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PubMed2002

Pseudomonas thermotolerans sp. nov., a thermotolerant species of the genus Pseudomonas sensu stricto.

A bacterium, strain CM3(T), which has an optimal growth temperature of approximately 47 degrees C and a maximal growth temperature of 55 degrees C, was isolated from a hexadecane enrichment culture, obtained from a sample of the industrial cooking water of a cork-processing plant. 16S rRNA gene sequence analysis demonstrated that this Gram-negative, aerobic, rod-shaped bacterium is related to species of the genus Pseudomonas. Phosphatidylethanolamine and phosphatidylglycerol were the major polar lipids of this isolate and the total fatty acid methyl ester profile revealed predominantly C16:1 and C18:1 at a growth temperature of 25 degrees C, whereas, at a growth temperature of 50 degrees C, C16:0 was the dominant fatty acid. This is the first report of a species of Pseudomonas sensu stricto that may be considered to be truly thermotolerant. Isolate CM3(T) (= DSM 14292(T) = LMG 21284(T)) represents the type strain of a novel species of the genus Pseudomonas, named Pseudomonas thermotolerans sp. nov.

Base Composition↗

PubMed1983

Molecular cloning of the Pseudomonas carboxypeptidase G2 gene and its expression in Escherichia coli and Pseudomonas putida.

The gene coding for carboxypeptidase G2 was cloned from Pseudomonas sp. strain RS-16 into Escherichia coli W5445 by inserting Sau3A-generated DNA fragments into the BamHI site of pBR322. The plasmid isolated, pNM1, was restriction mapped, and the position of the gene on the 5.8-megadalton insert was pinpointed by subcloning. The expression of carboxypeptidase in E. coli was 100-fold lower than in the Pseudomonas sp. strain. When the cloned gene was subcloned into the Pseudomonas vector pKT230 and introduced into Pseudomonas putida 2440, a 30-fold increase in expression over that obtained in E. coli was observed. High expression (up to 5% soluble protein) was obtained in E. coli by subcloning a 3.1-megadalton Bg/II fragment into the BamHI site of pAT153. The increased expression was orientation dependent and is presumed to be due to transcriptional readthrough from the Tc promoter of the vector. Production of carboxypeptidase was shown to be induced (two-fold) by the presence of folic acid, and the mature protein was shown to be located in the periplasmic space of E. coli.

Carboxypeptidases↗

PubMed2005

Production and properties of an inhibitor of the Pseudomonas autoinducer by Pseudomonas aeruginosa.

An inhibitor was found in the culture fluid of Pseudomonas aeruginosa PAO1, which could inhibit the activity of the Pseudomonas autoinducer (PAI). The maximal inhibitory activity occurred in stationary phase culture sup ernatant. The PAI inhibitor did not influence the cell growth and the PAI production by P. aeruginosa PAO1 when the PAI inhibitor was added into culture medium. The induced expression of lacZ in the reporter strain Agrobacterium tumefaciens NT1 was suppressed by this PAI inhibitor, whereas inhibition could be relieved by increasing the auto inducer concentration. The quorum sensing of P. aeruginosa was inhibited presumably by inhibiting the inducing activity of Pseudomonas autoinducer but not by inhibiting the production of Pseudomonas autoinducer. It was demonstrated that the structure of the PAI inhibitor was different from that of acyl-homoserine lactones.

4-Butyrolactone↗

PubMedDate not supplied

[Mobilization using incompatibility group P1 plasmids in strains of Pseudomonas pseudomallei and Pseudomonas mallei as potential vectors for DNA cloning].

The cells of Pseudomonas pseudomallei and Pseudomonas mallei have been shown to serve as recipients for the plasmid RSF1010 and its recombinant derivatives pVA1 and pVA4. The conjugative plasmids RP1 and pTH10 of the incompatibility group P1 are able to mobilize the nontransmissive vector plasmids for conjugation transfer into Pseudomonas pseudomallei and Pseudomonas mallei strains. The SmR determinant of the plasmid RSF1010 is expressed in the latter strains. These data makes the mentioned vector plasmids the candidates for DNA cloning in these strains.

Burkholderia pseudomallei↗

PubMed1994

[Controlled-expression vector for Pseudomonas bacteria involving regulatory elements of trpIBA genes of Pseudomonas putida].

