Biomedical subjects

A Bauernfeind

Publications and source records attributed to A Bauernfeind.

At least 127 records · Page 7Linked to original sources

PubMedDate not supplied

Qualitative and quantitative microbiological analysis of sputa of 102 patients with cystic fibrosis.

A microbiological analysis of 102 patients suffering from cystic fibrosis was conducted over a 22 month period. 20 microbial species with the following incidence were identified: Pseudomonas aeruginosa: 83.4%; Candida albicans: 29.4%; Staphylococcus aureus: 24.5%; Staphylococcus epidermidis: 11.8%; Haemophilus influenzae: 11.8%; Streptococcus pneumoniae; 6.9%; Pseudomonas maltophilia: 6.8%; Aspergillus fumigatus: 5.9%. Other species were present in less than 5% of the patients. In the majority of specimens with P. aeruginosa, more than one type (up to six) was detectable. These strains were identical in colony appearance, O-serotype and pyocin-type. Quantitative analysis revealed concentrations of colony-forming units of 10(7) to 10(9) for P. aeruginosa, 10(6) to 10(8) for P. maltophilia, 10(4) to 10(7) for S. aureus, 10(4) to 10(6) for S. epidermidis and 10(4) to 10(7) for C. albicans in the majority of specimens. Significant differences were observed in the time periods during which the pathogens persisted in the patients. Maximum persistence was observed for P. aeruginosa. P. maltophilia and A. fumigatus had about similar persistence rates, which were lower than those for P. aeruginosa but above those for S. aureus and H. influenzae. S. epidermidis was eliminated within shorter periods than S. aureus. C. albicans, although the second most frequent microorganism identified, showed a very low persistence rate. The microbiological analysis confirms results from other research centers (high incidence of P. aeruginosa), but reveals significant regional differences as well (Pseudomonas cepacia not detectable, higher incidence of P. maltophilia and C. albicans). This underlines the necessity for detailed qualitative and quantitative microbiological analysis of sputa from cystic fibrosis patients as a prerequisite for rational analysis of etiological, epidemiological and therapeutical aspects of cystic fibrosis.

Adolescent↗

PubMedDate not supplied

Selective procedure to isolate haemophilus influenzae from sputa with large quantities of Pseudomonas aeruginosa.

The identification of respiratory pathogens (e. g. Haemophilus influenzae, Streptococcus pneumoniae) is impaired by the presence of large quantities of Pseudomonas aeruginosa, as is the case in the sputum specimens of cystic fibrosis patients. A procedure has been evaluated whereby the selective inhibition of the proliferation of P. aeruginosa is achieved by a broad spectrum pyocin, whereas the growth of H. influenzae is not influenced. This technique has been tested over a two year period resulting in a significantly augmented rate of identification of H. influenzae.

Bacteriocins↗

PubMedDate not supplied

Serologic response to Candida albicans and Aspergillus fumigatus in cystic fibrosis.

In order to evaluate the role of fungi in patients with cystic fibrosis, we determined serum IgG antibodies against Candida albicans and Aspergillus fumigatus using an indirect ELISA in patients with or without fungi in the sputum and in sera of healthy individuals. For both C. albicans and A. fumigatus the antibody levels were significantly higher in the CF groups than in the control group, regardless of whether these fungi could be isolated during the observation time or not. In contrast to A. fumigatus, we found that in the majority of cases antibody levels increase significantly with the isolation of C. albicans from sputum. Therefore, we conclude that one has to pay more attention to C. albicans in CF patients. One must also particularly reevaluate long-term antibiotic treatment and look for means to prevent fungal recolonization and reinfection.

Adolescent↗

PubMedDate not supplied

The role of Campylobacter (Helicobacter) pylori in disorders of the gastrointestinal tract.

To evaluate the role of Campylobacter pylori in different gastrointestinal disorders, serum IgG antibodies against C. pylori were determined in dyspeptic patients and in a control group of healthy children and adults. Twenty-eight percent of the dyspeptic patients with normal mucosa were seropositive. Among the patients with altered mucosa, the seroprevalence increased from duodenitis (48%) to gastritis (89%) and gastric or duodenal ulcer, gastric stump gastritis and carcinoma (100%, for each group, respectively). The C. pylori detection rate was lowest in patients with duodenitis alone (19%) and highest in patients with duodenal ulcers (95%). Therefore, C. pylori does not play an important role in patients with duodenitis alone. About 30% of patients with gastritis, active duodenal or gastric ulcer had antibody levels as low as the seroconverted dyspeptic patients but with normal gastroduodenal mucosa. C. pylori was not considered a causative factor for mucosal damage in these patients.

