Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PSEUDOMONAS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 325 records · Page 18Linked to original sources
PubMed2004

Effects of antibiotics on Pseudomonas aeruginosa NK125502 and Pseudomonas fluorescens MF0 biofilm formation on immobilized fibronectin.

The effect of subminimal inhibitory concentration (1/2 MIC) of antibiotics on the biofilm formation on immobilized fibronectin by Pseudomonas was investigated by examining the reference strains NK125502 P. aeruginosa and MF0 P. fluorescens in a microtiter plates assay. When the antibiotics were added during bacterial growth and biofilm development, gentamicin was the only antimicrobial agent tested which decreased significantly the biofilm formation by the two strains. Cefsulodin and chloramphenicol also decreased the P. aeruginosa biofilm development (P<0.01), whereas polymyxin B inhibited biofilm formation by P. fluorescens (p<0.05). When the antibiotics were only present during bacterial growth and not during biofilm development, gentamicin was the only antibiotic tested to decrease significantly the biofilm formation by P. aeruginosa for incubation times of 20 and 72h (P<0.01), whereas P. fluorescens was not affected. This persistent inhibition of P. aeruginosa biofilm formation may be interesting in intermittent antibiotherapy treatments.

Anti-Bacterial Agents↗
PubMedDate not supplied

The pyoverdins of Pseudomonas syringae and Pseudomonas cichorii.

The structure elucidation of the cyclic (lactonic) forms of the pyoverdins with a succinamide side chain originally produced by the closely related species Pseudomonas syringae and P. cichorii is reported. Mass spectrometry and nuclear magnetic resonance analyses as well as the determination of the configuration of the amino acids after degradation indicate that these two pyoverdins differ only by the replacement of the first in-chain serine by glycine. The pyoverdins of P. syringae and P. cichorii and the dihydropyoverdin of P. syringae can be used by both species as siderophores.

Amino Acid Sequence↗
PubMedDate not supplied

[Electrophoretic differences in the proteins of the species Pseudomonas aeruginosa and Pseudomonas denitrificans capable of oxidizing n-alkanes].

Pseudomonas aeruginosa and Ps. denitrificans are capable of growing on n-alkanes, but differ in assimilation of higher and lower alkanes. The proteins of their cell-free homogenates were analysed by disc-electrophoresis in a system containing SDS. The "preliminarily adapted" strain of Ps. aeruginosa did not differ from the "non-adapted" to n-hexane strain, though both differed considerably from Ps. denitrificans in the composition of protein spectrum. Therefore, disc-electrophoresis of total proteins has shown that Ps. aeruginosa and Ps. denitrificans are not genetically identical; they exhibit certain common physiological properties, but apparently oxidize n-alkanes via different pathways.

Alkanes↗
PubMedDate not supplied

[Anti-Pseudomonas aeruginosa antibodies, circulating immune complexes, and anticytoplasm antibodies of neutrophils in patients with cystic fibrosis with and without Pseudomonas aeruginosa colonization].

Chronic lung infections, mainly due to Pseudomonas aeruginosa (Pa), account for the most of the morbidity and mortality in CF patients. The pathogenic factors predisposing to airway colonization are still nuclear. Host's immune response is not only poorly protective but can also act as a damaging factor in the development of the disease. Moreover, clinical manifestations of an overactive immune response, including vasculitis and arthropathy, have been recently described in the CF population. To deepen factors involved in the pathogenesis of lung injury, we evaluated the presence of anti-Pa precipitating antibodies, circulating immune complexes (CIC) and antineutrophil cytoplasmic antibodies (ANCA) in sera from 50 CF patients colonized and not by Pa. Number of anti-Pa precipitins was significantly different in chronically and in not colonized patients (p < 0.001; t = 7.75). Anti-Pa antibodies were positively correlated to age (p = 0.002, r = 0.42) and inversely correlated to lung function parameters (p = 0.031 r = -0.35 with respect to FVC). Mean C3-CIC levels in the sera were statistically higher in chronically colonized patients (p = 0.013; t = 2.57); while there was not a significant difference with respect to C1q-CIC values. Four patients, all chronically colonized by Pa, were ANCA-positive at indirect immunofluorescence, showing a cytoplasmic pattern. All 50 patients were found to be negative when tested for anti-mpo and anti-pr3 antibodies with ELISA. In conclusion, our data demonstrate that persistence of Pa provides a stimulus for chronic inflammation and the immune response in CF patients, leading to anti-Pa antibodies and CIC production. Even in the face of further research, we speculate that c-ANCA production is secondary to neutrophil activation with a consequent release of cytoplasmic enzymes that perpetuate and increase the inflammatory process. Since anti-mpo and anti-pr3 antibodies rarely occur in CF patients we suggest that other antigenic specificities may be involved in ANCA production.

