Mutagenesis by host antimicrobial peptides: insights into microbial evolution during chronic infections
Authors:Dominique H. Limoli and Daniel J. Wozniak
doi: 10.15698/mic2014.07.157
Volume 1, pp. 247 to 249, published 29/06/2014.
Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA.
Keywords:
mutagenesis, antimicrobial peptides, cystic fibrosis, Pseudomonas aeruginosa, DNA repair.
Corresponding Author(s):
Conflict of interest statement:
The authors declare no competing financial interests.
Please cite this article as:
Dominique H. Limoli and Daniel J. Wozniak (2014). Mutagenesis by host antimicrobial peptides: insights into microbial evolution during chronic infections. Microbial Cell 1(7): 247-249.
© 2014 Limoli and Wozniak. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduction in any medium, provided the original author and source are acknowledged.
Abstract:
Antimicrobial peptides (AMPs) are produced by the mammalian immune system to fight invading pathogens. The best understood function of AMPs is to integrate into the membranes of microbes, thereby disrupting and killing cells. However, a recent study [PLoS Pathogens (2014) 10, e1004083] provides evidence that at subinhibitory levels, AMPs promote mutations in bacterial DNA, which enhance bacterial survival. In particular, in the bacterium Pseudomonas aeruginosa, one AMP called LL-37 can promote mutations, which enable the bacteria to overproduce a protective sugar coating, a process called mucoid conversion. P. aeruginosa mucoid conversion is a major risk factor for those suffering from cystic fibrosis (CF), one of the most common lethal, heritable diseases in the US. LL-37 was found to produce mutations by penetrating the bacterial cell and binding to bacterial DNA. It was proposed that LL-37 binding DNA disrupts normal DNA replication and potentiates mutations. Importantly, LL-37 induced mutagenesis was also found to promote resistance to rifampicin in both P. aeruginosa and E. coli. This suggests that AMP-induced mutagenesis may be important for a broad range of chronic diseases and pathogens.