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W Ehret

Publications and source records attributed to W Ehret.

At least 37 records · Page 2Linked to original sources
PubMed1992

Influence of the pH-value on the growth of Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes in continuous culture.

A cutaneous isolate of Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes was grown in continuous culture at varying pH-values ranging from 5.0 to 8.5. In terms of the specific growth rate as well as the bacterial density during the plateau phase there were remarkable differences. In particular, Propionibacterium acnes grew much better in the pH 6.0 to 7.0 range than in a more acidic or alkaline milieu. Staphylococcus epidermidis resembled Staphylococcus aureus showing no major difference at pH 5.5 and 7.0. These findings substantiate the hypothesis that minor changes of the pH in the pH 5.5 to pH 6.0 range as to be induced by chemically neutral or alkaline skin cleansers on the human skin surface can increase the number of propionibacteria but not staphylococci remarkably due to the relative alkalinity by itself.

Culture Media↗
PubMed1992

[Microbiological diagnosis of Legionnaires' disease].

Besides other bacterial genera legionellae are a major causative agent of severe pneumonia. Therefore, it is essential to include legionnaires' disease into the diagnostics of pneumonia of unknown origin. The appreciable number of different species and serogroups of legionellaceae, most of them pathogenic for humans, render this task more difficult. The cultural isolation of legionellae from patient or environmental samples is easily performed, the identification of the isolates may be difficult, however. Structural features of the bacteria as determined by biochemical techniques may support the usual immunological identification. Now as before the serological determination of the patients' antibody production as well as the direct detection of bacteria by immunofluorescence microscopy are basic diagnostic procedures. In addition, it is possible to test for legionella antigens excreted in patients' urines; the diagnostic value of this assay, however, is dependent on the manufacturer of the system. As well the clinical diagnostic efficiency of a commercial nucleic acid probe has been questioned sometimes. In the future the polymerase chain reaction may prove as a valuable diagnostic tool but the ubiquity of legionellae in aquatic habitats requires a very critical evaluation of this high-sensitivity method.

Humans↗
PubMed1991

Phenotype versus genotype of the 19 kD peptido-glycan associated protein of Legionella (PpIA), among Legionellae and other gram-negative bacteria.

The protein PpIA (19 kD) cloned from a genomic library of Legionella pneumophila, Philadelphia 1, represents a peptido-glycan associated outer membrane protein in recombinant E. coli K-12 and L. pneumophila. It exhibits distinct sequence homology to lipoproteins of Haemophilus influenzae and E. coli. A ppIA specific DNA probe generated by PCR was used in Southern hybridizations of chromosomal DNA of Legionella strains and other Gram-negative pathogens. Under conditions of high stringency, hybridization could only be observed in L. pneumophila isolates, but all other Legionella strains tested displayed hybridization under lower stringency. No signals appeared after hybridization of chromosomal DNA from a variety of other bacteria. Using anti-PpIA monospecific polyclonal antibodies in Western blots, it was demonstrated that PpIA related proteins of nearly the same size are found in all L. pneumophila isolates and in a variety of, but not all, the Legionella species analysed here.

Bacterial Outer Membrane Proteins↗
PubMed1991

Evaluation of protective mAbs against Pseudomonas aeruginosa outer membrane protein I by C1q binding assay.

Seven monoclonal antibodies (mAbs) against the outer membrane proteins (OPRs) F, H and I of Pseudomonas aeruginosa were prepared. Western blot analysis has shown the mAbs to cross-react with all 17 serotypes of P. aeruginosa according to the International Antigenic Typing Scheme. Two of the mAbs (2A1, 6A4) protected mice against fatal P. aeruginosa pneumonia. The protective potential of the mAbs did not correlate with the immunoglobulin isotype nor with the fine antigen specificity and the in vitro bactericidal activity of the mAbs. Only the binding of the first complement component C1q of the mAbs as estimated in vitro by an ELISA was significantly correlated with their protective potential.

