title: A putative de-N-acetylase of the PIG-L superfamily affects fluoroquinolone tolerance in Pseudomonas aeruginosa.
abstract: A major cause of treatment failure of infections caused by Pseudomonas aeruginosa is the presence of antibiotic-insensitive persister cells. The mechanism of persister formation in P. aeruginosa is largely unknown, and so far, only few genetic determinants have been linked to P. aeruginosa persistence. Based on a previous high-throughput screening, we here present dnpA (de-N-acetylase involved in persistence; gene locus PA14_66140/PA5002) as a new gene involved in noninherited fluoroquinolone tolerance in P. aeruginosa. Fluoroquinolone tolerance of a dnpA mutant is strongly reduced both in planktonic culture and in a biofilm model, whereas overexpression of dnpA in the wild-type strain increases the persister fraction. In addition, the susceptibility of the dnpA mutant to different classes of antibiotics is not affected. dnpA is part of the conserved LPS core oligosaccharide biosynthesis gene cluster. Based on primary sequence analysis, we predict that DnpA is a de-N-acetylase, acting on an unidentified substrate. Site-directed mutagenesis suggests that this enzymatic activity is essential for DnpA-mediated persistence. A transcriptome analysis indicates that DnpA primarily affects the expression of genes involved in surface-associated processes. We discuss the implications of these findings for future antipersister therapies targeted at chronic P. aeruginosa infections.
authors.affiliation: Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium.
authors.forename: Veerle
authors.initials: V
authors.lastname: Liebens
authors.forename: Valerie
authors.initials: V
authors.lastname: Defraine
authors.forename: Annelies
authors.initials: A
authors.lastname: Van der Leyden
authors.forename: Valerie N
authors.initials: VN
authors.lastname: De Groote
authors.forename: Carolina
authors.initials: C
authors.lastname: Fierro
authors.forename: Serge
authors.initials: S
authors.lastname: Beullens
authors.forename: Natalie
authors.initials: N
authors.lastname: Verstraeten
authors.forename: Cyrielle
authors.initials: C
authors.lastname: Kint
authors.forename: Ann
authors.initials: A
authors.lastname: Jans
authors.forename: Emanuela
authors.initials: E
authors.lastname: Frangipani
authors.forename: Paolo
authors.initials: P
authors.lastname: Visca
authors.forename: Kathleen
authors.initials: K
authors.lastname: Marchal
authors.forename: Wim
authors.initials: W
authors.lastname: Versées
authors.forename: Maarten
authors.initials: M
authors.lastname: Fauvart
authors.forename: Jan
authors.initials: J
authors.lastname: Michiels
mesh_terms: D000123:Acetyltransferases; D000581:Amidohydrolases / Q000235:genetics* / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004361:Drug Tolerance; D024841:Fluoroquinolones / Q000494:pharmacology*; D017353:Gene Deletion; D016297:Mutagenesis, Site-Directed; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D000123:Acetyltransferases; D000581:Amidohydrolases
keywords: LPS; LmbE; persistence; phenotypic tolerance