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Biomedical subjects

G Seltmann

Publications and source records attributed to G Seltmann.

At least 37 records · Page 2Linked to original sources
PubMed1986

Surface hydrophobicity of plasmid-carrying virulent Shigella flexneri and their avirulent variants.

Five pairs of strains of S. flexneri each differing in the colour of their colonies after growth on Congo red agar have been tested for their ability to cause keratoconjunctivitis in the guinea pig eye, for the presence of the 140 Md virulence plasmid, for the presence of the virulence marker antigen, and for their ability to adsorb to hydrophobic surfaces (cellulose nitrate filters and Phenyl Sepharose). The results suggest that the presence of the 140 Md virulence plasmid provides the bacterial surface with a rather high degree of hydrophobicity; exceptions have been found.

Animals↗
PubMed1985

[Cell wall proteins of Escherichia coli: a substance resembling the thermolabile enterotoxin (LT)].

In ultrasonic extracts of all 19 investigated non-enterotoxigenic E. coli strains a substance (LTLS) could be detected reacting positively in all tests which are commonly used to detect specifically E. coli thermolabile enterotoxin (LT). Culture supernatants of these strains in general did not contain LTLS in detectable amounts. LTLS can be found in the whole cell, however, the membrane fraction contains the highest quantities. Released LTLS appears mainly aggregated with components of the cell wall, especially with lipopolysaccharides. This fact in combination with the very low quantities produced by the bacteria renders very difficult purification of LTLS.

Animals↗
PubMed1985

[Nourseothricin (streptothricin) inactivated by plasmid pIE 636-encoded acetyltransferase: detection of N-acetyl-beta-lysine in the inactivated product].

Nourseothricin (streptothricin) can be inactivated by an acetyl transferase synthesized by E. coli strains containing plasmid pIE 636. Nourseothricin inactivated in the presence of 14C-acetyl-coenzyme A was purified and submitted to partial acidic hydrolysis. By electrophoresis of the hydrolysate a 14C-containing substance moving only slowly towards the cathode could be isolated. This substance after complete hydrolysis yields only unlabelled beta-lysine.

Acetyltransferases↗
PubMed1985

Pathogenicity and virulence of methicillin resistant Staphylococcus aureus: slime layer production.

Nine methicillin-resistant (MR) mutants and three methicillin-sensitive (MS) substrains, all derived from naturally occurring heteroresistant isolates of Staphylococcus aureus were examined for slime production. All strains showed an increased mucoid character when cultured on a modified Staphylococcus Medium No. 110. The uranic acid content of the slime layer ranged from 2% to 6% in the MR mutants and from 1.3% to 5.1% in the MS substrains. The amount of uronic acid per g of dry bacteria ranged from 82.5 mg to 143.8 mg in the MR mutants, and between 51.4 mg and 98.8 mg in the MS substrains. In 3 pairs of MR mutants and MS substrains originating from the same parents, the MR cells possessed more of uronic acid than their MS counterparts. The partially purified polysaccharide part of the slime contained D-galactose, D-mannose, D-xylose, D-galacturonic acid, D-galactosamine and D-glucuronic acid in all strains studied. Its quantitative composition was identical in each pair of the MR mutant and MS substrain; there were, however, considerable differences among the strains and between the pairs. Methicillin resistance and slime formation seem to be independent properties in S. aureus. The presumable significance of the readiness of slime production by MR cocci during infections is discussed.

Anti-Bacterial Agents↗
PubMed1984

Plasmid-borne streptothricin resistance in gram-negative bacteria.

Plasmids, which code for a new type of drug resistance due to the acetylation of streptothricin and belonging to various incompatibility groups (I1, I2, W3, FII, S, X, and N) were identified in gram-negative bacteria. The gene for the acetyltransferase is closely linked to a gene for the streptomycin/spectinomycin adenylyltransferase AAD-3" on a novel type of a transposon, designated Tn1825. This is related to Tn7.

Acetyltransferases↗
PubMed1978

[Effectivity of murein preparations in the phage inhibition test--effect of Ca++ions and EDTA].

The inactivating efficacy for the typing phages 54, 83A, and 187 of the peptidoglycan of Staphylococcus aureus is decreased by increasing the Ca++-content of the medium; the irreversible inhibition of phage 187 becomes reversible. The percentage of its inhibition is proportional to the Ca++-content of the medium. Minute amounts of phage 187 bound irreversibly under Ca++-deprivation can be loosened by addition of Ca++-ions. Addition of EDTA up to the equivalence concentration of Ca++ present in the medium has no influence. Addition of EDTA up to the tenfold equivalence causes a significant increase of the inactivating efficacy of the peptidoglycan.

Bacteriophage Typing↗
PubMed1978

[The localization of the anodically-moving thermolabile antigen (ATA) of gram-negative bacteria with ferritin-labelled antibodies (author's transl)].

