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Bacterial aggregation in relation to peritoneal dialysis
G Reid1, S Schwarz-Faulkner, J A McGroarty
1Department of Surgery, University of Toronto, Ontario, Canada.
Abstract:
The ability of gram-positive cocci to aggregate and form biofilms at the exit site and on catheter surfaces in continuous ambulatory peritoneal dialysis (CAPD) has been associated with peritonitis. In the present study, 16 (80%) of 20 dialysate effluents from patients with staphylococcal peritonitis were found to contain aggregates of Staphylococcus epidermidis or S. aureus. Using an in vitro assay system, 20 (83%) of 24 pathogenic bacterial strains were found to aggregate in fresh dialysis solutions within 4 to 24 h at 37 degrees C. Further studies with one strain, S. epidermidis 1938, showed increased aggregation when the bacteria were incubated in dialysate effluents compared to fresh dialysis solutions. Viability experiments showed that aggregated bacteria were less sensitive to the killing effects of fresh dialysis solutions and that dialysate effluents could support bacterial growth. The results suggest that attention be paid to aggregation as a potential mechanism used by bacteria in causation of peritonitis.
Insights
Gram-positive bacteria aggregate in peritoneal dialysis fluids, forming biofilms linked to peritonitis. These aggregated bacteria are more resistant to killing, suggesting aggregation is a key factor in causing infection.
Area of Science:
- Microbiology
- Nephrology
- Infectious Diseases
Background:
- Gram-positive cocci aggregation and biofilm formation are linked to peritonitis in continuous ambulatory peritoneal dialysis (CAPD).
- Understanding bacterial behavior in dialysis environments is crucial for preventing infection.
Purpose of the Study:
- To investigate the aggregation of Staphylococcus species in dialysis solutions.
- To assess the role of bacterial aggregation in the pathogenesis of CAPD peritonitis.
Main Methods:
- Analysis of dialysate effluents from CAPD patients with staphylococcal peritonitis.
- In vitro aggregation assays using pathogenic bacterial strains in fresh dialysis solutions and dialysate effluents.
- Viability experiments to assess bacterial sensitivity to dialysis solutions.
Main Results:
- Aggregates of Staphylococcus epidermidis or S. aureus were found in 80% of dialysate effluents from patients with peritonitis.
- 83% of pathogenic bacterial strains aggregated in vitro within 4-24 hours in dialysis solutions.
- Bacterial aggregation was enhanced in dialysate effluents compared to fresh solutions, and aggregated bacteria showed reduced sensitivity to killing effects.
Conclusions:
- Bacterial aggregation is a significant factor in the development of CAPD peritonitis.
- Dialysate effluents can support bacterial growth and promote aggregation, contributing to infection.
- Targeting bacterial aggregation may offer a novel strategy for peritonitis prevention in CAPD patients.