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Ng RN, Grey LJ, Vaitekenas A, McLean SA, Rudrum JD, Laucirica DR, Poh MWP, Hillas J, Winslow SG, Iszatt JJ, Iosifidis T, Tai AS, Agudelo-Romero P, Chang BJ, Stick SM, Kicic A. Development and validation of a miniaturized bacteriophage host range screening assay against antibiotic resistant Pseudomonas aeruginosa. J Microbiol Methods 2021; 190:106346. [PMID: 34637818 DOI: 10.1016/j.mimet.2021.106346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 10/20/2022]
Abstract
Antimicrobial resistance is a current global health crisis, and the increasing emergence of multidrug resistant infections has led to the resurgent interest in bacteriophages as an alternative treatment. Prior to clinical application, phage suitability is assessed, via susceptibility testing and breadth of host range to bacteriophage, however, these are both large-scale manual processes and labor-intensive. The aim of the study was to establish and validate a scaled down methodology for high-throughput screening to reduce procedural footprint. In this paper, we describe a scaled-down adapted methodology that can successfully screen bacteriophages, isolated and purified from wastewater samples. Furthermore, we describe a miniaturized host range assay against clinical Pseudomonas aeruginosa isolates using a spot test (2 μL/ drop) that was found to be both sensitive (94.6%) and specific (94.7%). It also demonstrated a positive predictive value (PPV) of 86.4% and negative predictive value (NPV) of 98%. The breadth of host range of bacteriophages that exhibited lytic activity on P. aeruginosa isolates was corroborated using the scaled down assay. The high correlation achieved in this study confirms miniaturization as the first step in future automation that could test phage diversity and efficacy as antimicrobials.
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Affiliation(s)
- Renee Nicole Ng
- School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia; Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Lucinda Jane Grey
- School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia; Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Andrew Vaitekenas
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, Western Australia, Australia
| | - Samantha Abagail McLean
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Jack Dylan Rudrum
- School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia; Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Daniel Rodolfo Laucirica
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Medical School, The University of Western Australia, Perth, Western Australia, Australia
| | - Matthew Wee-Peng Poh
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Medical School, The University of Western Australia, Perth, Western Australia, Australia
| | - Jessica Hillas
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Scott Glenn Winslow
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Joshua James Iszatt
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, Western Australia, Australia
| | - Thomas Iosifidis
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, Western Australia, Australia; Center for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Anna Sze Tai
- Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; Institute for Respiratory Health, School of Medicine, The University of Western Australia, Perth, Western Australia, Australia
| | - Patricia Agudelo-Romero
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia
| | - Barbara Jane Chang
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Stephen Michael Stick
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Perth, Western Australia, Australia; Center for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia
| | - Anthony Kicic
- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Occupation, Environment and Safety, School of Population Health, Curtin University, Perth, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Perth, Western Australia, Australia; Center for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia, Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia.
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- Wal-Yan Respiratory Research Center, Telethon Kids Institute, Perth, Western Australia, Australia; Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Perth, Western Australia, Australia; Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Pediatrics, University of Melbourne, Melbourne, Victoria, Australia
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Kawalek A, Kotecka K, Modrzejewska M, Gawor J, Jagura-Burdzy G, Bartosik AA. Genome sequence of Pseudomonas aeruginosa PAO1161, a PAO1 derivative with the ICEPae1161 integrative and conjugative element. BMC Genomics 2020; 21:14. [PMID: 31906858 PMCID: PMC6945700 DOI: 10.1186/s12864-019-6378-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 12/08/2019] [Indexed: 12/20/2022] Open
Abstract
Background Pseudomonas aeruginosa is a cause of nosocomial infections, especially in patients with cystic fibrosis and burn wounds. PAO1 strain and its derivatives are widely used to study the biology of this bacterium, however recent studies demonstrated differences in the genomes and phenotypes of derivatives from different laboratories. Results Here we report the genome sequence of P. aeruginosa PAO1161 laboratory strain, a leu-, RifR, restriction-modification defective PAO1 derivative, described as the host of IncP-8 plasmid FP2, conferring the resistance to mercury. Comparison of PAO1161 genome with PAO1-UW sequence revealed lack of an inversion of a large genome segment between rRNA operons and 100 nucleotide polymorphisms, short insertions and deletions. These included a change in leuA, resulting in E108K substitution, which caused leucine auxotrophy and a mutation in rpoB, likely responsible for the rifampicin resistance. Nonsense mutations were detected in PA2735 and PA1939 encoding a DNA methyltransferase and a putative OLD family endonuclease, respectively. Analysis of revertants in these two genes showed that PA2735 is a component of a restriction-modification system, independent of PA1939. Moreover, a 12 kb RPG42 prophage and a novel 108 kb PAPI-1 like integrative conjugative element (ICE) encompassing a mercury resistance operon were identified. The ICEPae1161 was transferred to Pseudomonas putida cells, where it integrated in the genome and conferred the mercury resistance. Conclusions The high-quality P. aeruginosa PAO1161 genome sequence provides a reference for further research including e.g. investigation of horizontal gene transfer or comparative genomics. The strain was found to carry ICEPae1161, a functional PAPI-1 family integrative conjugative element, containing loci conferring mercury resistance, in the past attributed to the FP2 plasmid of IncP-8 incompatibility group. This indicates that the only known member of IncP-8 is in fact an ICE.
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Affiliation(s)
- Adam Kawalek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland.
| | - Karolina Kotecka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
| | - Magdalena Modrzejewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
| | - Jan Gawor
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, DNA Sequencing and Oligonucleotide Synthesis Laboratory, Warsaw, Poland
| | - Grazyna Jagura-Burdzy
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland
| | - Aneta Agnieszka Bartosik
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Department of Microbial Biochemistry, Warsaw, Poland.
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Trend S, Chang BJ, O'Dea M, Stick SM, Kicic A. Use of a Primary Epithelial Cell Screening Tool to Investigate Phage Therapy in Cystic Fibrosis. Front Pharmacol 2018; 9:1330. [PMID: 30546305 PMCID: PMC6280614 DOI: 10.3389/fphar.2018.01330] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 10/29/2018] [Indexed: 01/11/2023] Open
Abstract
Antimicrobial-resistant microbes are an increasing threat to human health. In cystic fibrosis (CF), airway infections with Pseudomonas aeruginosa remain a key driver of lung damage. With few new antibiotics on the development horizon, alternative therapeutic approaches are needed against antimicrobial-resistant pathogens. Phage therapy, or the use of viruses that infect bacteria, is one proposed novel therapy to treat bacterial infections. However, the airways are complex microenvironments with unique characteristics that may affect the success of novel therapies. Here, three phages of P. aeruginosa (E79, F116, and one novel clinically derived isolate, designated P5) were screened for activity against 21 P. aeruginosa strains isolated from children with CF. Of these, phage E79 showed broad antibacterial activity (91% of tested strains sensitive) and was selected for further assessment. E79 genomic DNA was extracted, sequenced, and confirmed to contain no bacterial pathogenicity genes. High titre phage preparations were then purified using ion-exchange column chromatography and depleted of bacterial endotoxin. Primary airway epithelial cells derived from children with CF (n = 8, age range 0.2–5.5 years, 5 males) or healthy non-CF controls (n = 8, age range 2.5–4.0 years, 4 males) were then exposed to purified phage for 48 h. Levels of inflammatory IL-1β, IL-6, and IL-8 cytokine production were measured in culture supernatant by immunoassays and the extent of cellular apoptosis was measured using a ssDNA kit. Cytokine and apoptosis levels were compared between E79-stimulated and unstimulated controls, and, encouragingly, purified preparations of E79 did not stimulate any significant inflammatory cytokine responses or induce apoptosis in primary epithelial cells derived from children with or without CF. Collectively, this study demonstrates the feasibility of utilizing pre-clinical in vitro culture models to screen therapeutic candidates, and the potential of E79 as a therapeutic phage candidate in CF.