Animals↗
PubMed1991

Do cutaneous coryneform bacteria produce short-chain fatty acids in vitro?

According to an opinion shared by many, human axillary and inguinal odour is related to short-chain fatty acids produced by gram-positive bacteria. Especially coryneform bacteria are said to produce these odiferous substances. After sampling 22 different strains of coryneform bacteria we cultured them for 48 h in a rich medium. Short-chain fatty acids were extracted afterwards by shaking the liquid medium with ether. Gas chromatography was used for detection. Only one of the tested bacteria produced propionic acid. Acetic acid, (iso)butyric acid or (iso)valeric acid could never be detected. The production of substances of the short-chain fatty acid type might, however, be a consequence of the particular substrate found under physiologic conditions by these organisms in human apocrine sweat. The theory that the metabolism of these skin bacteria necessarily produces short-chain fatty acids could not be supported. Another explanation might be that unspecific secreted enzymes of the bacteria are responsible for the production of short-chain fatty acids by a cleavage of skin surface lipids.

Actinomycetales↗
PubMed1990

[Encephalitis in Legionella bozemanii pneumonia].

A 44-year-old man, a known alcoholic and heavy smoker, was hospitalized with high fever and respiratory failure which a few hours later required intubation and artificial ventilation, although the chest x-ray had been unremarkable. Later serial chest x-ray films showed intrapulmonary infiltrations, while Legionella Bozemanii was demonstrated by direct immunofluorescence. Cranial computed tomography was unremarkable, despite the onset of tetraparesis and a severe midbrain syndrome. Cerebrospinal fluid contained merely mild lymphocytic pleocytosis. However, magnetic resonance imaging revealed symmetrical demyelinization foci in the brainstem as a sign of encephalitis. The neurological deficits regressed almost completely after several weeks of antibiotic treatment and rehabilitation measures over several months.

Adult↗
PubMed1989

Legionella infection of the colon presenting as acute attack of ulcerative colitis.

A 42-yr-old woman with long-standing ulcerative colitis of the descending colon, sigmoid, and rectum presented with bloody diarrhea, tenesmus, and high fever. Endoscopic findings were compatible with an acute attack of ulcerative colitis, which proved to be resistant to systemic corticosteroid treatment. In the presence of an acute abdomen with ascites and double-contoured colonic wall, hemicolectomy was performed. Postoperatively, high temperature, hyponatremia, and elevated liver enzyme levels persisted. Pleural effusions developed. Antibodies to Legionella pneumophila serogroup 3 were detected in the serum. Erythromycin therapy induced rapid improvement. In a massive submucosal edema of the affected colon, L. pneumophila of the same serogroup was demonstrated by direct immunofluorescence staining.

Acute Disease↗
PubMed1989

[Methods and problems of Legionella diagnosis].

33 species of legionellae with 50 different serotypes are known. Phenotypical and biochemical similarities as well as immunologic cross-reactions impede their identification. Chemical analysis of structural features such as isoprenoidquinones, fatty acids or membrane proteins may facilitate the species classification of new isolates. A simple analytical procedure exists for ubiquinone determination. The microbiological diagnostics of legionellosis remains complex, however. Culture, direct immunofluorescence, and antigen detection in urine should be used complementary. The development of nucleic acid probes is promising but has not yet reached the stage for wide application. Serological diagnostic assays are still useful; at least in the diagnostics of non-pneumophila legionellosis the result of enzyme immunoassay and immunofluorescence should be completed by immunoblotting with distinct membrane antigens.

Antibodies, Bacterial↗
PubMed1989

Lung tissue concentrations of ciprofloxacin following intravenous administration in patients.

