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J Wüst

Publications and source records attributed to J Wüst.

At least 19 recordsLinked to original sources
PubMed1998

[Sensitivity of bacteria to therapeutic drugs (Zurich 1996)].

This paper describes the frequency of susceptibility of Gram-negative and Gram-positive bacteria against antibacterial agents. The data are based on all susceptibility tests performed in 1996 at the Department of Medical Microbiology of the University of Zurich and at the private medical laboratory "medica" in Zurich. The evaluation of the results from 1975 to 1996 shows that susceptibilities against the antimicrobial agents tested have not changed markedly in this period with few exceptions. The tables may be a help for the physician in his decision for a "calculated chemotherapy" of bacterial infections.

Anti-Bacterial Agents↗
PubMed1998

Low specificity of the bacterial index for the diagnosis of bacterial pneumonia by bronchoalveolar lavage.

The bacterial index (BI) as defined by the sum of log10 colony-forming units (cfu) of microorganisms per milliliter of bronchoalveolar lavage (BAL) fluid, i.e., a multiplication of the single cfu/ml, has been used to distinguish between polymicrobial pneumonia (BI> or =5) and colonization (BI<5). Since many false-positive results are to be expected using this parameter, the diagnostic value of the BI was studied prospectively by obtaining bacteriologic cultures of BAL fluid in 165 consecutive unselected patients. In 27 cases the diagnosis of bacterial pneumonia was established on clinical criteria. In 133 patients pneumonia could be excluded, and in five patients the diagnosis remained unclear. Using a cut-off of > or = 10(5) cfu/ml BAL fluid, sensitivity and specificity for the diagnosis of pneumonia were 33% (9/27) and 99% (132/133), respectively. Sensitivity was mainly influenced by prior treatment with antibiotics, being 70% (7/10) in untreated and 12% (2/17) in treated patients. Applying the BI methodology at a cut-off of > or =5, however, resulted in an unacceptably high rate of 16 additional false-positive results, thus lowering the specificity to 87% (116/133; P<0.0001) while increasing the sensitivity to only 41% (11/27; P = 0.77). In conclusion, given the high rate of false-positive results, the methodology of the BI is of doubtful value for the diagnosis of bacterial pneumonia by BAL in an unselected patient group. By applying the absolute number of cfu/ml BAL fluid, however, positive bacteriologic cultures of BAL fluid are highly specific for the diagnosis of pneumonia. Their sensitivity is limited by previous antibiotic therapy.

Adolescent↗
PubMed1997

Molecular epidemiology of Mycobacterium tuberculosis strains isolated from patients in a human immunodeficiency virus cohort in Switzerland.

From 1989 to 1995, 46 patients infected with the human immunodeficiency virus were diagnosed with tuberculosis at the University Hospital in Zurich. Using the IS6110 insertion sequence as a genetic marker, restriction fragment length polymorphism analyses were done for 52 Mycobacterium tuberculosis isolates. We have found a large degree of IS6110 polymorphism, ranging from 1 to 16 copies. For isolates from patients from whom multiple isolates had been available, the IS6110 pattern remained virtually stable over a period of up to 4 years, as well as during emerging drug resistance. In none of the cases was a reinfection of a patient with another strain detected. For isolates from 10 patients we detected identical patterns which could be associated with four clusters. In one of these, the strains exhibited a low IS6110 copy number (four bands), and the strains were further analyzed by hybridizing with (i) the polymorphic GC-rich repetitive sequence (PGRS) and (ii) the 36-bp direct-repeat (DR) cluster sequence. One of these isolates had a different pattern with the PGRS as well as with the DR sequence and could therefore be safely excluded from that cluster. These findings point to the importance of applying more than one genetic criterion in the molecular biological study of strain relatedness.

AIDS-Related Opportunistic Infections↗
PubMed1997

In vitro activity of cefpirome against microorganisms isolated in haematology, oncology and intensive care units in Switzerland.

