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Biomedical subjects

A Bauernfeind

Publications and source records attributed to A Bauernfeind.

At least 73 records · Page 4Linked to original sources
PubMed1988

Bactericidal kinetics of various dosages of fleroxacin simulated in bacterial cultures.

From in-vitro data, recommendations for dosing with fleroxacin are presented. Serum pharmacokinetics of 250, 400, 500, 800, 1000 and 1500 mg once daily dosages were simulated in bacterial cultures. The bactericidal kinetics of clinical isolates of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus with MICs for fleroxacin similar to MIC90 or above were investigated. Bacterial populations of all strains with MICs equal to or below 2 mg/l were reduced by at least 99% by a once daily dosage of 400 mg of fleroxacin. 500 mg once per day was high enough to induce a two log reduction of P. aeruginosa MIC 4 mg/l. At a 250 mg dosing mutants with MICs four times above the MICs of the initial strains were selected. The increased concentrations of fleroxacin after multiple dosing enhanced bactericidal activity. Once daily dosing increased the initial rate of killing but reduced the extent of inactivation in comparison with twice daily dosing of the same total amount. From our in-vitro investigation a once daily dosage of 400 mg of fleroxacin should be effective against causative organisms with an MIC of up to 2 mg/l, both in the rate and extent of killing and to minimize the risk for selection of resistant mutants.

Anti-Infective Agents↗
PubMed1988

Sulbactam/ampicillin versus cefotaxime as initial therapy in serious soft tissue, joint and bone infections.

In an open, randomised comparative study, 23 patients with bone, joint or soft tissue infections were treated with ampicillin 2g plus sulbactam 1g 3 times a day or cefotaxime 2g 3 times a day as an initial 2-week therapy. Monoinfections with Staphylococcus aureus were the most common bone or joint infections. Clinical cure or improvement 2 weeks after the end of therapy was observed in all 13 patients treated with sulbactam/ampicillin and in 7 of the 8 patients evaluated for efficacy after treatment with cefotaxime. Most organisms identified before the onset of therapy were susceptible to the antibiotic randomly selected for therapy, although the majority of infections due to beta-lactamase-producing staphylococci could not have been treated with ampicillin without sulbactam. Treatment failed to eradicate S. aureus in 1 patient from each group. In addition, S. aureus infection recurred in 2 patients in the cefotaxime group within 2 weeks after the end of therapy. No serious side effects were observed.

Adolescent↗
PubMed1988

Significance of immunologic factors in cystic fibrosis.

We specifically investigated the significance of antibodies directed against pure preparations of lipopolysaccharide antigens and also against elastase of Pseudomonas aeruginosa. Antibodies were detected by an indirect enzyme-linked immunosorbent assay technique both in serum (IgG) and in sputum (sIgA). Patients with cystic fibrosis (CF) chronically infected with Ps. aeruginosa had significantly higher antibody titers both in serum and sputum than CF patients or non-CF persons not colonized with Ps. aeruginosa. There were differences in the antibody spectrum between the colonized CF group and the two non-colonized control group. The sensitivity was highest for homologous O-specific IgG in serum (91.9%), followed by homologous O-specific sIgA in sputum (79.4%) and sIgA anti-elastase in sputum (66.2%). O-specific IgG antibodies in serum indicate a previous contact with various O-antigens of Ps. aeruginosa rather than reflect the present condition of the patient. In the evaluation of the current status sIgA O-specific antibodies in sputum are an appropriate indicator, with titers increasing during acute exacerbations and decreasing to normal values subsequently.

Adolescent↗
PubMed1988

Microbiologic and therapeutic aspects of Staphylococcus aureus in cystic fibrosis patients.

Staphylococcus aureus was the most frequent (28.8%) gram-positive organism in 149 cystic fibrosis patients. Next to Pseudomonas aeruginosa, S. aureus was the most persistent bacterial pathogen as well. Persistence was not correlated to the age or sex of our patients. Colonization by S. aureus was not prevented completely by oral antibiotics like cotrimoxazole or oral cephalosporins. Persisting staphylococci were less susceptible to the antibiotic substances used than strains detectable only sporadically. Increase of sputum concentrations of P. aeruginosa was observed in episodes of treatment with purely antistaphylococcal compounds. Improvement of effectiveness of antibacterial therapy may be achievable by antibiotics more active against staphylococci, active both against staphylococci and P. aeruginosa, or adequate drug combinations.