Adolescent↗
PubMed2001

[Transfer and expression of tyrosinase gene of Pseudomonas maltophilia in Pseudomonas pseudoalcaligenes].

Pseudomonas pseudoalcaligenes is a notably killing maggots bacterium, which was isolated from natural dead maggots in the manure pits in the countryside of Yancheng. It easily die from effect of ultra-violet ray when it is exposed in the sun. Antiradiation effect of melanin is quite strong. Mel gene of P. maltophilia AT18 has been introduced into P. pseudoalcaligenes, and enabled it the ability of producing melanin steadily. Southern hybridization studies confirmed that the small fragment cloned in the P. pseudoalcaligenes comes from P. maltophilia DNA. SDS-PAGE analysis also revealed that an additional protein of 18 kD, which was equal to the size of the putative tyrosinase according to mel fragment, was exressed in the P. pseudoalcaligenes recombinant carrying the mel gene, The results of assay show that antiradiation effect of recombinant is quites strong, the effect time of killing maggats is longer than the recipient, the recombinant can't infect animals and fowls.

DNA, Bacterial↗
PubMedDate not supplied

Investigations on the efficacy of monovalent Pseudomonas aeruginosa vaccine for oral administration in Pseudomonas aeruginosa experimental infection.

Therapeutic efficacy of Pseudomonas aeruginosa vaccine for oral use (10(10) killed germs/ml), prepared from strain 4922, belonging to serotype XV, by Meitert-Meitert scheme, on 4 experimental models in mice (pneumonia, infected burn, septicaemia and urinary tract infection) was studied in comparison with monovalent Ps. aeruginosa vaccine serotype XV (10(9) killed germs/ml) for subcutaneous use and also with associated administration of the two vaccine variants. Mice immunization by using vaccine for oral use was performed by 0.5 ml vaccine per day, for 10 days and vaccine for subcutaneous use was administrated in a volume of 0.5 ml x 2, at 3 days interval. Mice immunization by using the two vaccine types, in association was concomitantly performed and in the same quantity as for separate immunization. In experimental pneumonia, Ps. aeruginosa vaccine for oral use protected mice in 35% of cases, those with infected burns were protected in 33.3% of cases, those with septicemia--in 96.6% of cases and those with urinary tract infection in 50% of cases. As compared to Ps. aeruginosa vaccine for subcutaneous use, the results obtained by vaccine for oral use are less favourable but associated administration of both vaccine variants led to superior results. Thus, in experimental pneumonia, it was obtained a surviving rate of 65% for animals immunized with both vaccine types, in comparison with 50% for animals immunized with vaccine for subcutaneous use only, and in Ps. aeruginosa infected burn, it was obtained a recovering rate of 79.1% for the animals immunized by using both vaccines, in comparison with 70.8% surviving for animals immunized with vaccine for subcutaneous use. In experimental septicaemia and urinary tract infection, combined use of both vaccine variants determined animals surviving and recovering in percents similar to those obtained by separate administration of vaccine for subcutaneous use (in septicemia--100% protection; in urinary tract infection--75% protection).

Administration, Oral↗
PubMed1988

[Interaction of heterologous bacteriophages: growth suppression of temperate PP56 phage of Pseudomonas putida by the transposable phage D3112 of Pseudomonas aeruginosa].

We have found an inhibiting effect of hybrid RP4::D3112 plasmid (where D3112 is represented as genome of a transposable phage specific for Pseudomonas aeruginosa) on the development of temperate P. putida phage PP56. The study of the effect has revealed a previously unknown locus (in the region 12-14.2 kb of the D3112 genome) which functions in the prophage state. The locus affects PP56 decreasing phage yield. Mutants of PP56 insensitive to inhibition were found.