A bireplicon controlled-expression vector pPS10 was developed based, on trpIBA genes of Pseudomonas putida. It is a low-copy-number vector in Pseudomonas bacteria, and a high-copy-number vector in Escherichia coli. The vector is 10.4 kilobase pairs (kb), determines resistance to kanamycin, carries a replicon of cryptic Pseudomonas pMK1 plasmid; a pBR322 replicon; the par locus of pMT2 plasmid; and the trpI gene of P. putida, which encodes the activator protein and the promoter Pba of trpBA genes. Expression of the promoter is induced by the TrpI protein activator and the precursor of tryptophan, indole-3-glycerolphosphate (InGP). InGP is an unstable compound, and its accumulation in bacterial cells is ensured by using trpE mutants grown in the presence of anthranilate; no InGP is produced among trpE mutants on the media supplemented with tryptophan. As shown in the pheA gene of E. coli, the expression of genetic material cloned under control of the Pba promoter into the pPS10 vector, may be enhanced more than 70-fold in cells of Pseudomonas under conditions of InGP accumulation.

Gene Expression Regulation, Bacterial↗

PubMed2006

Pseudomonas aeruginosa and Pseudomonas putida outbreak associated with contaminated water outlets in an oncohaematology paediatric unit.

This paper describes an outbreak of Pseudomonas aeruginosa and Pseudomonas putida that occurred in an oncohaematology paediatric unit between January and April 2005. Eight children had nosocomial infections due to P. aeruginosa (N=5) or P. putida (N=3), which were recovered from central venous catheter blood cultures (N=4), the catheter exit site alone (N=2), or the catheter exit site and the catheter tip (N=2). Subsequent investigation showed that contaminated water outlets represented the possible source of spread. Studies of nursing and environmental cleaning practices revealed two modes of catheter contamination. A reduction in the size of the catheter dressing at the exit site gave less protective cover during showers, and a detergent-disinfectant diluted with tap water had contaminated perfusion bottles. Repetitive intergenic consensus polymerase chain reaction indicated two discrete patterns for P. aeruginosa and one for P. putida. The water network was chlorinated, and disposable seven-day filters were fitted on all taps and showers. Due to the deleterious effects of chlorination on the water network and the cost of the weekly filter change, a water loop producing microbiologically controlled water was installed. In addition, the concentration of the detergent-disinfectant was increased and refillable sprayers were replaced with ready-to-use detergent-disinfectant solution for high-risk areas. Following these measures, no Pseudomonas spp. have since been isolated in clinical or environmental samples from the ward.

Adolescent↗

PubMed2004

PCR-based assay for differentiation of Pseudomonas aeruginosa from other Pseudomonas species recovered from cystic fibrosis patients.

Pseudomonas aeruginosa is the major opportunistic bacterial pathogen in persons with cystic fibrosis (CF); pulmonary infection occurs in approximately 80% of adult CF patients. Much of CF patient management depends on accurate identification of P. aeruginosa from sputum culture. However, identification of this species may be problematic due to the marked phenotypic variability demonstrated by CF sputum isolates and the presence of other closely related species. To facilitate species identification, we used 16S ribosomal DNA (rDNA) sequence data to design PCR assays intended to provide genus- or species-level identification. Both assays yielded DNA fragments of the predicted size. We tested 42 culture collection strains (including 14 P. aeruginosa strains and 28 strains representing 16 other closely related Pseudomonas species) and 43 strains that had been previously identified as belonging to 28 nonpseudomonal species also recovered from CF patient sputum. Based on these 85 strains, the specificity and sensitivity of both assays were 100%. To further assess the utility of the PCR assays, we tested 66 recent CF sputum isolates. The results indicated that preliminary phenotypic testing had misidentified several isolates. The 16S rDNA sequence was determined for 38 isolates, and in all cases it confirmed the results of the PCR assays. Thus, we have designed two PCR assays: one is specific for the genus Pseudomonas, while the other is specific for P. aeruginosa. Both assays show 100% sensitivity and specificity.

Bacterial Typing Techniques↗

PubMed2003

Molecular analysis of Pseudomonas aeruginosa protease IV expressed in Pseudomonas putida.

