Biomedical subjects

R Frei

Publications and source records attributed to R Frei.

At least 55 records · Page 3Linked to original sources

PubMed1998

Corynebacterium confusum sp. nov., isolated from human clinical specimens.

Three strains of a previously unknown coryneform bacterium were isolated from two patients with foot infections and from a blood culture of a third patient. The three non-lipophilic strains exhibited very slow fermentative acid production from glucose but not from maltose or sucrose, nitrate reductase activity, no tyrosinase activity and the presence of small amounts of tuberculostearic acid as the most significant phenotypic features. Differentiation of these strains from all other presently defined coryneform bacteria was readily achieved. Chemotaxonomic investigations revealed that the three strains unambiguously belonged to the genus Corynebacterium. Comparative 16S rRNA gene sequence analysis demonstrated that the isolates were almost identical and represented a new subline within the genus Corynebacterium, for which the designation Corynebacterium confusum sp. nov. is proposed. The type strain of Corynebacterium confusum is CCUG 38267T.

Abscess↗

PubMed1998

Characterization of glycopeptide-resistant enterococci from a Swiss hospital.

Between August 1994 and September 1996, 28 glycopeptide-resistant enterococci (GRE) were isolated from 8 infected patients and 11 intestinal carriers hospitalized at the University Hospital of Geneva. Identification to the species was made by both phenotypic (API 20 STREP and Rapid ID 32 STREP systems, and Vitek Gram Positive Identification Card) and genotypic methods using a multiplex PCR assay developed also for the determination of the genotype of glycopeptide resistance (vanA, vanB, vanC1, and vanC2-C3 genes). Fifteen isolates were identified as Enterococcus faecium, 8 as E. gallinarum, 4 as E. faecalis, and 1 as E. hirae. All of the phenotypic identification methods failed to differentiate some isolates of E. gallinarum from E. faecium, or vice versa. Both vanA (n = 18) and vanB (n = 4) glycopeptide resistance genotypes were found. For the first time, the vanB determinant was found in two isolates of E. gallinarum. Two patients were colonized by two different species containing the vanA gene and one by two different species containing the vanB gene. All vanA isolates were highly resistant to both vancomycin and teicoplanin except for three isolates which were susceptible to teicoplanin. Molecular typing by pulsed-field gel electrophoresis showed identical or similar patterns among E. faecium isolates with the vanA gene in five patients for whom the epidemiological link could not be always elucidated. This study emphasizes the necessity of utilizing both phenotypic and genotypic methods to characterize GRE.

Anti-Bacterial Agents↗

PubMed1997

Heterozygous peripheral myelin protein 22-deficient mice are affected by a progressive demyelinating tomaculous neuropathy.

Hereditary neuropathy with liability to pressure palsy (HNPP) is associated with a heterozygous 1.5 megabase deletion on chromosome 17 that includes the peripheral myelin protein (PMP) gene PMP22. We show that heterozygous PMP22 knock-out mice, which carry only one functional pmp22 allele and thus genetically mimic HNPP closely, display similar morphological and electrophysiological features as observed in HNPP nerves. As reported previously, focal hypermyelinating structures called tomacula, the pathological hallmarks of HNPP, develop progressively in young PMP22(+/0) mice. By following the fate of tomacula during aging, we demonstrate now that these mutant animals are also interesting models for examining HNPP disease mechanisms. Subtle electrophysiological abnormalities are detected in PMP22(+/0) mice >1 year old, and a significant number of abnormally swollen and degenerating tomacula are present. Thinly myelinated axons and supernumerary Schwann cells forming onion bulbs as fingerprints of repeated cycles of demyelination and remyelination are also encountered frequently. Quantitative analyses using electron microscopy on cross sections and light microscopy on single teased nerve fibers suggest that tomacula are intrinsically unstable structures that are prone to degeneration; however, the severity of morphological and electrophysiological abnormalities in PMP22(+/0) mice is variable. These combined findings are reminiscent of the disease progression in HNPP and offer a possible explanation about why some HNPP patients develop a chronic motor and sensory neuropathy later in life that resembles demyelinating forms of Charcot-Marie-Tooth disease by both morphological and clinical criteria.

