SEARCH · PubMed Health

Results for “PSEUDOMONAS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources

PubMed1996

[Pseudomonas spp. infections in patients with HIV infections].

BACKGROUND: The aim of this study was to describe the characteristics of the infections by Pseudomonas spp. observed in patients with HIV infection in Spain. METHODS: A retrospective study was performed of the isolations of Pseudomonas spp. in microbiologic samples of patients with HIV infection in three hospitals from Mallorca, Spain, since 1986. RESULTS: Twenty-nine patients with some positive culture for Pseudomonas were reviewed. In 20 cases the infection presented in advanced stages of the disease when the patient fulfilled AIDS criteria. The most frequent foci in both community acquired and nosocomial infection was respiratory (16 and 3 cases, respectively). Fifty percent of the cases presented bacteremia. The classically described predisposing factors for infection by this germ were presented in 19 patients. Pseudomonas aeruginosa was the most frequently isolated type (22 cases). Only 5 patients received the appropriate treatment on admission. Clinical cure was achieved in 23 patients, with recurrence being observed in 10. Five patients died in relation to the infection. CONCLUSIONS: Infections by Pseudomonas spp. in Spain appear to have increased in frequency in patients with HIV infection in the last decade. These infections appear in advanced phases of the disease and mainly involve the lung, with high rates of bacteremia and a high number of recurrence. Empiric treatment of patients with advanced HIV infection with suspicion of bacterial infection should include antipseudomonic drugs.

Adult↗

PubMed1997

[E-test to study small inhibitor concentrations, bacterial diversity and to identify presumptively beta-lactamases in strains of Pseudomonas aeruginosa and Acinetobacter baumannii associated with +nosocomial infections].

BACKGROUND: Pseudomonas aeruginosa and Acinetobacter baumanii are two important nosocomial agents that require permanent testing of their antimicrobial susceptibility. AIM: To use E-test to determine minimal inhibitory concentrations, estimate bacterial diversity and presumably identify B-lactamases of strains of Pseudomonas aeruginosa and Acinetobacter baumanii isolated from nosocomial infections. MATERIALS AND METHODS: Sixty eight strains of Pseudomonas aeruginosa and Acinetobacter baumanii isolated in a teaching hospital were analyzed with E-test strips to determine their minimal inhibitory concentrations for different antimicrobials. RESULTS: More than 75% of Acinetobacter baumanii were resistant to Piperacillin, Cefpirome, Cefepime, Gentamicin or Amikacin, 40% of strains were resistant to Ceftazidime, 27 and 53% of isolates had a decreased susceptibility to Meropenem and Piperacillin-tazobactam respectively. Twenty eight to 54% of Pseudomonas aeruginosa strains were resistant to Cefepime, Cefpirome, Ciprofloxacin and Gentamicin. Eighteen and 10% of strains were resistant to Meropenem and Imipenem respectively. Less than 10% of strains were resistant to Amikacin, Azireonam, Piperacillin-tazobactam or Ceftazidime. Most of beta-lactam resistance of Pseudomonas aeruginosa was associated to decreased susceptibility or resistance to Cefpirome, Cefepime or to Meropenem-Imipenem and did not match clearly with known beta-lactamase profiles. CONCLUSIONS: The knowledge of susceptibility of these bacteria responsible for nosocomial infections, will help to plan the appropriate use of antimicrobials.

Acinetobacter↗

PubMed1975

Allantoin racemase: a new enzyme from Pseudomonas species.

1. Allantoin racemase is a novel enzyme which catalyzes the conversion of S(+)-and R(minus)-allantoin into the racemate. 2. The enzyme is present in Pseudomonas testosteroni, Pseudomonas putida and five biotypes of Pseudomonas fluorescens, but absent in a number of other Pseudomonas species. 3. The enzyme of Ps. testosteroni was purified 133-fold and exposes optimal activity at pH 8.0-8.2 and 50 degrees C. The enzyme is stable on heating for 15 min at 70 degrees C. 4. The enzyme appeared to be specific for the optical isomers of allantoin and no cofactors are involved in the reaction. 5. The optical aspecificity of allantoinase of Proteus rettgeri was reaffirmed.