Bacteriophages↗
PubMed1985

[Expression of Pseudomonas aeruginosa transposable phages in Pseudomonas putida cells. I. The establishment of a lysogenic state and the effectiveness of lytic development].

Expression of transposable phages (TP) of Pseudomonas aeruginosa in the cells of P. putida was studied. The high efficiency of phage lytic development was shown both as a consequence of zygotic induction after transfer of the RP4::TPc+ plasmid into nonlysogenic recipients, and as a result of heat induction of lysogens PpG1 (D3112cts15). The high phage yield (20-25 particles of D3112cts phage per one cell of P. putida) is an evidence for a high level of transposition in the cells of this bacterial species. Plasmids RP4::TP are transferred into cells of PpG1 and PAO1 with similar frequency. However, the efficiency of establishment of the lysogenic state is lower in PpG1. Transposable phages of P. aeruginosa can integrate into the chromosome of PpG1 producing stable inducible lysogens. The presence of RP4 in the P. putida cells is not necessary for expression of transposable phages. The transposable phage D3112cts15 can be used in experiments of interspecies transduction of plasmids and chromosomal genes.

Bacteriolysis↗
PubMed1985

[Expression of Pseudomonas aeruginosa phage transposons in Pseudomonas putida PpG1 cells. II. Zygotic induction--a necessary condition for the formation of defective lysogens].

The transfer of hybrid plasmid RP4::PT (where PT is the genome of a transposable phage specific for Pseudomonas aeruginosa) into recipient cells of P. putida strain PpG1 occurs with the same frequency as into P. aeruginosa, the homologous host for PT. Approximately 1/3 of all PpG1 exconjugants carrying RP4 markers lost the capability to produce viable PT phage. In contrast, in a cross with homologous recipient P. aeruginosa all exconjugant clones contained nondefective prophages in the hybrid plasmids. Zygotic induction is an obligatory condition for detection of PpG1 exconjugants with defective phages. The defective prophages in RP4::PT hybrid plasmids have deletions of different size; the other carry mutations indistinguishable from point mutations in an essential phage gene. Some of deletions also cover plasmid genes. At least some of the defective prophages, including deleted ones, have arisen in the recipient cells of P. putida after transfer of the hybrid plasmid.

Bacteriophages↗
PubMedDate not supplied

[Regulation of the synthesis of the key enzymes for naphthalene catabolism in Pseudomonas putida and Pseudomonas fluorescens carrying the biodegradation plasmids NAH, pBS3, pBS2 and NPL-1].

Regulation of the synthesis of key enzymes catalysing naphthalene catabolism was studied in Pseudomonas strains containing different plasmids of naphthalene biodegradation. The synthesis of naphthalene oxygenase, salicylate hydroxylase, catechol-1,2-oxygenase and cathechol-2,3-oxygenase was shown to be regulated in both the coordinated and non-coordinated manner.

Biodegradation, Environmental↗
PubMed1982

[Protective effect of Pseudomonas-specific immunoglobulin from the rabbit and of active immunization in experimental Pseudomonas sepsis in mice].

Using the model of an experimental Pseudomonas septicemia in mice, the protective effect of specific antipseudomonal immunoglobulin from rabbits was examined. During bacterial spreading in the bloodstream, a protective effect could be demonstrated under certain conditions. The degree of protection was equivalent to that achieved by active immunization. After bacterial colonization and replication in parenchymal organs no further therapeutic effect could be detected.

Animals↗
PubMedDate not supplied

[Molecular DNA-DNA hybridization in Pseudomonas fluorescens and Pseudomonas putida].

Taxonomic analysis was carried out and DNA-DNA homology studied in cultures of subgroups formed by numerical classification of 124 Pseudomonas fluorescens and P. putida strains. The GC content in the DNA of strains belonging to P. fluorescens subgroups varied from 61.2 to 64.5%, and their DNA-DNA homology with the type strain P. fluorescens ATCC 13525 was 24 to 83%. The lowest genome relatedness with the type culture was found in biotype C of P. fluorescens and P. aureofaciens strains. The GC content in the DNA of strains belonging to two subgroups formed by numerical classification of P. putida varied from 63.8 to 65.0%, and the homology of their DNA with the DNA of the type strain of P. fluorescens was 0 to 10% (for strains of the first and second subgroups, respectively).

