Influence of the Antimicrobial LL-37 Peptide on Legionella dumoffii Phospholipids Adsorbed at the Air–Liquid Interface

Legionella dumoffii is an intracellular pathogen of freshwater protozoans capable infecting and multiplying in mammalian cells, causing a severe respiratory disease called Legionnaires’ disease. The pathomechanism infection development very complex depends on many factors, including the structure properties macromolecules that build components L. cell envelope. Phospholipids (PLs) forming biological membranes have significant impact integrity membrane as well interactions with host cells. changes its lipid profile under influence external which allows it to adapt living environment. One factors altering PL composition presence exogenous choline. aim this study was determine physicochemical model bacterial adsorbed at air–liquid interface (Langmuir monolayers). They were composed phospholipids isolated from cultured (PL+choline) without (PL−choline) Moreover, effect human cathelicidin (LL-37 peptide) added subphase these monolayers analyzed terms phospholipid–peptide interactions. results indicated PL+choline slightly more condensed than PL−choline. In LL-37, elasticity both increased; thus, their molecular packing ordering decreased. disturbing related peptide’s antibacterial activity.