Adolescent↗

PubMedDate not supplied

Perspectives of beta-lactamases inhibitors in therapy of infections caused by Escherichia coli or Klebsiella with plasmidic resistance to third generation cephalosporins.

New plasmidic beta-lactamases inactivating so far stable cephalosporins, aztreonam and cephamycins restrict the use of these antibiotics in therapy of infections, e.g., by Escherichia coli and Klebsiella. Thus, combinations of beta-lactamase inhibitors and beta-lactam antibiotics were investigated in vitro with regard to their therapeutic perspectives. Minimal inhibitory concentrations and the kinetics of killing in a pharmacodynamic model were determined. Extended broad spectrum beta-lactamases (EBS-beta-lactamases) representative both for the TEM- and SHV-type were included. None of the available fixed combinations of penicillins and beta-lactamase inhibitors appears useful for therapy of infections caused by producers of EBS-beta-lactamases. In contrast, combinations of piperacillin and tazobactam or sulbactam plus cephalosporins (cefoperazone, cefotaxime, ceftazidime) or aztreonam are highly active (both by their MICs and bactericidal activity) against TEM-type EBS-beta-lactamases, but less promising for the SHV-type EBS-beta-lactamases, and plasmidic cephamycinase. Of the beta-lactams available, the monobactam carumonam and the carbapenems (imipenem, meropenem) remain safe in infections caused by E. coli and Klebsiella EBSBase producers.

Anti-Bacterial Agents↗

PubMedDate not supplied

Staphylococcus aureus in patients with cystic fibrosis: an epidemiological analysis using a combination of traditional and molecular methods.

An epidemiological analysis of Staphylococcus aureus was conducted in a study group of 157 cystic fibrosis patients cultured over a 30-month period. The resulting S. aureus isolates were categorized by bacteriophage type, plasmid profile, and (in some instances) chromosomal restriction fragment pattern of the culture-positive patients with S. aureus (34 of 157) 44% only were sporadically infected while 68% shared identical strains with one or more other patients. Six patients exhibited persistent infection (for up to ten months) which, in three individuals, occurred as cycles of carriage and reappearance. By contributing toward our understanding of the persistence and spread of S. aureus in cystic fibrosis patients these data should aid in clarifying the role this organism may play in the course of the disease.

Bacteriophage Typing↗

PubMedDate not supplied

Antibacterial activity of cefpodoxime in comparison with cefixime, cefdinir, cefetamet, ceftibuten, loracarbef, cefprozil, BAY 3522, cefuroxime, cefaclor and cefadroxil.

The new oral cephalosporins cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten demonstrate enhanced activity against Enterobacteriaceae susceptible to the established compounds as well (e.g. cefuroxime, cefaclor, cefadroxil). In addition, cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten include in their spectrum species hitherto resistant to oral cephalosporins (Proteus vulgaris, Providencia spp., Yersinia enterocolitica). Besides, the majority of these compounds demonstrate relevant activity (MIC50 equal to or below 2 mg/l) against Enterobacter spp., Citrobacter freundii, Serratia spp. and Morganella morganii. Ceftibuten is the most potent oral cephalosporin against most of the Enterobacteriaceae. Non-fermentative bacilli (Acinetobacter spp., Pseudomonas spp.) remain completely resistant to oral cephalosporins (except some Acinetobacter species against cefdinir and Pseudomonas cepacia against ceftibuten). Antistaphylococcal activity for oral cephalosporins is highest for cefdinir followed by BAY 3522, cefprozil, cefuroxime and cefpodoxime. Loracarbef, cefaclor and cefadroxil are about equally active, while the other compounds are only weakly active (cefixime) or inactive (cefetamet, ceftibuten). Enterococci are insensitive to new generation oral cephalosporins as they have been to established compounds. The most active oral cephalosporins against hemolytic streptococci are cefdinir and cefprozil. Streptococcus pneumoniae, Streptococcus milleri and Streptococcus mitior are most susceptible to cefpodoxime, cefdinir, cefuroxime and BAY 3522. Penicillin resistant pneumococci have to be regarded as resistant to all oral cephalosporins. Fastidious pathogens like Haemophilus spp., Moraxella catarrhalis and Neisseria gonorrhoeae are more susceptible to cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten than to the other oral cephalosporins. The activity of oral cephalosporins is only weak against Listeria spp., Helicobacter pylori and anaerobic pathogens (except BAY 3522). Bordetella pertussis remains resistant to all absorbable cephalosporins. Progress in antibacterial activity of oral cephalosporins was mainly achieved by cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten against Enterobacteriaceae and the fastidious pathogens and against staphylococci and the nonenterococcal streptococci by cefdinir, BAY 3522, cefprozil and cefpodoxime.