Allantoin↗

PubMed1973

The amino acid sequences of cytochromes c-551 from three species of Pseudomonas.

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

Acetone↗

PubMed1988

A clinical trial of i.v. tetravalent hyperimmune Pseudomonas globulin G in burned patients.

Pseudomonas aeruginosa continues to be a common lethal pathogen in burned patients. Active and passive immunization represents an important therapeutic adjunct. Ten patients with Pseudomonas sepsis, eight with bacteremia, were passively immunized with tetravalent hyperimmune Pseudomonas-intravenous immunoglobulin G. The dose was 500 mg/kg given on two successive days. The IgG levels rose after infusions and were maintained in the normal range throughout the septic course. Antibodies to the immunotype of each of the Pseudomonas responsible for the bacteremias were present in the hyperimmune globulin. Clinical improvement in the patients was associated with a 3- to 125-fold postinfusion increase in antibody titers. Seventy per cent of the patients survived, including six of the seven with bacteremia.

Adolescent↗

PubMed1993

Iron-regulated salicylate synthesis by Pseudomonas spp.

Two iron-regulated compounds have been found in acidified ethyl acetate extracts from culture supernatants of Pseudomonas aeruginosa and Pseudomonas cepacia type-strains. Synthesis of both compounds paralleled iron-deficient growth, and was repressed in the presence of 100 microM-FeCl3. Yields of these substances varied among different strains and attained maximum levels during stationary phase. Thin layer chromatographic analysis in five different solvent systems revealed that the slower-moving compound chromatographed as two distinct bands, and showed RF values and spectral properties similar to pyochelin. The faster-moving compound co-migrated as a single band with a standard of commercial salicylic acid in each of the chromatographic systems tested. Moreover, a molecule with an identical RF was also produced by Pseudomonas fluorescens CHA401, which is known to synthesize salicylic acid as the only siderophore during iron-limited growth. Spectrophotometric and spectrofluorometric titrations led to the identification of this iron-regulated compound as salicylic acid, in agreement with the structure deduced from 1H-NMR and mass spectroscopy. The identity of the P. cepacia siderophore azurechelin as salicylic acid was also conclusively demonstrated. Salicylic acid, like pyochelin and pyoverdin, promoted P. aeruginosa growth in an iron-depleted medium. These results are consistent with a putative siderophore activity for salicylic acid, i.e. azurechelin, as has been demonstrated for P. aeruginosa, P. fluorescens and P. cepacia. Thus, salicylic acid is likely to act as a siderophore in more than one species belonging to the genus Pseudomonas.

Burkholderia cepacia↗

PubMed1963

NUTRITIONAL STUDIES ON THE "AUTO-PLAQUE" PHENOMENON IN PSEUDOMONAS AERUGINOSA.

Berk, Richard S. (Wayne State University, Detroit, Mich.). Nutritional studies on the "auto-plaque" phenomenon in Pseudomonas aeruginosa. J. Bacteriol. 86:728-734. 1963.-Examination of 20 cultures of Pseudomonas aeruginosa indicated that 18 cultures possessed the common property of spontaneously lysing to form "plaques" or erosions on themselves in the absence of a sensitive indicator strain. Maximal lysis and plaque production was found to occur on a medium with a Tryptone concentration of 2.0 to 2.5%. Reduction of the Tryptone concentration to 0.5% or less supported growth, but was usually inadequate for support of lysis. However, addition of l-asparagine or l-arginine to 0.5% Tryptone induced lysis. Examination of five strains of Pseudomonas, which routinely exhibited the autolytic phenomenon, indicated that all were both lysogenic and pyocinogenic when tested against other Pseudomonas strains on both 2 and 0.5% Tryptone. Culturing of autolytic strain Pa-1 on a simple medium composed of glucose and inorganic salts appeared to be inadequate for "auto-plaque" formation, although lysis occurred occasionally when a yeast extract concentration of 1% was incorporated into the medium. Suppression of auto-plaque formation was also effected by growing the culture on Technicon dialyzing membrane D3 overlaid on 2% Tryptone, although lysogenic lysis of an indicator strain was demonstrable on the membrane.