PURPOSE: In this study, the protease IV gene of Pseudomonas aeruginosa was expressed in the nonocular pathogenic host, Pseudomonas putida, to elucidate the molecular properties and virulence contribution of the enzyme. Recent determination of the protease IV gene sequence suggests that the protein of 463 amino acids contains a signal sequence, a propeptide domain, and a mature protease. The only form of this protein that has been detected previously is the extracellular mature protease. METHODS: The protease IV gene was cloned and expressed in a protease IV-negative Pseudomonas species, P. putida. The cloned protease IV gene product was analyzed to identify biochemical, enzymatic, and immunologic properties and its contribution to corneal virulence. RESULTS: P. putida expressing the cloned protease IV gene had significantly greater extracellular enzyme activity than P. aeruginosa. These P. putida cell extracts produced a protein with the same molecular mass as mature protease IV and two other polypeptides representing larger precursors, all of which were recognized by protease IV-specific antibodies. P. putida producing protease IV, relative to P. putida with the vector alone, caused a threefold increase in ocular inflammation and tissue damage when intrastromally injected into rabbit corneas. CONCLUSIONS: The present study demonstrates for the first time that protease IV is synthesized as a large precursor that is processed intracellularly through an intermediate form and secreted into the extracellular milieu as a mature protease. The results also confirm a significant correlation between production of protease IV and corneal virulence.

Amino Acid Sequence↗

PubMed1990

[Detection specificity of an optimal solid-phase enzyme immunoassay for Pseudomonas aeruginosa and Pseudomonas mallei].

The evaluation and application of an enzyme-immunoassay (EIA) for the detection of Pseudomonas (Ps.) aeruginosa and Ps. mallei is described. Polystyrene beads (1/4'') as the solid-phase are prepared by coating the balls with purified IgG from the serum of rabbits (9-12 micrograms/bead) in Coating-Buffer pH 9.6. After washing the balls they are saturated with 10% BSA or 10% FCS in PBS-Tween 20. The bacteria bound to the coated balls are detected by the specific peroxidase labelled IgG. This EIA using Ps. aeruginosa (P9) as a model is able to detect this bacterium within 5 hours, with stored coated balls 3.5 hours, with a detection limit of 10(4) CFU. Nine Pseudomonas-strains react stronger than other strains. These cross-reactions can be substantially reduced by absorbing the P9-conjugate with the cells of Ps. stutzeri (P15). With the other Pseudomonas-strains a high specificity is found with the P9-conjugate. After modifying this EIA for the detection of Ps. mallei (P18) the strains Ps. mallei (P57), Ps. pseudomallei (P17) and Ps. cepacia (P67) react with the P18-conjugate. With the other tested strains a high specificity is found at 10(7) CFU. The polystyrene bead-EIA is recommended as a sensitive and specific test for the detection of Ps. aeruginosa in about 5 resp. 3.5 hours. It only requires normal laboratory equipment and is thus a highly practicable method for routine diagnostic of Ps. aeruginosa.

Cross Reactions↗

PubMed1966

Metabolism of Pipecolic Acid in a Pseudomonas Species IV. Electron Transport Particle of Pseudomonas putida.

Baginsky, Marietta L. (University of California, San Francisco Medical Center, San Francisco), and Victor W. Rodwell. Metabolism of pipecolic acid in a Pseudomonas species. IV. Electron transport particle of Pseudomonas putida. J. Bacteriol. 92:424-432. 1966.-Enzymes of Pseudomonas putida P2 catalyzing oxidation of pipecolate to Delta(1)-piperideine-6-carboxylate are located in a subcellular fraction sedimenting at 105,000 x g. Since this fraction resembles the mammalian electron transport particle in both chemical composition and enzymatic activities, it was termed Pseudomonas P2 electron transport particle (P2-ETP). P2-ETP contains flavin adenine dinucleotide, flavin mononucleotide, iron, copper, and both b- and c-type cytochromes. The reduced type b cytochrome has absorption maxima at 558 to 559, 530, and 427 mmu. Its oxidized pyridine hemochromogen has an absorption maximum at 406 mmu, with a shoulder at 564 mmu. On dithionite reduction, absorption bands with maxima at 556, 522, and 418 mmu are obtained. The reduced type c cytochrome has absorption maxima at 552, 520, and 422 mmu; its reduced pyridine hemochromogen has maxima at 551, 516 to 519, and 418 mmu. No type a cytochrome was detected. P2-ETP catalyzes oxidation of pipecolate and of reduced nicotinamide adenine dinucleotide (NADH(2)) by oxygen. It can also oxidize these compounds, as well as succinate and reduced nicotinamide adenine dinucleotide phosphate, with 2,6-dichlorophenol-indophenol as electron acceptor. Mammalian cytochrome c can be used as an alternate artificial electron acceptor for the oxidation of pipecolate and succinate, but not for oxidation of NADH(2).