Anti-Bacterial Agents↗
PubMed1987

Microbiological perspectives of co-trimoxazole.

Trimethoprim-sulfamethoxazole in vitro activity was compared with ampicillin, tetracycline, sulfonamide and trimethoprim against isolates of 24 gram-negative and 11 gram-positive species. The incidence of more than 10% of strains with minimal inhibitory concentrations above 32 mg/l was restricted to Escherichia coli, Shigella spp., Klebsiella pneumoniae, Providencia rettgeri, Morganella morganii, methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. Occasionally, Streptococcus pneumoniae and Haemophilus influenzae strains with MICs above 32 mg/l were identified. Co-trimoxazole in vitro activity was superior to the comparative drugs for the majority of species. Co-trimoxazole remains an active combination against major pathogens of infections of the upper and lower respiratory, urinary tract and enteric infections with a still low incidence of resistant organisms.

Anti-Bacterial Agents↗
PubMed1987

Bacteriological effects of anti-Pseudomonas aeruginosa chemotherapy in cystic fibrosis.

Strains of Pseudomonas aeruginosa resistant to clinically relevant antibiotics (beta-lactams, quinolones, aminoglycosides) were detectable in sputa of cystic fibrosis patients. Correlations between in vitro susceptibility and bacteriological results in vivo were demonstrated at a quantitative level. P. aeruginosa strains susceptible prior to antibiotic therapy were observed to become resistant towards each of the compounds used for treatment. We conclude that antibiotic therapy in cystic fibrosis has to be optimized by culture specific selection of the drugs and consecutive bacteriological follow-ups.

Anti-Bacterial Agents↗
PubMed1987

Spectrum of bacterial pathogens in uncomplicated and complicated urinary tract infections.

The spectra of bacterial organisms of urinary tract infections (UTI) in patients with and without abnormalities in the urinary tract (complicated and uncomplicated UTIs) are compared. Data from the United Kingdom and the Federal Republic of Germany are included. In addition, the susceptibility of the pathogens to antibiotics (for oral or parenteral application) in both countries are compared. In conclusion, rational antibiotic therapy of complicated UTIs should strictly follow the antibiogram of the causative organism. For therapy of uncomplicated UTIs, the regional state of antibiotic susceptibility of the pathogens according to geographical location should be considered and kept up to date.

Escherichia coli Infections↗
PubMed1987

Urinary pathogens and bacterial sensitivity in hospitalized urological patients based upon clinical aspects.

For a total of 396 hospitalized urological patients with complicated and/or hospital-acquired urinary tract infections (UTI) urinary pathogens with colony counts of 10(5)/ml or more were determined, several species were then subclassified by epidemiological markers. The minimal inhibitory concentrations (MIC) were measured using the agar dilution method for seven penicillins and for four penicillin combinations, for six oral and 14 parenteral cefalosporins, for three older and five newer quinolones, for two aminoglycosides, for two monobactams, for trimethoprim alone and in combination with sulfamethoxazole, for fosfomycin and for imipenem. Sensitivity and resistance of the strains were defined using breakpoints according to DIN 58.940 or analogous concentrations. The bacterial spectrum and the rate of resistant strains were correlated to clinical aspects pertaining to sexual status, age and underlying abnormalities within the urinary tract. There was a statistical difference in the frequency of E. coli and enterococci between patients with (complicated UTI) and without (uncomplicated UTI) abnormalities. Within the group of complicated UTI Proteus spp. were found significantly more often in patients with urolithiasis, Klebsiella spp. and staphylococci in patients with prostatic tumours (benign and malignant), enterococci in patients with prostatic and other tumours and E. coli in patients with abnormalities other than urolithiasis or tumours. Almost all antibiotics tested could be used in patients with uncomplicated UTI for empiric or calculated therapy if a rate of resistance of up to 10% is acceptable. In patients with urolithiasis only the newer acylaminopenicillins, the newer (fluoro-)quinolones, trimethoprim in combination with sulfamethoxazole, fosfomycin and imipenem fulfill this criterion. In order to treat complicated UTI with underlying tumours within the urinary tract empirically only piperacillin, apalcillin, imipenem and some of the newer quinolones (ofloxacin, ciprofloxacin and pefloxacin) could be recommended. The same was true for patients with indwelling catheters still present or recently removed.

