PubMed Health⌕ Search

Biomedical subjects

T S Elliott

Publications and source records attributed to T S Elliott.

107 records · Page 6Linked to original sources
PubMed1985

Morphological response and growth characteristics of Legionella pneumophila exposed to ampicillin and erythromycin.

The morphological response of two strains of Legionella pneumophila to ampicillin 10 micrograms/ml and erythromycin 10 micrograms/ml in vitro was studied by electronmicroscopy, MIC estimations and viable counts. In the presence of ampicillin, discrete lesions appeared in the bacterial cell walls through which cytoplasmic contents extruded and lysis occurred. A few spheroplasts, together with minicells of 0.15-micron diameter, and apparently normal cells were present after exposure to ampicillin for several hours. Conversely, erythromycin initially resulted in inhibition of division and the formation of filamentous organisms. The cell walls of these filaments were eventually disrupted with numerous small membranous vesicles appearing on their surfaces. On further erythromycin treatment, breakage of the cell wall at a restricted number of sites occurred, leading to cell lysis. In the presence of erythromycin, a few morphologically normal cells were present but no spheroplasts or minicells were observed. Viable counts demonstrated that ampicillin killed the bacteria faster than erythromycin. Regrowth did not occur in the continued presence of either antibiotic, but after their removal regrowth was observed.

Ampicillin↗
PubMed1985

Can the rapid semiquantitative estimation of serum C reactive protein be adapted for the management of bacterial infection?

Serum C reactive protein concentrations measured by a laboratory based assay were compared with the semiquantitative results obtained with a visual agglutination method (Well-cotest, CRP kit). Using this agglutination kit, diluting serum 1/10 and 1/20 gave C reactive protein results which could be of more clinical value than those obtained using the 1/2, 1/4, 1/8, and 1/16 dilutions recommended by the manufacturers. The kit was also used on the ward by junior medical staff, who showed that after minimal training reproducible serum C reactive protein results could be obtained.

Bacterial Infections↗
PubMed1984

The morphological response of Pseudomonas aeruginosa to azthreonam, cefoperazone, ceftazidime and N-formimidoyl thienamycin.

The morphological responses of Pseudomonas aeruginosa to N-formimidoyl thienamycin, azthreonam, ceftazidime and cefoperazone were studied by transmission electron microscopy. They were correlated with the results of viable counts and continuous turbidimetric monitoring. N-formimidoyl thienamycin initially caused the formation of abnormally shaped cells which developed into spheroplasts. The other antibiotics caused filamentation of the bacteria, which subsequently underwent lysis. The degree and mechanism of lysis varied between the antibiotics. Exposure to azthreonam also resulted in the deposition of electron-dense intracellular material. As judged by conventional minimum-inhibitory-concentration tests, all the agents exhibited similar activity against the strains of P. aeruginosa tested, with ceftazidime displaying the highest activity. However, N-formimidoyl thienamycin caused the most extensive morphological damage and resulted in the most rapid fall in viable count.

Anti-Bacterial Agents↗
PubMed1984

Scanning electron microscopy of human bladder mucosa in acute and chronic urinary tract infection.

The morphological response of the bladder surface to acute and chronic urinary tract infection (UTI) was investigated using both scanning and transmission electron microscopy of bladder biopsies taken during routine cystoscopy. Acute bacterial infection only minimally altered bladder epithelium, whereas in chronic infections the surface layers showed gross changes which included loss of the outer layers of epithelial cells and alteration of the bladder contour. In addition, more erythrocytes and polymorphonucleocytes were present in chronic infection. In both acute and chronic urinary infection, bacteria were confined to a limited number of sites on the bladder surface and appeared to be arranged in microcolonies, but more bacteria were attached to bladder surfaces in chronic than in acute UTI. These findings were confirmed by studying epithelial cells shed from patients with proven urinary infections. A few patients who had been treated with antibiotics before cystoscopy and biopsy were also studied. These antibiotics included cephalosporins which had been previously shown to produce bacterial morphological variations in vitro. Some of these changes were subsequently observed in the biopsies and the results suggest mechanisms whereby bacteria involved in urinary tract infection can survive exposure to antibiotics.

Acute Disease↗
PubMed1984

C reactive protein concentrations in neonates: determination by a latex enhanced immunoassay.

A latex enhanced immunoassay on a centrifugal fast analyser was used to compare serum C reactive protein concentrations in maternal and neonatal blood. In the neonate the C reactive protein concentration at birth was less than 1.0 mg/l; the concentration rose slightly during the first two weeks of life. There was no correlation between C reactive protein concentrations in maternal and neonatal sera. No significant difference was found between the C reactive protein concentrations in blood obtained by either heel prick or venepuncture.

Blood Specimen Collection↗
PubMed1983

The response of Pseudomonas aeruginosa to azlocillin, ticarcillin and cefsulodin.

The morphological response of Pseudomonas aeruginosa to azlocillin, ticarcillin and cefsulodin was investigated by electron microscopy. Each antibiotic initially caused the formation of filaments. On further incubation in the presence of azlocillin, deposits of dense intracellular material were observed; these were absent from cells exposed to the other two antibiotics. On continued incubation, lysis of the filaments occurred, but the mode of lysis differed between the antibiotics: azlocillin caused breakage at a restricted number of sites in the cell wall, ticarcillin produced breakage at many points and cefsulodin caused extensive cell-wall damage. In addition, ticarcillin and cefsulodin appeared to cause more lysis and spheroplast formation than did azlocillin. The morphological changes correlated with turbidimetric measurements of bacterial response to the three antibiotics, which showed ticarcillin and cefsulodin to act more rapidly than azlocillin.

