In vivo Activity of Combination of N-acetyl Cysteine and Levofloxacin against Colonization and Catheter-Associated Infection.

Despite many recent advancements and improvements to infection control measures and practices in healthcare facilities, infections associated with intravascular catheters remain problematic and even fatal. Since these infections are generally biofilm-based, effective antibiofilm strategies combined with antimicrobial approaches that can inhibit pathogenic colonization are important in preventing catheter-associated infections. We evaluated in vivo the activities of intravascular catheters impregnated with a combination of N-acetyl cysteine, an antibiofilm agent, and levofloxacin (NACLEV) compared to chlorhexidine/silver sulfadiazine-treated catheters (CHSS) against bacterial colonization and device-associated infection with representatives of both Gram-positive and Gram-negative bacteria including Staphylococcus aureus, vancomycin-resistant enterococcus (VRE), Pseudomonas aeruginosa, or Klebsiella pneumoniae. NACLEV catheters inoculated with S. aureus, VRE, or K. pneumoniae were generally as effective as inoculated CHSS catheters against device colonization (75%, 70%, or 80% vs. 65%, 55%, or 85% colonization reduction, respectively) and device-associated infection (65%, 65%, or 60% vs. 50%,3%, or 50% device-associated infection reduction, respectively). However, NACLEV catheters inoculated with P. aeruginosa were significantly more effective compared to CHSS catheters against both colonization (80% vs. 10% colonization reduction, P < 0.001) and device-associated infection (55% vs. 5% device-associated infection reduction, P = 0.001). Furthermore, impregnation of catheters with the N-acetyl cysteine and levofloxacin combination did not affect the mechanical integrity of the catheters since the mean force at break of 30.91 N for the impregnated catheters with the combination was well above the threshold of 15 N as recommended by the International Organization for Standardization BS EN ISO 10555-1 and 10555-3.