Journal Article↗

PubMed2001

Isolation and characterization of group II introns from Pseudomonas alcaligenes and Pseudomonas putida.

Group II introns isolated from Pseudomonas alcaligenes NCIB 9867, Pseudomonas putida NCIB 9869, and P. putida KT2440 were closely related with nucleotide sequence identities of between 87 and 96%. The genome of P. alcaligenes also harbored a truncated group II intron of 682 bp that lacks the gene for the intron-encoded protein (IEP). Unlike most bacterial group II introns, the Pseudomonas introns were found to lack the Zn domains in their IEPs, did not appear to interrupt any genes, and were located downstream of open reading frames which were adjacent to hairpin loop structures that resemble rho-independent terminators. These structures also contain the intron binding sites 1 and 2 (IBS1 and IBS2 sequences) that were required for intron target site recognition in transposition. One of the group II introns found in P. alcaligenes, Xln3, was shown to have transposed from the chromosome to the endogenous pRA2 plasmid at a site adjacent to IBS1- and IBS2-like sequences.

Base Sequence↗

PubMed1987

[Experiences with a Pseudomonas immunoglobulin in ventilated patients with Pseudomonas pneumonia in a surgical intensive care station].

In a clinical trial, the efficacy of a Pseudomonas immunoglobulin was studied in ten ventilated patients suffering from Pseudomonas pneumonia. Compared to ten patients of a previous study who had received a polyvalent immunoglobulin (control group), patients treated with Pseudomonas immunoglobulin fared better with respect to clinical success and duration of treatment, the period of antibiotic treatment being significantly shorter than in the control group.

Adult↗

PubMedDate not supplied

[Experiences with a Pseudomonas immunoglobulin in artificially respirated patients with Pseudomonas pneumonia at a surgical intensive care unit].

Adult↗

PubMed2002

The role of the fatty acid beta-oxidation multienzyme complex from Pseudomonas oleovorans in polyhydroxyalkanoate biosynthesis: molecular characterization of the fadBA operon from P. oleovorans and of the enoyl-CoA hydratase genes phaJ from P. oleovorans and Pseudomonas putida.

In order to investigate the role of the putative epimerase function of the beta-oxidation multienzyme complex (FadBA) in the provision of (R)-3-hydroxyacyl-CoA thioesters for medium-chain-length polyhydroxyalkanoate (PHA(MCL)) biosynthesis, the fadBA(Po) operon of Pseudomonas oleovorans was cloned and characterized. The fadBA(Po) operon and a class-II PHA synthase gene of Pseudomonas aeruginosa were heterologously co-expressed in Escherichia coli to determine whether the putative epimerase function of FadBA(Po) has the ability to provide precursors for PHA accumulation in a non-PHA-accumulating bacterium. Cultivation studies with fatty acids as carbon source revealed that FadBA(Po) did not mediate PHA(MCL) biosynthesis in the E. coli wild-type strain harboring a PHA synthase gene. However, PHA accumulation was strongly impaired in a recombinant E. coli fadB mutant, which harbored a PHA synthase gene. These data indicate that in pseudomonads FadBA does not possess the inherent property, based on a putative epimerase function, to provide the ( R)-enantiomer of 3-hydroxyacyl-CoA efficiently and that other linking enzymes are required to efficiently channel intermediates of beta-oxidation towards PHA(MCL) biosynthesis. However, the phaJ gene from P. oleovorans and from Pseudomonas putida, both of which encoded a 3- Re enoyl-CoA hydratase, was identified. The co-expression of phaJ(Po/Pp) with either a class-II PHA synthase gene or the PHA synthase gene from Aeromonas punctata in E. coli revealed that PhaJ(Po/Pp) mediated biosynthesis of either PHA(MCL), contributing to about 1% of cellular dry mass, or of poly(3-hydroxybutyrate- co-3-hydroxyhexanoate), contributing to 3.6% of cellular dry mass, when grown on decanoate. These data indicate that FadBA(Po)does not mediate the provision of (R)-3-hydroxyacyl-CoA, which resembles FadBA of non-PHA-accumulating bacteria, and that 3- Re enoyl-CoA hydratases are required to divert intermediates of fatty acid beta-oxidation towards PHA biosynthesis in P. oleovorans.

Amino Acid Sequence↗

PubMed2005

Genotype versus phenotype in the circumscription of bacterial species: the case of Pseudomonas stutzeri and Pseudomonas chloritidismutans.