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Affiliation(s)
- Stephanie Trend
- Telethon Kids Institute, Perth, WA, Australia.,Division of Paediatrics, School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Barbara J Chang
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
| | - Mark O'Dea
- School of Veterinary and Life Sciences, Murdoch University, Perth, WA, Australia
| | - Stephen M Stick
- Telethon Kids Institute, Perth, WA, Australia.,Division of Paediatrics, School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia.,Department of Respiratory Medicine, Perth Children's Hospital, Perth, WA, Australia.,Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia and Harry Perkins Institute of Medical Research, Perth, WA, Australia
| | - Anthony Kicic
- Telethon Kids Institute, Perth, WA, Australia.,Division of Paediatrics, School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia.,Department of Respiratory Medicine, Perth Children's Hospital, Perth, WA, Australia.,Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia and Harry Perkins Institute of Medical Research, Perth, WA, Australia.,Occupation and the Environment, School of Public Health, Curtin University, Perth, WA, Australia
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Yamagiwa R, Kurahashi T, Takeda M, Adachi M, Nakamura H, Arai H, Shiro Y, Sawai H, Tosha T. Pseudomonas aeruginosa overexpression system of nitric oxide reductase for in vivo and in vitro mutational analyses. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:333-341. [PMID: 29499184 DOI: 10.1016/j.bbabio.2018.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/18/2018] [Accepted: 02/24/2018] [Indexed: 11/30/2022]
Abstract
Membrane-integrated nitric oxide reductase (NOR) reduces nitric oxide (NO) to nitrous oxide (N2O) with protons and electrons. This process is essential for the elimination of the cytotoxic NO that is produced from nitrite (NO2-) during microbial denitrification. A structure-guided mutagenesis of NOR is required to elucidate the mechanism for NOR-catalyzed NO reduction. We have already solved the crystal structure of cytochrome c-dependent NOR (cNOR) from Pseudomonas aeruginosa. In this study, we then constructed its expression system using cNOR-gene deficient and wild-type strains for further functional study. Characterizing the variants of the five conserved Glu residues located around the heme/non-heme iron active center allowed us to establish how the anaerobic growth rate of cNOR-deficient strains expressing cNOR variants correlates with the in vitro enzymatic activity of the variants. Since bacterial strains require active cNOR to eliminate cytotoxic NO and to survive under denitrification conditions, the anaerobic growth rate of a strain with a cNOR variant is a good indicator of NO decomposition capability of the variants and a marker for the screening of functionally important residues without protein purification. Using this in vivo screening system, we examined the residues lining the putative proton transfer pathways for NO reduction in cNOR, and found that the catalytic protons are likely transferred through the Glu57 located at the periplasmic protein surface. The homologous cNOR expression system developed here is an invaluable tool for facile identification of crucial residues in vivo, and for further in vitro functional and structural studies.
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Affiliation(s)
- Raika Yamagiwa
- Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan; RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan
| | - Takuya Kurahashi
- Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Mariko Takeda
- Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Mayuho Adachi
- Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Hiro Nakamura
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Hiroyuki Arai
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan
| | - Yoshitsugu Shiro
- Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan; RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan
| | - Hitomi Sawai
- Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan; RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan.
| | - Takehiko Tosha
- RIKEN SPring-8 Center, Kouto, Sayo, Hyogo 679-5148, Japan.
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NO-induced biofilm dispersion in Pseudomonas aeruginosa is mediated by an MHYT domain-coupled phosphodiesterase. J Bacteriol 2013; 195:3531-42. [PMID: 23729646 DOI: 10.1128/jb.01156-12] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Dispersion is a process used by bacteria to successfully transit from a biofilm to a planktonic growth state and to spawn novel communities in new locales. Alterations in bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) levels have been shown to be associated with biofilm dispersal in a number of different bacteria. The signaling molecule nitric oxide (NO) is known to induce biofilm dispersion through stimulation of c-di-GMP-degrading phosphodiesterase (PDE) activity. However, no c-di-GMP modulating enzyme directly involved in NO-induced dispersion has yet been described in the opportunistic pathogen Pseudomonas aeruginosa. Here, we characterized MucR (PA1727) and NbdA (PA3311, NO-induced biofilm dispersion locus A), two membrane-bound proteins with identical domain organization consisting of MHYT-GGDEF-EAL, with respect to their role in NO-induced dispersion. Inactivation of mucR impaired biofilm dispersion in response to NO and glutamate, whereas inactivation of nbdA only impaired biofilm dispersion upon exposure to NO. A specific role of NbdA in NO-induced dispersion was supported by increased PDE activity, resulting in decreased c-di-GMP levels in biofilms expressing nbdA upon exposure to NO, a response that was absent in the ΔnbdA strain. Moreover, increased PDE activity was mainly due to a transcriptional activation of nbdA upon addition of NO. Biochemical analyses of recombinant protein variants lacking the membrane-anchored MHYT domain support NbdA being an active PDE. In contrast, MucR displayed both diguanylate cyclase and PDE activity in vitro, which seemed regulated in a growth-dependent manner in vivo. This is the first description of a PDE specifically involved in NO-induced biofilm dispersion in P. aeruginosa.
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Barkovits K, Schubert B, Heine S, Scheer M, Frankenberg-Dinkel N. Function of the bacteriophytochrome BphP in the RpoS/Las quorum-sensing network of Pseudomonas aeruginosa. Microbiology (Reading) 2011; 157:1651-1664. [DOI: 10.1099/mic.0.049007-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The bacterial phytochrome of Pseudomonas aeruginosa (PaBphP) is an in vitro-active red/far-red light sensor histidine kinase of a two-component regulatory system. Despite solid biochemical data, its function in this heterotrophic, opportunistic pathogen is still unknown. Previous studies established that the genes encoding the two necessary phytochrome components BphO, a chromophore-producing haem oxygenase, and BphP, the apo-phytochrome, are co-transcribed in a bicistronic operon. Transcription has been shown to be induced in the stationary phase and to be dependent on the alternative sigma factor RpoS. Here we show an additional regulation of bphP expression through the quorum-sensing (QS) regulator LasR. This regulation is also reflected in a combination of expression profile experiments and proteome analyses of wild-type and phytochrome-deficient strains. While PaBphP has a pleiotropic effect on global gene expression, 66 % of the downregulated genes in the phytochrome mutant display a link to the Las QS system. Most of these genes seem to be indirectly regulated by LasR through BphP and the unknown response regulator BphR. A model of phytochrome function within the Las QS network is presented.
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Affiliation(s)
- Katalin Barkovits
- Physiology of Microorganisms, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
| | - Britta Schubert
- Physiology of Microorganisms, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
| | - Sabrina Heine
- Physiology of Microorganisms, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany
| | - Maurice Scheer
- Institute for Microbiology, Technical University Braunschweig, 38106 Braunschweig, Germany
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Garbe J, Bunk B, Rohde M, Schobert M. Sequencing and characterization of Pseudomonas aeruginosa phage JG004. BMC Microbiol 2011; 11:102. [PMID: 21569567 PMCID: PMC3120641 DOI: 10.1186/1471-2180-11-102] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 05/14/2011] [Indexed: 12/13/2022] Open
Abstract
Background Phages could be an important alternative to antibiotics, especially for treatment of multiresistant bacteria as e.g. Pseudomonas aeruginosa. For an effective use of bacteriophages as antimicrobial agents, it is important to understand phage biology but also genes of the bacterial host essential for phage infection. Results We isolated and characterized a lytic Pseudomonas aeruginosa phage, named JG004, and sequenced its genome. Phage JG004 is a lipopolysaccharide specific broad-host-range phage of the Myoviridae phage family. The genome of phage JG004 encodes twelve tRNAs and is highly related to the PAK-P1 phage genome. To investigate phage biology and phage-host interactions, we used transposon mutagenesis of the P. aeruginosa host and identified P. aeruginosa genes, which are essential for phage infection. Analysis of the respective P. aeruginosa mutants revealed several characteristics, such as host receptor and possible spermidine-dependance of phage JG004. Conclusions Whole genome sequencing of phage JG004 in combination with identification of P. aeruginosa host genes essential for infection, allowed insights into JG004 biology, revealed possible resistance mechanisms of the host bacterium such as mutations in LPS and spermidine biosynthesis and can also be used to characterize unknown gene products in P. aeruginosa.