Bacteria↗

PubMedDate not supplied

A new plasmidic cefotaximase in a clinical isolate of Escherichia coli.

Escherichia coli GRI was isolated from an ear exudate of a newborn. The strain was highly resistant to cefotaxime (MIC 128 mg/l). Resistance to cefotaxime and the majority of beta-lactam antibiotics was readily transferred to an Escherichia coli recipient strain. Both the wild type and the transconjugant strains are different in their resistance phenotype from TEM-3 beta-cefotaximase producers by higher MICs to the majority of beta-lactams and lower MICs to ceftazidime. The isoelectric point of the cefotaximase of E. coli GRI was 8.9 in comparison with 6.3 for TEM-3. Thus, the enzyme produced by E. coli GRI represents a new plasmidic (plasmid pMVP-3) broad spectrum beta-lactamase (CTX-M) which may not be closely related to either the TEM- oder SHV-family of extended broad spectrum beta-lactamases.

Cefotaxime↗

PubMedDate not supplied

Selective pressure of antistaphylococcal chemotherapeutics in favour of Pseudomonas aeruginosa in cystic fibrosis.

Pseudomonas aeruginosa is insensitive against the majority of oral chemotherapeutics active against staphylococci. During application of such compounds in patients colonized by P. aeruginosa the concentration of P. aeruginosa increased in the majority of treatment episodes by factors between 2.5 and 50000. So, from a microbiological point of view the application of purely antistaphylococcal drugs should not be used prophylactically against staphylococci.

Adolescent↗

PubMedDate not supplied

Comparative efficacy of ciprofloxacin, azlocillin, imipenem/cilastatin and tobramycin in a model of experimental septicemia due to Pseudomonas aeruginosa in neutropenic mice.

The in vivo activity of ciprofloxacin against Pseudomonas aeruginosa was studied in a septicemia model in neutropenic mice and compared to that of other antibiotics with established activity against P. aeruginosa. When given as a single agent, ciprofloxacin proved to be as effective as imipenem/cilastatin, whereas azlocillin and tobramycin were rather ineffective. After infection with higher challenge inocula, combinations of two (synergistic) antibiotics were more effective than single agent therapy in most instances. The combination of ciprofloxacin with azlocillin was at least as effective as that of imipenem/cilastatin with tobramycin. Selection of mutants with decreased sensitivity to ciprofloxacin occurred during therapy, however, post-therapy MICs of ciprofloxacin did not exceed a level of 1 mg/l and rises of MICs did not detrimentally influence treatment outcome. Taken together with the results of earlier studies, our data encourage the use of ciprofloxacin in gram-negative septicemia in neutropenic patients.

Agranulocytosis↗

PubMedDate not supplied

Extended broad spectrum beta-lactamase in Klebsiella pneumoniae including resistance to cephamycins.

A plasmid-encoded beta-lactamase conferring extended broad spectrum resistance including cephamycins was identified in a Klebsiella pneumoniae strain isolated from a patient's wound. Strains harbouring the plasmid pMVP-1 were resistant to penicillins, cephalosporins of all generations (parenteral and new oral compounds) cephamycins, aztreonam, tetracycline, chloramphenicol, sulfonamides and to all aminoglycosides modified by AAC-(6)-I-transferase. beta-lactams still active against these strains were temocillin, ceftazidime, cefpirome, carumonam and the carbapenems imipenem and meropenem. The new cephamycinase (CMY-1) was more strongly inhibited by sulbactam in the majority of combinations than by clavulanic acid or tazobactam. MICs of ceftazidime and carumonam were not reduced by inhibitors in the wild type and the transconjugant. A transferable plasmid (pMVP-1) of about 9.6 x 10(7) dalton was demonstrated by gel-electrophoresis. In the wild type and the transconjugant a beta-lactamase with an isoelectric point of 8.0 was identified. This enzyme CMY-1 is different from the other extended broad spectrum beta-lactamases (TEM-3 to TEM-10, SHV-2 to SHV-5). The incidence of this enzyme may be underestimated, since resistance to cephamycins in Klebsiella and Escherichia coli has so far been regarded as almost exclusively chromosomally encoded and sensitivity of CMY-1 to clavulanic acid is low. Therefore, screening for CMY-1 beta-lactamases by the usual double disk test including clavulanic acid is not sensitive enough to detect CMY-1 producers. Sulbactam (e.g. in combination with ampicillin) disks and a cephamycin should therefore be used as well when screening for super extended broad spectrum (SEBS-) beta-lactamases.

