In vitro activity of antimicrobial‐impregnated catheters against biofilms formed by KPC‐producing Klebsiella pneumoniae

• Published in: Journal of applied microbiology Vol. 127; no. 4; pp. 1018 - 1027
• Main Authors: Sousa, J.K.T., Haddad, J.P.A., Oliveira, A.C., Vieira, C.D., Santos, S.G.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.10.2019
• Subjects: Acetylcysteine; Acetylcysteine - pharmacology; Anti-Bacterial Agents - pharmacology; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Biofilms; Biofilms - drug effects; Biofilms - growth & development; Catheters; Catheters - microbiology; catheter‐related infections; central venous catheter; Chlorhexidine; Chlorhexidine - pharmacology; Colonization; Drug Resistance, Bacterial; Durability; Halos; Inhibition; Klebsiella; Klebsiella pneumoniae; Klebsiella pneumoniae - drug effects; Klebsiella pneumoniae - physiology; KPC‐producing Klebsiella pneumoniae; Levofloxacin; Levofloxacin - pharmacology; Medical instruments; Scanning electron microscopy; Silver Sulfadiazine - pharmacology; Statistical analysis; Subpopulations; Sulfadiazine; Time Factors; central venous catheter; KPC-producing Klebsiella pneumoniae; biofilms; Klebsiella pneumoniae; catheter-related infections
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.14372

Aim To evaluate the activity and effectiveness of impregnated central venous catheters (CVC) against Klebsiella pneumoniae biofilms. Methods and Results The antimicrobial activity and durability of impregnated‐CVCs were evaluated over time and the size of zones of inhibition (ZI) was measured. Biofilm formation was observed by quantitative culture and also by scanning electron microscopy. The catheters impregnated with chlorhexidine/silver sulfadiazine (CHX/SS) reduced bacteria counts by 0·3 log and were most effective (P < 0·01) against Klebsiella pneumoniae biofilms N‐acetylcysteine/levofloxacin (NAC/LEV) catheters. It was observed that the catheter impregnated with NAC/LEV had initially the largest average ZI size being statistically significant (P < 0·01). The NAC/LEV combination remained active until day 30, whereas the combination of CHX/SS was completely inactivated from day 15 on. Conclusions The NAC/LEV combination showed greater durability on the catheters, but it was the CHX/SS combination that had the greater initial efficacy in bacterial inhibition. It was also observed that NAC/LEV‐impregnated catheters do not prevent the emergence of resistant subpopulations inside the inhibition halos during antimicrobial susceptibility tests. Significance and Impact of the Study Our results highlighted that the in vitro efficacy of antimicrobial‐impregnated CVCs is limited by time and that their colonization occurred earlier than expected. Our data also demonstrated that NAC/LEV remained active until day 30 of evaluation and CHX/SS combination was completely inactivated from day 15 on. Our findings suggested that implantable devices should be carefully used by medical community.