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Affiliation(s)
- Julia Garbe
- Institute of Microbiology, Technische Universität Braunschweig, Spielmannstr. 7, 38106 Braunschweig, Germany
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Control of lipopolysaccharide biosynthesis by FtsH-mediated proteolysis of LpxC is conserved in enterobacteria but not in all gram-negative bacteria. J Bacteriol 2010; 193:1090-7. [PMID: 21193611 DOI: 10.1128/jb.01043-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite the essential function of lipopolysaccharides (LPS) in Gram-negative bacteria, it is largely unknown how the exact amount of this molecule in the outer membrane is controlled. The first committed step in LPS biosynthesis is catalyzed by the LpxC enzyme. In Escherichia coli, the cellular concentration of LpxC is adjusted by the only essential protease in this organism, the membrane-anchored metalloprotease FtsH. Turnover of E. coli LpxC requires a length- and sequence-specific C-terminal degradation signal. LpxC proteins from Salmonella, Yersinia, and Vibrio species carry similar C-terminal ends and, like the E. coli enzyme, were degraded by FtsH. Although LpxC proteins are highly conserved in Gram-negative bacteria, there are striking differences in their C termini. The Aquifex aeolicus enzyme, which is devoid of the C-terminal extension, was stable in E. coli, whereas LpxC from the alphaproteobacteria Agrobacterium tumefaciens and Rhodobacter capsulatus was degraded by the Lon protease. Proteolysis of the A. tumefaciens protein required the C-terminal end of LpxC. High stability of Pseudomonas aeruginosa LpxC in E. coli and P. aeruginosa suggested that Pseudomonas uses a proteolysis-independent strategy to control its LPS content. The differences in LpxC turnover along with previously reported differences in susceptibility against antimicrobial compounds have important implications for the potential of LpxC as a drug target.
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Garbe J, Wesche A, Bunk B, Kazmierczak M, Selezska K, Rohde C, Sikorski J, Rohde M, Jahn D, Schobert M. Characterization of JG024, a pseudomonas aeruginosa PB1-like broad host range phage under simulated infection conditions. BMC Microbiol 2010; 10:301. [PMID: 21110836 PMCID: PMC3008698 DOI: 10.1186/1471-2180-10-301] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 11/26/2010] [Indexed: 11/13/2022] Open
Abstract
Background Pseudomonas aeruginosa causes lung infections in patients suffering from the genetic disorder Cystic Fibrosis (CF). Once a chronic lung infection is established, P. aeruginosa cannot be eradicated by antibiotic treatment. Phage therapy is an alternative to treat these chronic P. aeruginosa infections. However, little is known about the factors which influence phage infection of P. aeruginosa under infection conditions and suitable broad host range phages. Results We isolated and characterized a phage, named JG024, which infects a broad range of clinical and environmental P. aeruginosa strains. Sequencing of the phage genome revealed that the phage JG024 is highly related to the ubiquitous and conserved PB1-like phages. The receptor of phage JG024 was determined as lipopolysaccharide. We used an artificial sputum medium to study phage infection under conditions similar to a chronic lung infection. Alginate production was identified as a factor reducing phage infectivity. Conclusions Phage JG024 is a suitable broad host range phage which could be used in phage therapy. Phage infection experiments under simulated chronic lung infection conditions showed that alginate production reduces phage infection efficiency.
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Affiliation(s)
- Julia Garbe
- Institute of Microbiology, Technische Universität Braunschweig, Spielmannstr, 7, 38106 Braunschweig, Germany
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Trunk K, Benkert B, Quäck N, Münch R, Scheer M, Garbe J, Jänsch L, Trost M, Wehland J, Buer J, Jahn M, Schobert M, Jahn D. Anaerobic adaptation in Pseudomonas aeruginosa: definition of the Anr and Dnr regulons. Environ Microbiol 2010; 12:1719-33. [PMID: 20553552 DOI: 10.1111/j.1462-2920.2010.02252.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The anaerobic metabolism of the opportunistic pathogen Pseudomonas aeruginosa is important for growth and biofilm formation during persistent infections. The two Fnr-type transcription factors Anr and Dnr regulate different parts of the underlying network in response to oxygen tension and NO. Little is known about all members of the Anr and Dnr regulons and the mediated immediate response to oxygen depletion. Comprehensive transcriptome and bioinformatics analyses in combination with a limited proteome analyses were used for the investigation of the P. aeruginosa response to an immediate oxygen depletion and for definition of the corresponding Anr and Dnr regulons. We observed at first the activation of fermentative pathways for immediate energy generation followed by induction of alternative respiratory chains. A solid position weight matrix model was deduced from the experimentally identified Anr boxes and used for identification of 170 putative Anr boxes in potential P. aeruginosa promoter regions. The combination with the experimental data unambiguously identified 130 new members for the Anr and Dnr regulons. The basis for the understanding of two regulons of P. aeruginosa central to biofilm formation and infection is now defined.
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Affiliation(s)
- Katharina Trunk
- Institute of Microbiology, Technische Universität Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
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Kawakami T, Kuroki M, Ishii M, Igarashi Y, Arai H. Differential expression of multiple terminal oxidases for aerobic respiration inPseudomonas aeruginosa. Environ Microbiol 2009; 12:1399-412. [DOI: 10.1111/j.1462-2920.2009.02109.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gliese N, Khodaverdi V, Görisch H. The PQQ biosynthetic operons and their transcriptional regulation in Pseudomonas aeruginosa. Arch Microbiol 2009; 192:1-14. [PMID: 19902179 DOI: 10.1007/s00203-009-0523-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 10/14/2009] [Accepted: 10/21/2009] [Indexed: 10/20/2022]
Abstract
Gene PA1990 of Pseudomonas aeruginosa, located downstream of pqqE and encoding a putative peptidase, was shown to be involved in excretion of PQQ into the culture supernatant. This gene is cotranscribed with the pqqABCDE cluster and was named pqqH. A PA1990::Km(r) mutant (VK3) did not show any effect in growth behaviour; however, in contrast to the wild-type, no excretion of PQQ into the culture supernatant was observed. The putative pqqF gene of P. aeruginosa was shown to be essential for PQQ biosynthesis. A pqqF::Km(r) mutant did not grow aerobically on ethanol, because of its inability to produce PQQ. Transcription of the pqqABCDEH operon was induced upon aerobic growth on ethanol, 1-propanol, 1,2-propanediol and 1-butanol, while on glycerol, succinate and acetate, transcription was low. Transcription of the pqqABCDEH operon was also found upon anoxic growth on ethanol with nitrate as electron acceptor, but no PQQ was produced. Expression of the pqqABCDEH operon is regulated at the transcriptional level. In contrast, the pqqF operon appeared to be transcribed constitutively at a very low level under all growth conditions studied.
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Affiliation(s)
- Nicole Gliese
- BioGenes GmbH, Koepenicker Strasse 325, Berlin, Germany
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Abstract
SUMMARYTwelve FPA-resistant mutants were selected on medium containingp-fluorophenylalanine and ethionine. Dominance tests in heterozygous diploids showed that 8 out of 12 are dominant and 4 recessive to their wild-type alleles. One mutant,fpa60, showed a partial requirement for tyrosine and was found to be allelic to anfpaAmutant described previously. A tyrosine non-requirer,fpa65, was also assigned to this locus. The other 10 mutants did not show any growth requirement and were simultaneously resistant to ethionine and 3-amino-L-tyrosine. Of the 8 dominant mutants, 3 were allelic to the permease-mutants at the locusfpaD.Dominant mutants showed higher degrees of resistance than recessive ones. Six new loci, identified after preliminary genetic analysis, were located on 3 linkage groups: 3 on linkage group VI, and one each on linkage groups I, V, and VIII. The recombinantfpaD11;fpaK69 was found to be sensitive to FPA.