Arginine↗

PubMed1964

SELECTIVE DESTRUCTION BY PSEUDOMONAS AERUGINOSA OF COMMON ANTIGEN OF ENTEROBACTERIACEAE.

Whang, H. Y. (Children's Hospital, Buffalo, N.Y.), and E. Neter. Selective destruction by Pseudomonas aeruginosa of common antigen of Enterobacteriaceae. J. Bacteriol. 88:1244-1248. 1964.-Supernatant fluids and filtrates from several strains of Pseudomonas aeruginosa, when incubated with common antigen from various enteric bacteria, will produce selective destruction of this antigen, leaving intact the simultaneously present O antigen. This effect is evidenced from hemagglutination, hemolysis, antibody absorption, hemagglutination inhibition, and immunization experiments. The Pseudomonas factor is heat-labile, being destroyed by heating at 100 C for 10 min. The action of this factor on the antigen is time-dependent and temperature-dependent, requiring incubation for 18 to 72 hr and progressing more rapidly at 50 or 56 C than at 37 C. The specificity of the reaction is indicated by the fact that supernatant fluids from cultures of Staphylococcus aureus and Bacillus subtilis, as well as several enzymes, such as pancreatic protease, trypsin, and lipase, have no effect on the common antigen. Utilization of the Pseudomonas factor, conceivably an enzyme, may aid in the eventual elucidation of the chemical nature of the common antigen of enteric bacteria.

Antigens↗

PubMedDate not supplied

[Introduction of King A and King B media for the diagnosis of Pseudomonas aeruginosa at the Teaching Pediatric Hospital of Centro Habana].

The use of King A and King B media for the faster diagnosis of Pseudomonas aeruginosa is introduced in the Microbiology Laboratory of Centro Habana Pediatric Teaching Hospital. The appropriate use of these media allows to classify as Pseudomonas aeruginosa 77.2% of the Pseudomonas sp. strains studied, which represent 95.2% of the total of strains identified as Pseudomonas aeruginosa, according to Hugh and Gilardi conventional technique. There are no significant differences in the implementation of the two procedures (X2: 0.5; p less than 0.05). The demonstrations of pyocines with King A medium is significantly superior to the method for extraction and solubility of the pigment in chloroform (X2: 15.05; p less than 0.01).

Bacterial Typing Techniques↗

PubMed1993

[Serodiagnosis of Pseudomonas aeruginosa infections in mucoviscidosis: comparative study of Western blotting, ELISA exotoxin A and ELISA phospholipase C].

Anti-Pseudomonas aeruginosa antibodies were studied by Western Blot, ELISA-exotoxin A and ELISA-phospholipase C for 91 serums from 31 patients with cystic fibrosis. More, for the two enzyme-linked immunosorbent assays, 44 serums from 44 healthy individuals were studied as controls. The study of these three parameters revealed the followings: with no infection by Pseudomonas aeruginosa all the results were negative, at the beginning of the infection, anti-exotoxin A antibodies appeared in first, followed in some cases by the reactions of Western Blot, anti-phospholipase C antibodies became positive at last and went on a par with the installation of the chronic characteristic of the infection, as soon as the chronicity were indisputable, the three methods revealed elevated serum antibodies amounts. Generally there was a correlation between detected antibodies and Pseudomonas aeruginosa isolation in sputum. Among these three methods, ELISA-exotoxin A appeared to be the most interesting because of its good reproducibility and its early positivity, before the others methods and sometimes before Pseudomonas aeruginosa isolation. It would be a significant argument to establish as soon as possible an antimicrobial therapy.