Base Composition↗
PubMed1982

[Expression of the genome of Mu-like phage D3112 specific for Pseudomonas aeruginosa in Escherichia coli and Pseudomonas putida cells].

The behavior of Escherichia coli cells carrying RP4 plasmid which contains the genome of a Mu-like D3112 phage specific for Pseudomonas aeruginosa was studied. Two different types of D3112 genome expression were revealed in E. coli. The first is BP4-dependent expression. In this case, expression of certain D3112 genes designated as "kil" only takes place when RP4 is present. As a result, cell division stops at 30 degrees C and cells form filaments. Cell division is not blocked at 42 degrees C. The second type of D3112 genome expression is RP4-independent. A small number of phage is produced independently of RP4 plasmid but this does not take place at 42 degrees C. No detectable quantity of the functionally active repressor of the phage was determined in E. coli (D3112). It is possible that the only cause for cell stability of E. coli (D3112) or E. coli (RP4::D3112) at 42 degrees C in the absence of the repressor is the fact of an extremely poor expression of D3112. In another heterologous system, P. putida both ways of phage development (lytic and lysogenic) are observed. This special state of D3112 genome in E. coli cells is proposed to be named "conditionally expressible prophage" or, in short, "conex-phage", to distinguish it from a classical lysogenic state when stability is determined by repressor activity. Specific blockade of cell division, due to D3112 expression, was also found in P. putida cells. It is evident that the kil function of D3112 is not specific to recognize the difference between division machinery of bacteria belonging to distinct species or genera. Protein synthesis is needed to stop cell division and during a short time period this process could be reversible. Isolation of E. coli (D3112) which lost RP4 plasmid may be regarded as an evidence for D3112 transposition in E. coli. Some possibilities for using the system to look for E. coli mutants with modified expression of foreign genes are considered.

Bacteriophages↗
PubMed1993

[Combined effects of anti-Pseudomonas antibiotics with G-CSF on systemic infections by Pseudomonas aeruginosa in a leukocytopenic mouse model].

A model with cyclophosphamide-induced leukocytopenic mice was employed to investigate combined effects of each of several antibiotics (sulbactam/cefoperazone (SBT/CPZ), ceftazidime, piperacillin and imipenem/cilastatin (IPM/CS)) with G-CSF on systemic infections caused by Pseudomonas aeruginosa. The ED50's of all the antibiotics except that of SBT/CPZ in these leukocytopenic mice were approximately two-fold higher than those in normal mice. No differences were observed between 2 groups of mice, one administered with G-CSF and the other without G-CSF, hence no additive or synergistic effects were observed between G-CSF and there antibiotics. With SBT/CPZ, however, the G-CSF-administered group showed higher ED50 than the group without G-CSF, and the ED50 of the former group was similar to that of normal mice, thus a synergistic effect was observed between SBT/CPZ and G-CSF.

Animals↗
PubMed1991

Respiratory tract colonization with Pseudomonas aeruginosa in cystic fibrosis: correlations between anti-Pseudomonas aeruginosa antibody levels and pulmonary function.

Chronic Pseudomonas aeruginosa respiratory tract colonization in patients with cystic fibrosis is associated with development of antibodies to the organism. In contrast to the protection usually afforded by humoral immunity to a bacterial pathogen, the immune response to P. aeruginosa may help perpetuate infection and contribute to pulmonary damage in cystic fibrosis. To determine if specific anti-P. aeruginosa antibody levels correlated with pulmonary dysfunction, we measured antibodies to seven P. aeruginosa serotypes, and correlated the geometric mean titer with pulmonary function tests. Patients were divided into groups without P. aeruginosa colonization (n = 20), with recent colonization (n = 20), and with chronic colonization (n = 60). Noncolonized patients had normal pulmonary function or mild obstructive lung disease, and low anti-P. aeruginosa titers. Pulmonary function tests in recently colonized patients were not different from those of noncolonized patients, but antibody titers were higher. Following colonization FEV1 declined and titers increased rapidly. Patients with chronic colonization had worse pulmonary function and higher titers, but while the former were stable the latter gradually increased. An inverse correlation was found between anti-P. aeruginosa titer and FVC, FEV1, and FEF25-75 (P less than 0.001) in these patients; age was not a factor. The strong correlation between severity of lung disease and anti-P. aeruginosa titer demonstrates that an exaggerated immune response to P. aeruginosa is associated with pulmonary damage in patients with cystic fibrosis.

