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Long-lasting contamination of a vitrectomy apparatus with Serratia marcescens
I Kappstein1, C M Schneider, H Grundmann
1Institute of Environmental Medicine and Hospital Epidemiology, University Hospital, Freiburg, Germany.
Objective:
To investigate the contamination of a vitrectomy apparatus with Serratia marcescens.
Design:
Descriptive microbiological and molecular environmental study.
Setting:
An 1,800-bed university hospital.
Results:
S. marcescens was found inside the vitrectomy apparatus at the pressure transducer. Molecular typing by randomly amplified polymorphic DNA-automated laser fluorescence analysis and pulsed-field gel electrophoresis identified a single pattern for all strains isolated from the apparatus. Surprisingly, the contaminating strain was identical to two strains of S. marcescens isolated nearly 2 years earlier from two patients who were involved in a small outbreak of acute postoperative endophthalmitis following cataract surgery at another hospital. The emergency vitrectomies in these patients were performed at our hospital with the same apparatus that was found to be contaminated 2 years later.
Conclusion:
Performing a systematic environmental search for the assumed bacterial reservoir within the system of the vitrectomy apparatus finally made it possible to find and eliminate the nidus for the gram-negative rod. Molecular typing demonstrated that all isolates belonged to a single genotype, and revealed unexpectedly a link to two vitrectomies performed 2 years earlier. The data support the hypothesis that the source of the contamination was one of these patients, and thus contamination of the apparatus was present for almost 2 years.
Insights
A vitrectomy apparatus was contaminated with Serratia marcescens for nearly two years. This gram-negative rod was found at the pressure transducer, linked to prior patient surgeries.
Area of Science:
- Ophthalmology
- Microbiology
- Infection Control
Background:
- Vitrectomy apparatus can harbor microorganisms.
- Serratia marcescens is an opportunistic pathogen.
- Postoperative endophthalmitis is a serious complication of eye surgery.
Purpose of the Study:
- To identify the source and extent of Serratia marcescens contamination in a vitrectomy apparatus.
- To investigate the persistence of bacterial contamination in surgical equipment.
Main Methods:
- Descriptive microbiological and molecular environmental study.
- Isolation and identification of bacteria from the vitrectomy apparatus.
- Molecular typing (randomly amplified polymorphic DNA-automated laser fluorescence analysis and pulsed-field gel electrophoresis) of Serratia marcescens strains.
Main Results:
- Serratia marcescens was identified within the vitrectomy apparatus at the pressure transducer.
- Molecular typing revealed a single genotype for all isolated strains.
- The contaminating strain was identical to strains isolated from patients nearly two years prior, linked to previous surgeries with the same apparatus.
Conclusions:
- A systematic environmental search identified and eliminated the bacterial reservoir within the vitrectomy apparatus.
- Molecular data confirmed a single source of contamination and a long-term presence (nearly two years).
- The findings suggest a patient undergoing vitrectomy was the likely source of the persistent contamination.