Chemical and biochemical studies for the differentiation of coagulase-positive staphylococci

The cell wall composition, the configuration of lactic acid produced from glucose under anaerobic conditions, the occurrence of fructose-1,6-diphosphate (FDP) activatedl-lactate dehydrogenase (l-LDH), and the esterase pattern were determined from more than 80 strains of coagulase-positive staphylococci isolated from man and animal. Strains isolated from man, swine, bovines and hares form a rather homogencous group. They exhibit a similar cell wall composition, produce predominantlyd,l-lactate and have a characteristic and simple esterase pattern. Coagulasepositive staphylococci isolated from dogs, horses, minks and pigeons are quite distinct from typicalStaphylococcus aureus strains. They exhibit a different cell wall composition, produce onlyl-lactate, possess anl-LDH which is specifically activated by FDP, and have a quite complex esterase pattern.List of Abbreviations BBP bromphenol blue - FDP fructose-1,6-diphosphate - d-LDH d-lactate dehydrogenase - l-LDH l-lactate dehydrogenase - NAD nicotinamide adenine dinucleotide     

A comparative immunological study of catalases from coagulase-positive staphylococci

Protein homology studies with catalase as a reference point were carried out with coagulasepositive staphylococci belonging to Staphylococcus aureus, S. intermedius and S. hyicus. Antisera against catalases of S. aureus ATCC 12600 and S. aureus ATCC 12601 reacted very weakly employing double immunodiffusion and quantitative microcomplementfixation assay with cell-free extracts or catalase enriched preparations of S. intermedius or S. hyicus. The differences between coagulase-positive staphylococci could be confirmed by using the antiserum against S. intermedius H 11 catalase. Within the strains of the species S. intermedius immunological distances ranging up to 25 indicate a heterogeneity which justify the separation of the biotypes E and F on a subspecies level. Coagulase-positive strains of S. hyicus revealed neither a close relationship to S. aureus nor to S. intermedius.     

Deoxyribonucleic acid reassociation in the taxonomy of the genus Chlorella

DNA hybridization techniques showed Chlorella fusca var. vacuolata and C. kessleri to be homogeneous species with DNA homologies of 90–100% C. fusca var. fusca and var. rubescens, however, have only about 15% DNA homology with C. fusca var. vacuolata and should no longer be regarded as varieties. A good correlation was found so far between biochemical and physiological characters used in the taxonomy of Chlorella and DNA relatedness. Mutant strains of Chlorella were tested for DNA homologies to prove the reliability of the taxonomical interpretation.     

Deoxyribonucleic acid reassociation in the taxonomy of the genus Chlorella

The genetic relationships of nine strains of Chlorella saccharophila were determined by DNA hybridization techniques. Four strains are closely related to the type strain 211-9a and one strain seems to be moderately related, whereas the taxonomic position of the remaining three strains is not clear. C. saccharophila, like C. sorokiniana, is another species of Chlorella containing strains which are heterogeneous in their overall DNA base sequence and partly also in morphological, biochemical and physiological characters.     

Deoxyribonucleic acid reassociation in the taxonomy of the genus Chlorella

DNA homologies of 14 strains of Chlorella protothecoides were determined. All strains are related by a high degree of DNA similarity (96–102% D) with the exception of strain 211-11 a which proved to belong to C. kessleri. There is, however, no detectable DNA homology with strains of the genus Prototheca which is supposed to have evolved from C. protothecoides by loss of photosynthetic pigments. Even within Prototheca the low degree of DNA similarity indicates a heterogeneity similar to that observed in the genus Chlorella.     

Deoxyribonucleic acid reassociation in the taxonomy of the genus Chlorella

Four species of the unicellular green alga Chlorella, C. vulgaris, C. luteoviridis, C. minutissima, and C. zofingiensis, were characterized with respect to DNA similarities as determined by quantitative DNA hybridization procedures. In contrast to previous DNA hybridization procedures. In contrast to previous results, C. vulgaris turned out to be a homogeneous species with the exception of strain 211-11c of the Göttingen collection, which was shown to belong to C. kessleri. Similary, C. luteoviridis and C. minutissima represent well defined species in terms of phenotypic and genotypic features. Whitin C. zofingiensis on strain is clearly different with respect to DNA base composition and DNA hybridization data even though it shares phenotypic characteristics with the other strains of C. zofingiensis.     