Adolescent↗
PubMed1993

Copper-containing nitrite reductase from Pseudomonas aureofaciens is functional in a mutationally cytochrome cd1-free background (NirS-) of Pseudomonas stutzeri.

The structural gene, nirK, for the respiratory Cu-containing nitrite reductase from denitrifying Pseudomonas aureofaciens was isolated and sequenced. It encodes a polypeptide of 363 amino acids including a signal peptide of 24 amino acids for protein export. The sequence showed 63.8% positional identity with the amino acid sequence of "Achromobacter cycloclastes" nitrite reductase. Ligands for the blue, type I Cu-binding site and for a putative type-II site were identified. The nirK gene was transferred to the mutant MK202 of P. stutzeri which lacks cytochrome cd1 nitrite reductase due to a transposon Tn5 insertion in its structural gene, nirS. The heterologous enzyme was active in vitro and in vivo in this background and restored the mutationally interrupted denitrification pathway. Transfer of nirK to Escherichia coli resulted in an active nitrite reductase in vitro. Expression of the nirS gene from P. stutzeri in P. aureofaciens and E. coli led to nonfunctional gene products. Nitrite reductase activity of cell extract from either bacterium could be reconstituted by addition of heme d1, indicating that both heterologous hosts synthesized a cytochrome cd1 without the d1-group.

Amino Acid Sequence↗
PubMed1975

Comparative biochemistry of alpha-glucan-utilization in Pseudomonas amyloderamosa and Pseudomonas saccharophila: physiological significance of variations in the pathway.

Growth patterns on and utilization of various alpha-glucans were investigated in Pseudomonas amyloderamosa and P. saccharophila. Maltose, maltodextrins (average chain length 7 glycosyl units) and glycogen supported excellent growth of both organisms and were extensively metabolized, although glycogen utilization in P. saccharophila was preceded by a prolonged lag phase. P. amyloderamosa produced limited growth on amylopectin and the carbohydrate was only partly degraded. It seemed likely that many of the unit chains liberated from amylopectin had a length exceeding the substrate range accepted by the maltodextrin permease (transport) system. A correlation was established between the pH of the medium and the utilization of glycogen and amylopectin for growth in P. amyloderamosa. The carbohydrates were at least partly utilizable at pH 6.0, whereas they could not support any growth at pH 6.5. Most likely, the lack of growth at the higher pH reflected the low activity of isolamylase at this pH. The enzyme patterns of maltodextrin catabolism in the two bacteria were established. Intracellularly, maltodextrin phosphorylase and 4-alpha-glucanotransferase occurred in both. Degradation of extracellular alpha-glucans was mediated by a mainly intracellular isoamylase in P. amyloderamosa, whereas P. saccharophila possessed an extracellular alpha-amylase and a firmly cell-bound pullulanase.

Amylases↗
PubMed1984

Comparative anti-Pseudomonas aeruginosa activity of chemically modified and native immunoglobulin G (human), and potentiation of antibiotic protection against Pseudomonas aeruginosa and group B Streptococcus in vivo.

Immunoglobulin G intravenous is prepared by controlled reduction and alkylation of approximately four interheavy chain disulfide bonds per molecule. To determine if the protective activity of antibody modified by this process is diminished, mice were treated with identical doses of reduced and alkylated IgG and native IgG prepared from the same plasma pool. Three hours later mice were given a 10 percent body surface burn followed by challenge with the seven Fisher-Devlin-Gnabasik immunotypes of Pseudomonas aeruginosa. Against five of the seven immunotypes, the 50 percent protective doses were approximately 100 mg or less per kg body weight. Overall there was no significant difference in protection afforded to the mice by the two immunoglobulin preparations indicating that in vivo the activity of IgG against P. aeruginosa remains unimpaired by reduction and alkylation. In the second part of this study, immunoglobulin G intravenous significantly enhanced the activity of tobramycin and carbenicillin in the treatment of P. aeruginosa infection in burned mice and of penicillin G in the treatment of group B Streptococcus 1C infection in normal mice.

Animals↗