Functional Characterization of Triclosan-Resistant Enoyl-acyl-carrier Protein Reductase (FabV) in Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is extremely resistant to triclosan. Previous studies have shown that P. aeruginosa encodes a triclosan-resistant enoyl-acyl-carrier protein reductase (ENR), FabV, and that deletion of fabV causes P. aeruginosa to be extremely sensitive to triclosan. In this report, we complemented a P. aeruginosa fabV deletion strain with several triclosan-resistant ENR encoding genes, including Vibrio cholerae fabV, Bacillus subtilis fabL and Enterococcus faecalis fabK. All complemented strains restored triclosan resistance to the level of the wild-type strain, which confirmed that triclosan-resistant ENR allows P. aeruginosa to be extremely resistant to triclosan. Moreover, fabV exhibits pleiotropic effects. Deletion of fabV led P. aeruginosa to show attenuated swarming motility, decreased rhamnolipid, pyoverdine and acyl-homoserine lactones (AHLs) production. Complementation of the fabV mutant with any one ENR encoding gene could restore these features to some extent, in comparison with the wild-type strain. Furthermore, we found that addition of exogenous AHLs could restore the fabV mutant strain to swarm on semisolid plates and to produce more virulence factors than the fabV mutant strain. These findings indicate that deletion of fabV reduced the activity of ENR in P. aeruginosa, decreased fatty acid synthesis, and subsequently depressed the production of AHLs and other virulence factors, which finally may led to a reduction in the pathogenicity of P. aeruginosa. Therefore, fabV should be an ideal target for the control of P. aeruginosa infectivity.

Only Acyl Carrier Protein 1 (AcpP1) Functions in Pseudomonas aeruginosa Fatty Acid Synthesis

“…The motility assay was carried out as described previously ( Huang et al, 2016 ). The swarming motility of P. aeruginosa was investigated using the following media: 0.45% tryptone, 0.13% yeast extract, 0.5% agarose, 0.22% NaCl, and 0.5% agar.…”

“…Rhamnolipids were extracted as previously described ( Huang et al, 2016 ). Briefly, cells were removed from PPGAS (NH 4 Cl 20 mM, KCl 20 mM, Tris-HCl pH 7.2 120 mM, MgSO 4 1.6 mM, glucose 0.5%, and peptone 1.0%) cultures grown at 30°C for 24 h by centrifugation (10 min at 6,000 × g ), and the supernatant was acidified to pH 2 with concentrated HCl.…”

“…Pseudomonas aeruginosa cells were grown in LB at 37°C for 12 h, and cells were removed from 10 mL growth medium by centrifugation at 5,000 × g for 10 min at 4°C. LasA protease activity was determined by measuring the ability of P. aeruginosa culture supernatants to lyse boiled Staphylococcus aureus RN4200 cells, as described previously ( Huang et al, 2016 ). A 30-mL overnight culture of S. aureus grown in tryptic soy broth was placed in a boiling water bath for 10 min and then centrifuged for 10 min at 10,000 × g .…”

Fighting the spread of antibiotic resistance with bacterial competence inhibitors

“…S3C). Furthermore, we could also exclude an interaction between TCL and clinically relevant antibiotics, including aminoglycosides, in another important human pathogen, Pseudomonas aeruginosa, which is intrinsically tolerant to TCL (MIC > 2 mg/ml) due to the presence of FabV, a TCL-resistant enoyl-ACP reductase 39 (Fig. S3D).…”

Targeting Acyl Homoserine Lactone (AHL) of Pseudomonas aeruginosa Responsible for Biofilm Formation using Plant Metabolites

“…The influence of bioactive compounds against the mechanisms regulated by quorum sensing such as the production of AHL, pigment production and rhamnolipid production was also studied along. The effective molecule was studied for its interaction against Enoyl acyl carrier protein reductase (ENR) enzyme responsible for the chain elongation that is involved in the fatty acid synthesis, which is highly responsible for AHL formation 20 .…”