The in vitro activity of cefpirome, a new parenteral fourth-generation cephalosporin, was investigated in the 5 university hospitals of Switzerland, and compared to 9 other antibiotics mainly used in hospitals, such as ceftazidime, ceftriaxone, cefotaxime, piperacillin, imipenem, gentamicin, vancomycin, ciprofloxacin and ofloxacin. A total number of 992 strains collected only from intensive care units and haematology-oncology units were tested by microdilution according to NCCLS. Cefpirome showed an excellent activity against all Enterobacteriaceae (MIC90 = 4 mg/l), methicillin-susceptible staphylococci (MIC90 = 1 mg/l), Streptococcus pneumoniae (MIC90 = 0.25 mg/l) and Haemophilus influenzae (MIC90 = 0.12 mg/l) isolates. Its activity was superior to that of third-generation cephalosporins against cephalosporinase-depressed mutants of Enterobacter cloacae and Citrobacter freundii isolates (MIC90 > 32 mg/l for third-generation cephalosporins vs 4 mg/l for cefpirome). The MICs of cefpirome of 3 strains of Klebsiella spp. with an extended-spectrum-beta-lactamase were lower (MIC90 = 2 mg/l) than those of third-generation cephalosporins (MICs90 > 32 mg/l). Against Pseudomonas aeruginosa cefpirome was as active as ceftazidime. The activity of cefpirome was poor against methicillin-resistant staphylococci, enterococci and nosocomial Gram-negative bacteria such as Stenotrophomonas maltophilia.

Anti-Bacterial Agents↗
PubMed1996

[Tips and requests by microbiologists].

Useful results of microbiological examinations can only be expected, when the specimens submitted to the laboratory are taken correctly. This overview shows appropriate and inappropriate specimens. Hints are given for a 'calculated antimicrobial chemotherapy'. A brief outline shows which bacteria should be tested for susceptibility to antimicrobial agents due to variable sensitivity.

Humans↗
PubMed1996

[Effectiveness of triple therapy to eradicate H. pylori in patients after failed therapy with omeprazole/amoxicillin].

Helicobacter pylori (H. pylori) eradication rates with omeperazole/amoxicillin range from 0-90%. The best regimen for retreatment after failure of omeprazole/amoxicillin has not been established so far. The aim of this prospective study was to evaluate the efficacy of triple therapy with bismuth, tetracycline and ornidazole in eradicating H. pylori after failure of omeprazole/amoxicillin. 79 duodenal ulcer patients with H. pylori infection were treated with oral omeprazole (40 mg bid) and amoxicillin solute (750 mg tid) for 10 days. Eradication rate was 28/79 (35%) and was distinctly lower in smokers (> 10 cigarettes/day) vs nonsmokers (10/49 [20%] vs 18/30 [60%], p < 0.001). 37 patients with persistent H. pylori infection in whom omeprazole/amoxicillin had failed agreed to retreatment with triple therapy. Persistence of H. pylori was confirmed by histology (3 antral and 2 gastric body biopsies; H&E, Giemsa), urease test (CLO) and/or H. pylori culture. Patients smoking > 10 cigarettes/day were classified as smokers. Retreatment consisted of oral bismuth-subcitrate 4 x 120 mg/d for 28 days (day 1-28), tetracycline 4 x 500 mg/d and ornidazole 3 x 500 mg/d for 10 days (day 1-10). Control endoscopy was done 30 days after the end of treatment. Criteria for H. pylori eradication was negative urease test, culture and histology. 34/37 patients (6 females/28 males; 39 [23-64] years) completed the study (24/34 smokers, 10/34 nonsmokers). 3/37 patients dropped out because of side effects (n = 1) or incompliance (n = 2). H. pylori subcultures for resistance testing were possible in 32/34 patients: H. pylori was metronidazole-sensitive in 11/32 (1 female, 10 males; 38 [24-55] years; 9 smokers, 2 nonsmokers) and metronidazole-resistant (minimal inhibitory concentration for metronidazole > 8 mg/ml) in 21/32 (5 females, 16 males; 40 [23-64] years; 13 smokers, 8 nonsmokers). The overall H. pylori eradication rate of the triple therapy was 27/34 (79%). H. pylori was eradicated in 19/24 (79%) smokers and in 8/10 (80%) nonsmokers. Eradication rate for metronidazole-sensitive H. pylori was 11/11 (100%) vs 14/21 (67%) for metronidazole-resistant H. pylori (p = 0.012). Triple therapy is effective and safe in eradicating H. pylori in patients after failure of omeprazole/amoxicillin. Smoking had no negative effect on the eradication rate of the triple therapy after failure of omeprazole/amoxicillin. Eradication failures were due to metronidazole-resistance.

Adult↗
PubMed1996

Prospective evaluation of a semiquantitative dip slide method compared with quantitative bacterial cultures of BAL fluid.

