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 541 records · Page 30Linked to original sources
PubMed1980

Mechanism for pulmonary protection by lipopolysaccharide pseudomonas vaccine.

Recent studies in guinea pigs indicated that active vaccination with a cell wall-derived, lipopolysaccharide (LPS) pseudomonas vaccine confers specific protection against acute pneumonia. This study analyzed the immune mechanisms by which LPS pseudomonas vaccine offers local protection to the lung. Neither parenteral vaccination nor direct exposure of lung tissues to living Pseudomonas activated alveolar macrophages. However, serum opsonic activity that specifically enhanced phagocytosis of Pseudomonas by alveolar macrophages was significantly increased (P < 0.05) in vaccinated animals. Serum pseudomonas opsonins were heat-stable but were sensitive to reduction of macroglobulins by 2-mercaptoethanol. Within 3 hr after establishment of experimental pseudomonas pneumonia, a fourfold increase in local pseudomonas opsonins was found in bronchial fluids from vaccinated animals, presumably secondary to diffusion of serum proteins into local inflammatory fluids. Thus, Pseudomonas-specific opsonic antibody appears necessary to augment alveolar macrophage phagocytosis after LPS vaccination, and local vaccination of the respiratory tract is not required to provide adequate local pseudomonas opsonins during acute pneumonia.

Animals↗
PubMed2006

Biofilm formation and cellulose expression among diverse environmental Pseudomonas isolates.

The ability to form biofilms is seen as an increasingly important colonization strategy among both pathogenic and environmental bacteria. A survey of 185 plant-associated, phytopathogenic, soil and river Pseudomonas isolates resulted in 76% producing biofilms at the air-liquid (A-L) interface after selection in static microcosms. Considerable variation in biofilm phenotype was observed, including waxy aggregations, viscous and floccular masses, and physically cohesive biofilms with continuously varying strengths over 1500-fold. Calcofluor epifluorescent microscopy identified cellulose as the matrix component in biofilms produced by Pseudomonas asplenii, Pseudomonas corrugata, Pseudomonas fluorescens, Pseudomonas marginalis, Pseudomonas putida, Pseudomonas savastanoi and Pseudomonas syringae isolates. Cellulose expression and biofilm formation could be induced by the constitutively active WspR19 mutant of the cyclic-di-GMP-associated, GGDEF domain-containing response regulator involved in the P. fluorescens SBW25 wrinkly spreader phenotype and cellular aggregation in Pseudomonas aeruginosa PA01. WspR19 could also induce P. putida KT2440, which otherwise did not produce a biofilm or express cellulose, as well as Escherichia coli K12 and Salmonella typhimurium LT2, both of which express cellulose yet lack WspR homologues. Statistical analysis of biofilm parameters suggest that biofilm development is a more complex process than that simply described by the production of attachment and matrix components and bacterial growth. This complexity was also seen in multivariate analysis as a species-ecological habitat effect, underscoring the fact that in vitro biofilms are abstractions of those surface and volume colonization processes used by bacteria in their natural environments.

Bacterial Adhesion↗
PubMed2006

Cultivation-independent analysis of Pseudomonas species in soil and in the rhizosphere of field-grown Verticillium dahliae host plants.

Despite their importance for rhizosphere functioning, rhizobacterial Pseudomonas spp. have been mainly studied in a cultivation-based manner. In this study a cultivation-independent method was used to determine to what extent the factors plant species, sampling site and year-to-year variation influence Pseudomonas community structure in bulk soil and in the rhizosphere of two Verticillium dahliae host plants, oilseed rape and strawberry. Community DNA was extracted from bulk and rhizosphere soil samples of flowering plants collected at three different sites in Germany in two consecutive years. Pseudomonas community structure and diversity were assessed using a polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) system to fingerprint Pseudomonas-specific 16S rRNA gene fragments amplified from community DNA. Dominant and differentiating DGGE bands were excised from the gels, cloned and sequenced. The factors sampling site, plant species and year-to-year variation were shown to significantly influence the community structure of Pseudomonas in rhizosphere soils. The composition of Pseudomonas 16S rRNA gene fragments in the rhizosphere differed from that in the adjacent bulk soil and the rhizosphere effect tended to be plant-specific. The clone sequences of most dominant bands analysed belonged to the Pseudomonas fluorescens lineage and showed closest similarity to culturable Pseudomonas known for displaying antifungal properties. This report provides a better understanding of how different factors drive Pseudomonas community structure and diversity in bulk and rhizosphere soils.

Brassica rapa↗
PubMed1998

A highly selective PCR protocol for detecting 16S rRNA genes of the genus Pseudomonas (sensu stricto) in environmental samples.

