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Biomedical subjects

G Ruckdeschel

Publications and source records attributed to G Ruckdeschel.

At least 73 records · Page 4Linked to original sources

Comparative in vitro activity of the new oxacephem antibiotic, flomoxef (6315-S).

The in vitro activity of flomoxef (6315-S) was determined and compared to that of different cephalosporins against 787 clinical isolates of staphylococci, Enterobacteriaceae and anaerobes. Flomoxef is similar in activity to latamoxef and cefotaxime against Enterobacteriaceae, slightly more active than cephalothin and cefamandole against oxacillin-sensitive strains of Staphylococcus aureus and minimally less active than cefamandole against oxacillin-resistant strains. Flomoxef showed similar or better activity than latamoxef and cefoxitin against most of the anaerobic species of medical importance.

Anti-Bacterial Agents↗

Significance of non-pneumophila Legionella species in adult community-acquired and nosocomial pneumonias.

The number of different Legionella species is increasing at an impressive rate. In two prospective studies, one involving 110 intensive-care unit (ICU) patients with mainly nosocomial pneumonias and the other 105 patients with community-acquired pneumonias, we investigated the incidence and significance of Legionella pneumophila and non-pneumophila pneumonias on the basis of 17 different main serogroups. In the first study, 14 ICU patients had 15 (13.6%) Legionella pneumonias, which, in 5 cases (33%), were of non-pneumophila etiology. In the second study, 9 patients with community-acquired pneumonias had 10 (9.5%) Legionella pneumonias. Leading this study were 6 L. gormanii infections, followed by 2 L. dumoffii and only 1 L. pneumophila and 1 L. longbeachae pneumonia. Of the total, 22 of 23 patients with Legionnaires' disease suffered from severe basic diseases and complications (acute renal failure, respiratory insufficiency, etc.) predominant among the nosocomial pneumonias. The mortality rate was significant in these patients at 33% (5 patients) in the ICU group and 10% (1 patient) in the group with community-acquired pneumonias. We conclude that non-pneumophila Legionella species should receive more diagnostic and therapeutic consideration in patients with nosocomial or community-acquired pneumonias.

Adolescent↗

A case of pneumonia caused by Legionella pneumophila serogroup 8 in West Germany. Etiological diagnosis by immunofluorescence, enzyme immunoassay, and immunoblot.

The severe and complicated course of a Legionella pneumonia in an 18-year-old female patient is reported. The serogroup 8 of Legionella pneumophila was identified as the infecting agent for the first time in West Germany. The etiological diagnosis was confirmed by immunofluorescence, enzyme immunoassay, and immunoblot. We emphasize the importance of serological testing of all Legionella pneumophila serogroups available.

Adolescent↗

Prevention of colonization and respiratory infections in long-term ventilated patients by local antimicrobial prophylaxis.

In a randomized clinical trial the prophylactic effects of locally administered antimicrobials on quantitative colonization and respiratory infections were studied in intubated patients with an expected period of mechanical ventilation of greater than 6 days. Nineteen patients received 50 mg of polymyxin B and 80 mg of gentamicin distributed among nose, oropharynx and stomach at 6-h intervals, as well as 300 mg of amphotericin B in the oropharynx. Twenty untreated patients served as controls. In the control group colonization by respiratory pathogens was more common (oropharynx 19 vs 6 patients (p less than 0.001); trachea 19 vs 11 (p less than 0.01)), and the number as well as the count of the colonizing species was usually higher. Fourteen patients of the control group developed respiratory infections, including nine cases of pneumonia, as compared to four patients with prophylaxis, including one case of pneumonia (p less than 0.01). Pneumonia-associated deaths were prevented with prophylaxis; however, the overall mortality remained unchanged. Respiratory infections in the prophylaxis group were associated with organisms resistant to the agents used, but the overall occurrence of resistance was not increased, as compared to the control group. We conclude that unrestrained upper airway colonization by respiratory pathogens and respiratory tract infection were causally related. Local antimicrobial prophylaxis proved to be a highly effective strategy for the prevention of potentially life-threatening pneumonias in critically ill patients, but in the present study the host setting appeared to be the major determinant of outcome.

Administration, Intranasal↗

[Antibody to lipoid A in the treatment of septic shock].

The protective effect of high-titer anti-lipid A hyperimmune globulin with respect to the course of the disease and the mortality rate was studied in patients with septicemia verified by positive blood cultures. Six patients were treated with anti-lipid A in an open study. Dramatic improvement in fever curves and clinical condition in some of the patients encouraged us to start a randomized double blind study. So far, 17 patients have entered the study, 16 of whom were evaluable. Immediately after a positive blood culture was found, patients received either high doses of anti-lipid A or placebo (saline solution) on two subsequent days. Before and after each infusion blood samples were taken in order to assess serum bactericidal activity and anti-lipid A titers. Because of the still small numbers of patients the results of both studies were summarized. In all patients treated with anti-lipid A clear-cut increases in anti-lipid A titers were shown. Patients with repeated gram-negative infections showed higher median anti-lipid A titers than patients without such a history. The patients treated with anti-lipid A immune globulin ran a significantly milder course than the placebo group. The severe signs of septic shock were reversed in seven of 15 patients on anti-lipid A compared to two of seven patients treated with placebo. In the anti-lipid A-treated group, three of 15 patients died, and in the placebo group two of seven. This difference is not statistically significant.

