Plastic stems placed for biliary drainage are at risk of blockage by bacterial biofilm. Recent data suggested that prophylactic antibiotic therapy is effective in prolonging stent patency. In vitro study demonstrated ciprofloxacin reduces adherence of E. coli. This study determines the long term benefit of ciprofloxacin in prevention of stent blockage. Methods: a clinical strain of E. coli isolated from blocked stents was used. The bacteria was cultured in Ox bile to achieve a steady growth (106 colony forming unit/ml) before being perfused through a Modified Robins Device (MRD) to determine its adherence to polyethylene stents mounted on the MRD. Two sets of MRDs were perfused with bile from the same reservoir. Using side arm attachments, ciprofloxacin was infused into one MRD to achieve a final concentration of 4 ug/ml after mixing with bile. To the other MRD, normal saline was infused at the same volume to achieve a similar dilution. The experiments were continued up to 30 days. The stent pieces were recovered on day 1,2,3 and then weekly and processed for bacterial culture and electron microscopy. The amount of bacteria recovered was expressed as CFU/sq. cm. Results: In the control group bacterial count reached 105, whereas the ciprofloxacin group showed a bacterial count of only 101. There was no significant changes in the concentration of bacteria in the effluent. Number of bacteria adhered to stents: Day Control (CFU/sq.cm) Antibiotic (CPU sq.cm) 1 0 0 2 0 0 3 7.0 × 103 0 8 3.4 × 104 0 14 7.6 × 105 11 22 7.1 × 105 60 30 2.5 × 105 50 Conclusion: Compared to control, ciprofloxacin treatment resulted in a significant reduction in bacterial adherence and biofilm formation. This long term study confirms the findings of previous in vitro study and suggests that an appropriate antibiotic at a suitable concentration is effective in preventing stent blockage. It remains to be confirmed what is the optimal antibiotic and treatment regime in a randomized clinical study.
|Original language||English (US)|
|Number of pages||1|
|State||Published - 1996|
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