Aging↗

PubMed1997

[Inter- and intrahospital transmission of methicillin-resistant Staphylococcus aureus].

Occurrence and spread of methicillin-resistant Staphylococcus aureus (MRSA) has become a major problem worldwide. The majority of hospitals in Switzerland have not so far been affected by this epidemic. We report two out-breaks of MRSA transmission in the surgical intensive care unit at the University Hospital of Geneva and show the possible inter- and intrahospital dissemination of MRSA. Evidence for cross-infection is confirmed by epidemiological investigation and molecular typing. Infection control measures and general precautions are necessary to halt further spread of MRSA.

Adult↗

PubMed1997

Low risk of bacteremia during catheter replacement in patients with long-term urinary catheters.

BACKGROUND: Geriatric patients with long-term urinary catheters have an increased morbidity and mortality. It is conceivable that catheter replacement causes bacteremia and contributes to this morbidity and mortality. The purpose of our study was to determine the incidence and clinical relevance of bacteremia induced by urinary catheter replacements. METHODS: We analyzed clinical signs and symptoms and laboratory measures (leukocyte count, C-reactive protein, urine sediment, urine culture) during 120 routine catheter replacements in geriatric patients. In addition, blood cultures were drawn before and at 5, 15, and 30 minutes after catheter replacement. RESULTS: The urine cultures showed growth of 1 to 5 different microorganisms before replacement. Of 480 blood cultures, 27 (5.6%) were positive. However, the same species grew from blood and urine in only 5 catheter replacements. None of the patients met criteria for systemic inflammatory response syndrome. There were no significant differences in clinical and laboratory findings between patients with and without bacteremia. Coagulase-negative staphylococci grew in 12 blood cultures. Their distribution over time suggested that they mainly represented catheter replacement-related bacteremia rather than contaminants. Consequently, 64 intraurethral catheter segments were additionally cultured. Coagulase-negative staphylococci grew in 10 catheter cultures, but in only 2 simultaneously cultured urine samples. CONCLUSION: Bacteremia induced by routine replacement of long-term urinary catheters occurred in 4.2% (5/120) of replacements in geriatric patients. Such bacteremia did not have a detectable clinical relevance in our study.

Aged↗

PubMed1997

[Endoscopic contamination with Mycobacterium tuberculosis].

A 60-year-old woman who had been investigated and treated unsuccessfully for chronic cough was referred for a bronchoscopy. The cultures of bronchial aspirates were positive for Mycobacterium tuberculosis. The radiological and endobronchial findings were typical of chronic bronchitis, but in the light of the positive cultures endobronchial tuberculosis was diagnosed and the patient was started on a standard 3-drug regimen. She developed a classical hypersensitivity reaction to isoniazid. Later the diagnosis had to be revised when molecular typing demonstrated contamination.

Antitubercular Agents↗

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

Outbreak of invasive mycoses caused by Paecilomyces lilacinus from a contaminated skin lotion.

BACKGROUND: Invasive mycoses are an important cause of illness and death in immunocompromised patients. Infections with molds other than aspergilli have been increasingly seen in patients with hematologic cancers, but epidemics of these infections have not yet been reported. OBJECTIVE: To describe an outbreak of invasive mycoses with Paecilomyces lilacinus in severely neutropenic patients. DESIGN: An outbreak investigation. SETTING: The hematology-oncology isolation and bone marrow transplantation unit of the University Hospital, Basel, Switzerland. PATIENTS: 25 consecutive patients admitted between 17 August 1993 (the date of the first manifestation of P. lilacinus infection) and 31 October 1993 (when the unit was closed). MEASUREMENTS: Clinical and microbiological data, including histologic findings; cultures from several patient sites; and environmental examinations of potential airborne, parenteral, enteric, and horizontal routes of transmission. Infections were defined by the isolation of P. lilacinus from clinically evident skin eruptions. RESULTS: 12 of the 25 patients (48%) were infected or colonized. Nine patients (36%), including all bone marrow transplant recipients, had documented invasive P. lilacinus infections. All 9 infected patients had papular, pustular, or necrotic skin eruptions. Two patients with severe graft-versus-host disease died with refractory fungal disease; 1 also had microbiologically documented endophthalmitis and kidney infiltrates. Seven affected patients no longer had P. lilacinus after recovery of bone marrow function. The organism was resistant in vitro to amphotericin B, itraconazole, and fluconazole. Patients did not respond clinically to these agents. The outbreak was ultimately traced to a contaminated, commercially available, pharmaceutically prepared skin lotion. The outbreak ended after the skin lotion was recalled and has not recurred after a follow-up period of 2 years. CONCLUSION: Contaminated skin lotion is a potential cause of opportunistic fungal infections in immunocompromised hosts. Paecilomyces lilacinus is a common saprophytic mold that can cause, by direct cutaneous inoculation, invasive infections associated with illness and death.

