|AMP > Discussion > Is there an induced
resistance to AMPs?
that AMPs are natural barriers to bacterial infections, pathogens ought
to have developeda variety of strategies that render them resistant to
antimicrobial host defenses.The only currently available structural
model explaining the mechanism of action of AMPs , the action of these
peptides is from the outside and over the pathogen’s membrane either by
increasing their permeability or by destabilizing
membranes by changing the net charge of the composed system.
Since biological membranes are indeed dynamic fluids, the generation of
resistance appears to be less likely to occur. Nonetheless,
pathogens have evolved countermeasures not to resist, but at least to
limit AMPs’ effectiveness, such as chemical modifications
and/or alternation of energy-dependent pumps at the membrane level (Peschel, 2002). The same is
true for intracellular bacterial pathogens, in which
resistance-limitation is less effective against mostly cationic
peptide-driven antimicrobial activity existing in the phagosomes of
circulating monocytes, neutrophils and some mucosal
epithelial cells . Additionally, the fact that the common features for
most peptides are a net positive charge and an amphipathic nature,
allows them to persist at water-lipid interfaces and then to disturb
microbial membrane components( Ruissen et al. 2001).
PESCHEL, A. How do bacteria resist human antimicrobial peptides? Trends in Microbiology, 2002, vol. 10, no. 4, p. 179-196.
RUISSEN, A.L.A.; GROENINCK, J.; HELMERHORST, E.J.; WALGREEN-WETERINGS, E.; VAN’T HOF, W.; VEERMAN, E.C.I. and NIEUW AMERONGEN, A.V. Effects of Histatin 5 and derived peptides on Candida albicans. Biochemical Journal,2001, vol. 356, no. 2, p. 361-368.