The effect of Galleria mellonella hemolymph polypeptides on Legionella gormanii.

Among Legionella species, which are recognized to be pathogenic for humans, L. gormanii is the second prevalent causative agent of community-acquired pneumonia after L. pneumophila. Anti-L. gormanii activity of Galleria mellonella hemolymph extract and apolipophorin III (apoLp-III) was examined. The extract and apoLp-III at the concentration 0.025 mg/ml caused 75% and 10% decrease of the bacteria survival rate, respectively. The apoLp-III-induced changes of the bacteria cell surface were analyzed for the first time by atomic force microscopy. Our studies demonstrated the powerful anti-Legionella effects of the insect defence polypeptides, which could be exploited in drugs design against these pathogens.