Deoxyribonucleic acid reassociation and interspecies relationships of the genusChlorella (Chlorophyceae)

Phylogenetic relationships within the genusChlorella were studied by means of DNA/DNA hybridization under both optimal and relaxed reassociation conditions as well as by determination of the thermal stability of hybrid DNA duplexes. The results indicate a relationship betweenC. fusca var.fusca, C. fusca var.rubescens, C. fusca var.vacuolata, and the genusScenedesmus. In addition, the strains endosymbiotic withParamecium bursaria seem to be related with theC. vulgaris/sorokiniana group. The relations between most other species, however, could not be sufficiently resolved by the above methods. This implies considerable phylogenetic divergency within the genusChlorella.     

Relatedness among coagulase-negative staphylococci: Deoxyribonucleic acid reassociation and comparative immunological studies

DNA-DNA-homology values were determined under restrictive to relaxed reassociation conditions with type strains and some additional strains of coagulase-negative staphylococci belonging to ten different species. The immunological relationship of the catalases present in the type strains of these species was also determined by applying double immunodiffusion and microcomplement fixation. The results of these studies support the previous proposal to subdivide the coagulase-negative staphylococci into at least ten separate species. However, it is evident that some of the species are more closely related than others and can form species groups. According to the results presented in this study, the coagulase-negative staphylococci can be combined into five species groups: The Staphylococcus saprophyticus group is composed of S. saprophyticus, S. xylosus and S. cohnii. The S. epidermidis group comprises S. epidermis, S. capitis and S. warneri. The S. hominis group which exhibits a significant relationship to S. epidermidis includes S. hominis and S. haemolyticus. The species group S. sciuri consists of S. sciuri ssp. sciuri and S. sciuri ssp. lentus and the species group S. simulans is presently represented by the corresponding single species.Abbreviations G+C guanosine + cytosine - SSC standard saline citrate buffer This work was supported by Deutsche Forschungsgemeinschaft     

Deoxyribonucleic acid reassociation in the classification of flavobacteria.

DNA-DNA reassociation studies showed that Flavobacterium emningosepticum strains had a genetic relatedness of 91 to 100% with inter-strain duplexes having high thermal stabilities. The only exception, strain NCTC10016, had an average relatedness of only 43% to other strains of F. meningosepticum. The apparent divergence in DNA base sequence of this strain was reflected in the structural differences of some enzymes. There was a gradation of DNA relatedness among the Flavobacterium group II-b strains, but three strains were sufficiently related to constitute a species. Low levels of genetic relatedness were confirmed between F. meningosepticum and strains of Flavobacterium group II-b, group II-f, F. aquatile, F. breve, F. heparinum, F. pectinovorum, F. odoratum and Moraxella saccharolytica. All strains had base compositions in the range 32 to 46% guanine plus cytosine. The genome sizes of representative strains of F. meningosepticum and Flavobacterium group II-b were 2-50 X 10(9) to 3-52 X 10(9) daltons. The taxonomic implications of these findings are discussed.     

Supplementary biochemical tests useful for the differentiation of oxidase positive staphylococci

Differentiation of the oxidase positive staphylococci, Staphylococcus sciuri, Staphylococcus lentus, Staphylococcus vitulinus and Staphylococcus fleurettii, based on tributyrin, urease, caseinase, gelatinase and DNase activity is described. These tests may be used for preliminary identification of oxidase positive isolates of staphylococci resulting in more accurate identification of these species.     

Chloroplast DNA reassociation and grass phylogeny

Sequence variation in chloroplast DNA (cpDNA) as measured by DNA reassociation was examined in 12 grass species to address systematic problems in thePoaceae at the subfamilial and tribal levels. Two species,Petunia (Solanaceae) andGlycine (Leguminosae), were included to determine degrees of sequence divergence in cpDNA between monocots and dicots. The data were analyzed phenetically and phylogenetically. Species were segregated into four major groups that corresponded to the subfamiliesPooideae, Oryzoideae, Chloridoideae, andPanicoideae. Representatives of thePooideae andOryzoideae grouped together as did members of theChloridoideae andPanicoideae. ThePooideae split into two major groups corresponding to the recently recognized supertribesTriticanae andPoanae. Internodes between subfamily branches were short which might indicate a burst of divergence in the family early in its evolution. Sequence similarity values between the monocot grass species and the two dicot taxa ranged from 0.15 to 0.27, representing the highly conserved sequences of the chloroplast genome.     