Antibody Formation↗

Identification of clinical and environmental isolates of Legionella pneumophila by analysis of outer-membrane proteins, ubiquinones and fatty acids.

47 strains of L. pneumophila, 9 reference strains of eight serogroups, 15 clinical isolates and 23 water-derived strains from different cities were analysed with respect to three chemical constituents of the cell envelope: outer- membrane proteins (OMPs), ubiquinones and fatty acids. The OMPs were obtained by Sarkosyl-extraction of a total membrane preparation and analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The ubiquinone content was quantitated by high-performance liquid chromatography (HPLC) and the fatty acid composition was established by gas-liquid chromatography coupled with mass spectrometry (GLC-MS). In all strains the OMP yielded the known characteristic pattern with the major component of 29 kilodalton. The ubiquinone content was very consistent within different strains revealing Q-12 with 65% as the predominant feature. Q-11 and Q-13 were present in amounts of 11% and 23%, respectively. Q-14 was found in trace amounts of about 0.65%. Only a very few ubiquinones with side chains shorter than 11 residues were present. GLC-MS allowed an unequivocal identification of each fatty acid. The branched chain fatty acid i-16:0 was the predominant feature with 33% followed by the unsaturated straight-chain acid 16:1. In this respect earlier reports by other authors were confirmed but minor compounds not detected so far could be revealed as 15:1, the doublet 18:1 and i-18:0, 19:1 and 20:1. OMP profiles are easy to establish and to interpret. They are well suited for identification of the species L. pneumophila. Ubiquinone analysis permits rapid but preliminary species identification, whereas fatty acid analysis by GLC-MS is an intricate technique providing a valuable chemical marker for L. pneumophila. The biochemical analyses presented here can supplement immunological studies, clarify immunological findings and help to identify new serogroups of L. pneumophila.

Bacterial Outer Membrane Proteins↗

Determination of aztreonam in faeces of human volunteers: a comparison of reversed-phase high pressure liquid chromatography and bioassay.

Aztreonam was given orally to eight healthy volunteers in two different dosage regimens. To determine the concentration of aztreonam in faecal specimens a method was established using reversed-phase high pressure liquid chromatography (HPLC). Comparison of microbiological and HPLC assays showed a linear relationship between both techniques which, however, was not 1:1. The microbiological assay tended to yield higher aztreonam levels than the HPLC method. The HPLC assay for aztreonam proved to be five-fold less sensitive than the bioassay; however, since in most cases high aztreonam levels were found in the faeces of the test subjects, this was not a disadvantage. The HPLC assay was much easier to perform than the bioassay and yielded easily quantifiable results in a wider concentration range. In the stool specimens of one volunteer no aztreonam could be detected by either method, indicating inactivation and/or degradation of the compound.

Adolescent↗

Effects of pentachlorophenol and some of its known and possible metabolites on different species of bacteria.

The antibacterial activity of pentachlorophenol and 35 of its known or possible metabolites against 30 different species of bacteria was tested. In comparison with pentachlorophenol, no increase of inhibitory activity was found for any of the chlorinated anisoles tested (except for pentachloroanisole against Streptomyces spp.), 2-chlorophenol, 2,6-dichlorophenol, 2,3,6- and 2,4,6-trichlorophenol, 2,3,5,6-tetrachlorophenol, tetrachloro-1,4- and -1,3-benzenediol (except for the 1,3-isomer against Streptomyces spp.), tetrachloro-1,3-dimethoxybenzene, and tetrachloro-1,3-benzenediol diacetate. Two chlorophenols, five dichlorophenols, four trichlorophenols, two tetrachlorophenols, and tetrachloro-1,2-benzenediol were more active than pentachlorophenol against some, but not all, of the strains tested.

Bacteria↗

[Treatment of respiratory tract infections with imipenem/cilastatin in critical patients with respiratory insufficiency].

