Summary auto-generated
This study evaluated how five different catheter materials affect bacterial adherence and viability using clinical isolates of Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, and Escherichia coli. Radiolabeled bacteria were incubated with catheter segments over 72 hours to measure adherence, while catheter eluates were tested for effects on bacterial growth. Results showed that PVC and siliconized latex catheters supported significantly higher bacterial adherence (2-6 times greater) compared to Teflon, polyurethane, and Vialon for all strains tested. P. aeruginosa reached maximum adherence after 24 hours, while other organisms peaked at 72 hours. Regarding viability, catheter eluates did not affect staphylococcal growth, but significantly promoted E. coli and P. aeruginosa growth from most materials, except siliconized latex eluate which killed E. coli. The findings suggest that catheter biomaterial composition influences bacterial colonization and that substances eluted from catheters may differentially affect microbial survival, highlighting the importance of evaluating new catheter materials before clinical use.
Key findings
- PVC and siliconized latex catheters demonstrated 2-6 times higher bacterial adherence compared to Teflon, polyurethane, and Vialon for all four bacterial species tested
- P. aeruginosa achieved maximal adherence within 24 hours while S. aureus, S. epidermidis, and E. coli required 72 hours to reach peak adherence levels
- Catheter eluates stimulated growth of gram-negative bacteria (E. coli and P. aeruginosa) but had no significant effect on staphylococcal growth, and siliconized latex eluate was bactericidal for E. coli
- Bacterial adherence patterns differed by both organism and catheter material, with lowest adherence observed on polyurethane/Vialon for staphylococci and Teflon for gram-negative bacteria
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Abstract
The kinetics of adherence of single isolates of Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa and Escherichia coli to catheters made of polyvinyl chloride (PVC), Teflon, siliconised latex, polyurethane and Vialon was evaluated by a radiometric assay. Radiolabelled bacteria (10(8) cfu/ml) were incubated in vials containing 1-cm lengths of catheter for up to 3 days. The peak of maximal adherence to each biomaterial was reached after 24 h for P. aeruginosa and after 72 h for the other strains. Bacterial adherence to PVC and siliconised latex was significantly higher (2-6 times; p less than 0.05) than to the other biomaterials for all the strains. The lowest values of adherence were observed with polyurethane and Vialon for the staphylococci but with Teflon for E. coli and P. aeruginosa. Bacterial viability and growth was evaluated in eluates obtained from incubation of segments of each catheter in buffer for 24 h. None of the eluates affected the viability of the staphylococci. However, all of them, significantly increased the growth of E. coli and P. aeruginosa with the exception of the eluate from siliconised latex, in which the inoculum count was reduced to an undetectable level for E. coli. We conclude that bacterial adherence to catheters may depend in part on the nature of the biomaterial and that certain substances eluted from the catheters may affect the viability and growth of different micro-organisms.