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W Ludwig

Publications and source records attributed to W Ludwig.

At least 163 records · Page 9Linked to original sources
PubMed1987

Comparative 16S rRNA oligonucleotide analyses and murein types of round-spore-forming bacilli and non-spore-forming relatives.

The phylogenetic incoherency of the genus Bacillus as presently described is demonstrated by analysis of both published and new data from comparative 16S rRNA cataloguing of nine Bacillus species and a number of related non-Bacillus taxa, i.e. Caryophanon latum, Filibacter limicola and Planococcus citreus. While the ellipsoidal-spore-forming bacilli, e.g. B. subtilis and allied species, formed a coherent cluster, the round-spore-forming bacilli showed a higher degree of relationship to the non-spore-forming organisms than these bacilli show among each other. Thus B. sphaericus clustered with C. latum, B. globisporus grouped with F. limicola, B. pasteurii with Sporosarcina ureae, and 'B. aminovorans' with P. citreus, respectively. These organisms formed two related subclusters which, in their phylogenetic depth, are comparable to that of the B. subtilis subline. With the exception of 'B. aminovorans', the 16S rRNA phylogeny was entirely consistent with the distribution of murein types. Even more distantly related to and grouping outside the main Bacillus cluster was B. stearothermophilus, which displayed a moderate relationship to Thermoactinomyces vulgaris. Taxonomic problems arising from the new insights into the intrageneric relationships of Bacillus are discussed.

Bacillus↗
PubMed1986

DNA hybridization probe for the Pseudomonas fluorescens group.

Plasmid pHF360 was constructed from cloned rRNA genes (rDNA) of Pseudomonas aeruginosa and used as hybridization probe for the Pseudomonas fluorescens group. The probe was tested by dot and in situ colony hybridizations to chromosomal DNAs from a wide variety of organisms. pHF360 DNA hybridized exclusively to chromosomal DNAs from bacteria representing the P. fluorescens group and separated them clearly from all other bacteria tested in the present study. Determination of the nucleotide sequence of the cloned DNA showed that it is a fragment from a 23S rRNA gene of P. aeruginosa. It was compared with the published 23S RNA sequence from Escherichia coli.

Base Sequence↗
PubMed1985

Prognostic importance of the white blood cell count for coronary, cancer, and all-cause mortality.

The relationship of white blood cell count (WBC) to fatal and nonfatal coronary heart disease (CHD) incidence and all-cause and cancer mortality was assessed in a subset of participants in the Multiple Risk Factor Intervention Trial (MRFIT). For this group of 6,222 middle aged men, total WBC count was found to be strongly and significantly related to risk of CHD, independent of smoking status. Change in WBC count from baseline to the annual examination just prior to the CHD event was found to be a significant and independent predictor of CHD risk. For each decrease in WBC count of 1,000/cu mm the risk for CHD death decreased 14%, controlling for baseline WBC count and other CHD risk factors (smoking, cholesterol level, diastolic blood pressure). The WBC count was strongly related cross-sectionally to cigarette smoking and smoking status as indicated by serum thiocyanate concentration. Smokers on average had a WBC count of 7,750/cu mm compared with 6,080/cu mm for nonsmokers. The WBC count was also significantly associated with cancer death, independent of reported smoking and serum thiocyanate levels.

Adult↗
PubMed1985

The phylogenetic position of Streptococcus and Enterococcus.

Streptococcus pyogenes, S. equinus, S. bovis, S. salivarius, S. sanguis, S. mutans, S. rattus, S. cricetus, S. lactis, S. raffinolactis and Enterococcus faecalis have been characterized by oligonucleotide cataloguing of their 16S ribosomal RNA. All the organisms form a loose but coherent group that is phylogenetically equivalent to those of lactobacilli, bacilli, the Brochothrix and Listeria group, and related taxa that constitute one of several sublines within the 'Clostridium' branch of Gram-positive eubacteria. Within the Steptococcus-Enterococcus group, organisms fall into three moderately related clusters defined by Enterococcus, the lactic acid streptococci and streptococci of the pyogenic and oral groups, respectively.

Animals↗
PubMed1985

Gram-positive bacteria: possible photosynthetic ancestry.

A 16S ribosomal RNA gene has been sequenced from Heliobacterium chlorum, the recently discovered photosynthetic bacterium that contains a novel form of chlorophyll. Comparisons with other 16S ribosomal RNA sequences show that the organism belongs to the Gram-positive bacteria (one of ten eubacterial "phyla")--more precisely to the so-called low G + C (G, guanine; C, cytosine) subdivision thereof. This brings to five the number of such phyla that contain photosynthetic species, the other four being the purple bacteria and relatives, the green sulfur bacteria, the green nonsulfur bacteria, and the cyanobacteria. The finding suggests that Gram-positive bacteria may be of photosynthetic ancestry, and it strengthens the case for a common photosynthetic ancestry for all eubacteria.

Bacteria↗
PubMed1983

A phylogenetic analysis of Legionella.

Four species of Legionella, L. pneumophila NCTC 11192, L. bozemanii NCTC 11368, L. micdadei NCTC 11371 and L. jordanis ATCC 33623 have been characterized by oligonucleotide cataloguing of their 16S ribosomal RNA. All four species are phylogenetically closely related, while no specific relationship could be detected with any other group of organisms investigated so far with respect to this method. At a low level of relationship legionellae are members of the broad group of purple photosynthetic bacteria and their non-phototrophic relatives, in which Legionella form an independent line of descent.

Legionella↗
PubMed1981

Rapid cataloging of ribonuclease T1 resistant oligonucleotides from ribosomal RNAs for phylogenetic studies.

A rapid and simple method of oligonucleotide cataloging for phylogenetic studies is presented. It involves in vitro 5'-32P-labelling of RNase T1 - resistant oligonucleotides of ribosomal 16S RNA and finger-printing by high voltage electrophoresis and gradient thinlayer chromatography. Oligonucleotide sequences are established by the mobility shift method, using controlled alkali cleavage, high voltage electrophoresis and homochromatography. These procedures facilitate in particular the analysis of long RNase T1 - resistant oligonucleotides. Oligonucleotide catalogs are established fo three Actinomycetes, namely Oerskovia turbata, Actinoplanes philippinensis and Ampullariella regularis. These catalogs are equivalent to those obtained by methods which were described by Sanger and Woese.

Actinomyces↗
PubMed1981

A phylogenetic analysis of staphylococci, Peptococcus saccharolyticus and Micrococcus mucilaginosus.

The intra- and intergeneric relationships of the genus Staphylococcus, and the phylogenetic position of Peptococcus saccharolyticus and Micrococcus (Staphylococcus salivarius), were investigated by comparative oligonucleotide cataloguing of 16S rRNA. All the staphylococci investigated form a phylogenetically coherent group at the genus level that, in addition, contains the anaerobic species Peptococcus saccharolyticus. The genus Staphylococcus belongs to the broad Bacillus-Lactobacillus-Streptococcus cluster that is defined by Gram-positive bacteria with a low DNA G+C content. Micrococcus mucilaginosus is not a genuine member of the genus Micrococcus. The binary matching coefficients between the 16S rRNA of Micrococcus mucilaginosus and those representatives of the Arthrobacter/Micrococcus group and related genera indicate that Micrococcus mucilaginosus should be regarded as a member of a new genus.

Base Sequence↗