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14
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Benkert B, Quäck N, Schreiber K, Jaensch L, Jahn D, Schobert M. Nitrate-responsive NarX-NarL represses arginine-mediated induction of the Pseudomonas aeruginosa arginine fermentation arcDABC operon. MICROBIOLOGY-SGM 2008; 154:3053-3060. [PMID: 18832311 DOI: 10.1099/mic.0.2008/018929-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Denitrification and arginine fermentation are major parts of the anaerobic metabolism of Pseudomonas aeruginosa, which is important for biofilm formation and infection. The two-component regulatory system NarX-NarL is part of the underlying network and is required for denitrifying growth. All target promoters identified so far are activated by NarL. In this study the effect of NarL on arginine fermentation was investigated using proteome, Northern blot and lacZ reporter gene analyses. NarL-dependent repression of the arcDABC operon was observed and the corresponding NarL-binding site in the arcD promoter region was functionally localized at -60 bp upstream of the transcriptional start site using site-directed promoter mutagenesis and reporter gene fusion experiments. The results clearly show that in the presence of nitrate NarL represses the arginine-dependent activation of the arcDABC operon mediated by ArgR. It does not influence the oxygen-tension-dependent activation via Anr. Thus, the anaerobic energy metabolism of P. aeruginosa is coordinated via NarX-NarL activity. In the presence of nitrate the highly efficient denitrification is preferred over the less attractive arginine fermentation.
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Affiliation(s)
- Beatrice Benkert
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
| | - Nicole Quäck
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
| | - Kerstin Schreiber
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
| | - Lothar Jaensch
- Division of Cell and Immune Biology, Proteome Research Group, Helmholtz Centre for Infection Research, Inhoffenstr. 7, D-38124 Braunschweig, Germany
| | - Dieter Jahn
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
| | - Max Schobert
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
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15
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SpoT-triggered stringent response controls usp gene expression in Pseudomonas aeruginosa. J Bacteriol 2008; 190:7189-99. [PMID: 18776018 DOI: 10.1128/jb.00600-08] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The universal stress proteins (Usps) UspK (PA3309) and UspN (PA4352) of Pseudomonas aeruginosa are essential for surviving specific anaerobic energy stress conditions such as pyruvate fermentation and anaerobic stationary phase. Expression of the respective genes is under the control of the oxygen-sensing regulator Anr. In this study we investigated the regulation of uspN and three additional P. aeruginosa usp genes: uspL (PA1789), uspM (PA4328), and uspO (PA5027). Anr induces expression of these genes in response to anaerobic conditions. Using promoter-lacZ fusions, we showed that PuspL-lacZ, PuspM-lacZ, and PuspO-lacZ were also induced in stationary phase as described for PuspN-lacZ. However, stationary phase gene expression was abolished in the P. aeruginosa triple mutant Deltaanr DeltarelA DeltaspoT. The relA and spoT genes encode the regulatory components of the stringent response. We determined pppGpp and ppGpp levels using a thin-layer chromatography approach and detected the accumulation of ppGpp in the wild type and the DeltarelA mutant in stationary phase, indicating a SpoT-derived control of ppGpp accumulation. Additional investigation of stationary phase in LB medium revealed that alkaline pH values are involved in the regulatory process of ppGpp accumulation.
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16
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Barkovits K, Harms A, Benkartek C, Smart JL, Frankenberg-Dinkel N. Expression of the phytochrome operon in Pseudomonas aeruginosa is dependent on the alternative sigma factor RpoS. FEMS Microbiol Lett 2008; 280:160-8. [DOI: 10.1111/j.1574-6968.2007.01058.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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17
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Boes N, Schreiber K, Härtig E, Jaensch L, Schobert M. The Pseudomonas aeruginosa universal stress protein PA4352 is essential for surviving anaerobic energy stress. J Bacteriol 2006; 188:6529-38. [PMID: 16952944 PMCID: PMC1595484 DOI: 10.1128/jb.00308-06] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During infection of the cystic fibrosis (CF) lung, Pseudomonas aeruginosa microcolonies are embedded in the anaerobic CF mucus. This anaerobic environment seems to contribute to the formation of more robust P. aeruginosa biofilms and to an increased antibiotic tolerance and therefore promotes persistent infection. This study characterizes the P. aeruginosa protein PA4352, which is important for survival under anaerobic energy stress conditions. PA4352 belongs to the universal stress protein (Usp) superfamily and harbors two Usp domains in tandem. In Escherichia coli, Usp-type stress proteins are involved in survival during aerobic growth arrest and under various other stresses. A P. aeruginosa PA4352 knockout mutant was tested for survival under several stress conditions. We found a decrease in viability of this mutant compared to the P. aeruginosa wild type during anaerobic energy starvation caused by the missing electron acceptors oxygen and nitrate. Consistent with this phenotype under anaerobic conditions, the PA4352 knockout mutant was also highly sensitive to carbonyl cyanide m-chlorophenylhydrazone, the chemical uncoupler of the electron transport chain. Primer extension experiments identified two promoters upstream of the PA4352 gene. One promoter is activated in response to oxygen limitation by the oxygen-sensing regulatory protein Anr. The center of a putative Anr binding site was identified 41.5 bp upstream of the transcriptional start site. The second promoter is active only in the stationary phase, however, independently of RpoS, RelA, or quorum sensing. This is the second P. aeruginosa Usp-type stress protein that we have identified as important for survival under anaerobic conditions, which resembles the environment during persistent infection.
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Affiliation(s)
- Nelli Boes
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7D-38106, Braunschweig, Germany
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18
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Schreiber K, Boes N, Eschbach M, Jaensch L, Wehland J, Bjarnsholt T, Givskov M, Hentzer M, Schobert M. Anaerobic survival of Pseudomonas aeruginosa by pyruvate fermentation requires an Usp-type stress protein. J Bacteriol 2006; 188:659-68. [PMID: 16385055 PMCID: PMC1347276 DOI: 10.1128/jb.188.2.659-668.2006] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recently, we identified a pyruvate fermentation pathway in Pseudomonas aeruginosa sustaining anaerobic survival in the absence of alternative anaerobic respiratory and fermentative energy generation systems (M. Eschbach, K. Schreiber, K. Trunk, J. Buer, D. Jahn, and M. Schobert, J. Bacteriol. 186:4596-4604, 2004). Anaerobic long-term survival of P. aeruginosa might be essential for survival in deeper layers of a biofilm and the persistent infection of anaerobic mucus plaques in the cystic fibrosis lung. Proteome analysis of P. aeruginosa cells during a 7-day period of pyruvate fermentation revealed the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the PPA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression was also found induced during the anaerobic and aerobic stationary phases. This aerobic stationary-phase induction is independent of the regulatory proteins Anr, RpoS, RelA, GacA, RhlR, and LasR, indicating a currently unknown mechanism of stationary-phase-dependent gene activation. PA3309 promoter activity was detected in the deeper layers of a P. aeruginosa biofilm using a PPA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria.
