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Biomedical subjects

U Ullmann

Publications and source records attributed to U Ullmann.

At least 19 recordsLinked to original sources
PubMed1992

Isolation of Klebsiella terrigena from clinical specimens.

In a three-year survey conducted from 1988 to 1990 Klebsiella isolates from human clinical specimens were subjected to additional tests to identify any Klebsiella terrigena strains. Ten strains of Klebsiella terrigena (0.4%) were found among 2355 indole-negative Klebsiella isolates. Most of the isolates were recovered from the respiratory tract. In the API20EC system almost exclusively biotypes no. 1777771 and 1777671 were observed. Serotyping revealed capsule types K2, K5 and K18 in two strains each. In antibiotic susceptibility tests the strains were shown to be comparable in sensitivity to Klebsiella pneumoniae.

Anti-Bacterial Agents↗
PubMed1992

Interaction of Klebsiella capsule type 7 with human polymorphonuclear leucocytes.

Klebsiella serotype K7 is found among the capsule types that are most prevalent in respiratory tract isolates. To evaluate the significance of the K7 antigen in bacteria-leucocyte interactions, K7-encapsulated Klebsiella pneumoniae strains and their non-capsulate mutants were investigated. The K7 isolates were compared to K2-capsulate strains and their respective K- derivatives. K7-capsulate bacteria were less hydrophilic, and more readily phagocytosed and killed by human polymorphonuclear leucocytes (PMNL) than K2 strains. Loss of the K7 antigen resulted in increased surface hydrophobicity but did not affect phagocytosis and killing, whereas loss of the K2 capsule caused greater susceptibility to the phagocytic and killing action of PMNL. Both the K7 and K2 antigen stimulated the extracellular release of lysozyme from neutrophils but not of myeloperoxidase, indicating degranulation of only secondary granules. All K- mutants induced the release of both lysozyme and myeloperoxidase. Our results suggest that, in contrast to the K2 antigen, the K7 capsular polysaccharide does not confer antiphagocytic properties on bacteria. However, the K7 antigen is able to impede the extracellular release of primary granule enzymes.

Antigens, Bacterial↗
PubMed1992

Siderophore production of Klebsiella species isolated from different sources.

A total of 481 Klebsiella pneumoniae and K. oxytoca strains isolated from different sources was examined for siderophore production. Screening for siderophore secretion by chrome azurol S agar revealed that 475 strains (98.8%) produced siderophores. The isolates were further investigated for synthesis of enterochelin and aerobactin by means of specific bioassays. Almost all Klebsiella strains (99.4%) excreted enterochelin. Aerobactin production, however, was rarely observed among K. pneumoniae (6%) and K. oxytoca (4%) isolates. The incidence of aerobaction-positive strains was similar in clinical, fecal, and environmental isolates. These results suggest that the aerobactin system does not represent a major mechanism of iron supply in Klebsiella spp.

Enterobactin↗
PubMed1992

Klebsiella capsular type K7 in relation to toxicity, susceptibility to phagocytosis and resistance to serum.

Klebsiella strains possessing capsule type K7 are found predominantly in respiratory secretions. To investigate the importance of this K antigen in virulence, 13 K7 strains were compared with K2 capsulate isolates which are generally regarded as highly virulent. The toxicity of the strains was determined in a mouse peritonitis model. Generally, K7 isolates were significantly less toxic for mice than K2 strains. In the absence of serum, neither capsule type showed much stimulation of leucocytes, measured as the chemiluminescence (CL) response of human polymorphonuclear leucocytes (PMNL). However, in the presence of normal human serum, CL values with K7 strains increased considerably, whereas the CL response to K2 isolates was unaffected. Correspondingly, intracellular killing by PMNL was observed with K7 strains only, whereas K2 isolates proved to be relatively resistant to phagocytic destruction. No correlation was found between capsule type K7 and serum resistance. These data suggest that, in contrast to K2, capsule type K7 may not be a critical factor in the virulence of K7-capsulate Klebsiella strains nor does it seem to act as an antiphagocytic barrier.

Animals↗
PubMed1979

[Quantitative determination of protein, albumin, and antibiotics in the nasal secretions of patients with acute sinusitis (author's transl)].

Forty outpatients with sinusitis were treated with equimolar doses of Ampicillin (556 mg) of Bacampicillin (800 mg) three times daily in a doubleblind fashion. To control the efficiency of the therapy the number of leukocytes, sedimentation rate, subjective and objective symptomes were evaluated before the first dose and on the 2nd and 10th day. On the 1st day nasal secretions were collected at the time the first dose was given and 1, 2, and 3 h later. In these samples the concentrations of the antibiotic, of protein and albumin were determined. The amount of nasal secretions collected as well as the protein and albumin content remains fairly constant during the experiment. The concentration of Bacampicillin in nasal secretions reaches its maximum of 0.92 microgram/ml 1 h after the application whereas with Ampicillin it is 0.59 microgram/ml after 2 h. These values correspond to the concentrations which were found in normal test persons. The clinical result of the therapy is slightly better with Bacampicillin only if patients with severe sinusitis were taken into account. In the patients with moderate or slight symptoms no difference was found. Two of the patients which were treated with Ampicillin had to stop the therapy because of severe diarrhoe. When using Bacampicillin no patients had diarrhoe. This study shows that Bacampicillin (as an inactive ester of Ampicillin) is resorbed quicker and gives higher concentrations in the nasal secretions. Thus, the therapeutic effect is better in severe cases as compared to Ampicillin. Moreover, the side effects are less.