In an open prospective study the efficacy and tolerance of imipenem/cilastatin was investigated in 24 critically ill patients on mechanical ventilation with nosocomial respiratory tract infection. Nine patients had previously received antibiotic therapy, eight of them with various other beta-lactam antibiotics which had failed. Imipenem was given in a dose of 1-3 g/24 h over 5-37 (mean 11) days. Seven patients were additionally treated with aminoglycosides, one patient with erythromycin. Pseudomonas aeruginosa (n = 14), Staphylococcus aureus (n = 4), Haemophilus influenzae (n = 4) and Escherichia coli (n = 3) were the potential pathogens most frequently isolated from tracheo-bronchial secretions. All of the isolates were susceptible to imipenem. 91% of the infections without and 77% with involvement of P. aeruginosa were successfully treated. Two patients who had not responded to previous treatment succumbed to the consequences of progressive respiratory distress syndrome. All of the gram-positive and 85% of the gram-negative pathogens (Pseudomonas not included) were eliminated in the course of therapy. By contrast, 64% of the isolates of P. aeruginosa persisted; half of these became imipenem-resistant. Nine patients showed adverse reactions including one case of pseudomembranous colitis or laboratory abnormalities which were all reversible. Imipenem/cilastatin proved highly effective and was relatively well tolerated; it is suitable as a single agent for the initial treatment of nosocomial respiratory tract infections in ventilated patients, although only with limitations in cases of infection due to P. aeruginosa.

Adolescent↗

[Bacteriologic studies of the use of incision drapes in orthopedic operations].

The usefulness of plastic adhesive drapes for the prophylaxis of wound infections following to orthopedic operations was investigated in a prospectively randomized study including 123 patients. The drape was used in 68 cases, 55 patients were operated without drape. In order to carry out qualitative bacteriological examinations, smears were taken prior to, one and two hours after the beginning and after the end of the operations. Bacterial infestation in the operation area was found in 30 patients (54.5%) operated without drape and in 30 patients (44.1%) in whose operations the drape was employed. Most of the bacteria found were coagulase-negative staphylococci, in some cases corynebacteria and aerobic spore-forming organisms. There were no postoperative wound infections. No evidence of a significant difference was shown by a statistical evaluation of the results using the chi 2 test. The use of incision drapes for the prophylaxis of postoperative wound infections is therefore not necessary in orthopedic surgery.

Bacteria↗

Effects of pentachlorophenol and some of its known and possible metabolites on fungi.

The fungicidal activity of pentachlorophenol and its derivatives against 16 species of fungi representing 14 genera was tested. In relation to pentachlorophenol, no increase in fungistatic activity was found for pentachloroanisole, pentachloronitrobenzene, hexachlorobenzene, pentachlorophenyl acetate, o- and p-chloranil, the three isomeric chlorophenols, 2,6-dichlorophenol, the three isomeric tetrachlorobenzenediols, the three isomeric tetrachlorodimethoxybenzenes, the three isomeric tetrachlorobenzenediol diacetates, and all of the isomeric mono-, di-, tri-, and tetrachloroanisoles, except for 2,3,5-trichloroanisole with Geotrichum candidadum PC 67 and for 2,3,5,6-tetrachloroanisole with Mucor circinelloides PC 1. Increasing fungistatic activities were seen with 3,5-dichlorophenol, four trichlorophenols, and 2,3,4,5-tetrachlorophenol for all of the strains, with four dichlorophenols, 2,4,6-trichlorophenol, and two tetrachlorophenols for some strains, and with 2,3,6-trichlorophenol for only one strain (M. circinelloides PC 1).

Chlorophenols↗

[Treatment of bronchopulmonary infections in patients during artificial respiration with imipenem/cilastatin].

In an open prospective study the efficacy and tolerance of imipenem/cilastatin was investigated in 24 critically ill patients on mechanical ventilation with nosocomial respiratory tract infection. Nine patients had previously received antibiotic therapy which had failed. Imipenem was given in a dose of 1-3g/24 h over 5-37 (mean 11) days. Seven patients were additionally treated with aminoglycosides, one patient with erythromycin. Pseudomonas aeruginosa, Staphylococcus aureus, Hemophilus influenzae and Escherichia coli were the most frequently isolated pathogens from tracheobronchial secretions. 91% of the infections without and 77% with involvement of Pseudomonas aeruginosa were successfully treated. All of the gram-positive and 85% of the gram-negative pathogens (Pseudomonas not included) were eliminated in the course of therapy. By contrast, 64% of the isolates of Pseudomonas aeruginosa persisted; half of these became imipenem-resistant. Nine patients showed adverse reactions including one case of pseudomembranous colitis which were reversible. Imipenem/cilastatin proved highly effective and was relatively well tolerated; limitations in the efficacy were seen in cases of infection due to Pseudomonas aeruginosa.

Adolescent↗

Discrimination between clinical and environmental strains of Legionella pneumophila by a monoclonal antibody.