BACKGROUND: Quantitative bacteriologic workup of BAL fluid (BALF) has evolved as a sensitive and specific technique for the diagnosis of bacterial pneumonia. Conventional quantitative cultures are expensive, time-consuming, and often unavailable on a 24-h basis. Therefore, we evaluated a dip slide method for the semiquantitative measurement of bacterial cultures in BALF specimens and compared the results with those from conventional quantitative cultures. METHODS: Fifty BALF specimens from 45 patients with suspected pulmonary infection were examined prospectively with both methods. We compared the microbiologic results of conventional quantitative cultures with those of the dip slide method that is commercially available for blood cultures. Cost-effectiveness analysis of both methods was performed. RESULTS: In 37 BALF specimens, 64 bacterial strains were detected with both techniques. The dip slide method and conventional cultures showed a high correlation with respect to the colony counts of the individual organisms per milliliter BALF (r=0.935; p= 0.0001) and the sum of colony counts in individual patients (r=0.947; p=0.0001). Although five strains were not detected by the dip slide technique, the diagnostic accuracy was not influenced. In 13 BALF samples, there was no growth of bacteria with both techniques. While the diagnostic yield of both methods was similar, the dip slide technique was 44 to 66% less expensive than conventional cultures. CONCLUSIONS: The examination of BALF with a clip slide method is highly comparable to conventional quantitative culture techniques, less expensive, and can be used independently of a specialized microbiology laboratory on a 24-h basis.

Adolescent↗
PubMed1995

[sensitivity of bacteria to chemotherapeutic agents (Zurich, 1993)].

This paper describes the incidence of Gram-negative and Gram-positive bacteria susceptible to antibacterial agents. The data are based on all susceptibility tests performed at the Department of Medical Microbiology of the University of Zurich. The evaluation of the results from 1987 to 1993 shows that susceptibilities against the antimicrobial agents tested have not changed markedly in this period with few exceptions. The tables may be of help to the physician in his decision for a 'calculated chemotherapy' of bacterial infections.

Anti-Bacterial Agents↗
PubMed1995

Soft tissue infections of the upper extremities with special consideration of abscesses in parenteral drug abusers. A prospective study.

Despite surgical advances and new antibiotics, upper extremity infections continue to present a serious problem. Soft tissue infections of the upper extremities were prospectively examined to elucidate incidence, cause, bacterial pathogens involved, and treatment. Special attention was paid to infections associated with parenteral drug abuse. During an 18-month period all patients over 16 years of age presenting for treatment of an established infection were included in the study. Conservative treatment consisted of immobilization and antibiotics. Radical débridement with removal of all necrotic tissue was the guideline for operative care. In addition, for both regimens a penicillinase-resistant antibiotic was administered. A total of 415 patients (271 men and 144 women; mean age 36.7 +/- 14.5 years) were enrolled into the study, 55 of whom were parenteral drug abusers; 45 of these were HIV-reactive. Infections of fingers (excluding paronychia), paronychia and abscesses at injection sites were the most common diagnoses. Operative and conservative treatment were performed in 285 and 130 patients respectively. Staphylococcus and streptococcus species were the predominant organisms recovered from 212 specimens of pus. Anaerobic bacteria and yeasts were of minor importance. Therefore, a penicillinase-resistant antibiotic is a good initial choice.

Abscess↗
PubMed1995

Assignment of Actinomyces pyogenes-like (CDC coryneform group E) bacteria to the genus Actinomyces as Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov.

In a previous study the authors reported the characterization of some facultatively anaerobic, Gram-positive, non-sporeforming rods which were found in mixed cultures from various infectious processes, including patients with otitis, empyema, perianal abscesses and decubitus ulcers. Phenotypically these organisms closely resembled Actinomyces pyogenes although their precise taxonomic position remained unknown. In the present investigation the authors have determined the 16S rRNA gene sequences of some representative strains of the Actinomyces pyogenes-like bacteria and report the results of a comparative sequence analysis. On the basis of the results of the present and earlier findings two new Actinomyces species, Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov. are proposed. The type strains are DSM 9169T and DSM 9168T, respectively.

Actinomyces↗
PubMed1995

Antimicrobial susceptibilities and serotypes of invasive Streptococcus pneumoniae strains in Switzerland.

In 1993 and 1994, 10 microbiological laboratories in Switzerland collected 351 strains of Streptococcus pneumoniae from invasive infections. Susceptibilities to the main representatives of the chemical classes were as follows: penicillin, 93%; chloramphenicol, 92%; erythromycin, 94%; sulfamethoxazole-trimethoprim, 86%; tetracycline, 92%; vancomycin, 100%. Forty-three strains showed resistance to one agent, and 35 strains showed resistance to two or more antimicrobial agents simultaneously; i.e., 22% of the strains were resistant to at least one antimicrobial agent. Four strains (1%) were fully resistant to penicillin, whereas 21 strains (6%) showed reduced susceptibility. Of these 25 strains not fully susceptible to penicillin, 10 were resistant to one, 3 were resistant to two, and 8 were resistant to three additional antimicrobial agents. Of the quinolones, sparfloxacin was the most active substance, with an MIC at which 90% of the strains are inhibited of 0.5 mg/liter. The most common serotypes were types 6 (13.6% of isolates), 7 (10.5%), 19 (10.5%), 14 (9.1%), and 1 (8.5%) as well as 3 and 23 (8.0% each). Reduced susceptibility to penicillin was found mainly among serotypes 6, 14, 19, and 23. The currently available 23-valent pneumococcal vaccine covers 320 (91%) of the pneumococci isolated. Regional differences within Switzerland with regard to serotypes and antimicrobial resistance were not observed.