ADP Ribose Transferases↗

PubMed1995

Ornibactin production and transport properties in strains of Burkholderia vietnamiensis and Burkholderia cepacia (formerly Pseudomonas cepacia).

Several strains of Burkholderia vietnamiensis, isolated from the rhizosphere of rice plants, and four strains formerly known as Pseudomonas cepacia including two collection strains and two clinical isolates were compared for siderophore production and iron uptake. The B. vietnamiensis (TVV strains) as well as the B. cepacia strains (ATCC 25416 and ATCC 17759) and the clinical isolates K132 and LMG 6999 were all found to produce ornibactins under iron starvation. The two ATCC strains of B. cepacia additionally produced the previously described siderophores, pyochelin and cepabactin. Analysis of the ratio of isolated ornibactins (C4, C6 and C8) by HPLC revealed nearly identical profiles. Supplementation of the production medium with ornithine (20 mM) resulted in a 2.5-fold increase in ornibactin synthesis. Ornibactin-mediated iron uptake was independent of the length of the acyl side chain and was observed with all strains of B. vietnamiensis and B. cepacia, but was absent with strains of Pseudomonas aeruginosa, Pseudomonas fluorescens and Pseudomonas stutzeri, known to produce pyoverdines or desferriferrioxamines as siderophores. These results suggest that ornibactin production is a common feature of all Burkholderia strains and that these strains develop an ornibactin-specific iron transport system which is distinct from the pyoverdine-specific transport in Pseudomonas strains.

Biological Transport↗

PubMed2001

Effect of 2,4-Diacetylphloroglucinol Producing, Overproducing, and Nonproducing Pseudomonas fluorescens F113 in the Rhizosphere of Pea.

Pseudomonas fluorescens F113lacZY and modified strains carrying different function modifications were assessed for their impact in the rhizosphere of pea. Strain F113lacZY naturally produces the anti-fungal metabolite 2,4-diacetylphloroglucinol (Phl) useful in plant disease control. The first modified strain of F113 was repressed in production of Phl, creating the Phl negative strain F113G22. The second was a plasmid based overproducer of Phl (F113Rif (pCUGP)). Both the F113lacZY and the F113Rif (pCUGP) strains increased the rhizoplane fungal populations, whereas the same strains reduced the rhizosphere soil fungal populations with respect to the control. Similar results were found with the rhizoplane and rhizosphere soil bacterial populations. The F113G22 treatment resulted in a significantly greater indigenous fluorescent Pseudomonas population than the F113lacZY and F113Rif (pCUGP) treatments and a greater total Pseudomonas population than the control, F113lacZY, and F113Rif (pCUGP) treatments. Overproduction of Phl did not affect the establishment of the introduced Pseudomonas population. None of the inocula displaced the indigenous populations, but the F113G22 inocula had an additive effect on the total Pseudomonas population. P (phosphatase), S (sulphatase), and N (urease) cycle enzyme activities were increased while C (glucosidase, NAGase) cycle activities were decreased by the F113lacZY and F113Rif (pCUGP) treatments, suggesting C leakage from the roots. Overall, most effects of inoculation compared to the wild type were found with the non-Phl-producing strain. Overproduction of Phl had little environmental effect in relation to wild-type inocula.

Journal Article↗

PubMed1995

Variation in Sensitivity of Gaeumannomyces graminis to Antibiotics Produced by Fluorescent Pseudomonas spp. and Effect on Biological Control of Take-All of Wheat.

