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 non-inherited 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 anti-persister therapies targeted at chronic P. aeruginosa infections.
Liebens, V., Defraine, V., Van der Leyden, A., De Groote, V.n., Fierro, C., Beullens, S., et al. (2014). A putative de-N-acetylase of the PIG-L superfamily affects fluoroquinolone tolerance in Pseudomonas aeruginosa. PATHOGENS AND DISEASE, 71(1), 39-54 [10.1111/2049-632X.12174].
A putative de-N-acetylase of the PIG-L superfamily affects fluoroquinolone tolerance in Pseudomonas aeruginosa.
VISCA, PAOLO;
2014-01-01
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 non-inherited 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 anti-persister therapies targeted at chronic P. aeruginosa infections.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
