Lytic action of lysozyme on candida albicans

Yeast cells ofCandida albicans in lysozyme glucose solution were incubated in a 37° C water bath for 6 hours, spread on the surface of a Sabouraud's agar plate and incubated at 37° C for 18–24 hours. Scattered small colonies were seen on the agar surface compared with the thick full growth of the control culture incubated without lysozyme. Twenty-one strains of 6 standard Candida species of human isolation other thanCandida albicans; C. stellatoidea, C. tropicalis, C. pseudotropicalis, C. krusei, C. parapsillosis, C. guilliermondii, showed essentially the same results asCandida albicans. A constant quantity of lysozyme caused destruction of Candida cells to an equal degree, regardless of varied concentrations of glucose. Dilution of lysozyme greater than 100 times the original (5 mg/ml) showed the same degree of candicidal activity, however, was dependent on the presence of minute amounts of glucose. The presence of NaCl prevented the lysis of Candida by lysozyme in various solutions. Candida cells with lysozyme in glucose solution was incubated for 6 hours in a 37° C water bath. Microscopic observations revealed drastic changes in cell morphology. Most of the cells were swollen, degenerated and some completely destroyed. The gram-positive characteristics of Candida cells changed to gram-negative. The combined activity of lysozyme with complement and antibody may play an important role in the protection against Candidiasis in vivo.

---

Zusammenfassung Candida albicans-Zellen sind in Lysozyme-glukose-Lösung bei 37° C in Wasserbad für 6 Stunden bebrütet worden; sie sind dann an der Oberfläche von Sabouraud's Agarplatten ausgestrichen und bei 37° C für 18–24 Std. bebrütet worden. Zerstreute, kleine Kolonien sind an der Agarfläche erschienen, im Vergleich mit dem dicken, vollen Wachstum der Kontrolkultur, die ohne Lysozyme bebrütet worden ist. Einundzwanzig Stämme von sechs Standard-Candida Arten aus menschlichen Quellen außerC. albicans: d.h.C. stellatoidea, C. tropicalis, C. pseudotropicalis, C. krusei, C. parapsillosis, C. guilliermondii, zeigten im wesentlichen dasselbe Ergebnis wieC. albicans. Eine konstante Quantität von Lysozyme bewirkte die Zerstörung der Candida-Zellen zu gleichem Grade ohne Rücksicht auf die wechselnde Konzentration der Glukose. Eine großere Verdünnung von Lysozyme als die hundertfache des Originals (5mg/ml) zeigte denselben Grad der candicidalen Aktivität, jedoch war sie von der Gegenwart einer kleinsten Menge von Glukose abhängig. Die Gegenwart von NaCl hat die Lyse von Candida durch Lysozyme in verschiedenen Lösungen verhindert. Candida-Zellen waren mit Lysozyme in Glukoselösung für 6 Std. in Wasserbad bei 37° C bebrütet. Mikroskopische Beobachtung hat einen großen Wechsel in der Zellmorphologie enthüllt. Die meisten Zellen waren geschwollen, degeneriert, und manche völlig zerstört. Die grampositive Eigenart der Candida-Zellen wechselte in die gram-negative. Die vereinigte Aktivität von Lysozyme mit Komplement und Antikörper mag eine wichtige Schutzrolle gegen Candidiasis in vivo spielen.

     

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.     

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.     

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.     

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.

---

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.

     

The heritability of metabolic profiles in newborn twins

Identifying genetic and metabolic biomarkers in neonates has the potential to improve diagnosis and treatment of common complex neonatal diseases, and potentially lead to risk assessment and preventative measures for common adulthood illnesses such as diabetes and cardiovascular disease. There is a wealth of information on using fatty acid, amino acid and organic acid metabolite profiles to identify rare inherited congenital diseases through newborn screening, but little is known about these metabolic profiles in the context of the ‘healthy'' newborn. Recent studies have implicated many of the amino acid and fatty acid metabolites utilized in newborn screening in common complex adult diseases such as cardiovascular disease, insulin resistance and obesity. To determine the heritability of metabolic profiles in newborns, we examined 381 twin pairs obtained from the Iowa Neonatal Metabolic Screening Program. Heritability was estimated using multilevel mixed-effects linear regression adjusting for gestational age, gender, weight and age at time of sample collection. The highest heritability was for short-chain acylcarnitines, specifically C4 (h²=0.66, P=2 × 10⁻¹⁶), C4-DC (h²=0.83, P<10⁻¹⁶) and C5 (h²=0.61, P=1 × 10⁻⁹). Thyroid stimulating hormone (h²=0.58, P=2 × 10⁻⁵) and immunoreactive trypsinogen (h²=0.52, P=3 × 10⁻⁹) also have a strong genetic component. This is direct evidence for a strong genetic contribution to the metabolic profile at birth and that newborn screening data can be utilized for studying the genetic regulation of many clinically relevant metabolites.     