Isolates of Gaeumannomyces graminis var. tritici, the causal agent of take-all of wheat, varied in sensitivity in vitro to the antibiotics phenazine-1-carboxylic acid (PCA) and 2,4-diacetylphloroglucinol (Phl) produced by fluorescent Pseudomonas spp. shown previously to have potential for biological control of this pathogen. None of the four isolates of G. graminis var. avenae examined were sensitive to either of the antibiotics in vitro at the concentrations tested. The single isolate of G. graminis var. graminis tested was insensitive to PCA at 1.0 (mu)g/ml. Pseudomonas fluorescens 2-79 and Pseudomonas chlororaphis 30-84, both of which produce PCA, effectively suppressed take-all caused by each of two PCA-sensitive isolates of G. graminis var. tritici. PCA-producing strains exhibited a reduced ability or complete inability to suppress take-all caused by two of three isolates of G. graminis var. tritici that were insensitive to PCA at 1.0 (mu)g/ml. P. fluorescens Q2-87, which produces Phl, suppressed take-all caused by three Phl-sensitive isolates but failed to provide significant suppression of take-all caused by two isolates of G. graminis var. tritici that were insensitive to Phl at 3.0 (mu)g/ml. These findings affirm the role of the antibiotics PCA and Phl in the biocontrol activity of these fluorescent Pseudomonas spp. and support earlier evidence that mechanisms in addition to PCA are responsible for suppression of take-all by strain 2-79. The results show further that isolates of G. graminis var. tritici insensitive to PCA and Phl are present in the pathogen population and provide additional justification for the use of mixtures of Pseudomonas spp. that employ different mechanisms of pathogen suppression to manage this disease.

Journal Article↗

PubMed1996

Pseudomonas aeruginosa in otitis externa. A particular variety of the bacteria?

BACKGROUND: Pseudomonas aeruginosa rarely affects the epithelium in healthy persons except for the external ear canal, raising the possibility that P aeruginosa in otitis externa is a specific variety that displays particular characteristics. DESIGN: A cohort study was designed to outline distinct characteristics of P aeruginosa in otitis externa compared with P aeruginosa in other infections. The study period was October 1, 1994, to March 27, 1995. PATIENTS: Isolates of P aeruginosa from nonhospitalized patients were collected at the bacteriological laboratory at Karolinska Hospital, Stockholm, Sweden; there were 53 strains of P aeruginosa isolated from otitis externa and 59 strains of P aeruginosa from varicose ulcers and urinary tract infections. METHODS: Pseudomonas aeruginosa was characterized by pigmentation, growth habits, production of mucoid, and biochemical characteristics. RESULTS: Pseudomonas aeruginosa in otitis externa produced less pyocyanin and less urease and exhibited no mucoid-producing strains. CONCLUSIONS: Pseudomonas aeruginosa in otitis externa displayed fewer of the usual biochemical features of the species than did the strains isolated from other infections. Some of these features, such as the production of pyocyanin, are influenced by nutritional factors; strains found in otitis externa probably represent the type of strains present in the natural habitat in water, as opposed to the strains that have adapted to the environment of other human infections. Increased knowledge of the characteristics of the strains found in otitis externa is important in understanding the pathogenesis of the disease and why P aeruginosa is the dominant infectious agent in otitis externa.

Humans↗

PubMed2001

New alkane-responsive expression vectors for Escherichia coli and pseudomonas.

We have developed Escherichia coli and Pseudomonas expression vectors based on the alkane-responsive Pseudomonas putida (oleovorans) GPo1 promoter PalkB. The expression vectors were tested in several E. coli strains, P. putida GPo12 and P. fluorescens KOB2Delta1 with catechol-2,3-dioxygenase (XylE). Induction factors ranged between 100 and 2700 for pKKPalk in E. coli and pCom8 in Pseudomonas strains, but were clearly lower for pCom8, pCom9, and pCom10 in E. coli. XylE expression levels of more than 10% of total cell protein were obtained for E. coli as well as for Pseudomonas strains.

Alkanes↗

PubMed1995

Efficacy of topical gentamicin treatment after 193-nm photorefractive keratectomy in an experimental Pseudomonas keratitis model.

