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Biomedical subjects

R Zbinden

Publications and source records attributed to R Zbinden.

At least 19 recordsLinked to original sources
PubMed2006

Central venous catheter infection with Brevibacterium sp. in an immunocompetent woman: case report and review of the literature.

Brevibacterium spp. were considered apathogenic until a few reports of infections in immunocompromised patients were published. Herein, we present a case of a catheter-related septicemia with Brevibacterium casei in an immunocompetent patient receiving continuous iloprost infusion for pulmonary arterial hypertension and review the clinical presentation of this mainly emerging opportunistic pathogen.

Actinomycetales Infections↗
PubMed2006

In vitro inhibition of coagulase-negative staphylococci by vancomycin/aminoglycoside-loaded cement spacers.

BACKGROUND: Successful treatment of allograft infections by the temporary implantation of an antibiotic-loaded polymethylmethacrylate cement spacer depends on the diffusion of antibiotics out of the cement and inhibition of bacterial growth in the surrounding tissue. We investigated with an in vitro model how long antibiotics are released by the cement and if gentamicin-resistant coagulase-negative staphylococci (CNS) are inhibited by vancomycin mixed with the gentamicin-loaded cement. MATERIALS AND METHODS: Four formulations of antibiotic-loaded cement disks, i.e. gentamicin, tobramycin, vancomycin and tobramycin combined with vancomycin, respectively, were used to test the inhibition of eight isolates of Staphylococcus epidermidis and two reference strains of Staphylococcus aureus by an agar diffusion test on Mueller-Hinton (MH) agar similar to the routine laboratory disk diffusion method. Moreover, cement spacer cylinders loaded with gentamicin alone or combined with vancomycin were submerged in MH agar for weeks and the capacity to inhibit five different isolates of S. epidermidis was measured. RESULTS: The size of the inhibition zones around the antibiotic-loaded cement disks correlated with the minimal inhibitory concentration (MIC) of the antibiotics against the tested strains. All five strains of S. epidermidis were inhibited by vancomycin-loaded cement spacers for at least 30 days. However, two gentamicin-resistant S. epidermidis strains with MICs of 4 mg/l and 16 mg/l could not be inhibited longer than 3 days by the gentamicin-loaded cement spacer. CONCLUSION: The in vitro data suggest that antibiotic-loaded cement spacers inhibit susceptible bacteria for 4-6 weeks. The addition of vancomycin to commercial aminoglycoside-loaded cements might be helpful in allograft infections in tumor patients to inhibit a broad range of bacteria including gentamicin-resistant CNS very commonly found in such infections.

Aminoglycosides↗
PubMed2006

[Risk of bacterial contamination after povidone-iodine disinfection for cataract surgery].

BACKGROUND: Povidone-iodine alone or in combination with antibiotics is commonly used for presurgical disinfection in cataract surgery. In spite of the use of the combination Povidone-iodine and ofloxacin, the rate of ocular contamination as assessed from surgical knives was reported to be as high as 26 %. The aim of this study was to investigate the efficacy of diluted Povidone-iodine alone for surgical disinfection. PATIENTS AND METHODS: 126 consecutive patients undergoing elective cataract surgery with a conjunctival wound and a scleral tunnel received prior to surgery a disinfection with diluted Povidone-iodine eye drops (Braunol 1:10 diluted = 0.8 % Povidone-iodine, 3 times every 5 min). To assess residual bacteria on the ocular surface after disinfection, the surgical knives for the side ports and the scleral tunnel were cultured in thioglycolate broth. RESULTS: In 8 out of 126 (6 %) patients the culture from the surgical knives revealed a positive result (89 % coagulase negative Staphylococci). Four of these 8 cases occurred during a single list. All control cultures remained negative. CONCLUSION: Diluted Povidone-iodine eye drops alone are highly effective for bacterial disinfection when applied properly. The rate of contamination using 0.8 % Povidone-iodine in our series was considerably lower as compared to that of other studies.

Adult↗
PubMed2006

16S rRNA gene sequencing versus the API 20 NE system and the VITEK 2 ID-GNB card for identification of nonfermenting Gram-negative bacteria in the clinical laboratory.

