Chlamydospore production in candida albicans

Summary A review of the literature correlated with laboratory studies of the influence of carbon source, temperature, and pH on chlamydospore formation, substantiate the enzymatic hypothesis of morphogenesis inCandida albicans.     

Phosphate directed Y-M variation in candida albicans

Summary The influence of pH, O-R potential, dextrose/inorganic phosphate ratio, nitrogen source, and various cations on filamentation ofCandida albicans when grown on phosphate enriched Sabouraud Dextrose Agar (Difco) at 37° C were investigated. The dextrose/phosphate ratio apparently plays a key role under these conditions. It is postulated that magnesium ion trapped within the cell by excess polyphosphate formation leads to filamentation.Supported by U.S.P.H.S. E-1700 and U.N.C. Research Council 324-ALU-1 (360).     

Role of candida albicans infection in napkin rashes

Skin scrapings, mouth swabs, and faecal specimens from children with eruptions in the napkin area and from a series of normal infants were examined for the presence of Candida albicans.This was found in 41% of all napkin eruptions but in only one of the 68 normal infants. While C. albicans is a common secondary invader of all types of napkin eruption, primary Candida infection of the skin in the napkin area is probably uncommon.No evidence was found that generalized psoriasiform or eczematous eruptions occurring in association with napkin rashes are due to an allergic response to the fungus. C. albicans is more likely to be present in a napkin rash if the organism has been found in the alimentary tract.     

Flocculation phenomenon of Candida albicans by lysozyme

Young colonies of Sabouraud's glucose agar room temperature culture ofCandida species from human isolation were suspended in distilled water. The suspension was mixed with a solution of lysozyme and incubated in a 37° C water bath. Within 3–5 hours, various species ofCandida cells showed flocculation to varying degrees which occurred at varying periods of onset. Among sevenCandida species,Candida albicans andCandida stellatoidea showed the strongest flocculation, earliest onset and most solution clarity than did any other species.Candida stellatoidea was indistinguishable fromCandida albicans in its degree of flocculation, and in the clarity of solution.Candida species may be arranged in the following order according to their decreasing positivity in flocculation:

1. Candida albicans
2. Candida stellatoidea
3. Candida tropicalis
4. Candida krusei
5. Candida pseudotropicalis
6. Candida parapsilosis
7. Candida guilliermondii
8. Saccharomyces species may be placed afterCandida guilliermondii.

It seems possible to separate theCandida species into 3 groups by the rate of flocculation, and clarity of solution. Group I.Candida albicans andCandida stellatoidea. Group II.Candida tropicalis, C. krusei andCandida pseudotropicalis. Group III.Candida parapsilosis andCandida guilliermondii. Saccharomyces specimens (S. cerevisiae and others) were placed after group III.     

Lytic action of strepzymes from micromonospora AS

Summary The effect of lytic enzymes of Micromonospora AS on isolated cell walls and intact or heat killed cells of Candida utilis was investigated. Several substances normally used as stabilizers during protoplast formation were tested for their effect on the lytic action of strepzyme M on intact and dead cells: NaCl and KCl markedly inhibited lysis, sucrose only to 40%. Sorbitol and MgSO₄ have no inhibitory effect. MgSO₄ was selected for further research as it was found to protect the protoplasts. Phosphate buffer pH 6.8 should not be used at concentrations above 0.01 m. When grown submerged in shaking flasks or in pilot fermentation tanks, in liquid medium containing yeast cells and salts, Micromonospora AS gave the highest yield of lytic enzymes. The strepzyme M preparation is thermolabile.     

The pathological activity of metabolic products of candida albicans on newborn mice

Summary Concentrated filtrates ofCandida albicans have an inhibiting effect on the growth of newborn mice. Occasionally, this inhibition of growth is very distinct and the clinical picture corresponds to human progeria.Increased dosages of subcutaneous injections of filtrates did not increase the frequency of appearance of distinctly retarded growth in mice, but the mice showed a great area of baldness.In the number of mice, which did not show progeria, there were degenerative changes in liver and kidneys morphologically suggesting glycogenosis. The same type of changes were also observed when contents of disruptedC. albicans cells were injected into newborn mice. In the later case there was positive histochemical staining for the deposits of glycogen.The induction of pathological changes through fungus filtrates is a newly described biological phenomenon, which may play a greater role in pathology.     

