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D T Drewry

Publications and source records attributed to D T Drewry.

5 recordsLinked to original sources
PubMed1990

Staphylococcal slime: a cautionary tale.

Slime production by Staphylococcus epidermidis may be important in the adherence to and colonization of biomedical devices, and slime has been proposed to have various effects on the immune system. Attempts were made to isolate, purify, and chemically characterize slime from S. epidermidis cultivated under fluid on tryptic soy broth-agar medium. "Crude slime" from slime-producing strain RP-12 was characterized by a high galactose content. Similar materials in similar yields were isolated from slime-producing strain Kaplan, a non-slime-producing mutant, Kaplan-6A, and sterile medium controls, suggesting that crude slime was derived mainly from the medium. The occurrence of D- and L-galactose and pyruvate and sulfate residues and methylation analysis of these crude slime preparations, monitored by gas-liquid chromatography and mass spectrometry, showed that the agar was the main source of crude slime, suggesting that the preparation was largely an artifact of the growth and isolation procedures. Similar high-galactose-content preparations from both S. epidermidis and Staphylococcus aureus, assumed to be bacterial products and with a variety of biological activities, have been described by other investigators. Growth attached to a solid surface appears to be important for slime production. An accumulation of turned-over cell surface molecules and released macromolecules such as DNA may contribute to slime production. Avoidance of agar and development of a chemically defined medium for slime production are recommended for further studies.

Culture Media↗
PubMed1975

Studies of polysaccharide fractions from the lipopolysaccharide of Pseudomonas aeruginosa N.C.T.C. 1999.

Two polymeric water-soluble fractions were isolated by gel filtration after mild acid hydrolysis of the lipopolysaccharide from Pseudomonas aeruginosa N.C.T.C. 1999. The fraction of higher molecular weight retained the O-antigenic specificity of the lipopolysaccharide and may be 'side-chain' material. This fraction was rich in N (about 10%) and gave several basic amino compounds on acid hydrolysis; fucosamine (at least 2.8% w/w) was the only specifc component identified. The fraction of lower molecular weight was a phosphorylated polysaccharide apparently corresponding to 'core' material. The major components of this fraction and their approximate molar proportions were: glucose (3-4); rhamnose (1); heptose (2); 3-deoxy-2-octulonic acid (1); galactosamine (1); alanine (1-1.5); phosphorus (6-7). In the intact lipopolysaccharide this fraction was probably linked to lipid A via a second residue of 3-deoxy-2-octulonic acid, and probably also contained additional phosphate residues and ethanolamine. The residues of 3-deoxy-2-octulonic acid were apparently substituted in the C-4 or C-5 position, and the phosphorylated heptose residues in the C-3 position. The rhamnose was mainly 2-substituted, though a little 3-substitution was detected. The glucose residues were either unsubstituted or 6-substituted. Four neutral oligosaccharides were produced by partial acid hydrolysis and were characterized by chemical, enzymic, chromatographic and mass-spectrometric methods of analysis. The structures assigned were: Glcpalpha1-6Glc; Glcpbeta1-2Rha; Rhapalpha1-6Glc; Glcpbeta1-2Rhapalpha1-6Glc. The galactosamine was substituted in the C-3 or C-4 position, the attachment of alanine was indicated, and evidence that the amino sugar linked the glucose-rhamnose region to the 'inner core' was obtained.

Alanine↗
PubMed1973

Studies of lipid A fractions from the lipopolysaccharides of Pseudomonas aeruginosa and Pseudomonas alcaligenes.

Lipid A fractions from Pseudomonas aeruginosa and Pseudomonas alcaligenes have similar compositions and structural features. By means of hydrazinolysis of the parent lipopolysaccharides and partial hydrolysis of the deacylation products, it was established that both lipids are derived from the beta-(1-->6)-linked disaccharide of glucosamine. Phosphorylated derivatives of the disaccharide from Ps. aeruginosa were also characterized. The lipids differ mainly in the absence of hexadecanoic acid and 2-hydroxydodecanoic acid from the lipid from Ps. alcaligenes. Evidence that in Ps. aeruginosa these acids are ester-linked to residues of 3-hydroxyalkanoic acids (including 3-hydroxydecanoic acid) was obtained. Heterogeneity of lipid A fractions was indicated by t.l.c., and by gel filtration of de-O-acylation products from mild alkaline methanolysis of the lipids.

Acylation↗
PubMed1972

Low-molecular-weight solutes released during mild acid hydrolysis of the lipopolysaccharide of Pseudomonas aeruginosa.

A careful examination of the low-molecular-weight solutes released during mild acid hydrolysis of the lipopolysaccharide of Pseudomonas aeruginosa (N.C.T.C. 1999) revealed the presence of ethanolamine triphosphate. During storage, the compound decomposed to give ethanolamine pyrophosphate, identified in a previous study (Drewry et al., 1971); PP(i) may be a further decomposition product. Evidence for the attachment of ethanolamine triphosphate to a polysaccharide fraction was obtained, but the possibility that some was attached to the lipid A moiety was not excluded. Basic compounds released during the hydrolysis of lipopolysaccharide included amino acids, polyamines and oligopeptides.

Amino Acids↗