Over a period of 26 months, we have evaluated in a prospective fashion the use of 16S rRNA gene sequencing as a means of identifying clinically relevant isolates of nonfermenting gram-negative bacilli (non-Pseudomonas aeruginosa) in the microbiology laboratory. The study was designed to compare phenotypic with molecular identification. Results of molecular analyses were compared with two commercially available identification systems (API 20 NE, VITEK 2 fluorescent card; bioMérieux, Marcy l'Etoile, France). By 16S rRNA gene sequence analyses, 92% of the isolates were assigned to species level and 8% to genus level. Using API 20 NE, 54% of the isolates were assigned to species and 7% to genus level, and 39% of the isolates could not be discriminated at any taxonomic level. The respective numbers for VITEK 2 were 53%, 1%, and 46%, respectively. Fifteen percent and 43% of the isolates corresponded to species not included in the API 20 NE and VITEK 2 databases, respectively. We conclude that 16S rRNA gene sequencing is an effective means for the identification of clinically relevant nonfermenting gram-negative bacilli. Based on our experience, we propose an algorithm for proper identification of nonfermenting gram-negative bacilli in the diagnostic laboratory.

Bacterial Typing Techniques↗
PubMed2005

Cultural recovery and determination of antimicrobial susceptibility in Helicobacter pylori by using commercial transport and isolation media.

BACKGROUND: Antimicrobial resistance of Helicobacter pylori is the main reason for eradication failure. We have studied the feasibility of a commercial transport medium for cultural recovery and subsequent drug susceptibility testing. PATIENTS AND METHODS: From March to December 2000, 79 consecutive gastric biopsies, positive in a rapid urease test, were transferred into a commercial transport medium and sent within 24 hours from the district hospital to the microbiological laboratory for culture and susceptibility testing. A commercial agar plate and an in-house Wilkins-Chalgren agar plate were used for culture. Susceptibility data were compared with data collected from 1992 to 2003 in the University Hospital of Zurich. RESULTS: Cultural recovery and susceptibility testing of H. pylori was successful in 55 of 79 patients. In 17 cases cultural recovery failed because of technical problems (n = 14), long transport time (n = 1) and unknown reason (n = 2). Failure of susceptibility testing (n = 7) was mainly due to fungal overgrowth. Resistance to metronidazole and clarithromycin was found in 15 (27%) and in 12 patients (22%), respectively; resistance to amoxicillin was not observed. Five patients (9%) showed resistance both to metronidazole and to clarithromycin. Eradication therapy failed in all patients with macrolide resistance. Resistance rates were higher in females than in males; 30% vs 12% for clarithromycin and 33% vs 20% for metronidazole. Resistance to metronidazole was significantly lower in Swiss patients (15%) than in non-Swiss patients (39%). CONCLUSION: Antimicrobial resistance data can reliably be obtained by sending the biopsy specimen in a commercial transport medium to a microbiological laboratory. This is especially important after eradication failure. Resistance to metronidazole and clarithromycin is highly prevalent and more common in women and non-Swiss patients.

Amoxicillin↗
PubMed2005

Influence of diabetes mellitus on coronary collateral flow: an answer to an old controversy.

OBJECTIVES: To determine the influence of diabetes mellitus on coronary collateral flow by accurate means of collateral flow measurement in a large population with variable degrees of coronary artery disease. METHODS: 200 patients (mean (SD) age 64 (9) years; 100 diabetic and 100 non-diabetic) were enrolled in the study. Coronary collateral flow was assessed in 174 stenotic and in 26 angiographically normal vessels with a pressure guidewire (n = 131), Doppler guidewire (n = 36), or both (n = 33) to calculate pressure or flow velocity derived collateral flow index (CFI). Diabetic patients were perfectly matched with a non-diabetic control group for clinical, haemodynamic, and angiographic parameters. RESULTS: CFI did not differ between the diabetic and the non-diabetic patients (0.21 (0.12) v 0.19 (0.13), not significant). Likewise, CFI did not differ when only angiographically normal vessels (0.20 (0.09) v 0.15 (0.08), not significant) or chronic total coronary occlusions (0.30 (0.14) v 0.30 (0.17), not significant) were compared. Fewer patients in the diabetic group tended to have angina pectoris during the one minute vessel occlusion (60 diabetic v 69 non-diabetic patients, p = 0.15). CONCLUSION: Quantitatively measured coronary CFI did not differ between diabetic and non-diabetic patients with stable coronary artery disease.