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Affiliation(s)
- Kerstin Schreiber
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
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19
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Arai H, Hayashi M, Kuroi A, Ishii M, Igarashi Y. Transcriptional regulation of the flavohemoglobin gene for aerobic nitric oxide detoxification by the second nitric oxide-responsive regulator of Pseudomonas aeruginosa. J Bacteriol 2005; 187:3960-8. [PMID: 15937158 PMCID: PMC1151720 DOI: 10.1128/jb.187.12.3960-3968.2005] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2005] [Accepted: 03/09/2005] [Indexed: 11/20/2022] Open
Abstract
The regulatory gene for a sigma54-dependent-type transcriptional regulator, fhpR, is located upstream of the fhp gene for flavohemoglobin in Pseudomonas aeruginosa. Transcription of fhp was induced by nitrate, nitrite, nitric oxide (NO), and NO-generating reagents. Analysis of the fhp promoter activity in mutant strains deficient in the denitrification enzymes indicated that the promoter was regulated by NO or related reactive nitrogen species. The NO-responsive regulation was operative in a mutant strain deficient in DNR (dissimilatory nitrate respiration regulator), which is the NO-responsive regulator required for expression of the denitrification genes. A binding motif for sigma54 was found in the promoter region of fhp, but an FNR (fumarate nitrate reductase regulator) box was not. The fhp promoter was inactive in the fhpR or rpoN mutant strain, suggesting that the NO-sensing regulation of the fhp promoter was mediated by FhpR. The DNR-dependent denitrification promoters (nirS, norC, and nosR) were active in the fhpR or rpoN mutants. These results indicated that P. aeruginosa has at least two independent NO-responsive regulatory systems. The fhp or fhpR mutant strains showed sensitivity to NO-generating reagents under aerobic conditions but not under anaerobic conditions. These mutants also showed significantly low aerobic NO consumption activity, indicating that the physiological role of flavohemoglobin in P. aeruginosa is detoxification of NO under aerobic conditions.
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Affiliation(s)
- Hiroyuki Arai
- Department of Biotechnology, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
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20
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Pinedo CA, Smets BF. Conjugal TOL transfer from Pseudomonas putida to Pseudomonas aeruginosa: effects of restriction proficiency, toxicant exposure, cell density ratios, and conjugation detection method on observed transfer efficiencies. Appl Environ Microbiol 2005; 71:51-7. [PMID: 15640169 PMCID: PMC544212 DOI: 10.1128/aem.71.1.51-57.2005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of restriction proficiency and premating exposure to toxicants on conjugal transfer of the TOL plasmid between Pseudomonas spp. was investigated by examinations of filter matings. A Pseudomonas putida KT2442-derived strain carrying a gfp-tagged variant of the TOL plasmid was used as a donor, and both restriction-deficient (PAO1162N) and -proficient (PAO2002N) Pseudomonas aeruginosa strains were used as recipients. The in situ enumeration of conjugation events allowed us to obtain frequency estimates that were unbiased by transconjugant growth or plasmid retransfer. We observed a strong dependence of the plasmid transfer frequency on the initial donor-to-recipient ratio of surface matings, which invalidated the use of mass action-based plasmid transfer kinetic estimators. Careful control of the initial parental cell densities permitted evaluations of the true effects of restriction proficiency and toxicant exposure on TOL transfer. At standard donor-to-recipient ratios (10(-3) for PAO1162N and 2 x 10(1) for PAO2002N) and total cell densities (10(5) cells/mm(2) for PAO1162N and 10(6) cells/mm(2) for PAO2002N), plasmid transfer frequencies without toxicant exposure were approximately 10(-7) (events/mm(2))(-1) for PAO1162N and 10(-11) (events/mm(2))(-1) for PAO2002N based on in situ observations of conjugation events. The enumeration of transconjugants via selective plating yielded transfer frequencies that were up to 1 order of magnitude lower. Premating exposure to sodium dodecyl sulfate (1 to 10 mM) significantly increased the transfer frequency for the restriction-proficient strain PAO2002N (P < 0.05) but not for the restriction-deficient strain PAO1162N. On the other hand, premating exposure to ethanol, toluene, or phenol had no positive effect on the plasmid transfer frequency. Clearly, restriction proficiency provides a strong barrier to interspecific transfer of the TOL plasmid, and this barrier was only marginally attenuated by recipient exposure to toxicants within the ranges examined.
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Affiliation(s)
- Catalina Arango Pinedo
- Environmental Engineering Program, Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut, USA
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21
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Eschbach M, Schreiber K, Trunk K, Buer J, Jahn D, Schobert M. Long-term anaerobic survival of the opportunistic pathogen Pseudomonas aeruginosa via pyruvate fermentation. J Bacteriol 2004; 186:4596-604. [PMID: 15231792 PMCID: PMC438635 DOI: 10.1128/jb.186.14.4596-4604.2004] [Citation(s) in RCA: 182] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Denitrification and arginine fermentation are central metabolic processes performed by the opportunistic pathogen Pseudomonas aeruginosa during biofilm formation and infection of lungs of patients with cystic fibrosis. Genome-wide searches for additional components of the anaerobic metabolism identified potential genes for pyruvate-metabolizing NADH-dependent lactate dehydrogenase (ldhA), phosphotransacetylase (pta), and acetate kinase (ackA). While pyruvate fermentation alone does not sustain significant anaerobic growth of P. aeruginosa, it provides the bacterium with the metabolic capacity for long-term survival of up to 18 days. Detected conversion of pyruvate to lactate and acetate is dependent on the presence of intact ldhA and ackA-pta loci, respectively. DNA microarray studies in combination with reporter gene fusion analysis and enzyme activity measurements demonstrated the anr- and ihfA-dependent anaerobic induction of the ackA-pta promoter. Potential Anr and integration host factor binding sites were localized. Pyruvate-dependent anaerobic long-term survival was found to be significantly reduced in anr and ihfA mutants. No obvious ldhA regulation by oxygen tension was observed. Pyruvate fermentation is pH dependent. Nitrate respiration abolished pyruvate fermentation, while arginine fermentation occurs independently of pyruvate utilization.
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Affiliation(s)
- Martin Eschbach
- Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, D-38106 Braunschweig, Germany
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22
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Hasegawa N, Arai H, Igarashi Y. Two c-type cytochromes, NirM and NirC, encoded in the nir gene cluster of Pseudomonas aeruginosa act as electron donors for nitrite reductase. Biochem Biophys Res Commun 2001; 288:1223-30. [PMID: 11700043 DOI: 10.1006/bbrc.2001.5919] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Three c-type cytochromes, NirM, NirC, and NirN, are encoded in the nirSMCFDLGHJEN gene cluster for cytochrome cd(1)-type nitrite reductase (NIR) of Pseudomonas aeruginosa. nirS is the structural gene for NIR. NirM (cytochrome c(551)) is reported to be a physiological electron donor for nitrite reductase. The respective functions of NirC and NirN have remained unclear. In this study, we produced recombinant NirC and NirN in P. aeruginosa, and purified them from the periplasmic fraction. N-terminal amino acid sequences of the purified proteins showed that the N-terminal 31 and 18 residues of NirC and NirN precursors were cleaved, respectively, indicating that cleaved peptides act as signals for membrane translocation. In addition, the ability of NirC for electron donation to nitrite reductase was investigated. NirC, as well as NirM, was able to mediate the electron donation from the membrane electron pathway to NIR, suggesting that the structural gene for NIR is followed by the genes for two electron donors for NIR.
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Affiliation(s)
- N Hasegawa
- Department of Biotechnology, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
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23
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Arai H, Kodama T, Igarashi Y. Effect of nitrogen oxides on expression of the nir and nor genes for denitrification in Pseudomonas aeruginosa. FEMS Microbiol Lett 1999; 170:19-24. [PMID: 9919648 DOI: 10.1111/j.1574-6968.1999.tb13350.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The activity of the promoters involved in transcription of the genes (nirS, nirQ and norC) required for anaerobic reduction of nitrite and nitric oxide was investigated in NIR- and NOR-deficient mutants of Pseudomonas aeruginosa. The transcriptional activity of these three promoters was induced by nitrite in a wild-type strain and the activity was low in an nirS mutant. In norCBD and nirQOP mutants, which were expected to accumulate nitric oxide because of a lack of nitric oxide reductase activity, the norC and nirQ promoters showed significantly enhanced activity in promoting transcription relative to the parental strain, even at low nitrite concentrations. These results suggest that the nirQ and norC promoters are regulated by the concentration of endogenous nitric oxide rather than that of nitrite.