Serum and corresponding lung tissue concentrations of ciprofloxacin (Ciprobay) were investigated in 25 patients undergoing open lung surgery for pulmonary malignancies. Drug levels were measured at various times (50-240 min) after completion of a single i.v. dose of 200 mg by bioassay and HPLC. Lung tissue concentrations peaked within one hour after dosing (bioassay: 3.2 micrograms/g, HPLC: 4.5 micrograms/g). Tissue levels exceeded corresponding serum level 3- to 4fold throughout the observation period. The results demonstrate excellent penetration properties of this new antimicrobial compound into lung tissue. Ciprofloxacin was concentrated in the lung and thus by far exceeded known minimum inhibitory concentrations for most nosocomial respiratory pathogens.

Adult↗
PubMed1988

Cloning and characterization of cDNAs coding for the heavy and light chains of a monoclonal antibody specific for Pseudomonas aeruginosa outer membrane protein I.

A set of seven monoclonal antibodies (MAb) directed against outer membrane proteins of Pseudomonas aeruginosa has been examined by Western blot analysis, indirect immunofluorescence tests and subclass typing. The hybridoma cell line secreting MAb 6A4, which reacts with outer membrane protein I, belongs to the IgG2a subclass and crossreacts with the 17 P. aeruginosa serotypes as listed in the International Antigenic Typing System, was selected as source for the preparation of poly(A)+RNA which in turn was used as template for cDNA synthesis and cloning. Full length cDNA clones of the gamma heavy chain as well as the kappa light chain were obtained and characterized by nucleotide sequence analysis. The complete cDNA sequences coding for the heavy and light chains will be the prerequisite for the construction and heterologous expression of a chimeric human-mouse monoclonal antibody which might be used in therapy of P. aeruginosa infections.

Amino Acid Sequence↗
PubMed1988

Computer-aided densitometric analysis of protein patterns of Clostridium difficile.

The applicability of whole-cell protein patterns obtained by sodium dodecylsulfate-polyacrylamide gel electrophoresis as a typing method for Clostridium difficile was examined using a total of 227 strains isolated from 191 patients and their surroundings. Computer-aided densitometric analysis was used to establish a reliable standardization technique with which a large number of protein patterns could be efficiently classified. The normalized tracks could be electronically superimposed and compared to give reproducible results. The influence of sample preparation for electrophoresis was found to be negligible. By this technique 35 subgroups could be differentiated, and further discrimination was possible within each subgroup using minor, even very weak protein bands. Epidemiologically related strains of Clostridium difficile yielded absolutely identical patterns, allowing unequivocal identification. Thus protein electrophoresis combined with densitometric analysis was shown to be useful for typing Clostridium difficile isolates.

Bacterial Proteins↗
PubMed1988

Humidifier lung and humidifier fever.

The aim of our study was to evaluate clinical diagnoses in symptomatic persons exposed to aerosols from humidifiers or air conditioners. In addition, we tried to identify the causative antigens. Results of clinical investigations, including inhalation challenge tests, demonstrated a typical hypersensitivity pneumonitis (humidifier lung) in 9 persons and isolated systemic symptoms without significant changes in lung function and chest x-rays (humidifier fever) in 3 persons. Microbiological studies revealed a variety of fungi and bacteria in the water supplies of humidifiers and air conditioners at patients' workplaces. The detection of 4 members of the order Sphaeropsidales (Deuteromycotina), not previously associated with humidifier-induced diseases, is of special interest. By means of an improved polystyrene tube-immunoradiometric assay, high concentrations of IgG antibodies against extracts prepared from water of patients' humidifier systems were found in all cases. In addition, patients demonstrated low concentrations of IgG antibodies against thermophilic Actinomycetes, and usually also against various fungi, such as Alternaria tenuis, Aureobasidium pullulans, Penicillium notatum, Aspergilli, and fungi of the order Sphaeropsidales, which were isolated and cultured from humidifier water supplies. The much higher concentrations of antibodies against humidifier/air conditioner water extracts seem to result from sensitization to a variety of antigens from different fungi and bacteria. For in vivo and in vitro diagnostic tests in humidifier-induced lung diseases, we especially recommend using extracts from water systems installed at the corresponding workplaces.

Adult↗
PubMed1987

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↗
PubMed1987

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↗
PubMed1987

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↗