BACKGROUND: The treatment of Pseudomonas keratitis has many limitations, and further investigation to identify more effective approaches is required. We therefore studied the possible contribution of the debridement effect of 193-nm excimer laser on Pseudomonas keratitis in rabbit eyes. METHODS: Pseudomonas keratitis was induced in 30 rabbit eyes by inflicting controlled central corneal scratches and applying a drop of Pseudomonas aeruginosa suspension. After 24 h, one cornea of each animal was photo-ablated (excimer laser: fluency 90 mJ/cm2, 10 Hz, 213 pulses), yielding 50 microns of tissue ablation, while the follow cornea served as control. Five groups of six animals each were formed and received: a subconjunctival injection of gentamicin 20 mg (group 1), topical 14 mg/ml gentamicin hourly (group 2) or every 2.5 h (group 3), or NaCl 0.9% hourly (group 4) for 8 h. In group 5, animals were sacrificed without additional treatment. After 9 h corneas were excised, homogenized, serially diluted, and plated on agar blood plates. The numbers of colony-forming units (CFU) per cornea were statistically evaluated (Mann-Whitney test). RESULTS: In control eyes, a greater decrease of CFU was observed in group 2 than in group 3 (P = 0.03). In laser-ablated eyes, there was no difference in CFU between groups 2 and 3. Comparison of the excimer-treated and control eyes revealed a greater number of bacteria (CFU) in controls only in group 3 (P = 0.02). CONCLUSION: Our study suggests that controlled debridement of cornea with excimer laser may improve the effect of topical antibiotics.

Administration, Topical↗

PubMed1993

Pseudomonas aeruginosa promoters which contain a conserved GG-N10-GC motif but appear to be RpoN-independent.

The proC gene of Pseudomonas aeruginosa encodes the constitutive delta 1-pyrroline 5-carboxylate reductase (the third enzyme of proline biosynthesis) and ranks among the numerous Pseudomonas genes which are poorly transcribed in Escherichia coli. The promoters of the proC gene were located by deletion mapping. The 5' ends of the proC transcripts originating from one promoter were determined by primer extension. This promoter has a GG-N10-GC motif with a 16 bp spacing between the GC doublet and the transcription start site. Such spacing is unusually long for sigma 54-dependent promoters. In rpoN mutants of P. aeruginosa and P. putida a proC'--'lacZ fusion was expressed at wild-type levels, suggesting that sigma 54 RNA polymerase is not involved in proC transcription. The expression of another P. aeruginosa gene, anr (for anaerobic regulation of nitrate respiration and anaerobic arginine degradation), also appeared to be independent of RpoN in Pseudomonas and occurred at a very low level in E. coli. The proC and anr promoters have sequence similarities in addition to the conserved GG--N10--GC motif and may also be related to some alg (alginate) promoters of P. aeruginosa. We propose that the proC and anr promoters are activated by proteins, including perhaps an alternative sigma factor, which are present in Pseudomonas but absent from E. coli.

Base Sequence↗

PubMedDate not supplied

Studies of lung infections caused by Pseudomonas aeruginosa in mice treated with cyclophosphamide.

An experimental Pseudomonas aeruginosa lung infection was induced by aerosol exposure in mice which had been pretreated with cyclophosphamide. A single dose of 200 mg/kg cyclophosphamide resulted in leukopenia which lasted for three days. At the lowest PMN levels, the mice were exposed to aerosols containing varying doses of bacteria. The survival time of the mice and the number of viable bacteria in their lungs were determined. A dramatic rise in the viable counts of Pseudomonas organisms was found between 18 and 24 hours after infection. Mice which had not been pretreated with cyclophosphamide remained healthy and did not show any lung lesions. The number and phagocytic function of the alveolar macrophages remained unaltered after cyclophosphamide treatment. Thus, PMNs seem to play an important role in the lung's early defence mechanisms against Pseudomonas aeruginosa. This animal model could be of use in evaluating additional therapies for lung infections caused by Pseudomonas aeruginosa.

Animals↗