Bacterial Vaccines↗
PubMed1995

Analysis of restriction fragment length polymorphism and ribotyping of multiresistant Stenotrophomonas maltophilia isolated from persisting lung infection in a cystic fibrosis patient.

A cystic fibrosis patient was infected by Stenotrophomonas maltophilia over at least 15 months. The bacteria became increasingly resistant to antimicrobial agents. Determination of restriction fragment length polymorphism and ribotyping showed that resistance was due to changes in that S. maltophilia rather than to infection by another strain.

Adult↗
PubMed1994

[Antibiotic sensitivity of gram-negative bacteria in intensive care units in Switzerland].

The sensitivity to the major antimicrobial agents of consecutively isolated gram-negative rods in intensive care units in Switzerland was investigated. A majority of strains originated from clinical specimens where infection or colonization could not be distinguished from each other. A total of 1024 isolates from 482 patients were tested by a standardized microtiter method. Of the beta-lactam antibiotics, imipenem (92% of bacteria sensitive), ceftazidime (90%), and aztreonam (85%) showed the greatest activity. 94% of the isolates were sensitive to ciprofloxacin, and 93% and 91% to amikacin and tobramycin respectively. There where considerable differences locally and in time, probably reflecting small outbreaks due to resistant bacteria and because selective pressure is locally dependent on the antimicrobial agents used. 122 patients were observed for an extended period. In 67 (55%) the same gram-negative rods persisted for up to 42 days without development of resistance. In 41 patients (34%) there was a change to other more resistant bacteria, especially to multi-resistant Pseudomonas aeruginosa, Flavobacterium meningo-septicum, Xanthomonas maltophilia or Enterobacter cloacae. In 12 patients (10%) bacteria of the same species with resistance to additional antimicrobial agents were observed.

Anti-Bacterial Agents↗
PubMed1994

[Multicenter evaluation of oral antibiotics: resistance behavior in 5 Swiss centers].

The susceptibility of 2196 fresh clinical isolates to twelve different oral compounds was assessed in five Swiss microbiology institutions during summer 1992. A standardized microdilution system including all other material necessary was employed to assess the antibacterial activity of penicillin G, ampicillin, ampicillin + sulbactam, amoxycillin + clavulanic acid, cefadroxil, cephalexin, cefaclor, cefuroxime, cefetamet, doxycycline, erythromycin and clindamycin. The aminopenicillins (including the beta-lactamase inhibitor combinations) were highly active against the streptococci, in combination with a beta-lactamase inhibitor they covered the majority of the bla+ E. coli and Proteus mirabilis and between 60 to 80% of the Klebsiella spp. and Proteus vulgaris isolates. All the cephalosporins exhibited good activity against the streptococci, they were active against Gram-negative fermentative rods to a varying degree. Cefetamet was also active against many cefaclor and cefuroxime-resistant isolates. A considerable part of the species studied exhibited resistance to doxycycline; the observed resistance of S. agalactia, P. mirabilis, and Morganella morganii agreed with previous findings. Most of the Streptococcus spp. were inhibited by erythromycin and clindamycin. There were only single penicillin resistant S. pneumoniae isolates in the five Swiss centers. Taking account of the above particulars the epidemiology of antimicrobial resistance in Switzerland can be considered satisfactory.

Anti-Bacterial Agents↗
PubMed1994

[Eradication of metronidazole-resistant Helicobacter pylori: is omeprazole/amoxicillin a therapeutic alternative?].

