Activity of five antimicrobial peptides against periodontal as well as non-periodontal pathogenic strains.

: Due to the increasing emergence of multi-resistant bacteria the search for alternative antimicrobial substances is of high interest. Promising agents are antimicrobial peptides which are host defense molecules of the innate immune system in a wide range of different species. : The aim of this study was to assess the activity of nisin, melittin, lactoferrin, parasin-1 and LL-37 against 35 oral bacteria and employing the gold standard method for anaerobic susceptibility testing. : The activity of the peptides was determined by an agar dilution method under anaerobic and aerobic conditions. The test media contained final peptide concentrations between 0.125 µg/ml and 8 µg/ml (melittin, lactoferrin, parasin-1, LL-37) and between 0.125 µg/ml and 128 µg/ml (nisin). : Nisin completely inhibited the growth of sp., and . Melittin and lactoferrin reduced the growth of sp., (melittin) and (lactoferrin). Parasin-1 and LL-37 showed no activity. : AMPs, especially nisin and to a smaller degree lactoferrin, might be promising alternatives to antibiotics because of their antimicrobial activity, high resistance to environmental conditions and partially low costs.