Resistance against antimicrobial peptides is independent of Escherichia coli AcrAB, Pseudomonas aeruginosa MexAB and Staphylococcus aureus NorA efflux pumps.
Rieg. Siegbert S; Huth. Anja A; Kalbacher. Hubert H; Kern. Winfried V WV
Key Findings
- Efflux pumps AcrAB (E. coli), MexAB (P. aeruginosa) and NorA (S. aureus) did not protect the bacteria from LL‑37 or other human antimicrobial peptides.
- Resistance to LL‑37 is independent of the tested multidrug‑resistance efflux systems.
- The results suggest MDR pumps aren’t a major way bacteria evade innate immune peptides.
Practical Outcomes
- For biohackers, this means LL‑37’s antibacterial action isn’t likely to be undermined by these common resistance pumps, but the study doesn’t provide dosing or safety guidance for human use. It reinforces that LL‑37 remains a promising natural antimicrobial, though more research is needed before practical supplementation.
Summary
The study found that common drug‑pumping mechanisms in E. coli, P. aeruginosa and S. aureus don’t help these bacteria dodge the human antimicrobial peptide LL‑37 (or similar peptides). In plain terms, the bacteria’s usual resistance tricks don’t work against LL‑37, so this peptide’s natural killing ability isn’t blocked by those pumps.
Abstract
The role of clinically important multidrug resistance (MDR) efflux pumps in bacterial resistance to various human antimicrobial peptides (AMPs), including cathelicidin LL-37, the alpha-defensins human neutrophil peptides (HNPs)-1-3 and HD-5 and the beta-defensins hBD-2 and -3, was investigated. AMP susceptibility testing was performed by killing assays and standard minimal inhibitory concentration assays. AMP susceptibility was determined in Escherichia coli and Pseudomonas aeruginosa strains overexpressing resistance-nodulation-cell division (RND)-type pumps AcrAB and MexAB, respectively, and in their pump-deficient parental strains. Furthermore, the impact of a member of the major facilitator (MF) efflux pump family was investigated in Staphylococcus aureus overexpressing NorA and in wild-type strains. The E. coli AcrAB and P. aeruginosa MexAB RND-type efflux pumps as well as the S. aureus NorA MF efflux pump were unable to confer resistance to AMPs. These findings do not support a critical role of MDR efflux pumps in the tested pathogens as a strategy to increase virulence by circumventing the antimicrobial action of innate defence AMPs.
Study Information
pubmed
2008
2008-10-21T00:00:00.000Z
10.1016/j.ijantimicag.2008.07.032
43
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