Blood Flow Velocity↗
PubMed2004

Comparison of conventional and molecular methods for identification of aerobic catalase-negative gram-positive cocci in the clinical laboratory.

Over a period of 18 months we have evaluated the use of 16S ribosomal DNA (rDNA) sequence analysis as a means of identifying aerobic catalase-negative gram-positive cocci in the clinical laboratory. A total of 171 clinically relevant strains were studied. The results of molecular analyses were compared with those obtained with a commercially available phenotypic identification system (API 20 Strep system; bioMérieux sa, Marcy l'Etoile, France). Phenotypic characterization identified 67 (39%) isolates to the species level and 32 (19%) to the genus level. Seventy-two (42%) isolates could not be discriminated at any taxonomic level. In comparison, 16S rDNA sequencing identified 138 (81%) isolates to the species level and 33 (19%) to the genus level. For 42 of 67 isolates assigned to a species with the API 20 Strep system, molecular analyses yielded discrepant results. Upon further analysis it was concluded that among the 42 isolates with discrepant results, 16S rDNA sequencing was correct for 32 isolates, the phenotypic identification was correct for 2 isolates, and the results for 8 isolates remained unresolved. We conclude that 16S rDNA sequencing is an effective means for the identification of aerobic catalase-negative gram-positive cocci. With the exception of Streptococcus pneumoniae and beta-hemolytic streptococci, we propose the use of 16S rDNA sequence analysis if adequate species identification is of concern.

Aerobiosis↗
PubMed2003

[Diagnosis of chronic prostatitis: 4 or 2 glass sample?].

Chronic pelvic pain syndrome is still an important clinical problem. The NIH-prostatitis classification introduced 1998 for diagnosis and treatment measures is based on extended microbiological analysis of urine, expressed prostate secretion (4-glass test), and ejaculate. We investigated if a simple urine analysis of an urine sample before and after prostatic massage (2-glass test) could replace the 4-glass test. 143 patients with the diagnosis chronic prostatitis were included in this prospective study. The results showed that the expensive and time consuming 4-glass test can be replaced by a simple 2-glass test. Extended examinations should only be performed in special cases.

Adult↗
PubMed2003

[Four-glass or two glass test for chronic prostatitis].

Chronic pelvic pain syndrome is still an important clinical problem. The NIH prostatitis classification introduced in 1998 for diagnosis and treatment measures is based on extended microbiological analysis of urine and expressed prostate secretion (4-glass test). In 1997 J.C. Nickel proved that the culture and microscopic examination of urine before and after prostatic massage leads to the same results as the 4-glass test. In our prospective study on 143 patients with a diagnosis of chronic prostatitis, we analyzed this statement and came to the same results. We therefore recommend replacing the expensive and time-consuming 4-glass test by a simple preprostatic and postprostatic massage urine culture. Further examinations should only be performed in special cases.

Adult↗
PubMed2003

Ribosomal DNA sequencing for identification of aerobic gram-positive rods in the clinical laboratory (an 18-month evaluation).

We have evaluated over a period of 18 months the use of 16S ribosomal DNA (rDNA) sequence analysis as a means of identifying aerobic gram-positive rods in the clinical laboratory. Two collections of strains were studied: (i) 37 clinical strains of gram-positive rods well identified by phenotypic tests, and (ii) 136 clinical isolates difficult to identify by standard microbiological investigations, i.e., identification at the species level was impossible. Results of molecular analyses were compared with those of conventional phenotypic identification procedures. Good overall agreement between phenotypic and molecular identification procedures was found for the collection of 37 clinical strains well identified by conventional means. For the 136 clinical strains which were difficult to identify by standard microbiological investigations, phenotypic characterization identified 71 of 136 (52.2%) isolates at the genus level; 65 of 136 (47.8%) isolates could not be discriminated at any taxonomic level. In comparison, 16S rDNA sequencing identified 89 of 136 (65.4%) isolates at the species level, 43 of 136 (31.6%) isolates at the genus level, and 4 of 136 (2.9%) isolates at the family level. We conclude that (i) rDNA sequencing is an effective means for the identification of aerobic gram-positive rods which are difficult to identify by conventional techniques, and (ii) molecular identification procedures are not required for isolates well identified by phenotypic investigations.

Bacteria, Aerobic↗
PubMed2003

Immunological alterations in the ejaculate of chronic prostatitis patients: clues for autoimmunity.