Albumins↗
PubMed1979

[Quantitative determination of protein, albumin, and antibiotics in nasal secretions of healthy probands (author's transl)].

This study on the pharmacokinetics of antibiotics in nasal secretions was carried out with two orally applicable penicillin derivatives which show different resorption patterns. Each of the antibiotics (Ampicillin and Bacampicillin) was given in equimolar doses to 20 healthy young volunteers, with normal mucosa, in a double blind cross over fashion. Nasal secretions were collected 1, 2, 3, 4, 6, and 8 h after the application of a single dose to the overnight fasted persons. In 10 of them blood was taken at 0.5, 1, 1.5, 2, 3, and 4 h after the administration. For the sampling of the nasal secretions cotton wool was weighed together with an airtight vial containing 300 microliter of phosphate buffered saline (PBS). The dry cotton wool stayed in the nasal cavity for 20 min, was then put into the PBS and weighed again. The difference determines the amount of secretions collected. After 30 min the soaked cotton wool was pressed out into a vial with a sterile syringe. One hundred microliters of this solution was taken to determine the antibiotic concentration by a micromodification of the agar diffusion technique. In the remaining fluid total protein and albumin were quantitatively determined. The amount of nasal secretions which have been collected are, on average, independent of the time (Fig. 1). With rising secretion the protein content decreases (Fig. 5) as is the case with the albumin concentration. Regarding all persons, the protein content and albumin (Fig. 4) remain constant during the experiment from 8 a.m. to 4 p.m. The differences between the values shown in the figures are not significant. Comparing the mean concentration for the antibiotic at different times after the application, it is obvious that the agents show different curves (Fig. 6). With ampicillin the maximum of 0.13 microgram/ml is reached at 2 h after the administration whereas with becampicillin the maximum of 0.84 microgram/ml is reached after 1 h. The concentrations in the nasal secretions are clearly dependent of the serum values. In the serum the maximum of the mean values plotted against the time of 2.7 microgram/ml is to be found at 2 h, if ampicillin is given, whereas the maximum of 9.3 microgram/ml is reached at 1 h after bacampicillin administration. In both cases in serum and nasal secretions the mean concentration maximum is about three times higher after bacampicillin as compared with ampicillin. As a reference for the concentration of the antibiotic the total protein content of the sample is more suitable as compared with sample volume and albumin because of its easy and exact determination. The results show that the nasal secretions can be used as a model to evaluate the pharmacokinetics in the mucosa of the upper respiratory tract if an adequate number of test persons is used.

Adult↗
PubMed1979

Antibacterial active components in human urine after administration of penicillins.

Four-hourly urine from volunteers and patients who had received penicillins orally or intravenously was investigated by means of thin layer chromatography and bioautography. Antibacterially active metabolites were not detected with only two of 12 penicillins, namely amoxicillin and mezlocillin. In the case of the other penicillins the metabolites possessed variable antibacterial activity as could be demonstrated using different test microorganisms. After administration of carbenicillin esters three antibacterially active spots were detected, one of which corresponded to penicillin G; the other two were active against Pseudomonas aeruginosa. The bioautogram after treatment with azlocillin showed two components which were active against Bacillus subtilis, Staphylococcus aureus and Escherichia coli; only the rapid moving component was active against P. aeruginosa, however. The formation and chemical nature of these additional active components is still to a large extent not understood. It is quite possible, however, that they affect the bio-availability of an antibiotic.

Administration, Oral↗
PubMed1979

[Thin layer and high pressure liquid chromatography investigations with cefaclor in urine and serum (author's transl)].

After oral administration of 500 mg cefaclor, antibacterially active metabolites could not be detected in human urine using thin layer chromatography followed by bioautography. Degradation products of cefaclor could also not be detected in the serum of human volunteers (n = 10) using high pressure liquid chromatography with a reversed phase system. Cefaclor was eluated as a single and homogenous peak with a retention period of 2.9 min. High pressure liquid chromatography for the measurement of cefaclor serum levels and a technique for preparation of serum samples are described. After administration of 500 mg cefaclor to volunteers (n = 10), the average peak serum concentration of 9.8 mg/l, determined by high pressure liquid chromatography, was observed after one hour. Four hours later the serum level was 0.3 mg/l. Using microbiological methods no statistically significant difference was obtained in comparison with the chromatography results. Some of the sera stored at -75 degrees C for four weeks showed a substantial loss of activity of cefaclor.

