Bacteriophage antimicrobial-lock technique for staphylococcus aureus central venous catheter-related infection: an in-vivo evaluation

Abstract

Purpose Bacteriophages are viruses that selectively infect and kill bacteria. The purpose of this project was to determine whether a bacteriophage antimicrobial lock technique can reduce bacterial colonization and biofilm formation on indwelling central venous catheters in a rabbit model. Materials and Methods This study was performed in 10 female New Zealand white rabbits (weight range 3-4 kg). Broviac catheters (4.2 French, BARD access systems, NJ) were inserted into the jugular vein under image guidance and tunneled in an intrascapular position. Catheters were then inoculated for 24h with broth culture of Methicillin sensitive staphylococcus aureus (0.5 McFarland standard). The inoculate was aspirated and rabbits were randomized into two equal groups for 24h: (i) untreated controls (heparinized saline lock), (ii) Bacteriophage antimicrobial-lock (Staphylococcal Bacteriophage K, propagated titer > 10 8 ). At the completion of the experiment blood cultures were obtained via peripheral veins, the catheters were removed for quantitative culture and scanning electron microscopic analyses, and the animals were sacrificed. Statistical testing for substantial differences in distal catheter segment colonization was carried out using the rank sum test. Results Mean distal catheter segment colony forming units (CFU) per cm 2 as a measure of biofilm was significantly decreased in experimental animals compared to controls (control 1.2 × 10 5 CFU/cm 2 , experimental 7.58 × 10 3 , P=0.016). Scanning electron microscopic analysis of the catheter segments demonstrated qualitative reduction of biofilm in treated catheter segments compared to untreated controls. Blood culture results were not significantly different between the groups (control 3/5 positive (60%), experimental 4/5 positive (80%), (p=1.0). Conclusion In a rabbit model, treatment of infected central venous catheters with a bacteriophage antimicrobial-lock technique significantly reduced bacterial colonization and biofilm presence. Our data suggests that bacteriophage lock solution may be a feasible strategy for prevention and treatment of central venous catheter infections.