DNA reassociation kinetics and hybridization in different angiosperms

Reassociation kinetics ofDaucus carota andPetroselinum crispum (Apiaceae), andDatura innoxia (Solanaceae) are presented. Hybridization of³H-labelled DNA of two carrot cultivars indicate strong qualitative homologies of DNA sequences; nevertheless, certain quantitative differences in some Cotregions seem to exist. However, homologous sequences ofDaucus DNA with DNA ofDatura, and, suprisingly, even with DNA ofPetroselinum are very restricted: between 8% in the repeated regions and ca. 7–9% in the unique regions.     

Improved high-performance liquid chromatographic separation of peptidoglycan isolated from various Staphylococcus aureus strains for mass spectrometric characterization

Reversed-phase high-performance liquid chromatography (RP-HPLC) of muropeptides, obtained by muramidase digestion of peptidoglycan in combination with amino acid analysis and plasma desorption time-of-flight mass spectrometry is today by far the best tool to analyze the fine structure of the peptidoglycans. Here we report further improvements of the RP-HPLC separation of muropeptides for analyzing the peptidoglycans of various methicillin-resistant strains of Staphylococcus aureus, with emphasis on a more detailed characterization of the interpeptide bridge of the peptidoglycans of this species.     

Deoxyribonucleic acid base composition of simonsiellaceae

The molar percentages of guanine plus cytosine in the DNA of 51 strains of Simonsiellaceae were determined by buoyant density ultracentrifugation of cell lysates in CsCl. The DNA base ratios ranged from 41–55 mole-% guanine plus cytosine. These values fall within the range known for the Order Cytophagales, the non-fruiting gliding bacteria, and are out-side the range of the Order Myxobacterales, the fruiting myxobacteria. Among the strains of the genus Simonsiella, four distinct groups can be delineated on the basis of source of origin (sheep, dog, cat, human) and GC content. The neotype of Alysiella filiformis has a GC content of 45.4 mole-%.     

一株金黄色葡萄球菌噬菌体的裂解谱特异性和分子分类研究

[目的]从医院污水中分离金黄色葡萄球菌噬菌体,观察其形态,确证裂解谱特征并研究生物学和基因学特性,为噬菌体的临床应用奠定实验基础.[方法]将金黄色葡萄球菌ATCC25923作为宿主菌,采用双层琼脂平板法从医院污水中分离纯化噬菌体,电镜下观察形态并测定其最佳感染复数、一步生长曲线及裂解谱;全基因组测序并进行基因结构分析和...     

Inhibition of wall autolysis of staphylococci by sodium polyanethole sulfonate “liquoid”

Summary Liquoid (polyanethole sulfonate) was neither capable of influencing the growth nor the viability of staphylococci. But liquoid induced a suppression of the activity of different autolytic wall systems of normally growing staphylococci, i.e., autolysins which participate in cross wall separation as well as autolysins which are responsible for cell wall turnover. Additionally, the lysostaphin-induced wall disintegration of staphylococci was inhibited by liquoid.However, no indication could be found for a direct inhibition of lytic wall enzymes by liquoid; rather an interaction of liquoid with the target structure for the autolytic wall enzymes, the cell wall itself, was postulated. On the basis of the experimental data with the teichoic acid^- mutant S. aureus 52A5 the sites of wall teichoic acid were supposed to be an important target for the binding of liquoid to the staphylococcal cell wall.     

Proline betaine is a highly effective osmoprotectant for Staphylococcus aureus

Proline betaine is an osmoprotectant that is at least as effective as glycine betaine, and more effective than L-proline, for various strains of Staphylococcus aureus, and Staphylococcus epidermidis and Staphylococcus saprophyticus. ¹³C NMR studies revealed that proline betaine accumulated to high levels in osmotically stressed S. aureus, but was also detected in organisms grown in its presence in the absence of osmotic stress. Competition experiments indicated that proline betaine was taken up by the proline transport systems of S. aureus, but not by the high affinity glycine betaine transport system.Abbreviations PYK Peptode - Yeast extract K₂HPO₄     

Genotypic relationships between Prochloron samples from different localities and hosts as determined by DNA-DNA reassociations

Genotypic relationships between seven Prochloron samples isolated from different didemnid ascidian hosts collected at the Palau archipelago and Munda (Solomon Islands) and one cyanobacterial (Synechocystis) strain were determined by DNA-DNA reassociations. Thermal stability values of DNA-DNA hybrids indicate that all Prochloron samples involved are mutually very closely related and only slightly related with the Synechocystis strain. It is concluded that the Prochloron samples tested are representatives of one and the same species.