Recommended therapies with the highest eradication rates for Helicobacter pylori (HP) are triple therapies comprising bismuth salts, nitroimidazole and amoxicillin or tetracycline. Primary and secondary resistance of HP to nitroimidazole, however, represents a major problem of this treatment since it is the main cause of eradication failure. In these cases therapeutic regimes without nitroimidazole could prove more successful. High dose omeprazole/amoxicillin has been suggested as a simple and effective therapy with few side effects. The effectiveness of this combination in eradicating metronidazole resistant HP has not been established so far. The aim of this study was to evaluate high dose omeprazole/amoxicillin in eradicating metronidazole resistant HP in our population. 33 patients (6 women, 27 men, mean age 39 [range 21-68]) with recurrent duodenal ulcer and gastric colonization by metronidazole resistant HP were examined. Smokers were defined as patients currently smoking > 10 cigarettes/day. Exclusion criteria were: gastric surgery or intake of antibiotics, omeprazole bismuth salts and NSAIDs within four weeks before study entry endoscopy. Biopsy specimens were obtained in a standardized manner: 5 from the gastric antrum (1 CLO, 1 culture, 3 histology: H & E, Giemsa) and 2 from the gastric body (histology). Resistance testing for penicillin, amoxicillin and metronidazole was performed using a disk diffusion test (E-test, AB Biodisk, Sweden). Metronidazole resistance was defined as a minimal inhibitory concentration (MIC) of metronidazole of > 8 micrograms/ml. Eradication therapy consisted of oral omeprazole (40 mg bid) and amoxicillin solute (750 mg tid) for 10 days. Subsequently, for ulcer treatment, patients were given omeprazole (20 mg per day) for 20 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Omeprazole/amoxicillin: improved eradication of Helicobacter pylori in smokers because of N-acetylcysteine].

Colonization of Helicobacter pylori (HP) beneath the protective film of gastric mucus enables the organism to survive in the hostile environment of the gastric mucosa. N-acetylcysteine (NAC), a sulfhydryl compound with potent mucolytic activity, induces a reduction of gastric barrier mucus thickness of about 75% and reduces mucus viscoelasticity. We therefore tested the hypothesis whether better eradication results could be achieved by addition of NAC to omeprazole/amoxicillin (OME/AMOX). 34 HP positive outpatients with endoscopically documented recurrent duodenal ulcer were included in an ongoing, prospective, randomized trial. Exclusion criteria were: alcoholism, previous gastric surgery, or intake of antibiotics, OME, bismuth salts, corticosteroids or NSAIDs within 4 weeks before study entry. Patients currently smoking > 10 cigarettes/day were classified as smokers. HP infection was confirmed by histology (3 biopsy specimens from gastric antrum and 2 from gastric body; H&E, Giemsa) and at least positive rapid urease test or culture. All 34 patients underwent ulcer therapy with OME (20 mg per day) for 20 days (d 1-20). Group A: in 17 patients (5 females, 12 males, mean age 46 [29-74] years; 8 smokers, 9 nonsmokers) the subsequent eradication therapy, consisting of oral OME (40 mg bid) and AMOX solute (750 mg tid) for 10 days, was combined with NAC solute (2 x 600 mg bid (d 21-30). Group B: 17 patients (2 females, 15 males, mean age 39 [19-70] years; 11 smokers, 6 nonsmokers) underwent eradication therapy without NAC (d 21-30). Control endoscopy was done after a minimal interval of 30 days from the end of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcysteine↗
PubMed1994

[Omeprazole/amoxicillin: impaired eradication of Helicobacter pylori in smoking but not in premedication with omeprazole].

The efficacy of high dose omeprazole/amoxicillin (OME/AMOX) for eradication of Helicobacter pylori (HP) is controversial. Reported eradication rates range from 0% to 90%. Different therapy schedules and unknown factors may be crucial; in particular, pretreatment with OME has been thought to endanger HP eradication by subsequent OME/AMOX. Preliminary findings suggested that smoking may impair eradication with OME/AMOX. The aims of this study were (1) to establish whether HP eradication rates differ depending on whether eradication with OME/AMOX was performed before or after ulcer therapy with OME, (2) to determine whether smoking impairs HP eradication by OME/AMOX and (3) to evaluate the efficacy of OME/AMOX in our population. 52 HP positive outpatients with endoscopically documented recurrent duodenal ulcer were included. Exclusion criteria were: alcoholism, previous gastric surgery, or intake of antibiotics, OME, bismuth salts, corticosteroids and NSAIDs within four weeks before study entry. Patients currently smoking > 10 cigarettes/day were classified as smokers. HP infection was confirmed by histology (3 biopsy specimens from the gastric antrum and 2 from the gastric body; H&E, Giemsa) and at least positive rapid urease test (CLO) or culture. Eradication therapy consisted of oral OME (40 mg bid) and AMOX solute (750 mg tid) for 10 days (OME/AMOX). This therapy preceded (group A) or followed (group B) ulcer therapy with OME (20 mg per day for 20 days). In group A 17 patients (2 females, 15 males, mean age 39 [19-70]; 11 smokers, 6 nonsmokers) underwent ulcer therapy with OME (d 1-20) before OME/AMOX d 21-30).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