The metabolic basis of Candida albicans morphogenesis and quorum sensing

Candida albicans is a polymorphic fungus that has the ability to rapidly switch between yeast and filamentous forms. The morphological transition appears to be a critical virulence factor of this fungus. Recent studies have elucidated the signal transduction pathways and quorum sensing molecules that affect the morphological transition of C. albicans. The metabolic mechanisms that recognize, and respond to, such signaling molecules and promote the morphological changes at a system level, however, remain unknown. Here we review the metabolic basis of C. albicans morphogenesis and we discuss the role of primary metabolic pathways and quorum sensing molecules in the morphogenetic process. We have reconstructed, in silico, the central carbon metabolism and sterol biosynthesis of C. albicans based on its genome sequence, highlighting the metabolic pathways associated with the dimorphic transition and virulence as well as pathways involved in the biosynthesis of important quorum sensing molecules.     

Induction of candidicidal activity in mice by immunization with Candida albicans ribosomes

Abstract Mice immunized with ribosomes from Candida albicans are protected against experimental systemic candidiasis. In this study we investigated the candidacidal activity of spleen cells from immunized animals as measured by ⁵¹Cr release from pre-labelled yeast cells. It was found that the anti-candidal cytotoxic activity of splenocytes from immunized mice was significantly higher than that of spleen cells from non-immunized controls with various effector to target (E:T) ratios, but optimal results were obtained with an E:T ratio of 10:1. The cytotoxic activity of splenocytes as measured by the ⁵¹Cr release assay correlated well with the capacity of the cells to inhibit candidal growth as determined by quantitative plating. This candidacidal activity was not antibody dependent but increased killing was obtained by adding fresh (but not heat inactivated) mouse serum. The enhanced candidicidal activity was inhibited by removal of plastic- or nylon-adherent cells from the cell suspension but not by treatment with anti-Thy 1.2 serum and complement. The data indicate that a candidacidal cell population is induced in the spleens of animals immunized with C. albicans ribosomes.     

Production of glycoprotein by Candida albicans in a synthetic medium and its influence on the growth of newborn mice

Summary Growth ofCandida albicans on a synthetic medium for a period of 6 weeks produces glycoprotein substance in the approximate amount of 150 mg per liter. The polysaccharide component is formed by glucose and mannose in the approximate ratio 3:1. The protein component is composed of at least 15 different amino acids. Half percent of glucosamine was also found. The glycoprotein substance is water soluble and toxic to Swiss mice. LD50 is 0.75 mg/g of body weight when injected intravenously. Subcutaneous injection to newborn Swiss mice produced inhibition of growth. The degree of inhibition varied with the dosage. On one occasion when using a small amount of compound, stimulation of growth was also seen.This work was supported by Damon Runyon Memorial Fund Grant 720 and Joan Sloan Memorial Fund.     

Effect of metabolic substances of oral Actinomyces on Candida albicans

Actinomyces naeslundii, Actinomyces viscosus and Candida albicans are associated with root cavity. The aim of this study was to determine, in vitro, the effect produced by the metabolic substances elaborated by Actinomyces naeslundii and Actinomyces viscosus on Candida albicans. The strains were isolated of saliva. There were used the double plaque diffusion method (DPDM) and the method of radial diffusion (MRD). The effect of the time of incubation and of different concentrations of metabolic substances elaborated by Actinomyces naeslundii and Actinomyces viscosus on the kinetics of growth of C. albicans were studied. Later, the nature of the substances produced by the two strains of Actinomyces was determined. It was found that there was no inhibition of the growth of C. albicans by A. naeslundii and A. viscosus in the DPDM and the MRD. There was stimulation of the growth of C. albicans by the two strains of Actinomyces when the DPDM was used. In the MRD the results were negative. Metabolic substances produced by both species stimulated the growth of C. albicans in low concentrations but at high concentrations inhibition was observed. The best concentration of the stimulating factor, a protein substance stable to 70 degrees C, corresponds to a dilution of 1/80. The inhibition of the growth of C. albicans was produced by the decrease of the pH, the higher effect being obtained with the dilution 1/5. The metabolic substances produced by A. naeslundii and A. viscosus can have both inhibitory and stimulant effects on C. albicans, according to their concentration. These metabolic interactions would condition the proportion of C. albicans in the oral microbial ecosystems.