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Biomedical subjects

T Elmros

Publications and source records attributed to T Elmros.

27 records · Page 2Linked to original sources
PubMed1977

Survival of Neisseria gonorrhoeae on surfaces.

The survival of Neisseria gonorrhoeae was investigated. It was found that gonococci could survive 24 hours in urethral secretion on a glass slide and on a towel at 22 degrees C, and 120 hours at 4 degrees C. A method was developed by which the survival of gonococci could be followed in vitro. With this method, gonococci grown in vitro were found to be protected by human serum, in contrast to gonococci resuspended in NaCl. The factors affecting the survival are discussed.

Bacteriological Techniques↗
PubMed1976

Autolysis of Neisseria gonorrhoeae.

Autolysis of Neisseria gonorrhoeae was studied under different conditions. It was found that low pH and temperature, as well as the presence of divalent cations, spermine, sucrose, and polyvinylpyrrolidone, stabilized nongrowing gonococci. Ethylenediaminetetraacetic acid alone promoted lysis, whereas lysozyme had only a limited additive effect. The autolytic behavior of gonococci appears to be connected with their prolonged cell division process. The relative dependence on the outer membrane and the peptidoglycan layer for the mechanical stability of gonococci is discussed.

Bacteriolysis↗
PubMed1976

Scanning electron microscopy of Neisseria gonorrhoeae. Age-induced changes in macro- and microstructure of virulent and avirulent colonies.

Virulent and avirulent gonococcal colonies were studied in the scanning electron microscope. Cells in virulent, in contrast to avirulent, colonies were found to be connected by numerous strands. After longer incubation periods, type 2 colonies segregated out regions of cells virtually lacking these strands. Cells within these areas probably represent avirulent segregants. The microstructure of individual colonies revealed no topographical differences. In certain colonies large smooth spherical cells were seen, probably representing wall-deficient gonococcal variants.

Microscopy, Electron, Scanning↗
PubMed1976

Cell envelope of Neisseria gonorrhoeae. A comparative study with Escherichia coli.

The cell envelope of Neisseria gonorrhoeae was studied and compared to that of Escherichia coli. Outer membranes (OM) from both species were isolated by an identical method, and subjected to biochemical analysis. Differences in OM structure were sought that might explain the dissimilarity in OM permeability of these two species. The most pronounced difference appeared to reside in the OM proteins as judged by gel electrophoresis. Moreover, gonococcal OM proteins appeared to be more hydrophilic than those of E. coli.

Bacterial Proteins↗
PubMed1976

Autolysis of Neisseria gonorrhoeae. Relation between mechanical stability and viability.

The relationship between the mechanical stability and the viability of N. gonorrhoeae (Type 4) in suspension was investigated. A correlation between viability and optical density recordings was often found. However, in spite of increased mechanical stability in solutions with low pH (5-2) or containing Cu++ or sucrose (10 per cent.), these environments were toxic to the gonococci. A viability preserving effect by Mg++ (4 mM), Ca++ (4 mM), spermine (0-5 mM), polyvinylpyrrolidone (10 per cent.), and low temperature (4 degrees C) was demonstrated. The possibility of improving transport media for gonococci is discussed.

Bacteriolysis↗
PubMed1976

Bacteria in hip surgery. A study of routine aerobic and anaerobic cultivation from skin and closed suction wound drains.

One hundred and seven patients with closed suction wound drains after hip surgery were investigated with regard to bacteria in the drain. In one-third of the cases bacterial contamination of the wound was found. In more than half the total number of cases the bacteria in the wound were not identical with those found on the skin, either pre- or post-operatively. Anaerobe bacteria occurred only in one case. Penicillin administration considerably reduced the frequency of positive cultures. These findings support the prophylactic use of antibiotics in the prevention of late infections in endoprosthesis operations even when the early infection rate is satisfactorily low.

Bacillus↗
PubMed1975

Cell envelope of Neisseria gonorrhoeae: outer membrane and peptidoglycan composition of penicillin-sensitive and-resistant strains.

The cell envelope of Neisseria gonorrhoeae, colony type 4, was studied. Outer membrane was isolated by lysozyme and ethylenediaminetetraacetic acid treatment of plasmolyzed cells according to Wolf-Watz et al. (1973). The degree of purity of the membrane preparations was checked by electron microscopy. The membrane fraction obtained had a density of 1.25 g/cm(3), was rich in phospholipase A and lysophospholipase, and contained only 10% of the total membrane activity of succinate dehydrogenase and d-lactate dehydrogenase. The outer membrane protein profile after sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed at least six major proteins. The predominating protein showed a molecular weight of 35,000. The lipopolysaccharide component was characterized by gas chromatography. The carbohydrates found were galactose, glucose, and glucosamine. d-Glycero-l-manno-heptose was present in very low amounts. Lipid A contained lauric acid, stearic acid, and beta-hydroxy-myristic acid. About 20% of the fatty acids in the outer membrane was derived from lipid A. The phospholipids were characterized as phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. There was no evidence for a lipoprotein anchored to the peptidoglycan. The peptidoglycan of N. gonorrhoeae was of the chemotype I. The cell envelope of N. gonorrhoeae was found to be highly permeable to gentian violet. Cell envelopes of one penicillin-resistant and two penicillin-sensitive strains were compared. Only moderate differences in fatty acid composition were found.

Carbohydrates↗
PubMed1975

Scanning electron microscopic study of virulent and avirulent colonies of Neisseria gonorrhoeae.

A preparation procedure for scanning electron microscopy was developed by which gononcoccal colonies can be studied directly on the agar surface. After glutaraldehyde fixation directly in petri dishes, small agar pieces were cut out and dehydrated stepwise in increasing concentrations of ethanol. The blocks were thereafter transferred to a critical-point drying apparatus, via steps of increased gradients up to 100% amyl acetate. By this method five different gonococcal colony types could be distinguished analogous to light microscopic observations made by others. At higher magnifications an abundance of intercellular strands was found between the cells in virulent type 1 and 2 colonies, but not in the avirulent types 3 through 5. These strands seemed to anchor the cells to each other and to the agar surface. The presence of such structures probably explains the highly convex surface of virulent colonies and explains why colonies of avirulent strains exhibit a radial extension and a flat upper surface. The nature of these filamentous intercellular strands is discussed.

Amylases↗