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Affiliation(s)
- H Arai
- Institute of Physical and Chemical Research (RIKEN), Saitama, Japan
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24
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Hasegawa N, Arai H, Igarashi Y. Activation of a consensus FNR-dependent promoter by DNR of Pseudomonas aeruginosa in response to nitrite. FEMS Microbiol Lett 1998; 166:213-7. [PMID: 9770276 DOI: 10.1111/j.1574-6968.1998.tb13892.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Expression of the enzymes for anaerobic nitrate respiration of Pseudomonas aeruginosa requires two CRP/FNR-related transcriptional regulators, ANR and DNR. Activity of the consensus CRP- or FNR-dependent promoter in the anr and dnr deficient mutants was investigated. The CRP-dependent promoter was active in the mutant strains. Both regulators could activate the promoter with a consensus FNR-binding motif. DNR-dependent activation was nitrite-dependent, whereas activation by ANR was not, suggesting that only DNR is involved in sensing nitrogen oxides.
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Affiliation(s)
- N Hasegawa
- Department of Biotechnology, University of Tokyo, Japan
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25
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Kawasaki S, Arai H, Kodama T, Igarashi Y. Gene cluster for dissimilatory nitrite reductase (nir) from Pseudomonas aeruginosa: sequencing and identification of a locus for heme d1 biosynthesis. J Bacteriol 1997; 179:235-42. [PMID: 8982003 PMCID: PMC178684 DOI: 10.1128/jb.179.1.235-242.1997] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The primary structure of an nir gene cluster necessary for production of active dissimilatory nitrite reductase was determined from Pseudomonas aeruginosa. Seven open reading frames, designated nirDLGHJEN, were identified downstream of the previously reported nirSMCF genes. From nirS through nirN, the stop codon of one gene and the start codon of the next gene were closely linked, suggesting that nirSMCFDLGHJEN are expressed from a promoter which regulates the transcription of nirSM. The amino acid sequences deduced from the nirDLGH genes were homologous to each other. A gene, designated nirJ, which encodes a protein of 387 amino acids, showed partial identity with each of the nirDLGH genes. The nirE gene encodes a protein of 279 amino acids homologous to S-adenosyl-L-methionine:uroporphyrinogen III methyltransferase from other bacterial strains. In addition, NirE shows 21.0% identity with NirF in the N-terminal 100-amino-acid residues. A gene, designated nirN, encodes a protein of 493 amino acids with a conserved binding motif for heme c (CXXCH) and a typical N-terminal signal sequence for membrane translocation. The derived NirN protein shows 23.9% identity with nitrite reductase (NirS). Insertional mutation and complementation analyses showed that all of the nirFDLGHJE genes were necessary for the biosynthesis of heme d1.
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Affiliation(s)
- S Kawasaki
- Department of Biotechnology, University of Tokyo, Bunkyo-ku, Japan
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26
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Smets BF, Rittmann BE, Stahl DA. Quantification of the effect of substrate concentration on the conjugal transfer rate of the TOL plasmid in short-term batch mating experiments. Lett Appl Microbiol 1995; 21:167-72. [PMID: 7576502 DOI: 10.1111/j.1472-765x.1995.tb01033.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Batch mating experiments with Pseudomonas putida PAW 1 (TOL) as a donor and Pseudomonas aeruginosa PAO 1162 as a recipient strain were performed to quantify the effect of the substrate concentration in the mating medium on the observed plasmid transfer rate coefficient. The impact of the substrate concentration in the mating medium was highly correlated with the growth history of the donor strain. When the donor strain was harvested in exponential growth phase, no impact was observed; when the donor strain was taken from the stationary phase, however, a strong impact of the substrate concentration was measured: a 10-fold reduction in the substrate concentration decreased the observed plasmid transfer rate by 55%.
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Affiliation(s)
- B F Smets
- Department of Civil and Environmental Engineering, University of Connecticut, Storrs 06269-2037, USA
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27
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Arai H, Igarashi Y, Kodama T. Expression of the nir and nor genes for denitrification of Pseudomonas aeruginosa requires a novel CRP/FNR-related transcriptional regulator, DNR, in addition to ANR. FEBS Lett 1995; 371:73-6. [PMID: 7664887 DOI: 10.1016/0014-5793(95)00885-d] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A gene, designated dnr, was identified in the vicinity of the structural genes for nitrite reductase (nirS) and nitric oxide reductase (norCB), and the gene for activation of the reductases (nirQ) from Pseudomonas aeruginosa. It encodes a protein of 227 amino acids homologous with the CRP/FNR-family transcriptional regulators. Promoter activities for nirS, nirQ and norCB were considerably reduced in the dnr mutant as well as in the mutant of anr, the other fnr-like regulatory gene from P. aeruginosa. This is the first finding that two CRP/FNR-related regulators are involved in denitrification in one strain.
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Affiliation(s)
- H Arai
- Department of Biotechnology, University of Tokyo, Japan
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28
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Smets BF, Rittmann BE, Stahl DA. Stability and conjugal transfer kinetics of a TOL plasmid in Pseudomonas aeruginosa PAO 1162. FEMS Microbiol Ecol 1994. [DOI: 10.1111/j.1574-6941.1994.tb00256.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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29
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Fang FC, Durland RH, Helinski DR. Mutations in the gene encoding the replication-initiation protein of plasmid RK2 produce elevated copy numbers of RK2 derivatives in Escherichia coli and distantly related bacteria. Gene X 1993; 133:1-8. [PMID: 8224880 DOI: 10.1016/0378-1119(93)90217-q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Mini-replicons of the broad-host-range plasmid RK2 with increased copy number (cn) due to mutations in the gene encoding the essential replication initiation protein TrfA are described. The cn of these derivatives have been determined in Escherichia coli, Pseudomonas aeruginosa and Agrobacterium tumefaciens and were found to be elevated in all three bacterial hosts. One of the cn mutations was introduced into the intact 60-kb RK2 plasmid by homologous recombination in vivo, resulting in an approximately twofold cn increase. The expression of trfA from this mutant RK2 plasmid did not respond to the cn change as predicted by a simple transcription rate-limitation, replication control model. Implications for the model of RK2 replication control and the potential use of mutant RK2 mini-replicons as high-copy broad-host-range gene cloning vectors are discussed.
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Affiliation(s)
- F C Fang
- Center for Molecular Genetics, University of California, San Diego, La Jolla 92093-0634
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30
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Smets BF, Rittmann BE, Stahl DA. The specific growth rate of Pseudomonas putida PAW1 influences the conjugal transfer rate of the TOL plasmid. Appl Environ Microbiol 1993; 59:3430-7. [PMID: 8250565 PMCID: PMC182470 DOI: 10.1128/aem.59.10.3430-3437.1993] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The kinetics of the conjugal transfer of a TOL plasmid were investigated by using Pseudomonas putida PAW1 as the donor strain and P. aeruginosa PAO 1162 as the recipient strain. Short-term batch mating experiments were performed in a nonselective medium, while the evolution of the different cell types was determined by selective plating techniques. The experimental data were analyzed by using a mass action model that describes plasmid transfer kinetics. This method allowed analysis of the mating experiments by a single intrinsic kinetic parameter for conjugal plasmid transfer. Further results indicated that the specific growth rate of the donor strain antecedent to the mating experiment had a strong impact on the measured intrinsic plasmid transfer rate coefficient, which ranged from 1 x 10(-14) to 5 x 10(-13) ml per cell per min. Preliminary analysis suggested that the transfer rates of the TOL plasmid are large enough to maintain the TOL plasmid in a dense microbial community without selective pressures.
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Affiliation(s)
- B F Smets
- Department of Civil Engineering, University of Illinois, Urbana 61801
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31
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Arai H, Igarashi Y, Kodama T. Nitrite activates the transcription of the Pseudomonas aeruginosa nitrite reductase and cytochrome c-551 operon under anaerobic conditions. FEBS Lett 1991; 288:227-8. [PMID: 1652475 DOI: 10.1016/0014-5793(91)81040-f] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The transcription of the Pseudomonas aeruginosa denAB operon, which consists of the nitrite reductase and cytochrome c-551 genes, is induced under anaerobic conditions. However, under anaerobic non-denitrifying conditions (anaerobic growth on arginine), the promoter activity of the operon was approximately one-fifth of that under anaerobic denitrifying conditions (anaerobic growth in the presence of nitrite or nitrate). This result clearly demonstrates that the presence of nitrite or nitrate activates the transcription of P. aeruginosa denAB operon under anaerobic conditions.
