Quorum-Quenching Acylase Reduces the Virulence of
            <i>Pseudomonas aeruginosa</i>
            in a
            <i>Caenorhabditis elegans</i>
            Infection Model

Papaioannou, Evelina; Wahjudi, Mariana; Nadal‐Jimenez, Pol; Koch, Guillaume; Setroikromo, Rita; Quax, Wim J.

doi:10.1128/aac.00380-09

Cited by 98 publications

(64 citation statements)

References 25 publications

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“…Production of these virulence factors is regulated to a large extent by a cell density-dependent gene regulatory mechanism termed quorum sensing (QS) (35). The importance of QS in P. aeruginosa virulence has been clearly elucidated in studies using a range of infection models (10,33,48) and cultured host cells (8,41).…”

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confidence: 99%

Anaerobiosis-Induced Loss of Cytotoxicity Is Due to Inactivation of Quorum Sensing in Pseudomonas aeruginosa

et al. 2011

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Pseudomonas aeruginosa, an opportunistic pathogen of clinical importance, causes chronic airway infections in patients with cystic fibrosis (CF). Current literature suggests that pockets with reduced oxygen tension exist in the CF airway mucus. However, virulence features of this opportunistic pathogen under such conditions are largely unknown. Cell-free supernatant of the standard laboratory P. aeruginosa strain PAO1 obtained from anaerobic culture, but not aerobic culture, failed to kill A549 human airway epithelial cells. Further investigation revealed that this reduced cytotoxicity upon anaerobiosis was due to the suppressed secretion of elastase, a virulence factor controlled by P. aeruginosa quorum sensing (QS). Both a lacZ-reporter fusion assay and quantitative real-time PCR (RT-PCR) analysis demonstrated that transcription of the elastase-encoding lasB gene was substantially decreased during anaerobic growth compared with aerobic growth. Moreover, transcription of other genes controlled by the LasI/R QS system, such as rhlR, vqsR, mvfR, and rsaL, was also repressed under the same anaerobic growth conditions. Importantly, synthesis of 3-oxo-C 12 -HSL (PAI-1), an autoinducer molecule that mediates induction of the LasI/R QS system, was >22-fold decreased during anaerobic growth while C 4 -HSL (PAI-2), which mediates RhlI/R QS, was nondetectable under the same growth conditions. Transcription of the lasB gene was restored by exogenous supplementation with autoinducers, with PAI-2 more effective than PAI-1 or Pseudomonas quinolone signal (PQS) at restoring transcription of the lasB gene. Together, these results suggest that anaerobiosis deprives P. aeruginosa of the ability to regulate its virulence via QS and this misregulation attenuates the pathogenic potential of this important pathogen.

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Anaerobiosis-Induced Loss of Cytotoxicity Is Due to Inactivation of Quorum Sensing in Pseudomonas aeruginosa

et al. 2011

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“…The effect of overexpressing and deleting the pa0305 gene on the virulence of P. aeruginosa in the C. elegans model. C. elegans nematodes were fed on a layer of Pseudomonas cells as described previously (Papaioannou et al, 2009). Wild-type P. aeruginosa PAO1, P. aeruginosa PAO1 Dpa0305 and P. aeruginosa PAO1 harbouring pMMB-pa0305 were used as feeding layers.…”

Section: Discussionmentioning

confidence: 99%

“…Slow-killing kinetics of C. elegans by PAO1 and its derivatives were determined by using the procedure described previously (Papaioannou et al, 2009). Briefly, Pseudomonas strains were grown overnight at 37 uC in LB broth supplemented with appropriate antibiotics and then diluted 100-fold into fresh broth.…”

Section: Full Name Of Ahl Abbreviationmentioning

confidence: 99%

“…The fusion product was then digested with HindIII and EcoRI and cloned into the similarly digested pEX18-Gm (Hoang et al, 1998). The subsequent deletion procedure was performed as described previously (Papaioannou et al, 2009). The sequences of the primers and probes (ForG and RevG) are listed in Table 2.…”