Adolescent↗

PubMed1996

[Clinical aspects and prognosis of candidemia, a 6-year retrospective study].

In recent decades an increase in the incidence of fungal infection has been reported. We retrospectively analyzed 41 patients with candidemia seen at Basel University Hospital over a six-year period. 1.2-6.7 candidemias per 10000 admissions were observed. In contrast to other studies, there was no increase during the study period. Out of 41 patients, 19 were hospitalized in ICUs. All patients had risk factors such as intravascular catheters (92.7%), antibiotic therapy (88%), immunosuppressive therapy (31%), indwelling Foley catheters (54%) and previous surgery (63%). The most frequent symptoms were fever with rigor, tachycardia and hypotension. The isolates were Candida albicans (n = 28), Torulopsis glabrata (n = 5), C. krusei (n = 3), C. parapsilosis (n = 2), C. guilliermondii, C. kefyr and C. lusitaniae (n = 1 each). In 22 patients, candida colonization had been documented and 5 patients had superficial mucocutaneous candidiasis before candidemia. The initial foci were the gastrointestinal tract (n = 13), an intravascular catheter (n = 8), the urinary tract (n = 5), the respiratory tract, or intravenous drug use (n = 3 each). Out of 32 patients who were treated either with amphotericin B or fluconazole, 13 died. 5 of the untreated patients died, in 3 instances before microbiological diagnosis. The mortality was similar for treatment with amphotericin B and with fluconazole (50% vs. 33%) (p = 0.3).

Adult↗

PubMed1996

Oral fleroxacin prophylaxis in transurethral surgery.

PURPOSE: A prospective trial was done to test the efficacy of antimicrobial prophylaxis in patients undergoing transurethral surgery. MATERIALS AND METHODS: A total of 75 adults with preoperatively sterile urine was randomized to receive either 400 mg. oral fleroxacin once daily or placebo as long as the catheter was in place. Urine cultures were obtained preoperatively and after removal of the catheter just before hospital discharge. Growth of 10(4)/ml. or more bacteria was considered a positive urine culture. RESULTS: Postoperative urinary tract infection rates were significantly lower in the fleroxacin group (3%) than in the placebo group (23%). Our study demonstrated the benefit of antimicrobial prophylaxis in preventing urinary tract infection after transurethral surgery, including resection of the prostate, in patients with sterile urine. CONCLUSIONS: The oral administration of 1 daily tablet of fleroxacin for the duration of catheterization is a safe, efficacious and clinically feasible regimen.

Administration, Oral↗

PubMed1996

[Reliability of the rapid Streptococcus A test].

The results of three second-generation immune assays for direct detection of group A streptococcus were compared in 65 patients with acute pharyngitis. The assays included Strep A Plus, (Abbott), Concise Strep A (Hybritech) and Cards Plus (Pacific Biotech). A standard culture was used as reference. Additionally a nucleic acid hybridization assay (Gen-Probe) was applied after enhanced broth culturing. The sensitivities and specificities of the three immunoassays were similar and showed that Strep A Plus had an 84.2% sensitivity and 88.9% specificity, Concise Strep A an 82.4% sensitivity and 92.3% specificity, and Cards Plus an 84.2% specificity and 90.7% sensitivity. The Concise Strep A had significantly more doubtful results in comparison with the two other rapid immune assays (9.7% versus 2.3%, P = 0.034. The standard culture and the DNA probe test gave the same results in 94% of cases. Clinical parameters were found to be unreliable for the diagnosis of group A streptococcal pharyngitis. However, findings show that when the rapid immune assay is positive, it is reasonable to start antibiotic treatment without performing a bacterial culture. In cases with a negative assay, management is best tailored to clinical symptoms and laboratory examinations.