The phenotypic characteristic of strain AW-1(T) of Pseudomonas chloritidismutans that is most relevant from the taxonomic point of view appears to be the capacity of growth under anaerobic conditions using chlorate as electron acceptor. This property is not restricted to this species only within the genus Pseudomonas, since it is also present in strains of genomovars 1 or 5, and 3 of Pseudomonas stutzeri. P. chloritidismutans has been described as a non-denitrifying species, but the isolation of variants that are able to grow anaerobically in the presence of nitrate is possible after subcultivation under selective conditions. The subdivision of P. stutzeri into a number of species on the basis of these characteristics does not help to clarify the phylogenetic relationships among the members of an otherwise coherent group of strains, and the considerations presented in this communication support the reclassification of the new species name P. chloritidismutans, which in our opinion, should be considered as a Junior name of P. stutzeri. A multilocus sequence analysis, together with a phenotypic analysis of the anaerobic oxidative metabolism, gives new insights into the phylogeny and evolution of the species.

Chlorates↗

PubMed1987

Analysis of transcription from the trfA promoter of broad host range plasmid RK2 in Escherichia coli, Pseudomonas putida, and Pseudomonas aeruginosa.

Reverse transcriptase mapping has been used to analyze transcription from the trfA promoter of broad host range plasmid RK2. The results show that trfA operon mRNA has the same 5' end in Pseudomonas aeruginosa, Pseudomonas putida, and Escherichia coli. The strengths of wild-type and mutant trfA promoters, which differ by defined base substitutions, have been compared and the positions of their transcriptional start sites determined. While these base substitutions do not alter the transcriptional start site, they do have marked effects on promoter strength which are broadly similar in each of the host species. A single base pair substitution, which lies in the region corresponding to the E. coli promoter consensus, brings about a large reduction in gene expression while the introduction of a second mutation, at a locus outside this region, has no further effect on promoter strength. The results indicate that these Pseudomonas species possess an RNA polymerase which recognizes the same region of the trfA promoter as that utilized by E. coli RNA polymerase. Within the limits of these observations it is clear that the trfA operon is transcribed from a single promoter which can function efficiently in diverse species, a property which may be important for its broad host range.

Chromosome Mapping↗

PubMed1987

Specific cleavage of Pseudomonas cytochrome-c peroxidase by elastase from Pseudomonas aeruginosa.

The occasional cleavage of the Pseudomonas cytochrome-c peroxidase (ferrocytochrome-c:hydrogen-peroxide oxidoreductase, EC 1.11.1.5) molecule into two well-defined fragments during the preparation of the enzyme is shown to be identical to that caused by elastase isolated from the culture solution of Pseudomonas aeruginosa. A cyanogen bromide fragmentation of proteolytically cleaved and of intact enzyme shows the cleaved peptide bond to be situated in cyanogen bromide fragment II. The amino-acid sequence of this fragment was established by sequencing peptides obtained with trypsin, thermolysin, chymotrypsin and o-iodosobenzoate. It is concluded from the sequence homology that the polypeptide chain of Pseudomonas peroxidase is wrapped around the high-potential heme in a similar manner as in high-potential cytochromes c in general. The specific proteolytic cleavage occurs at a Ser-Val (Leu-Pro) region which is assumed to be the site of attachment between enzyme and membrane. The cleavage of the Ser-Val bond renders the peroxidase molecule enzymatically inactive by impeding the conformational changes essential for the function of the native enzyme.

Amino Acid Sequence↗

PubMed1977

Experimental pneumonia due to Pseudomonas aeruginosa in leukopenic dogs: prolongation of survival by combined treatment with passive antibody to Pseudomonas and granulocyte transfusions.

Treatment with type-specific IgG antibody to Pseudomonas aeruginosa significantly increased rates of survival after experimental induction of pseudomonas pneumonia in leukopenic dogs. Longer survival times were correlated with higher titers of circulating antibody in serum; however, no animals treated with antibody alone were long-term survivors. Subsequent development of sepsis or the recovery of Pseudomonas from infected lung tissue was not altered by treatment with antibody. Therapy with granulocyte transfusions plus gentamicin was associated with a 27% rate of long-term survival. Passive immunization with IgG (reciprocal mean hemagglutination titer, 52) in addition to granulocyte transfusions and treatment with gentamicin resulted in a rate of long-term survival of 67% (P less than 0.05). Dogs that died while receiving this combination therapy still had a survival time significantly longer than those of controls or animals treated only with granulocytes and antibiotic.

Animals↗