Administration, Oral↗
PubMed1979

Bacteriological studies with cefsulodin (CGP 7174/E), the first antipseudomonal cephalosporin.

The new cephalosporin, cefsulodin, has considerable antibacterial activity against Pseudomonas aeruginosa. When 217 strains of Ps. aeruginosa were tested against both azlocillin and cefsulodin, 26.3% were found to have the same minimal inhibitory concentration (MIC); the MIC for azlocillin was lower than that for cefsulodin in 16.6% of strains, but higher in 57.1%. 22 gentamicin-resistant strains were all susceptible to cefsulodin. Biophotometer investigations demonstrate less bactericidal effects for cefsulodin and azlocillin than for carbenicillin and ticarcillin using higher inocula than used in the agar of tube dilution test. Cefsulodin and gentamicin are synergistic against Ps. aeruginosa. Using high pressure liquid chromatography and biological techniques, cefsulodin is found to be moderately stable in solution and in standard solid laboratory media.

Anti-Bacterial Agents↗
PubMed1978

[Spectrum of pathogens in odontogenous abscesses in the patients of the Tübingen Department of Maxillofacial Surgery].

Bacteriological examination and evaluation of 475 smears of pus taken from odontogenous abcesses showed that the spectrum of pathogens is extremely broad. Chemotherapy therefore should not be started before the pathogen has been identified and an antibiogram has been made due to possible resistance on the part of the microorganisms. Clindamycin may be used for "blind treatment" until the bacteriologic findings are available because it is effective against streptococcus and staphylococcus as well as gram-negative asporous anaerobes. The risk of the possible ineffectiveness of clindamycin against gramnegative anaerobes however must be taken. Clindamycin and gentamicin together may be helpful in life-threatening situations because the combination covers an extremely broad spectrum of possible pathogens.

Clindamycin↗
PubMed1978

[Contamination of surgical wounds in the maxillofacial region with microoranisms].

The analysis of 226 wound smears were statistically evaluated. Smears were taken immediately after beginning surgery (105) and during the course of the operation, usually toward the end (121). No bacteria were identified at the beginning of the operation in 11.6% of the smears; 8.6% of the smears taken toward the end of the operative procedure showed no bacteria. Microorganisms usually found in the buccal cavity were identified in approximately two thirds of the wounds. Every third or fourth wound contained facultative pathogenic bacteria at the beginning of the operation. The necessity of antimicrobial measures was discussed.

Face↗
PubMed1977

Correlation of minimum inhibitory concentration and beta-lactamase activity.

The beta-lactamase activity of 510 recently isolated Enterobacteriaceae was investigated with a quantitative photometric test. Beta-lactamase could be detected in 55 percent of the Enterobacteriaceae. At the same time minimal inhibition concentration (MIC) of beta-lactam antibiotics was determined. There was no correlation between MIC values and lactamase activity. For correct antibacterial therapy the clinician requires information on the lactamase activity of isolated bacteria in addition to the antibiogram. The qualitative test is useful for screening.

Amidohydrolases↗
PubMed1977

Antibacterial activity of ticarcillin, tobramycin and gentamicin alone and in combination against Pseudomonas aeruginosa in vitro.

Using the biophotometer with ticarcillin no persistent bactericidal effect was found against Pseudomonas aeruginosa NCTC 10490. After addition of 1.2 microgram/ml gentamicin an increase of multiplication of bacteria was observed, but not after 1.2 microgram/ml tobramycin. With 6.2 microgram/ml tobramycin bactericidal effects lasted more than 24 h. In tube dilution test with Isotonic Sensi-test Broth out of 109 examined strains 51% were resistant to gentamicin, 16% to tobramycin and 4.5% to ticarcillin. If MIC values of gentamicin and tobramycin were calculated for magnesium-free media the resistance rate would be 10% for gentamicin and 3% for tobramycin. Combining subinhibitory doses of gentamicin or tobramycin with ticarcillin, most of the strains resistant to gentamicin and tobramycin became susceptible. The rate of inactivation of tobramycin by ticarcillin depends on the fluid into which they are placed. In combination therapy both antibiotics should be applied separately and immediately one after the other.

Anti-Bacterial Agents↗
PubMed1977

[The growth curves of enterobacteriaceae and the estimation of L-forms under the influence of cephalosporin antibiotics].

The antibacterial effectiveness of cephalothin, cefazolin, cephacetrile and cephradine was investigated on growing cultures of Klebsiella pneumoniae recording the growth curves with a biophotometer. Thereby cefazolin has a greater antibacterial activity than the other cephalosporins. By raising the dose to 100 microgram/ml after initial bactericidal effect a second growth phase was observed. Phase microscopic observation showed that this was caused by an increasing number of L-forms. This phenomenon could be observed with two other strains and seems to be a strain-specific characteristic. It occurs only using cephalosporins and isotonic nutrient media. The medical importance of the described ability of some bacteria as a factor of pathogenicity is discussed.

Cefazolin↗