title: Effect of modified oligopeptides from the beetle Allomyrina dichotoma on Escherichia coli infection in mice.
abstract: The novel peptides based on a putative active site of defensin, an anti-bacterial peptide from the beetle Allomyrina dichotoma, were synthesized. These synthetic oligopeptides exhibited strong anti-bacterial activity in vitro, even against antibiotic-resistant pathogenic bacteria. Then, anti-bacterial activity of two newly synthesized peptides, RLYLRIGRR-NH(2) (peptide A) and RLRLRIGRR-NH(2) (peptide B) was also examined by macroscopic and histopathologic assessment during the course of infection in mice inoculated with antibiotic-resistant pathogenic Escherichia coli (E. coli) in vivo. Peptide B decreased the mortality of mice inoculated with antibiotic-resistant pathogenic E. coli. The results of macroscopic and histopathologic examinations revealed that peptide B could protect the mice from infection. In contrast, peptide A failed to protect mice from infection with antibiotic-resistant pathogenic E. coli. Also, modified peptides A and B produced no toxicity or side effects in mice. These results suggest that peptide B is useful for developing novel antibiotics against antibiotic-resistant pathogenic bacteria.
authors.affiliation: National Institute of Animal Health, Tsukuba, Ibaraki, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Yamada
authors.forename: Kikuyasu
authors.initials: K
authors.lastname: Nakamura
authors.forename: Hisako
authors.initials: H
authors.lastname: Saido-Sakanaka
authors.forename: Ai
authors.initials: A
authors.lastname: Asaoka
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamakawa
authors.forename: Toshiya
authors.initials: T
authors.lastname: Sameshima
authors.forename: Maki
authors.initials: M
authors.lastname: Motobu
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hirota
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000737:chemistry; D023082:Defensins / Q000737:chemistry; D004195:Disease Models, Animal; D004927:Escherichia coli Infections / Q000188:drug therapy*; D007150:Immunohistochemistry; D051379:Mice; D009842:Oligopeptides / Q000627:therapeutic use*; D013753:Tetracycline Resistance
chemical_list: D023082:Defensins; D009842:Oligopeptides