans grown in the presence of cholic acid
salt was less able to adhere to animal cells than
control C. albicans, although the presence of cholic
acid salt did not directly suppress adherence.
Several of the steroids interacted with commonly
used antifungal agents: cholic acid salt and
amphotericin B had a synergistic effect, clotrimazole
antagonized the effect of deoxycholic acid salt,
chenodeoxycholic acid, and hyocholic acid. Miconazole
antagonized hydeoxycholic acid, and amphotericin B
antagonized hyocholic acid. Hemisuccinoyldeoxycholic
acid and amphotericin B antagonized each other.|
|Description: ||A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.|
|Sponsor: ||Science and Engineering Research Council|
|Appears in Collections:||PhD Theses (Chemistry)|
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