The aim of this prospective study was to observe immunophenotypic patterns in the ejaculate of patients with noninflammatory chronic pelvic pain syndrome (Cat IIIB CPPS) and to test for a possible autoimmune aetiology. Thirty-five patients of a total of 88 patients with chronic prostatitis Cat IIIB were consecutively selected. Monthly ejaculate testing was carried out for IgG, IgA, IgM, IL-1alpha, sIL-2R and IL-6. The control group for ejaculate analysis was composed of 96 normal ejaculates (according to the WHO criteria). Immunohistochemical detection of CD3 cells (T lymphocytes) and CD20 cells (B lymphocytes) was performed in 71 biopsy cylinders of Cat IIIB CPPS patients and in 25 prostate biopsy cylinders of subjects without symptoms or obstruction. Intra-acinar T-lymphocytic infiltrates were dominated by T-cytotoxic cells (P = 0.05). Ejaculate IL-6 and ejaculate IgA increased significantly and dropped again, correlating with a release of clinical symptoms. Inflammatory ejaculate interleukin concentrations correlated with the immunohistochemical findings with presence of large numbers of T cells (all P-values < or = 0.01). Immunomodulation was performed in a pilot series of three patients by five monthly cycles of IgG (Sandoglobulin), 1 g kg-1 body weight. Immunomodulation with IgG decreased pain moderately and did not change ejaculate interleukin and immunoglobulin concentrations. In summary, interleukin and immunoglobulin determinations in the ejaculate revealed an inflammatory process even in Cat IIIB CPPS. The findings of intra-acinar T-cell rich infiltrates and the associated inflammatory reaction may indicate a possible autoimmune component in the aetiology of CPPS. Exact origin and role of interleukin changes in the ejaculate of CPPS patients need to be further evaluated. Unfortunately, pilot series with immunomodulation with IgG do not seem to provide clear clinical benefit.

Adult↗
PubMed2002

Molecular epidemiology of predominant clones and sporadic strains of methicillin resistant Staphylococcus aureus in Switzerland and comparison with European epidemic clones.

OBJECTIVE: To assess the molecular epidemiology and risk factors of predominant clones and sporadic strains of methicillin-resistant Staphylococcus aureus (MRSA) in Swiss hospitals and to compare them with European strains of epidemic clones. MATERIAL AND METHODS: One-year national survey of MRSA cases. Analysis of epidemiological and molecular typing data (PFGE) of MRSA strains. RESULTS: In 1997, 385 cases of MRSA were recorded in the five Swiss university hospitals and in 47 community hospitals. Half of the cases were found in Geneva hospitals where MRSA was already known to be endemic. Molecular typing of 288 isolates (one per case) showed that 186 (65%) belong to four predominant clones, three of which were mostly present in Geneva hospitals. In contrast, the fourth clone (85 cases) was found in 23 hospitals (in one to 16 cases per hospital). The remaining 35% of the strains were clustered into 62 pulsed field gel electrophoresis types. They accounted for one to five patients per hospital and were defined as sporadic. Multivariate analysis revealed no independent risk factors for harboring a predominant versus a sporadic strain, except that transfer from a foreign hospital increases the risk of harboring a sporadic strain (OR, 42; 95% CI, 5-360). CONCLUSION: While cases with predominant clones were due to the local spread of these clones, most sporadic cases appear to be due to the continuous introduction of new strains into the country. With the exception of a transfer from a hospital outside Switzerland, no difference in the clinical or epidemiological characteristics was observed between patients harboring a predominant clone and those with a sporadic strain.

Anti-Bacterial Agents↗
PubMed2002

In vitro activities of BAL9141, a novel broad-spectrum pyrrolidinone cephalosporin, against gram-negative nonfermenters.

The activities of BAL9141 (formerly Ro 63-9141), a novel pyrrolidinone-3-ylidenemethyl cephalosporin, against 244 strains of gram-negative nonfermenters were evaluated. The overall MIC at which 50% of isolates are inhibited (MIC50) and the overall MIC90 were 2 and 64 microg/ml, respectively, which are similar to those of imipenem, lower than those of the other cephalosporins tested, amoxicillin, and the ticarcillin-clavulanic acid combination, and much higher than those of ciprofloxacin. BAL9141 shows species-dependent activity in vitro against a variety of gram-negative nonfermentative pathogens.

Cephalosporins↗