Identification of a new gene PA5017 involved in flagella-mediated motility, chemotaxis and biofilm formation in Pseudomonas aeruginosa

College of Life Sciences, Nankai University, Tianjin, China.
FEMS Microbiology Letters (Impact Factor: 2.12). 08/2007; 272(2):188-95. DOI: 10.1111/j.1574-6968.2007.00753.x
Source: PubMed


Flagella-mediated motility is recognized as one of the major factors contributing to virulence in Pseudomonas aeruginosa. During a screening of a mini-Mu transposon mutant library of P. aeruginosa PA68, a mutant partially deficient in swimming and swarming motility was identified in a new locus that encodes a predicted protein of unknown function annotated PA5017 in the P. aeruginosa PAO1 genome sequence. Chemotaxis plate assay indicated that inactivation of the PA5017 gene led to a decreased chemotactic response. Complementation of the PA5017 mutant with the wild-type PA5017 gene restored normal motility and chemotaxis phenotype. A promoter-lacZ reporter activity assay of the cheYZAB operon from chemotaxis gene cluster 1 showed that there was almost a twofold difference in expression levels of the wild-type PA68 and the PA5017 mutant. This suggested that the PA5017 affected expression of the cheYZAB operon negatively. Further study showed that inactivation of the PA5017 gene in PA68 led to increased biofilm formation in a static system and to the formation of a heterogeneous biofilm in a flow-chamber system. These results suggested that PA5017 possibly affected flagellum-dependent motility and in turn biofilm formation via the chemotaxis signal transduction pathway.

Download full-text


Available from: Huiming Xia, Sep 02, 2014
18 Reads
  • Source
    • "It is known in E. coli and S. Typhimurium that c-di-GMP binds the YcgR protein and this complex interacts with the flagellar motor to reduce velocity and inhibit rotor reversal events (Ryjenkov et al., 2006; Boehm et al., 2010; Paul et al., 2010; Zorraquino et al., 2013). A P. aeruginosa pch mutant reduces swimming and swarming motility as determined by bulk, agar-based assays (Li et al., 2007; Roy et al., 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Individual cell heterogeneity is commonly observed within populations, although its molecular basis is largely unknown. Previously, using FRET-based microscopy, we observed heterogeneity in cellular c-di-GMP levels. In this study, we show that c-di-GMP heterogeneity in Pseudomonas aeruginosa is promoted by a specific phosphodiesterase partitioned after cell division. We found that subcellular localization and reduction of c-di-GMP levels by this phosphodiesterase is dependent on the histidine kinase component of the chemotaxis machinery, CheA, and its phosphorylation state. Therefore, individual cell heterogeneity in c-di-GMP concentrations is regulated by the activity and the asymmetrical inheritance of the chemotaxis organelle after cell division. c-di-GMP heterogeneity results in a diversity of motility behaviors. The generation of diverse intracellular concentrations of c-di-GMP by asymmetric partitioning is likely important to the success and survival of bacterial populations within the environment by allowing a variety of motility behaviors. DOI:
    eLife Sciences 12/2013; 2:e01402. DOI:10.7554/eLife.01402 · 9.32 Impact Factor
  • Source
    • "enterica (Lamberg et al. 2002; Kiljunen et al. 2005; Laasik et al. 2005); Pseudomonas aeruginosa (Shan et al. 2004; Xu et al. 2005; Bai et al. 2007; Li et al. 2007); Bacillus amyloliquefaciens (Hao et al. 2006); Staphylococcus aureus, Streptococcus pyogenes and Streptococcus suis (Pajunen et al. 2005; Tu Quoc et al. 2007). However, the technique has not yet been shown to be functional in L. lactis, an important industrial organism used as a cheese starter and nisin production host. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper describes optimization of electrotransformation of Mu transposition complexes into Lactococcus lactis cells and identification of genes affecting nisin production. The highest transformation efficiency, 1.1 x 10(2) transformants microg(-1) of input transposon DNA, was achieved when cells were grown to an OD(600) of 0.5 in the presence of 1.5% of glycine and treated with 20 microg ml(-1) ampicillin for 60 min. Three insertions affecting nisin production, which were identified at nisB, fhuR, and rpiA genes, were screened from a library of approximately 2000 erythromycin-resistant transformants using a nisin bioassay method. NisB is part of the nisin biosynthetic machinery, explaining the loss of nisin production in nisB mutant. FhuR is a transcription regulator involved in sulphur acquisition. Inactivation of fhuR presumably results in a low cellular cystein level, which affects nisin biosynthesis that involves utilization of cystein. RpiA is involved in pentose phosphate pathway and carbon fixation. The rpiA mutant showed reduction in nisin production and slow growth rate. The results showed that Mu transposition complex mutagenesis can be used to identify genes in L. lactis. Three genes involved in nisin production were identified. Expanding the Mu transposition-based mutagenesis to Lactococci adds a new tool for studies of industrially important bacteria.
    Journal of Applied Microbiology 01/2009; 106(1):41-8. DOI:10.1111/j.1365-2672.2008.03962.x · 2.48 Impact Factor
    • "Shiga toxin production. Shiga toxin production was assayed as previously described (Karmali et al., 1985a; Tam & Lingwood, 2007). Briefly, 1.5610 4 Vero cells were seeded into 96-well tissue culture plates and grown for 24 h at 37 uC, 5 % CO 2 prior to the experiment. "
    The Canadian veterinary journal. La revue veterinaire canadienne 12/2000; 80(4):741-744. DOI:10.4141/A00-025 · 0.52 Impact Factor
Show more