Review of chemosystematics: multivariate approaches to oral bacteria and yeasts

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.

Distinction ofPrevotella intermediaandPrevotella nigrescensfrom Endodontic Bacteremia through their Fatty Acid Contents

Prevotella nigrescens has recently been recognized as a new species distinct from Prevotella intermedia. The distinction is based largely on DNA-DNA hybridization, electrophoretic migration of malate and glutamate dehydrogenase, and peptidase and lipase activities of type strains. Gas chromatography of cellular fatty acids can be a useful adjunct for characterization and identification of bacterial species. In the present study, cellular fatty acid profiles were determined for seven strains of P. intermedia and six strains of P. nigrescens. Six of these 13 strains were isolated from the root canal and blood of three patients during endodontic therapy of teeth with Asymptomatic apical periodontitis. The bacteria were cultivated anaerobically in 10 mL prereduced anaerobically sterilized peptone-yeast extract-glucose broth for 24 h. Dried cells of each isolate were methanolysed and their fatty acid contents determined by the Microbial Identification System software package by MIDI. The data were treated by principal component analysis, which distinguished P. nigrescensfromP. intermedia. Cellular fatty acid profiles of these strains of the species in blood matched the profiles of their respective root canal isolates, as demonstrated by Euclidean Distance Square assessment. This suggested that the organisms in the root canal had spread to the bloodstream during endodontic treatment.

Chemotaxonomy of Bacteroides: a review

The loose definition of Bacteroides, some species of which are important etiologic agents of oral diseases, has enabled isolates with only marginal similarities to be reposited in this genus. Many attempts have been made over the years to improve the taxonomy of this heterogeneous group of bacteria. The present article reviews major chemotaxonomic characters and techniques that have been used for this purpose: pigmentation, metabolites, whole-cell fatty acids, phospholipids, isoprenoid quinones, carbohydrates of lipopolysaccharide, whole-cell proteins, peptidoglycans, enzymes, pyrolysis mass spectrometry, DNA composition, restriction fragment length polymorphisms of DNA and ribosomal (r) RNA, homology of DNA and RNA, DNA-rRNA hybridization, and 16S and 5S rRNA oligonucleotide cataloging and sequencing. Despite improvements in their taxonomy, some bacteroides are still misclassified. Suggestions for further improvements in the taxonomy of bacteroides are made.

Recent approaches to the chemotaxonomy of the Actinobacillus-Haemophilus-Pasteurella group (family Pasteurellaceae)

Many members of the Actinobacillus-Haemophilus-Pasteurella group (family Pasteurellaceae) have been misclassified. This article reviews the chemotaxonomic characters that recently have been provided to improve the taxonomy of Pasteurellaceae. These include fatty acids of whole cells, of lipopolysaccharides and of single colonies, together with sugar contents of whole cells, of whole defatted cells, of lipopolysaccharides and of single colonies. This article also reviews taxonomy aided by distribution of proteins in whole cells and outer membranes, distribution of enzymes in outer membrane vesicles and in whole cells, bacteriolysis induced by ethylenediaminetetraacetic acid and hen eggwhite lysozyme and the distribution of respiratory quinones. Furthermore, an overview of characters obtained through studies on genetic transformation, restriction enzyme analysis, restriction fragment length polymorphism, DNA-DNA hybridization, DNA-rRNA hybridization, and 16S rRNA sequencing is given.