Legionellae are widely spread in natural and man-made habitats. In many instances contaminated tap water has been linked to sporadic or endemic cases of human pulmonary infections, but it is not known why, in spite of frequent occurrence, legionellae only rarely cause disease. Monoclonal antibodies against Legionella pneumophila serogroup 1 (Philadelphia 1) were prepared in order to distinguish between subtypes of this serogroup. Balb/c mice were immunized i.v. three times with heat inactivated bacteria. Antibody formation was detected by an enzyme-linked immunosorbent assay (ELISA) technique using peroxidase-conjugated antimouse IgG. Spleen cells were then fused with NS-1 myeloma cells and cloned by limiting dilution. Four monoclonal antibodies were studied in detail. The study included 47 strains of L. pneumophila: 19 strains were of human origin and 28 were isolated from different environmental sources. Most were from tap water, but none from natural habitats. All strains belonged to serogroup 1 as defined by direct immunofluorescence (DFA) using monospecific FITC-labelled polyclonal antisera from rabbits. The strains were further characterized by beta-lactamase production, activity of catalase, oxidase and proteases, analysis of ubiquinones, and demonstration of membrane protein patterns by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. A strong homogenicity between all the strains could be revealed by these methods independent of their origin. One of the monoclonal antibodies (B-1) was able to distinguish between human and environmental isolates. Eighteen of the 19 human strains reacted very strongly in DFA using antimouse immunoglobulin. No reaction, however, was seen with all of the environmental strains. Immunoblots were performed for characterization of the distinguishing feature using membrane complexes of all strains on nitrocellulose strips. The blots were incubated with antibody B-1, and immune complexes were detected by 125I-protein A. Broad intense blackening was seen between 22 and 70 kilodalton. This result suggests that no single protein, but rather a smaller component such as an oligosaccharide attached to constituents of different molecular weights, might be responsible for the discriminating reaction.

Animals↗

Membrane proteins of legionellaceae. I. Membrane proteins of different strains and serogroups of Legionella pneumophila.

The protein composition of the outer membranes of eight serogroups of Legionella pneumophila has been determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Outer membranes were prepared by detergent extraction using sodium lauryl sarcosinate or by isopycnic sucrose gradient centrifugation. With both techniques one major outer membrane protein of about 29,000 daltons was found to be characteristic for the species L. pneumophila. It was the predominating feature in all 22 strains of L. pneumophila studied, regardless of serogroup. SDS-PAGE patterns of non inactivated L. pneumophila strains were compared with those following formaldehyde-, heat- or ether inactivation. Formaldehyde inactivation gave the fewest protein bands while the outer membrane protein profiles of non inactivated as well as of heat- or ether-inactivated strains revealed some additional minor components. With the exception of a 46,000 dalton band that showed, in some strains, an altered electrophoretic mobility of ca. 48,000 dalton, all strains and serogroups of L. pneumophila presented with the same outer membrane protein pattern. Analysis of outer membrane protein profiles by SDS-PAGE should therefore be a valuable tool for the identification of L. pneumophila. Comparing total membrane preparations the 29,000 dalton component was also the predominant feature, an appreciable number of additional bands, however, allow a clear discrimination between different strains. The protein profiles of outer and total membranes of L. pneumophila as determined by SDS-PAGE therefore may be used for taxonomical and epidemiological studies.

Bacterial Outer Membrane Proteins↗

Membrane proteins of Legionellaceae. II. Serogroup- and species-specific antigens in the outer membrane of Legionella pneumophila.

Antigens of the outer membrane of Legionella pneumophila were investigated by means of the immunoblotting-technique using rabbit antisera against three different formaldehyde-inactivated strains, and one heat-inactivated strain of L. pneumophila serogroup 1. Nitrocellulose blots were prepared from membrane fractions extracted with sodium-N-lauryl-sarcosinate from 14 strains of L. pneumophila (eight strains of serogroup 1, and one strain each of serogroups 2-7) and 12 strains of gram-negative rods of various species. After incubation with 125I-protein A or 125I-anti-rabbit IgG immune complexes were identified. These results were compared with Coomassie-stained and silver-stained SDS gels. There was a diffuse reaction in the homologous system between 20 and 80 kilodalton (kDal) after incubation with 125I-protein A, and an intense reaction between 22 and 29 kDal after incubation with 125I-anti-rabbit IgG. Membrane preparations of the different strains of serogroup 1 exhibited clearly discernible patterns. Immunoblots of formaldehyde-inactivated strains when reacted with antiserum against heat-inactivated immunogen showed a single species-specific antigen of approximately 22.5 kDal which could not be assigned to a major protein. Immunoblots of the same antiserum but with heat-inactivated cell wall preparations gave a second species-specific band of approximately 65 kDal. Antisera against formaldehyde-inactivated bacteria demonstrated more complex characteristic patterns, with protein-associated components occurring at 29, 44, 46, 48, 65 and 80 kDal; in addition, cross-reacting fractions were present at 15.5, 17.5 and 22.5 kDal. The 29 kDal major outer membrane protein was immunogenic in most but not all cases.

Animals↗