Azlocillin↗
PubMed1983

Campylobacter enteritis in Nottingham.

The incidence of campylobacter gastroenteritis in the population of Nottingham over a period of 3 years was studied. There was a seasonal variation with the highest number of cases occurring in the summer months. Campylobacter sp. were isolated from the stools of a total of 780 patients over this period. Of these 160 patients with gastroenteritis required admission to hospital. These patients' illness had an acute onset, and the predominant features were diarrhoea, severe abdominal pain, nausea and bright red blood with the stool. However not all the patients had diarrhoea. More than a third of the patients studied were less than 10 years old. The mean duration of symptoms was 4 days and the average stay in hospital was 5 days; some patients required prolonged admission (14 days). In a few cases campylobacter enteritis mimicked other clinical conditions including acute appendicitis. This study emphasises the importance of campylobacter enteritis as a cause of gastroenteritis in the community and the degree of morbidity associated with this illness.

Adolescent↗
PubMed1979

The response of Staphylococcus aureus to benzylpenicillin.

The response to benzylpenicillin of 2 strains of Staphylococcus aureus was investigated in vitro using 3 techniques in parallel: continuous turbidimetric monitoring, continuous microscopic monitoring, and thin-section electron microscopy. Cultures of staphylococci were exposed to several concentrations of penicillin for various intervals of time before terminating the antibiotic activity with penicillinase. Bacterial lysis by penicillin was concentration-dependent and showed an optimal dosage effect which was very marked for one of the strains. The growth and division of cells continued for up to 1 h in the presence of penicillin. A variety of morphological responses was observed at each penicillin concentration. These changes ranged from complete bacterial lysis to apparently normal cells, and included several different types of aberrant morphological forms. On addition of penicillinase to cultures exposed to penicillin, there was a time interval before survivors began to divide. This period was increased by raising the concentration of penicillin or by increasing the period of exposure to penicillin. Bacteria resuming growth after surviving penicillin action exhibited markedly aberrant septation. Most of the survivors were found to originate from clumps of cocci rather than from individual cells or small groups.

Dose-Response Relationship, Drug↗
PubMed1975

Formation of cell wall polymers by reverting protoplasts of Bacillus licheniformis.

The biosynthesis of peptidoglycan and teichoic acid by reverting protoplasts of Bacillus licheniformis 6346 His-, in cubated at 35 C on medium containing 2.5% agar, is detectable after 40 min. The amount of N-acetyl-[1-14C]glucosamine incorporated into peptidoglycan and teichoic acid on continued incubation doubles at the same rate as the incorporation of [3H]tryptophan into protein. At the early stages of reversion the average glycan chain length, measured by the ratio of free reducing groups of muramic acid and glucosamine to total muramic acid present, is very short. As reversion proceeds, the average chain length increases to a value similar to the found in the wall of the parent bacillus. The extent of cross-linkage found in the peptide side chains of the peptidoglycan also increases as reversion proceeds. At the completion of reversion the wall material synthesized has similar characteristics to those of the walls of the parent bacilli, containing peptidoglycan and teichoic and teichuronic acids in about the same proportions. Soluble peptidoglycan can be isolated from the reversion medium, amounting to 30% of the total formed after 3 h of incubation and 8% after 12 h. This amount was reduced by the presence in the medium of the walls of an autolysin-deficient mutant; they were not formed at all by reverting protoplasts of the autolysin-deficient mutant itself. Analysis of the soluble material provided additional evidence for their being autolytic products rather than small unchanged molecules. When protoplasts were incubated on medium containing only 0.8% agar, 53 to 67% of the peptidoglycan formed after 3 h of incubation was soluble, and 21% after 12 h. Fibers that appeared to be sheared from the protoplasts at intermediate stages of reversion on medium containing 2.5% agar were similar in composition to the bacillary walls.

Alanine↗
PubMed1975

Ultrastructural study of the reversion of protoplasts of Bacillus licheniformis to bacilli.

The reversion of protoplasts of Bacillus licheniformis 6346 His- on a medium containing 2.5% agar has been studied in sectioned material after reaction with a ferritin-conjugated antibody specific to the peptidoglycan isolated from the walls of the bacilli. Freeze etching has also been used. Fibrils of material reacting with the antibody have been detected emerging from isolated areas of the protoplasts after 3 h of incubation. This material gradually covers the cell and can eventually (at 6 h) be seen in freeze-etched preparations as a fringe of up to 400 nm around the cells and covering the surfaces with particles that can be removed by lysozyme. At later stages the wall begins to take on a compact, well-defined appearance that can be seen in sections; however, the cells are still grossly deformed. A transitory emergence, beyond the wall of long fibers of 6 nm in diameter, takes place after about 12 h of incubation. These fibers react with the conjugated antibody and after freeze etching show a regular banded structure. They are probably indentical with the fibers isolated elsewhere (Elliott et al., 1975) and shown to contain all the wall constituents (i.e., peptidoglycan, teichoic acid, and teichuronic acid). These fibers are not detectable in the final stages of reversion.

Antibodies, Bacterial↗
PubMedDate not supplied

Blood for culture.

Explore the source record for details and available documents.

Bacteremia↗
PubMedDate not supplied

Infections and intravascular devices.

Complications associated with intravascular devices include infections mainly caused by Staphylococcus epidermis and S. aureus. The reported incidence of these infections varies. Several factors influence the propensity for catheter infections. We recommend strategies for the prevention and treatment of catheter-related sepsis.

Asepsis↗