In studies on the antigenic structure of shigellae, an anodically-moving thermolabile antigen (ATA) was found, which furthermore could be detected in many other enterobacteriae (9, 10). ATA is a glycoprotein with a high molecular heterogeneity, resulting from aggregates of a subunit with a molecular weight of about 22000 Daltons. In the present paper the antigen was localized on the cell surface of several species by means of the immunoferritin technique. Antibodies against the purified ATA were raised in rabbits and were coupled with ferritin using glutaraldehyde. The antigen was found focally distributed over the whole circumference of the cell. According to the location of the ferritin granules, the ATA is tightly attached to the outer membrane. Especially some rough forms of the bacteria were heavily labelled on their surface. From the results obtained we conclude that in the smooth form the polysaccharide side chains of the somatic antigen cover the ATA.

Antibodies, Bacterial↗
PubMed1978

[Chemical and immunogenic properties of the capsular antigen of Staphylococcus aureus. III. Protective activity of capsular antigen in experiments on mice].

Experiments were conducted on 1500 albino mice; protective activity of 7 batches of S. aureus capsular antigen isolated from 5 strains was studied. The animals were immunized subcutaneously with different doses of the preparation (from 0.001 to 10000 microgram) once, twice, and thrice, and infected intraperitoneally with 6 encapsulated cultures. Capsular antigen proved to possess weak protective properties. The following regularities were revealed: 1) high antigen doses (over 5 microgram) increased mouse sensitivity to staphylococcus infection; 2) the greatest protective activity was shown by doses within 0.01-1 microgram; 3) there was no distinct "dose-effect" dependence; 4) single immunization was less effective than double and triple; 5) antigenic specificity of the capsular material was not connected with its protective properties.

Animals↗
PubMed1977

[Structure of shigella antigens. Heterogeneity of specific polysaccharides of 2 Shigella flexneri strains and 2 Sh. flexneri/Escherichia coli hybrids].

The S-specific polysaccharide from 2 Sh. flexneri wild strains (with serological var. X- and var. Y-specificity, respectively) and 2 Sh. flexneri E. coli hybrids (with the same specificities) can be separated by means of gel chromatography on Sephadex G-200 and G-50 into altogether 6 fractions per strain. Fraction G-200/1 (molecular weight greater than 10(6)D) represents a polymer consisting nearly exclusively of glucose and is present mainly in the two Y-type strains, much less in the two X-type strains. Fractions G-200/2 and G-200/3 (molecular weight approximately 10(5)D and approximately 2 - 10(4)D, respectively) seem to consist mainly of the S-specific side chains while fraction G-50/2 (molecular weight approximately 2000 D) presumably contains an SR-polysaccharide (core with one repeating unit.) Fraction G-50/3 (molecular weight approximately 100 D) contains the core polysaccharide and fraction G-50/4 splitting products (mainly KDO). No significant differences in chromatographical behaviour and quantitative composition could be found between the polysaccharides of the wild strains and the hybrid strains. Because of the well-known stability of the glucosaminyl linkages the sugar analysis was not only performed after acidic hydrolysis. In some cases the acid hydrolysate was reacted with HNO2 to cleave the glucosaminyl linkages. In most cases the values obtaines now were higher than those obtained directly.

Antigens, Heterophile↗
PubMed1977

[Utilization of inorganic sulfur sources by Staphylococcus aureus strains].

Staphylococcus aureus strains of different host-adapted variants (Meyer 1966) have been tested for their ability to use inorganic sulfur sources. All the 25 strains tested were able to utilize sodium sulfide as sulfur source in a medium similar to that described by Kloos and Pattee (1965). Using S. aureus strain 116/74 grown in a medium containing Na2-35S as the only sulfur source we studied incorporation and insertion of inorganic sulfide into sulfur containing amino acids. In disintegrated and fractionated cellular material we could find 35S labelled homocystine and methionine as major compounds, and cystine, cysteic acid, homocysteic acid, and beta-sulphopyruvate as minor compounds. The occurrence of homocystine and the sulfonic acids in bacterial proteins is rather uncommon.

Bacterial Proteins↗
PubMed1977

[Glycine dependence of Staphylococcus aureus strains].

Glycine dependent Staphylococcus aureus var. bovis strains (TSCHAPE and RISCHE 1971) were tested for their ability to grow on glycine containing and glycine deprived media. We observed glycine dependence only in minimal media. In complete media the strains grew in absence of glycine. Testing the ability of some glycine precursors we found that in minimal media glycine could be replaced by threonine and in some cases by serine. One mutant (Gly 100 Glyox.r.) was able to metabolize glyoxylate instead of glycine. Aspartic acid was metabolized in presence of glycine. Using 14C-aspartic acid we detected 14C-glycine and 14C-threonine. Presumably the bacteria metabolize aspartic acid to glycine via threonine.

Aspartic Acid↗