Oral ketoconazole therapy for experimental candida albicans keratitis in rabbits

Oral ketoconazole (100 mg daily for 3 weeks) markedly reduced the severity of experimental Candida albicans keratitis in a group of 10 rabbits. Clinical scores of affected eyes were statistically significantly lower in the treated group than in a control group of 10 untreated rabbits. All cultures of corneal scrapings in the treated eyes were negative on the 15th day after the inoculation, whilst three positive cultures were still obtained on the 21st day in the control animals. Histopathological examination of eyes from treated and untreated rabbits showed great differences in the intensity of inflammatory changes in the two groups.     

The in vitro interactions of candida albicans with nonspecific serum proteins

Conclusions Iron has a pivotal role in serum inhibition and filamentation. That there may be an inverse relationship between inhibition and filamentation is suggested by the observations that free serum iron abolishes inhibition and stimulates filamentation.Evidence indicates that filamentation results from the interaction of substrates, growth conditions, and temperature, rather than from a single factor. Filamentation occurs during clumping and appears to be necessary for the manifestation of this later process, but any further relationship is unknown.Opsonins seem to be a part of the complement system or their function at least is dependent upon complement activity. Their interaction with surface antigens form chemotactic stimulants but their contribution to the phagocytic destruction of C. Albicans is unclear. All of these serum-Candida interactions are in vitro observations. Although opsonization and phagocytosis probably play a vital role in the in vivo defenses against invading Candida, the contribution of these other interactions to host resistance remain unknown.To prevent the repetitious use of terms germ tube formation, germination, filamentation, and Y M conversion will be used interchangeably. All these terms have been used by various authors to describe this morphological event.     

Development and evaluation of a rapid identification test for candida albicans

Summary A new technique for the rapid identification ofC. albicans has been developed and evaluated. This yeast can be identified in one hour by the formation of germ tubes after inoculation in 1/2 ml of human or animal plasma, and commercial plasma substitutes.C. albicans also forms germ tubes within 2 to 4 hours after inoculation in human serum and incubation at 37° C.Filamentation ofC. albicans in these blood derivatives is a reliable method for the identification of this yeast. It is more rapid than the assimilation and fermentation sugar tests and chlamydospore formation.Assimilation and fermentation sugar tests are used to identify those isolates ofCandida that fail to produce filaments in plasma or serum.     

Argasid tick lysozyme action on HEp-2 cells

The cytotoxic effect on Argasidae lysozyme was shown on a model of cell line HEp-2 in comparison to egg lysozyme. The lysozyme was obtained from homogenates of Ornithodoros papillipes of subfamily Ikodoidea. The lysozyme in concentrations of 300 and 500 gamma/ml had a cytotoxic effect, while in doses of 50 and 100 gamma/ml it has no such activity. The cells of line FL were not sensitive to the above concentrations of the lysozyme. In concentrations of 500 gamma/ml and higher the egg lysozyme had an analogous cytotoxic effect on the cells of line Hep-2. The comparative study of the cariogrammes of the cell monolayer treated with the Argasidae and egg lysozymes, as well as the study of the level of 3H-thimidine incorporation into the cell DNA showed the absence of the preparations effect of the mitotic activity of the cells and DNA synthesis by them.     

A glutinous rice culture medium for demonstration of chlamydospores of candida albicans

Thirty-four recent isolates ofCandida albicans from clinical material were cultured on glutinous rice agar at 21 pH values ranging from 2.2 to 11.9. After incubation at 25°C all isolates produced chlamydospores on this medium at pH values from 6.6 to 8.0 with an optimum pH of 7.1. Nineteen stock cultures and all recent isolates ofCandida albicans were used to compare the new glutinous rice agar with 9 other culture media recommended for chlamydospore formation. The results indicated that the new medium was superior in terms of (1) economy, (2) rapid production of chlamydospores, (3) transparency and (4) ease of investigation by direct microscopic examination.

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Zusammenfassung Vierunddreißig jüngst isolierte Stämme vonCandida albicans aus klinischem Material sind auf Glutin-Reisagar innerhalb 21 pH-Werte vom 2.2 bis 11.9 gezüchtet worden. Nach Inkubation bei 25°C haben alle Stämme auf diesem Medium bei den Werten von pH 6.6 bis 8.0 Chlamydosporen produziert mit dem Optimum bei pH 7.1. Neunzehn Stammkulturen und alle jüngst isolierten Stämme vonC. llbicans sind verwendet worden um den neuen Glutin-Reisnährboden mit neun anderen, empfohlenen Nährböden fur Chlamydosporen-Produktion zu vergleichen. Die Ergebnisse zeigten, daß der neue Nährboden in folgenden Beziehungen vortrefflicher war: 1) Wirtschaftlichkeit; 2) rasche Chlamydosporen-Produktion; 3) Durchsichtigkeit; 4) Leichtigkeit bei direkter mikroskopischer Untersuchung.