Section: Full Name Of Ahl Abbreviationmentioning

confidence: 99%

“…The high resistance of this bacterium to common antibiotics has been linked to biofilm formation and to the regulation of the QS system (de Kievit, 2009). Inhibition of QS, a process referred to as quorum quenching, is thought to provide means of fighting P. aeruginosa infections (Papaioannou et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

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PA0305 of Pseudomonas aeruginosa is a quorum quenching acylhomoserine lactone acylase belonging to the Ntn hydrolase superfamily

et al. 2011

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The Pseudomonas aeruginosa PAO1 genome has at least two genes, pvdQ and quiP, encoding acylhomoserine lactone (AHL) acylases. Two additional genes, pa1893 and pa0305, have been predicted to encode penicillin acylase proteins, but have not been characterized. Initial studies on a pa0305 transposon insertion mutant suggested that the gene is not related to the AHL growth phenotype of P. aeruginosa. The close similarity (67 %) of pa0305 to HacB, an AHL acylase of Pseudomonas syringae, prompted us to investigate whether the PA0305 protein might also function as an AHL acylase. The pa0305 gene has been cloned and the protein (PA0305) has been overproduced, purified and subjected to functional characterization. Analysis of the purified protein showed that, like b-lactam acylases, PA0305 undergoes post-translational processing resulting in a-and b-subunits, with the catalytic serine as the first amino acid of the b-subunit, strongly suggesting that PA0305 is a member of the N-terminal nucleophile hydrolase superfamily. Using a biosensor assay, PA0305his was shown to degrade AHLs with acyl side chains ranging in length from 6 to 14 carbons. Kinetics studies using N-octanoyl-L-homoserine lactone (C 8 -HSL) and N-(3-oxo-dodecanoyl)-L-homoserine lactone (3-oxo-C 12 -HSL) as substrates showed that the enzyme has a robust activity towards these two AHLs, with apparent K cat /K m values of 0.14¾10 4 M "1 s "1 towards C 8 -HSL and 7.8¾10 4 M "1 s "1 towards 3-oxo-C 12 -HSL. Overexpression of the pa0305 gene in P. aeruginosa showed significant reductions in both accumulation of 3-oxo-C 12 -HSL and expression of virulence factors. A mutant P. aeruginosa strain with a deleted pa0305 gene showed a slightly increased capacity to kill Caenorhabditis elegans compared with the P. aeruginosa PAO1 wild-type strain and the PAO1 strain carrying a plasmid overexpressing pa0305. The harmful effects of the Dpa0305 strain on the animals were most visible at 5 days post-exposure and the mortality rate of the animals fed on the Dpa0305 strain was faster than for the animals fed on either the wild-type strain or the strain overexpressing pa0305. In conclusion, the pa0305 gene encodes an efficient acylase with activity towards longchain homoserine lactones, including 3-oxo-C 12 -HSL, the natural quorum sensing signal molecule in P. aeruginosa, and we propose to name this acylase HacB.

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Plant Pathogenic Bacteria: Role of Quorum Sensing and Biofilm in Disease Development

Dwivedi

Khare

Chaturvedi

et al. 2017

Biofilms in Plant and Soil Health

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Quorum-Quenching Acylase Reduces the Virulence of Pseudomonas aeruginosa in a Caenorhabditis elegans Infection Model

Cited by 98 publications

References 25 publications

Anaerobiosis-Induced Loss of Cytotoxicity Is Due to Inactivation of Quorum Sensing in Pseudomonas aeruginosa

Anaerobiosis-Induced Loss of Cytotoxicity Is Due to Inactivation of Quorum Sensing in Pseudomonas aeruginosa

PA0305 of Pseudomonas aeruginosa is a quorum quenching acylhomoserine lactone acylase belonging to the Ntn hydrolase superfamily

Plant Pathogenic Bacteria: Role of Quorum Sensing and Biofilm in Disease Development

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