DiferenciaciÓn de Candida albicans y Candida dubliniensis por técnicas de electroforesis en geles de almidón y de poliacrilamida / Oral Candida albicans and Candida dubliniensis differentiatioin by multilocus enzyme electrophoresis and sodium dodecylsulphate-polyacrylamide gel electrophoresis

Cinco cepas de Candida albicans y otras cinco de C. dubliniensis así como sus cepas-patrón fueron evaluadas mediante el empleo de técnicas de electroforesis en geles de almidón y de poliacrilamida. Después de las electroforesis y evaluación numérica, se obtuvieron dos taxa muy distintos, que pueden justificar el uso de MLEE y SDS-PAGE como métodos confiables para la diferenciación e identificación complementaria de C.dubliniensis.

Differentiation and numerical analysis of oral yeasts based on SDS-Page profiles. Influence of the culture media on the whole-cell protein extracts

The application of gel electrophoresis and numerical analysis of yeast soluble proteins analysis to the investigation of 12 oral yeast strains belonging to five species is described. It involves one-dimensional electrophoresis of SDS-solubilized whole-cell proteins using different culture media for the cultivation of the cells, integration densitometries in the areas of the gels and percentages of the proteins extraction. These extracts were prepared from four isolates of Candida albicans, two of C. tropicalis, C. guilliermondii, C. parapsilosis and C. krusei. The extracts from whole-cells proteins using different culture media for the cultivation of the cells were fractionated by slab electrophoresis using a discontinuous buffer system. The corresponding patterns showed at least 36 polypeptides in the range of 14.4-200 kDa. Different isolates of each species were clearly different in each of the five species. The data obtained suggest that different nutritional compositions led to the expression of different proteins derived from alternatives metabolic pathways expressed by the electrophoretic profiles. The construction of a database of protein fingerprints and numerical analysis based on such data, may have some implications in the classification and identification of such species with epidemiological, ecological and taxonomic purposes. A well defined or synthetic culture media seems to be much properly

Analysis of parity between protein-based electrophoretic methods for the characterization of oral Candida species

Electrophoretic studies of multilocus-enzymes (MLEE) and whole-cell protein (SDS-PAGE) were carried out in order to evaluate the parity between different methods for the characterization of five Candida species commonly isolated from oral cavity of humans by numerical taxonomy methods. The obtained data revealed that sodium dodecyl sulfate polyacrylamide gel electrophoresis is more efficient in grouping strains in their respective species while MLEE has much limited resolution in organizing all strains in their respective species-specific clusters. MLEE technique must be regarded for surveys in which just one species of Candida is involved

Criteria for Candida albicans numerical analysis based on electrophoretic protein patterns

Even in normalized gels, some problems with the choice and position of protein bands always have hindered the processing of electrophoretic data. We have developed a way to establish which criterion best fits the necessities in order to maximize the similarity indexes for numerical analysis. Some repetitions of a Candida albicans strain were carried out in eleven different gels. After staining, the bands were scored in numbers within ranges of +/- n values with increases of one quarter steps (+/- 0.25 kDa, +/- 0.5 kDa, +/- 0.75 kDa, +/- 1.0 kDa, +/- 1.25 kDa) that will limit the possibility of variation for the same bands that will appear on the repetitions. Using this criterion, we have determined that values scored within +/- 1.25 kDa could optimize the minimum limiting value of similarity in different dendrograms built.

Evaluation of different dehydrogenases to recognize Candida species commonly isolated from human oral cavities

Electrophoresis of some dehydrogenases were carried out in order to establish relatedness degrees among five Candida species commonly isolated from oral cavity of humans, by numerical taxonomy methods. The obtained data revealed that some dehydrogenases are capable of distinguishing strains of different species, but most of these enzymes could not organize all strains in their respective clusters. Numerical classifications based on dehydrogenase polymorphism must be considered for surveys involving just one species of yeast genus, where this resource had already shown to be useful.

Mensuración salivar y biotipos de cándida en niños brasileños de 6-8 años teniendo un fondo socioeconómico / Salivary counts of candida species and biotypes in Brazilian children aged 6-8 year old having a socio-economic background

En este estudio se evaluó la frecuencia y biotipos de Cándida sp. en la saliva de portadores sanos, tomando en consideración la actividad cariogénica de dichos individuos a través de informaciones epidemiológicas. La muestra consistió en 239 niños tomados al azar, divididos en cinco estratos sociales. La saliva de cada uno de estos pacientes fue, cultivadas en medios específicos para el crecimiento del hongo. Posterior al crecimiento de las levaduras, las mismas fueron identificadas bioquímicamente mediante pruebas de fermentación. Los resultados obtenidos demostraron que Cándida albicans fue la especia de mayor prevalencia en todas las categorías socioeconómicas evaluadas. En 5 por ciento de las muestras se evidenció la presencia de más de una especie de Cándida coexistiendo en la cavidad bucal, incluyendo asociación de C. albicans con C. tropicalis, C. parapsilosis y C. krusei. En ninguno de los casos las especies fueron detectadas individualmente

Salivary counts of mutans streptococci and lactobacilli in children ageing 6-8 year old having a socioeconomic background in Brazil.

Saliva samples from students aged 6 to 8 year-old were analysed in order to determine the incidence of Streptococcus group mutans and Lactobacillus. Two hundred children were examined, distributed in five socioeconomic categories (A to E). Stimulated saliva samples were collected and inoculated into the SB20 and Rogsa agar culture medium for the Streptococcus and Lactobacillus cultivation. After growth, the number of these microorganisms (CUF/mL) was determined after identification of the representative colonies by biochemical methods on the basis of carbohydrate fermentation. A significative part of the population, particularly among the lower socioeconomic categories (D/E) was considered a high risk group in developing dental caries because of the high number of Streptococcus group mutans and Lactobacillus.