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Affiliation(s)
- H Arai
- Department of Agricultural Chemistry, University of Tokyo, Japan
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32
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Arai H, Igarashi Y, Kodama T. Anaerobically induced expression of the nitrite reductase cytochrome c-551 operon from Pseudomonas aeruginosa. FEBS Lett 1991; 280:351-3. [PMID: 1849489 DOI: 10.1016/0014-5793(91)80329-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The nitrite reductase gene (denA) and the cytochrome c-551 gene (denB) are located only 50 bp apart from each other in the Pseudomonas aeruginosa chromosome. We report evidence that these two genes are co-transcribed as an operon only under anaerobic (denitrifying) conditions. The nucleotide sequence of the promoter (regulatory) region of the operon is highly AT-rich and contains a sequence closely resembling the consensus FNR binding site in E. coli.
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Affiliation(s)
- H Arai
- Department of Agricultural Chemistry, University of Tokyo, Japan
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33
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Chen JH, Chen ZY, Chow TY, Chen JC, Tan ST, Hsu WH. Nucleotide sequence and expression of the isoamylase gene from an isoamylase-hyperproducing mutant, Pseudomonas amyloderamosa JD210. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1087:309-15. [PMID: 2248978 DOI: 10.1016/0167-4781(90)90004-l] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The isoamylase gene (ISO) of Pseudomonas amyloderamosa JD210, an isoamylase-hyperproducing mutant, was cloned in an isoamylase-deficient and transformable mutant strain K31. By deletion analysis, the ISO gene was found to be located within a 3.3 kilobases BamHI fragment. Its nucleotide sequence contained an open reading frame of 2328 nucleotides (776 amino acids) encoding a secreted isoamylase precursor. The ISO gene fragment was inserted into plasmids pKT230 and pBR 322 in opposite orientations. The expression of the ISO gene in the constructed plasmids was compared in P. amyloderamosa K31, Pseudomonas aeruginosa PAO1-161, Pseudomonas putida mt-2 and Escherichia coli HB101. In all transformed cells, the majority of the isoamylase produced was secreted and higher isoamylase activities were obtained in transformats with the transcriptional direction of the ISO gene similar to the nearby drug-determinant gene of the vector.
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Affiliation(s)
- J H Chen
- Culture Collection and Research Center, Food Industry Research and Development Institute, Hsinchu, Taiwan, China
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Nieto C, Fernández-Tresguerres E, Sánchez N, Vicente M, Díaz R. Cloning vectors, derived from a naturally occurring plasmid of Pseudomonas savastanoi, specifically tailored for genetic manipulations in Pseudomonas. Gene 1990; 87:145-9. [PMID: 2110095 DOI: 10.1016/0378-1119(90)90507-n] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A minimal replicon of 1.8 kb isolated from a 10-kb plasmid of Pseudomonas savastanoi, pPS10, has been used to obtain a collection of small vectors specific for Pseudomonas (P. savastanoi, P. aeruginosa and P.putida). In addition, shuttle vectors that can be established both in Pseudomonas and Escherichia coli have been constructed by adding a pMB9 replicon. The vectors permit cloning of DNA fragments generated by a variety of restriction enzymes using different antibiotic resistance markers for selection and offer the possibility to screen recombinants by insertional inactivation. This cloning system can be used to establish recombinant plasmids in Pseudomonas either at low or high copy number. pPS10 derivatives are compatible with other Pseudomonas vectors derived from broad-host-range replicons of the incompatibility groups P1, P4/Q and W. Introduction and expression of the iaaMH operon in a P. savastanoi mutant deficient in the production of indoleacetic acid has been achieved using one of these vectors.
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Affiliation(s)
- C Nieto
- Centro de Investigaciones Biológicas, (C.S.I.C.) Madrid, Spain
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35
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Cervantes C, Ohtake H, Chu L, Misra TK, Silver S. Cloning, nucleotide sequence, and expression of the chromate resistance determinant of Pseudomonas aeruginosa plasmid pUM505. J Bacteriol 1990; 172:287-91. [PMID: 2152903 PMCID: PMC208430 DOI: 10.1128/jb.172.1.287-291.1990] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The chromate resistance determinant of Pseudomonas aeruginosa plasmid pUM505 was cloned into broad-host-range vector pSUP104. The hybrid plasmid containing an 11.1-kilobase insert conferred chromate resistance and reduced uptake of chromate in P. aeruginosa PAO1. Resistance to chromate was not expressed in Escherichia coli. Contiguous 1.6- and 6.3-kilobase HindIII fragments from this plasmid hybridized to pUM505 but not to P. aeruginosa chromosomal DNA and only weakly to chromate resistance plasmids pLHB1 and pMG6. Further subcloning produced a plasmid with an insert of 2,145 base pairs, which was sequenced. Analysis of deletions revealed that a single open reading frame was sufficient to determine chromate resistance. This open reading frame encodes a highly hydrophobic polypeptide, ChrA, of 416 amino acid residues that appeared to be expressed in E. coli under control of the T7 promoter. No significant homology was found between ChrA and proteins in the amino acid sequence libraries, but 29% amino acid identity was found with the ChrA amino acid sequence for another chromate resistance determinant sequenced in this laboratory from an Alcaligenes eutrophus plasmid (A. Nies, D. Nies, and S. Silver, submitted for publication).
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Affiliation(s)
- C Cervantes
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago 60680
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36
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Frey J, Mudd EA, Krisch HM. A bacteriophage T4 expression cassette that functions efficiently in a wide range of gram-negative bacteria. Gene X 1988; 62:237-47. [PMID: 3259198 DOI: 10.1016/0378-1119(88)90562-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have constructed a derivative of the broad-host-range vector RSF1010. This plasmid, p alpha omega, contains an expression cassette derived from bacteriophage T4 gene 32, into which we have inserted the coding sequence for the xylE enzyme (C2,3O) of the TOL plasmid pWWO. The composite plasmid, p alpha xylE omega, was transferred by conjugal mobilisation into a variety of Gram-negative bacteria (Agrobacter, Paracoccus, Erwinia, Pseudomonas, Rhizobium and Xanthomonas). High levels of C2,3O activity were found in almost all of the extracts. Polyacrylamide gel electrophoresis of these extracts revealed a prominent protein band at 35 kDa whose identity as the C2,3O gene product was confirmed by immunoblotting. We have mapped the 5' ends of the gene 32/xylE hybrid transcripts. In all of the Gram-negative bacteria, the proximal P2 promoter is the most efficient promoter in the cassette. In most of the strains a weaker and more distal promoter activity (Pl) was also detected. In both uninfected and phage-infected Escherichia coli cells, the transcript produced from this promoter is processed at a specific site upstream from the gene 32 start codon. The same processing occurred in all the bacterial species examined. The decay of the hybrid xylE transcript has been analyzed in E. coli and Erwinia, and in both strains this mRNA was among the most stable.
