title: The antibacterial activity of BF-30 in vitro and in infected burned rats is through interference with cytoplasmic membrane integrity.
abstract: Cathelicidin-BF (BF-30) is found in the venom of the snake Bungarus fasciatus and exhibits broad antimicrobial activity against bacteria and fungi. Nevertheless, its antibacterial activity in vivo and antibacterial mechanism is unknown. In the present study, we examined the antibacterial activity of BF-30 in vitro against drug-resistant Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, first identifying its protection against P. aeruginosa in infected burns and then delineating the antimicrobial mechanism of BF-30. The data showed that BF-30 had stronger antimicrobial activities against a broad spectrum of microorganisms than gentamicin, ampicillin or bacitracin. The killing curves of BF-30 against P. aeruginosa and S. aureus showed that CFU counts rapidly decreased by almost 2 logs within 6min, and it took just less than 2h to kill all the bacteria. In addition, we investigated whether BF-30 had antibacterial activity in a burn/acute infection rat model. Dose-response (0.75, 3, 12mg/kg/day) studies indicated that BF-30 significantly reduced the colonization of P. aeruginosa in the burn eschars, lungs and liver of burn injured rats and that it could prevent subsequent systemic infection and development of inflammation. The peptide induced chaotic membrane morphology and cell debris, as determined by electron microscopy, and caused the cytoplasmic membrane to crack, resulting in β-galactosidase leakage and EtBr accumulation. This suggests that the antimicrobial activity of BF-30 is based on cytoplasmic membrane permeability. Taken together, our data demonstrate that antibacterial activity of BF-30 has potential therapeutic value for the prevention and treatment of burn and wound infections.
authors.affiliation: School of Life Science & Technology, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, PR China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhou
authors.forename: Jie
authors.initials: J
authors.lastname: Dou
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhou
authors.forename: Yunman
authors.initials: Y
authors.lastname: Li
authors.forename: Changlin
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D001424:Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D017838:Bungarus / Q000378:metabolism; D002056:Burns / Q000188:drug therapy* / Q000382:microbiology; D054804:Cathelicidins / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D002462:Cell Membrane / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects; D005260:Female; D008099:Liver / Q000187:drug effects / Q000293:injuries / Q000382:microbiology*; D055370:Lung Injury / Q000188:drug therapy / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D008854:Microscopy, Electron; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013211:Staphylococcus aureus / Q000187:drug effects; D014946:Wound Infection / Q000188:drug therapy* / Q000382:microbiology; D001616:beta-Galactosidase / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D054804:Cathelicidins; D010455:Peptides; D001616:beta-Galactosidase