Discriminant analysis of cellular fatty acids of Candida species, Torulopsis glabrata, and Cryptococcus neoformans determined by gas-liquid chromatography.

We used discriminant analysis of cellular fatty acid compositions determined by gas-liquid chromatography to differentiate yeastlike fungi (a total of 190 strains; including 37 Candida albicans strains, 21 Candida krusei strains, 13 Candida guilliermondii strains, 37 Candida tropicalis strains, 10 Candida pseudotropicalis strains, 24 Candida parapsilosis strains, 32 Torulopsis glabrata strains, and 16 Cryptococcus neoformans strains). Previous results with a standard strain of C. albicans indicated that reproducible fatty acid chromatograms can be obtained with cells grown in a medium of 2% Sabouraud glucose agar at 35 degrees C for between 48 and 72 h. These conditions were also maintained in cultures of the other organisms that we studied. The cellular fatty acid compositions of the organisms were determined quantitatively by gas-liquid chromatography and analyzed by discriminant analysis. The total correct identification expressed as relative peak percent was 95.8% (89.2% for C. albicans to 100% for C. krusei, C. guilliermondii, C. pseudotropicalis, T. glabrata, and C. neoformans). The total correct identification expressed as the common peak (palmitic acid) ratio was 94.7% (87.5% for C. parapsilosis to 100% for C. pseudotropicalis, T. glabrata, and C. neoformans). Both results suggest that cellular fatty acid compositions can be differentiated by this method.

Diagnóstico de laboratorio de hongos del género cryptococcus, mediante un sistema convencional y uno computarizado / Laboratory diagnosis of fungi: of the genus Cryptococcus by conventional and computarized methods

Se estudiaron 6 cepas de hongos del género Cryptococcus aisladas de varios productos patológicos (líquido cefalorraquídeo, macerado de meninges y lesiones de piel) a las cuales se les aplicó un esquema de identificaciòn convencional y otro, utilizando técnicas de computaciòn que permitieron un determinación más rápida de las especies. Se analizan los posibles factores que se deben tener en cuenta en el diagnòstico de laboratorio de las cryptococcosis y se ofrecen los criterios de clasificaciòn

Fluorescence of Blastomyces and other fungi in Papanicolaou-stained pulmonary cytology preparations: comparison with light microscopy.

In this study, 152 Papanicolaou-stained pulmonary cytologic smears from 15 known cases of pulmonary fungal infection were randomly mixed with 194 control pulmonary smears. All slides were examined for fungi by three observers, first by light microscopy and then by fluorescent microscopy. The results of the light and fluorescent microscopy were compared. It was concluded that when both methods were used for fungal detection, the yield of positive results was higher.

Identification of species of Candida, Cryptococcus, and Torulopsis by gas-liquid chromatography.

Gas-liquid chromatography was used to identify species of Candida, Cryptococcus, and Torulopsis by fatty-acid analysis of the whole-cell hydrolysate. Candida albicans characteristically revealed 2-OH C14:0 and C19:0 (chain length:number of double bonds); these were absent in other organisms. Candida curvata was characterized by a ratio of C16:1 to C16:0 of greater than 1.0. Candida guilliermondii contained C10:0, and Candida tropicalis had no C12:0, these features were used for their identification. Cryptococcus was characterized by the absence of C16:1. Torulopsis was characterized by a C16:1 to C16:0 ratio of greater than 10 accompanied by the presence of one unidentified fatty acid. These data suggested that certain Candida, Cryptococcus, and Torulopsis (the clinically important yeast-like organisms) may be identified by gas-liquid chromatography.

[Technics for isolation of ATP from microorganisms]. / O metodakh vydeleniia ATF iz mikroorganizmov

A technique for isolation of ATP from microorganisms is suggested. The technique is based on increasing permeability of the cell membrane for substances of low molecular weight during dehydration. Treatment of the dry biomass with boiling water gives a higher yield of ATP from the cells of eukaryote and prokaryote microorganisms as compared with other techniques, and permits to register the amount of APT at the moment of experiment.

Cryptococcus laurentii cell envelope glycoprotein. Evidence for separate oligosaccharide side chains of different composition and structure.

Particulate enzyme preparations of the fungus imperfectus Cryptococcus laurentii catalyze transfer of mannosyl and galactosyl residues from GDP-[14C]mannose and UDP-[3H]-galactose to the same endogenous acceptor. After solubilization with pronase, the major portion of both labels is retarded on Sepharose columns and forms a symmetrical peak, in which 14C and 3H coincide. Label also coincides with endogenous protein and carbohydrate. Both labels bind to Sepharose-Concanavalin A (Con A) and are eluted with alpha-methylglucoside. After beta elimination with NaOH-NaBH4 only 14C label retains binding to Sepharose-Con A; 3H label representing (6-O-alpha-galactosyl)10-O-beta-galactosyl-O-mannitol as previously reported (Raizada, M. K., Kloepfer, H. G., Schutzbach, J. S., and Ankel, H. (1974) J. Biol. Chem. 249, 6080-6086) no longer binds. The [14C]mannose-containing material after beta elimination yields a pentasaccharide and a trisaccharide. Similar penta- and trisaccharides can be isolated following beta elimination of particulate preparations of the organism after pronase treatment. Analytical data suggest that the structure of the isolated pentasaccharides corresponds to that of a pentasaccharide previously synthesized de novo using cell-free enzyme preparations of the organism: 2-O-alpha-mannosyl-6-O-alpha-mannosyl-3-O-alpha-mannosyl-(2-O-beta-xylosyl)-O-mannose (Schutzbach, J. S., Raizada, M. K., and Ankel, H. (1974) J. Biol. Chem. 249, 2953-2958). The trisaccharide has the structure 2-O-alpha-mannosyl-2-O-alpha-mannosyl-O-mannitol. The data are consistent with a glycoprotein structure in which these three types of oligosaccharides are bound to a common polypeptide core through O-glycosidic linkages to threonyl and seryl residues.

Microbial fermentation of rice straw: nutritive composition and in vitro digestibility of the fermentation products.

Rice straw was fermented with Cellulomonas sp. and Alcaligenes faecalis. Microbial cells and undigested residue, as well as chemically treated (NaOH or NH4OH) and untreated straws, were analyzed for nutrient composition and in vitro digestibility. In a typical fermentation, 75% of the rice straw substrate was digested, and 18.6% of the total substrate weight that disappeared was recovered as microbial protein. The microbial cell fraction was 37% protein and 5% crude fiber; the residue was 12% protein and 45% crude fiber. The microbial protein amino acid profile was similar to alfalfa, except for less cysteins. The microbial cells had more thiamine and less niacin than Torula yeast. In vitro digestibility of the microbial protein was 41.2 to 55%, that of cellulose was 52%.