title: The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23) with High Potential to Control American Foulbrood.
abstract: Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23) encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0), showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Oliveira
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Leite
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
authors.forename: Leon D
authors.initials: LD
authors.lastname: Kluskens
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
authors.forename: Sílvio B
authors.initials: SB
authors.lastname: Santos
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
authors.forename: Luís D R
authors.initials: LD
authors.lastname: Melo
authors.affiliation: CEB-Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Azeredo
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001435:Bacteriophages / Q000502:physiology*; D001516:Bees / Q000382:microbiology*; D010450:Endopeptidases / Q000302:isolation & purification / Q000494:pharmacology*; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000662:veterinary*; D007814:Larva / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D056507:Paenibacillus / Q000187:drug effects / Q000821:virology*; D016133:Polymerase Chain Reaction; D013171:Spores, Bacterial / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D010450:Endopeptidases; C001143:endolysin