Adolescent↗

PubMed1995

[Dysphagia, cavernous changes of the lungs and subarachnoid hemorrhage following kidney transplantation].

A 54-year-old patient with polycystic kidney disease developed relapsing urinary-tract infections after renal transplantation. In the post-transplantation period he underwent two rejection episodes. The general condition worsened without obvious reason. Six months after transplantation the patient was hospitalized due to gram-negative sepsis. Despite adequate antimicrobial treatment he continued to lose weight and complained of dysphagia. Chest X-ray and computer tomogram of the thorax showed multiple cavitating infiltrations of the lung. A few days later the patient died from an extended subarachnoidal hemorrhage.

Deglutition Disorders↗

PubMed1995

[Septic abortion in Campylobacter jejuni infection].

Case report of a 24 year old woman II G/I P with enterocolitis and septicaemia caused by Campylobacter jejuni (C.) in the following time abortion at 16 weeks of gestation. Diagnostics, therapy, review of literature.

Abortion, Septic↗

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

[Therapy of infectious endocarditis].

The response of infective endocarditis to antimicrobial therapy is slow because host defence mechanisms in heart valves are absent, high bacterial densities occur in vegetations and the infecting agents have a low metabolic activity. In this situation, only an optimal antibiotic treatment can be effective; therefore early identification of the microorganism by means of blood cultures and the use of bactericidal antibiotics with proven efficacy in clinical trials are essential. The antibiotics should be administered intravenously, because constant and high serum levels are important. The choice of the empirical therapy is based on the patient's history, on clinical signs and symptoms as well as on some additional examinations in order to define the most probable organisms involved. As soon as the infecting agent is identified, the treatment should be optimized. A daily clinical examination of the patient and frequent laboratory controls are needed. In case of poor clinical response to the antimicrobial therapy, the search for complications is frequently more appropriate than changing the antibiotics. The duration of therapy depends on the infecting agent, the evolution and the antibiotic regimen that has been chosen. After treatment, blood cultures should be taken at four and eight weeks, since most relapses appear within this period.

Anti-Bacterial Agents↗

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

[Helicobacter pylori resistance against metronidazole in Switzerland: implications for eradication therapy?].

Gastroduodenal ulcers are strongly associated with Helicobacter pylori (HP) infection. Successful eradication drastically diminishes ulcer recurrence. Most of the eradication schemes include metronidazole (Flagyl). The present study was designed to establish the metronidazole resistance rate in Switzerland. Antral biopsies were taken in 153 patients with suspected ulcers (115 men, 38 women, mean age 46 +/- 16 [SD] years) during upper endoscopy for bacteriological testing. Metronidazole resistance (> 8 micrograms/ml) was found in 47/153 (31%) of the isolates. Resistance was found in no case to amoxicillin (Clamoxyl) (0/104 = 0%) and only in 3% (2/66) to clarithromycin (Klazid). Metronidazole resistance of HP in a third of the isolates studied is comparable to numbers found in other European countries. These findings raise the question whether eradication schemes including metronidazole without prior sensitivity testing are justified. Amoxicillin and clarithromycin appear to be valid alternatives.

Adult↗

PubMed1994

Use of capillary affinity electrophoresis for the determination of lectin-sugar interactions.

Capillary affinity electrophoresis was used to study the interactions of lectins from Tetragonolobus purpuras with L-(-)-fucose 1-phosphate. The electrophoretic mobilities of three lectin peaks were influenced by the complexation with the negatively charged fucose derivative. A model that allows the calculation of the complex formation constant from the change in mobility at different concentrations of fucose 1-phosphate has been derived. Calcium ions added to the buffer solution promoted the complex formation of the three lectins. This technique required only minute amounts of the lectins and enabled the simultaneous study of the complex formation of several proteins.

Calcium↗