Cephamycins↗

PubMedDate not supplied

A new plasmidic cefotaximase from patients infected with Salmonella typhimurium.

Salmonella typhimurium strains resistant to most beta-lactams, co-trimoxazole, tobramycin and gentamicin were isolated from patients in two hospitals in Buenos Aires, Argentina, beginning in August 1990. The patients were suffering from meningitis, septicaemia or enteritis. Therapy including ampicillin, ceftriaxone and gentamicin failed. The strains produced a plasmidic (pMVP-4) extended broad-spectrum beta-lactamase which is more active against cefotaxime than against ceftazidime (Vmax for cefotaxime 350 times higher than for ceftazidime). This cefotaximase demonstrates similarity to the previously described CTX-ase-M-1 from Escherichia coli, but it is distinctly different from CTX-ase-M-1 by its isoelectric point (7.9 for CTX-ase-M-2 in comparison with 8.9 for CTX-ase-M-1) as well as in its lower susceptibility to the beta-lactamase inhibitors sulbactam, clavulanic acid, tazobactam and BRL 42715. Thus, the beta-lactamase produced by S. typhimurium strains from Argentina appears to represent a new member (CTX-ase-M-2) of a novel group of plasmidic extended broad-spectrum beta-lactamases designated as cefotaximases.

Argentina↗

PubMedDate not supplied

Meropenem monotherapy versus cefotaxime plus metronidazole combination treatment for serious intra-abdominal infections.

In an open, randomised, multicentre trial, the efficacy and tolerability of empirical meropenem monotherapy (1 g intravenously every 8 hours) and cefotaxime (2 g every 8 hours) plus metronidazole (0.5 g intravenously every 8 hours) for 5 to 10 days was compared in 94 patients with serious intra-abdominal infection who required surgery. Eighty-three patients had an evaluable clinical response. Significantly more patients in the meropenem group had a satisfactory clinical response at the end of treatment (41/43 [95.3%] vs 30/40 [75.0%]; p = 0.008). The bacteriological response was also higher in the meropenem group (31/33 vs 26/32). In the bacteriologically evaluable population, a satisfactory clinical response was observed in 31/33 of those who received meropenem compared to 24/32 of the cefotaxime/metronidazole recipients (p = 0.03). Empirical meropenem monotherapy should prove a useful alternative to the currently standard combination treatment for serious intraabdominal infections.

Adult↗

PubMedDate not supplied

Comparative pharmacodynamics of clarithromycin and azithromycin against respiratory pathogens.

The differences between the antibacterial activities of new macrolides such as clarithromycin (CLA) and azithromycin (AZI) against common respiratory tract pathogens are only minor. However, CLA and AZI constitute macrolides with extremely different pharmacokinetic profiles. This constellation presents an opportunity to evaluate the effect of the pharmacokinetic profile on antibacterial kinetics comparatively. In a pharmacodynamic model simulating the dynamics of serum concentrations in bacterial cultures, both CLA and AZI demonstrate bactericidal activity at concentrations reached in human blood at recommended dosages (CLA 250 mg b.i.d., AZI 500 mg o.i.d.). Bactericidal activity of CLA against the variety of pathogens included is superior to that of AZI in the rate and the extent of killing in this model. These results are considered to correlate with the antibacterial effect of macrolides in vivo in cases where pathogens enter the blood stream. Furthermore, mutants with susceptibility reduced between 8 and 16 times in relation to the initial strain of all strains having an initial minimal inhibitory concentration (MIC) < or = 0.25 mg/l, are selected during exposure to AZI, but not to CLA. The pharmacokinetic profiles of CLA and AZI thus strongly influence their antibacterial effect in the pharmacodynamic model, allowing both higher bactericidal activity and greater reduction of the risk of selection of resistant mutants with CLA than with AZI. As a whole, the pharmacodynamics of these macrolides are determined more by the proportion of the MICs to the maximum serum concentration than by the relation of the MICs to the area under the curve.

