title: Broad activity against porcine bacterial pathogens displayed by two insect antimicrobial peptides moricin and cecropin B.
abstract: In response to infection, insects produce a variety of antimicrobial peptides (AMPs) to kill the invading pathogens. To study their physicochemical properties and bioactivities for clinical and commercial use in the porcine industry, we chemically synthesized the mature peptides Bombyx mori moricin and Hyalophora cecropia cecropin B. In this paper, we described the antimicrobial activity of the two AMPs. Moricin exhibited antimicrobial activity on eight strains tested with minimal inhibitory concentration values (MICs) ranging between 8 and 128 μg/ml, while cecropin B mainly showed antimicrobial activity against the Gramnegative strains with MICs ranging from 0.5 to 16 μg/ml. Compared to the potent antimicrobial activity these two AMPs displayed against most of the bacterial pathogens tested, they exhibited limited hemolytic activity against porcine red blood cells. The activities of moricin and cecropin B against Haemophilus parasuis SH 0165 were studied in further detail. Transmission electron microscopy (TEM) of moricin and cecropin B treated H. parasuis SH 0165 indicated extensive damage to the membranes of the bacteria. Insights into the probable mechanism utilized by moricin and cecropin B to eliminate pathogens are also presented. The observations from this study are important for the future application of AMPs in the porcine industry.
authors: State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Disease, Huazhong Agricultural University, Wuhan, Hubei, China.
authors: Han
authors: H
authors: Hu
authors: Chunmei
authors: C
authors: Wang
authors: Xiaozhen
authors: X
authors: Guo
authors: Wentao
authors: W
authors: Li
authors: Yang
authors: Y
authors: Wang
authors: Qigai
authors: Q
authors: He
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects; D044137:Haemophilus parasuis / Q000187:drug effects / Q000648:ultrastructure; D019476:Insect Proteins / Q000138:chemical synthesis / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D013552:Swine / Q000382:microbiology*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D019476:Insect Proteins; C097209:moricin protein, Bombyx mori; C031162:cecropin B protein, Insecta