title: Periplasmic lysozyme inhibitor contributes to lysozyme resistance in Escherichia coli.
abstract: The product of the Escherichia coli ORFan gene ykfE was recently shown to be a strong inhibitor of C-type lysozyme in vitro. The gene was correspondingly renamed ivy (inhibitor of vertebrate lysozyme), but its biological function in E. coli remains unknown. In this work, we investigated the role of Ivy in the resistance of E. coli to the bactericidal effect of lysozyme in the presence of outer-membrane-permeabilizing treatments. Both in the presence of lactoferrin (3.0 mg/ml) and under high hydrostatic pressure (250 MPa), the lysozyme resistance of E. coli MG1655 was decreased by knock-out of Ivy, and increased by overexpression of Ivy. However, knock-out of Ivy did not increase the lysozyme sensitivity of an E. coli MG1655 mutant previously described to be resistant to lysozyme under high pressure. These results indicate that Ivy is one of several factors that affect lysozyme resistance in E. coli, and suggest a possible function for Ivy as a host interaction factor in commensal and pathogenic E. coli.
authors.affiliation: Laboratory of Food Microbiology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, 3001 Leuven, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Deckers
authors.forename: B
authors.initials: B
authors.lastname: Masschalck
authors.forename: A
authors.initials: A
authors.lastname: Aertsen
authors.forename: L
authors.initials: L
authors.lastname: Callewaert
authors.forename: C G M
authors.initials: CG
authors.lastname: Van Tiggelen
authors.forename: M
authors.initials: M
authors.lastname: Atanassova
authors.forename: C W
authors.initials: CW
authors.lastname: Michiels
mesh_terms: D002352:Carrier Proteins; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D006874:Hydrostatic Pressure; D007781:Lactoferrin / Q000737:chemistry / Q000494:pharmacology; D013058:Mass Spectrometry; D009113:Muramidase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*; D009154:Mutation; D009997:Osmotic Pressure; D019897:Periplasm / Q000378:metabolism*; D011312:Pressure; D013997:Time Factors; D019076:Transgenes
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C429555:Ivy protein, E coli; D009113:Muramidase; D007781:Lactoferrin