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Biomedical subjects

A F Widmer

Publications and source records attributed to A F Widmer.

10 recordsLinked to original sources
PubMed1992

A new standard for sterility testing for autoclaved surgical trays.

Sterility testing on autoclaved surgical trays provides scientific information on the duration for which an item can be safely stored. Previous studies were performed by sampling at various time-points after storage and did not take into account potential injuries (moving, lifting etc.) to these trays as they occur in a clinical setting. A standardized protocol was developed by an expert panel based on events which were frequently observed in the Central Sterilization area. We tested 600 samples in 100 surgical trays that were moved and transported according to the standardized protocol. Moved surgical trays were contaminated in 8.3% of tests, a figure much higher than that reported by previous studies. These data suggest that current standards for sterility testing of autoclaved surgical trays can be improved by the addition of event-related testing.

Central Supply, Hospital↗
PubMed1992

Antimicrobial treatment of orthopedic implant-related infections with rifampin combinations.

The purpose of this prospective clinical study is to evaluate the role of combination chemotherapy with rifampin in the treatment of orthopedic device-related infections in which the implant could not be removed. Eleven patients with orthopedic implant-related infections due to staphylococci or streptococci were treated with the implant in situ. Each antimicrobial regimen included rifampin in combination with a beta-lactam antibiotic or ciprofloxacin. The median duration of treatment with rifampin was 86 days (range, 15-336 days) with a median follow-up of greater than 24 months after cessation of therapy. Treatment was successful for 82% of patients. Failures were associated with documented inappropriate treatment. These preliminary clinical data are supported by data from in vitro studies and animal experiments. Combination therapy with rifampin, in particular rifampin and a quinolone, should be considered for patients with orthopedic implant-related infections if the implant cannot be removed.

Adult↗
PubMed1992

The clinical impact of culturing central venous catheters. A prospective study.

The semiquantitative culture technique is a standard procedure for the laboratory diagnosis of catheter-associated infections and catheter-associated bacteremia. In a prospective observational study, we evaluated the clinical impact of the semiquantitative culture results on the treatment of the patient. Clinical impact was defined as a change in diagnosis or therapy on the basis of the semiquantitative culture result. One hundred fifty-seven catheters consecutively submitted from the surgical intensive care unit to the laboratory were studied. In 96% of the episodes, no clinical impact was observed. In the other 4%, clinical decisions were guided mainly by the concurrent positive blood cultures. Newer laboratory techniques that do not require removal of the catheter are needed to guide therapeutic decisions.

Anti-Bacterial Agents↗
PubMed1991

Amebiasis.

Explore the source record for details and available documents.

Amebicides↗
PubMed1991

Killing of nongrowing and adherent Escherichia coli determines drug efficacy in device-related infections.

Antimicrobial therapy of device-related infections often fails, despite the in vitro susceptibility of the infecting strain. Therefore, alternative laboratory-based in vitro tests are required to predict the outcome. Fleroxacin, ciprofloxacin, aztreonam, and co-trimoxazole were tested against Escherichia coli ATCC 25922 in vitro and in the tissue-cage animal model. The importance of early treatment was evaluated by starting the drugs either 30 min before or 4, 12, and 24 h after bacterial challenge. Results were compared with the in vitro drug efficacy against nongrowing and adherent Escherichia coli ATCC 25922. The alternative in vitro tests correlated highly with the outcome in the tissue-cage animal model. In the prophylaxis group (drug given 30 min before bacterial challenge), co-trimoxazole was less efficacious than the other three drugs (P less than 0.001). In delayed treatment, ciprofloxacin showed the highest cure rate. It was also more potent than the other drugs against nongrowing and adherent E. coli ATCC 25922. The efficacies of aztreonan, fleroxacin, and ciprofloxacin dropped significantly (P less than 0.01) when the time interval between bacterial challenge and the start of treatment was delayed to greater than 4 h. These data emphasize (i) the need for proper timing of prophylaxis in patients undergoing implant surgery, and (ii) the possibility of successful treatment of established device-related infections with drugs which kill not only growing but also nongrowing and adherent bacteria.

Animals↗
PubMed1990

Correlation between in vivo and in vitro efficacy of antimicrobial agents against foreign body infections.

Implant-associated infections are often resistant to antibiotic therapy. Routine sensitivity tests fail to predict therapeutic success. Therefore experimental in vitro tests were sought that would better correlate with drug efficacy in device-related infections. The activity of six different antibiotics against methicillin-resistant Staphylococcus epidermidis was investigated. In vivo studies were performed with the guinea pig tissue-cage animal model; in vitro studies with minimum inhibiting and bactericidal concentrations, time-kill studies of growing and stationary-phase microorganisms, the killing of glass-adherent S. epidermidis. Drug efficacy on stationary and adherent microorganisms, but not minimum inhibiting concentrations, predicted the outcome of device-related infections. Rifampin cured 12 of 12 infections and was also the most efficient drug in any experimental in vitro test. Similarly, the failure of ciprofloxacin to eradicate foreign body infections correlated with its low efficacy on stationary-phase and adherent S. epidermidis.

Animals↗
PubMed1990

Salmonella infection in total hip replacement: tests to predict the outcome of antimicrobial therapy.

We report a hematogenous implant infection with Salmonella dublin in a renal transplant patient with total hip replacement. A 16-month treatment with cotrimoxazole failed, as evidenced by culture and electron microscopy, despite persisting low MIC after therapy. Data from a foreign body animal model and in vitro tests, which take into account the properties of adhering and stationary-phase bacteria, explain the failure of a long-term treatment with cotrimoxazole. The patient was subsequently cured by ciprofloxacin which was successful in these tests. No relapse was noted after a follow-up of 1 year.

Adult↗