Inhibition and destruction of Pseudomonas aeruginosa biofilms by antibiotics and antimicrobial peptides.
Dosler. Sibel S; Karaaslan. Elif E
Key Findings
- LL‑37 (and CAMA) at 1/10 of its biofilm‑killing dose cuts the needed antibiotic concentration by up to 8× against P. aeruginosa biofilms.
- Both LL‑37 and the tested antibiotics can block bacterial attachment and early biofilm formation at sub‑MIC levels.
- Time‑kill experiments showed a 3‑log reduction in viable biofilm bacteria within 24 hours for most antibiotic‑peptide combos, especially ciprofloxacin with LL‑37 or CAMA.
Practical Outcomes
- For biohackers interested in tackling resistant infections, adding a low dose of LL‑37 (or a similar synthetic peptide) to standard antibiotics could make the drugs work better against biofilm‑related Pseudomonas infections. While LL‑37 isn’t widely sold as a supplement, the concept supports using peptide‑antibiotic combos or agents that block bacterial attachment as a strategy to enhance treatment efficacy.
Summary
The study shows that the natural antimicrobial peptide LL‑37 can boost the power of common antibiotics against stubborn Pseudomonas aeruginosa biofilms. When LL‑37 (or a similar peptide called CAMA) is added at a low dose, the amount of antibiotic needed to kill the biofilm drops up to eight‑fold, and the combination can also stop the bacteria from sticking to surfaces and forming new biofilms.
Abstract
Pseudomonas aeruginosa is one of the major nosocomial pathogen that can causes a wide variety of acute and chronic infections P. aeruginosa is a dreaded bacteria not just because of the high intrinsic and acquired antibiotic resistance rates but also the biofilm formation and production of multiple virulence factors. We investigated the in vitro activities of antibiotics (ceftazidime, tobramycin, ciprofloxacin, doripenem, piperacillin and colistin) and antimicrobial cationic peptides (AMPs; LL-37, CAMA: cecropin(1-7)-melittin A(2-9) amide, melittin, defensin and magainin-II) alone or in combination against biofilms of laboratory strain ATCC 27853 and 4 clinical strains of P. aeruginosa. The minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC) and minimum biofilm eradication concentrations (MBEC) were determined by microbroth dilution technique. The MBEC values of antibiotics and AMPs were 80->5120 and 640->640mg/L, respectively. When combined with the LL-37 or CAMA at 1/10× MBEC, the MBEC values of antibiotics that active against biofilms, were decreased up to 8-fold. All of the antibiotics, and AMPs were able to inhibit the attachment of bacteria at the 1/10× MIC and biofilm formation at 1× or 1/10× MIC concentrations. Time killing curve studies showed 3-log10 killing against biofilms in 24h with almost all studied antibiotics and AMPs. Synergism were seen in most of the studied combinations especially CAMA/LL-37+ciprofloxacin against at least one or two strains' biofilms. Since biofilms are not affected the antibiotics at therapeutic concentrations, using a combination of antimicrobial agents including AMPs, or inhibition of biofilm formation by blocking the attachment of bacteria to surfaces might be alternative methods to fight with biofilm associated infections.
Study Information
pubmed
2014
2014-10-05T00:00:00.000Z
10.1016/j.peptides.2014.09.021
225
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