Aminoglycosides↗
PubMed1986

[Imipenem/cilastatin: in vitro activity, concentrations in plasma and prostatic adenoma and therapeutic results in patients with complicated urinary tract infections].

Minimal inhibitory concentrations (MICs) of imipenem, ceftazidime, piperacillin, tobramycin, azthreonam and carumonam were assessed for 400 urinary isolates from hospitalized patients with complicated and/or nosocomial urinary tract infections yielding greater than or equal to 10(5) colony forming units (cfu). More than 90% of the gram-negative pathogens were sensitive to all the antibiotics tested. However, only imipenem and piperacillin exhibited MIC90 values in the therapeutic range for gram-positive pathogens (approximately half of which were staphylococci and enterococci). Perioperative prophylaxis with 0.5 g imipenem/cilastatin administered at different time intervals before the operation (up to six hours) was performed in patients undergoing resection (n = 31), respectively enucleation (n = 1) of a prostatic adenoma or lithotriptic treatment (n = 4). Imipenem yielded peak plasma concentrations of 12.2 to 134.8 mg/l (mean 49.4 mg/l). The estimated half life time in these patients was approximately three hours. Considerable intra as well as interindividual variations were found for imipenem concentrations in prostatic adenoma. However, they were sufficiently high to reach sensitive pathogens (MICs up to 1 mg/l) for up to two-and-a-half hours. Up to six hours after dosing the concentrations in prostatic secretions ranged between 1 and 2 mg/l. A total of 20 urological patients suffering from complicated urinary tract infections (15 men, five women) received a short-term i.v. infusion of 0.5 mg imipenem/cilastatin t.i.d. for seven to 16 days (median seven days). In all these patients urines were sterile during therapy as well as one to two days after therapy. Follow-up examinations performed seven to ten days after the end of treatment in 19 of these patients showed ten patients to be free of infection (55%); these patients were classified as success. Seven patients (37%) presented a relapse (same pathogen) and two patients (10%) a re-infection (different pathogen). Imipenem/cilastatin was well tolerated locally and systemically.

Adult↗
PubMed1986

[Bone concentrations of imipenem after a dose of imipenem/cilastatin].

The concentration of imipenem in organic bone, determined in 16 patients by bioassay after short infusion (15 min) of 1 g imipenem/cilastatin was 4.3 +/- 2.06 mg/kg (geometric mean +/- standard deviation, n = 13) after 45 minutes, and 2.8 +/- 1.86 mg/kg (n = 26) after 88 minutes. Imipenem penetrates into inorganic hydroxylapatite (imbution), however, its antimicrobial activity is lost. The mean serum concentration in 12 patients (mean age 77 years) with normal renal and hepatic function 15 minutes after the beginning of the infusion was 93.1 mg/l imipenem. The mean serum half life t (1/2 beta) was 1.32 hours, the total body clearance 108.6 1/h, and the volume of distribution during the beta phase V(beta) 12.4 1.

Aged↗
PubMed1986

[Imipenem resistance in Pseudomonas aeruginosa].

Mutants of P. aeruginosa resistant to imipenem can be selected at high frequency in vitro. They remain susceptible to other beta-lactams. Strains resistant both against imipenem and other beta-lactams are, however, detectable in vitro and in vivo. Imipenem-resistant strains appeared in blood cultures and emergence of IMI-resistance during therapy has been observed. The activity of other beta-lactams against P. aeruginosa is antagonized in the presence of IMI, because of beta-lactamase induction by imipenem. In addition to the risk of emergence of IMI-resistance of P. aeruginosa during therapy, there is an increasing incidence of IMI-resistant strains already existing prior to therapy. In the treatment of infections caused by P. aeruginosa combination therapy including a non-beta-lactam antibiotic active against the pathogen is indicated.

Drug Therapy, Combination↗
PubMed1986

Changes in microbial ecology by therapeutic use of aminoglycosides.

Alterations in microbial ecology caused by the usage of aminoglycosides for therapy of human infections are due to their selective pressure favouring insensitive or resistant species or strains. There is a positive correlation between aminoglycoside consumption and the incidence of resistance to aminoglycosides. This correlation is, however, modified by measures of infection control. At the present time, the overall incidence of resistance to aminoglycosides does not show major changes. The ecological impacts of aminoglycoside consumption appear to be less significant as compared to other antibiotics due to factors specific for the aminoglycoside group.

Aminoglycosides↗