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Affiliation(s)
- J Frey
- Department of Biochemistry, University of Geneva, Switzerland
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37
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Andersen K, Wilke-Douglas M. Genetic and physical mapping and expression in Pseudomonas aeruginosa of the chromosomally encoded ribulose bisphosphate carboxylase genes of Alcaligenes eutrophus. J Bacteriol 1987; 169:1997-2004. [PMID: 3106327 PMCID: PMC212071 DOI: 10.1128/jb.169.5.1997-2004.1987] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have previously shown that functional ribulose bisphosphate carboxylase (RuBPCase, rbc) genes in Alcaligenes eutrophus ATCC 17707 are present both on the chromosome and on the indigenous plasmid pAE7. Here we demonstrate that the chromosomal rbc locus encodes both a large (rbcL)- and a small (rbcS)-subunit gene. A 2.3-kilobase DNA fragment containing both subunit genes was subcloned into the broad-host-range vector pRK310 to yield plasmid pAE312. This plasmid was transferred into Pseudomonas aeruginosa in which expression of both the rbcL and rbcS genes took place, as demonstrated by Western blot analysis. A high level of RuBPCase activity was observed for P. aeruginosa(pAE312), suggesting that assembly of the subunits took place. Plasmid pAE312 was mutagenized with Tn5 in Escherichia coli. Complementation of A. eutrophus RuBPCase structural gene mutants with pAE312 containing mapped Tn5 insertions allowed functional analysis of the rbc gene region. The polar effect of the Tn5 insertions suggested that the two subunit genes were cotranscribed in A. eutrophus, with rbcL located promoter proximal. Northern blot analysis of total RNA from P. aeruginosa(pAE312) confirmed cotranscription of the two subunit genes. DNA probes containing both the rbcL and rbcS genes, or fragments of each gene, all hybridized to a predominant transcript about 2.1-kilobases long. These observations indicate that the chromosomally encoded rbcL and rbcS genes of A. eutrophus constitute an operon.
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Mermod N, Ramos JL, Lehrbach PR, Timmis KN. Vector for regulated expression of cloned genes in a wide range of gram-negative bacteria. J Bacteriol 1986; 167:447-54. [PMID: 3525513 PMCID: PMC212908 DOI: 10.1128/jb.167.2.447-454.1986] [Citation(s) in RCA: 105] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A pKT231-based broad-host-range plasmid vector was constructed which enabled regulation of expression of cloned genes in a wide range of gram-negative bacteria. This vector, pNM185, contained upstream of its EcoRI, SstI, and SstII cloning sites the positively activated pm twin promoters of the TOL plasmid and xylS, the gene of the positive regulator of these promoters. Expression of cloned genes was induced with micromolar quantities of benzoate or m-toluate, the inexpensive coinducers of the pm promoters. Expression of a test gene, xylE, which specifies catechol 2,3-dioxygenase, cloned in this vector was tested in representative strains of a variety of gram-negative bacteria. Regulated expression of xylE was observed in most strains examined, and induced levels of enzyme representing up to 5% of total cellular protein and ratios of induced:noninduced levels of enzyme up to a factor of 600 were observed. The level of xylE gene expression in different bacteria tended to be correlated with their phylogenetic distance from Pseudomonas putida.
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Bagdasarian M, Lurz R, Rückert B, Franklin FC, Bagdasarian MM, Frey J, Timmis KN. Specific-purpose plasmid cloning vectors. II. Broad host range, high copy number, RSF1010-derived vectors, and a host-vector system for gene cloning in Pseudomonas. Gene X 1981; 16:237-47. [PMID: 6282695 DOI: 10.1016/0378-1119(81)90080-9] [Citation(s) in RCA: 862] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Host-vector systems have been developed for gene cloning in the metabolically versatile bacterial genus Pseudomonas. They comprise restriction-negative host strains of Pseudomonas aeruginosa and P. putida and new cloning vectors derived from the high-copy-number, broad-host-range plasmid RSF1010, which are stably maintained in a wide range of Gram-negative bacteria. These plasmids contain EcoRI, SstI, HindIII, XmaI, XhoI, SalI, BamHI, and ClaI insertion sites. All cloning sites, except for BamHI and ClaI, are located within antibiotic-resistance genes' insertional inactivation of these genes during hybrid plasmid formation provides a readily scored phenotypic change for the rapid identification of bacterial clones carrying such hybrids. One of the new vector plasmids is a cosmid that may be used for the selective cloning of large DNA fragments by in vitro lambda packaging. An analogous series of vectors that are defective in their plasmid-mobilization function, and that exhibit a degree of biological containment comparable to that of current Escherichia coli vector plasmids, are also described.
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41
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Yano K, Nishi T. pKJ1, a naturally occurring conjugative plasmid coding for toluene degradation and resistance to streptomycin and sulfonamides. J Bacteriol 1980; 143:552-60. [PMID: 7009551 PMCID: PMC294313 DOI: 10.1128/jb.143.2.552-560.1980] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Pseudomonas sp. TA8 isolated by m-toluate enrichment from an aqueous sample metabolized toluene and m- and p-xylenes via the meta cleavage pathway, and manifested specific resistance to streptomycin and sulfonamides. A variety of experiments revealed that the pKJ1 plasmid of about 150 megadaltons carried by TA8 specified both the toluene and xylene degradative function (the Tol function) and streptomycin/sulfonamide resistance. The deletion of a segment of pKJ1 (about 22 megadaltons) resulted in the loss of the Tol function. pKJ1 was not assigned to Pseudomonas incompatibility group P-1, P-2, P-3, or P-9.
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43
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Nakazawa T. TOL plasmid in Pseudomonas aeruginosa PAO: thermosensitivity of self-maintenance and inhibition of host cell growth. J Bacteriol 1978; 133:527-35. [PMID: 415040 PMCID: PMC222054 DOI: 10.1128/jb.133.2.527-535.1978] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The TOL plasmid originally isolated in Pseudomonas putida (arvilla) mt-2 was transmissible to strains of the fluorescens group of Pseudomonas, i.e., P. putida, P. fluorescens, and P. aeruginosa, except for a strain of P. aeruginosa, strain PAO. The same strain, however, could accept the plasmid when its restriction and modification abilities were lost by mutations or by growing at high temperature. In addition, the transmissibility of the TOL plasmid from strain PAO to P. putida was low when the plasmid was modified by the donor. By using P. aeruginosa PAO carrying the TOL plasmid, the stability and genetic expression of the plasmid as well as its effect on the host cell growth were examined. Thus the self-maintenance of the plasmid was found to be thermosensitive. Furthermore, the TOL plasmid inhibited the growth of strain PAO at high temperature, accompanied by the formation of some filamentous cells. These thermosensitive properties of the TOL plasmid were host dependent and not exhibited in another strain of P. aeruginosa.
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44
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Sutherland R, Rolinson GN. -amino-p-hydroxybenzylpenicillin (BRL 2333), a new semisynthetic penicillin: in vitro evaluation. Antimicrob Agents Chemother 1976; 10:411-5. [PMID: 5000265 PMCID: PMC429762 DOI: 10.1128/aac.10.3.411] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
A class of mutants in Pseudomonas aeruginosa have been found that are tolerant to aeruginocin 41 and also hypersensitive to aminoglycosides. They do not show any changes in susceptibility to a wide range of other toxic agents, including antibiotics and surfactants. This tol locus, tolA, has been mapped at 10 min from the FP2 origin and linked to carA (carbamyl phosphate synthetase) by transduction and conjugation. By selecting for revertants of the hypersensitivity phenotype, revertants to tol+ were found, indicating that it is the tolA locus that is responsible for this specific hypersensitivity. The results indicate that a specific mechanism exists for the intrinsic resistance of P. aeruginosa to aminoglycosides.
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45
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Jenkins ST, Beard JP, Howe TG. Male-specific bacteriophage MS2 propagation in fluorophenylalanine-resistant Escherichia coli K12. J Virol 1974; 14:50-5. [PMID: 4599509 PMCID: PMC355477 DOI: 10.1128/jvi.14.1.50-55.1974] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mutation of Escherichia coli K12 HfrH to resistance to fluorophenylalanine resulted in changes in the plaque morphology of bacteriophage MS2 on this strain and led to an increased efficiency of propagation of the phage in liquid cultures. Evidence was obtained that the mutation resulted in inhibition of early lysis in infected cells and that lysis involved the production of a lysozyme. Genetic studies suggested that the observed pleiotropy of the resistance mutation was due to informational suppression.
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46
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Krishnapillai V. A novel transducing phage. Its role in recognition of a possible new host-controlled modification system in Pseudomonas aeruginosa. MOLECULAR & GENERAL GENETICS : MGG 1972; 114:134-43. [PMID: 4622961 DOI: 10.1007/bf00332784] [Citation(s) in RCA: 99] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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