Anti-Bacterial Agents↗

PubMedDate not supplied

Spread of Klebsiella pneumoniae producing SHV-5 beta-lactamase among hospitalized patients.

The first outbreak of infections caused by an SHV-5 producing strain of Klebsiella pneumoniae is reported. Within a period of 1 year and 9 months, multiresistant K. pneumoniae strains caused severe infections, mostly of the lower respiratory tract, in 22 patients. The strains were resistant to penicillins, third-generation cephalosporins, aztreonam, chloramphenicol, tetracycline and co-trimoxazole. The resistance determinants were transferable to Escherichia coli. All isolates produced a beta-lactamase with a pI of 8.2. Ceftazidime was hydrolyzed at this band. These characteristics, together with the resistance phenotype, are identical to those of a reference strain producing the beta-lactamase SHV-5. The K. pneumoniae strains of all patients were identical in their capsular serotype (K1), plasmid pattern and plasmid fingerprint after digestion with Dra I restriction endonuclease. We conclude that this outbreak was caused by the spread of one clone of K. pneumoniae producing SHV-5 beta-lactamase among patients of different wards. Our results indicate a real risk for failure of therapy by third-generation cephalosporins in intensive care patients due to SHV-5 producing pathogens.

Anti-Bacterial Agents↗

PubMedDate not supplied

Comparative antimicrobial spectrum and activity of ceftibuten against clinical isolates from West Germany.

The in vitro activity of a new oral cephalosporin, ceftibuten, was determined against 837 clinical isolates by agar dilution technique and compared with that of the oral cephalosporins, cefaclor, cefuroxime, cefixime, cefpodoxime, and cefprozil. Against Enterobacteriaceae, ceftibuten was the most active of the compounds. Ceftibuten MIC90s were less than or equal to 0.25 micrograms/ml for most members of the family Enterobacteriaceae, 0.13 microgram/ml for Haemophilus influenzae, 4 micrograms/ml for Moraxella catarrhalis, and 0.5 microgram/ml for Neisseria gonorrhoeae. Ceftibuten also was active against beta-haemolytic streptococci (serogroups A, C, and G) and penicillin-susceptible strains of Streptococcus pneumoniae (MIC90, 4 micrograms/ml), but was not active against Staphylococcus spp. or the anaerobic bacteria studied. Cefpodoxime and cefuroxime were the most active of the cephalosporins against nonenteric streptococci; cefprozil and cefuroxime were the most active against staphylococci, and cefaclor demonstrated the greatest activity against some Bacteroides spp. Most strains of Acinetobacter baumanii, Pseudomonas spp., and methicillin-resistant staphylococci, as well as all strains of Clostridium difficile, were resistant to each of the cephalosporins tested.

Anti-Infective Agents, Urinary↗

PubMedDate not supplied

Ceftibuten and bactericidal kinetics. Comparative in vitro activity against Enterobacteriaceae producing extended spectrum beta-lactamases.

Ceftibuten, compared to cefixime, cefetamet, cefpodoxime, loracarbef, cefprozil, cefuroxime, cefaclor, and cefadroxil, was the most active oral cephalosporin derivative against Enterobacteriaceae producing plasmid-encoded broad spectrum beta-lactamases. In a pharmacodynamic model, ceftibuten was bactericidal for Haemophilus influenzae and Streptococcus pneumoniae at concentrations simulating human serum levels following 200 mg, p.o., b.i.d.

Administration, Oral↗

PubMedDate not supplied

An open, comparative study of sulbactam plus ampicillin vs. cefotaxime as initial therapy for serious soft tissue and bone and joint infections.

In an open, randomized, comparative study, patients with bone, joint, or soft-tissue infections were treated with sulbactam sodium plus ampicillin (sulbactam/ampicillin, 1 g of sulbactam and 2 g of ampicillin three times a day) or with cefotaxime (2 g three times a day) for two weeks as initial therapy. Thirteen patients were entered into the sulbactam/ampicillin group and nine into the cefotaxime group. Two weeks after the end of therapy, clinical cure or improvement was observed in all 13 patients treated with sulbactam/ampicillin and in seven of nine patients treated with cefotaxime. Staphylococcus aureus was not eliminated from one patient in each group. Recurrence of S. aureus infection occurred in two patients in the cefotaxime group within two weeks after the end of therapy. No adverse effects warranting discontinuation of antibiotic therapy were observed. The combination of sulbactam sodium plus ampicillin was at least equivalent to cefotaxime for the initial treatment of acute serious soft tissue and bone and joint infections.

Acute Disease↗