Pseudomonas species are plant, animal, and human pathogens; exhibit plant pathogen-suppressing properties useful in biological control; or express metabolic versatilities valued in biotechnology and bioremediation. Specific detection of Pseudomonas species in the environment may help us gain a more complete understanding of the ecological significance of these microorganisms. The objective of this study was to develop a PCR protocol for selective detection of Pseudomonas (sensu stricto) in environmental samples. Extensive database searches identified a highly selective PCR primer pair for amplification of Pseudomonas 16S rRNA genes. A protocol that included PCR amplification and restriction analysis, a general cloning and sequencing strategy, and phylogenetic analyses was developed. The PCR protocol was validated by testing 50 target and 14 nontarget pure cultures, which confirmed the selectivity to 100%. Further validation used amplification of target sequences from purified bulk soil DNA followed by cloning of PCR products. Restriction analysis with HaeIII revealed eight different fragmentation patterns among 36 clones. Sequencing and phylogenetic analysis of 8 representative clones indicated that 91.7% of the products were derived from target organisms of the PCR protocol. Three patterns, representing only 8.3% of the 36 clones, were derived from non-Pseudomonas or chimeric PCR artifacts. Three patterns, representing 61.1% of the clones, clustered with sequences of confirmed Pseudomonas species, whereas two patterns, representing 30.6% of the clones, formed a novel phylogenetic cluster closely associated with Pseudomonas species. The results indicated that the Pseudomonas-selective PCR primers were highly specific and may represent a powerful tool for Pseudomonas population structure analyses and taxonomic confirmations.

DNA Primers↗
PubMed2004

Gamma interferon does not enhance clearance of Pseudomonas aeruginosa but does amplify a proinflammatory response in a murine model of postseptic immunosuppression.

Patients that have suffered a major injury may sustain a period of immunocompromise and altered Th1/Th2 cytokine balance that can predispose them to opportunistic infections. Pseudomonas aeruginosa is frequently a causative organism for nosocomial infections in critically ill patients and is associated with high mortality. We previously mimicked this clinical scenario by challenging mice with P. aeruginosa 5 days after a cecal ligation and puncture (CLP) procedure. Mice that were subjected to CLP had reduced ability to clear bacteria, significantly lower gamma interferon (IFN-gamma) concentrations in plasma, and significantly elevated levels of interleukin 10 (IL-10) in plasma in response to the Pseudomonas challenge compared to uninjured control mice. We investigated the significance of the alteration in IFN-gamma by administering recombinant IFN-gamma to post-CLP mice at the time of Pseudomonas challenge and by challenging IFN-gamma knockout (IFN-gamma KO) mice with Pseudomonas. Administration of IFN-gamma to post-CLP mice attenuated IL-10 secretion and enhanced IL-12 secretion but did not improve bacterial clearance or survival after Pseudomonas challenge. Furthermore, IFN-gamma KO mice had significantly higher plasma IL-10 concentrations but did not exhibit impaired bacterial clearance or increased mortality following Pseudomonas challenge. These data indicate that systemic administration of IFN-gamma effectively reverses alterations in immune function that are commonly associated with immunosuppression in critically injured mice but does not improve bacterial clearance or survival following Pseudomonas challenge. Further, endogenous IFN-gamma does not appear to contribute significantly to early clearance of Pseudomonas bacteremia, nor does it affect the mortality rate after a lethal Pseudomonas challenge.

Animals↗
PubMed1989

The pulmonary clearance of smooth and rough strains of Pseudomonas aeruginosa.

Upper airway colonization with rough strains of Pseudomonas is associated with clinical deterioration in patients with cystic fibrosis. These rough strains are less toxic than smooth strains in the burned mouse model and in vitro assays. We measured the 4-h pulmonary clearance of 10(4) and 10(6) rough and smooth Pseudomonas after intrabronchial inoculation. After 10(4) Pseudomonas, rough strains were cleared more efficiently than smooth strains (89 +/- 13% versus 140 +/- 19% of the original inoculum, respectively, p less than 0.05). This was associated with more total bronchoalveolar lavage PMNs after inoculation with rough as compared with smooth Pseudomonas (1.60 +/- 0.38 x 10(5) versus 0.55 +/- 0.09 x 10(5), respectively, p less than 0.05). After inoculation with 10(6) Pseudomonas, rough were cleared less efficiently than smooth Pseudomonas (380 +/- 45% versus 134 +/- 12% of the original inoculum, respectively, p less than 0.05). There was no difference in the BAL PMNs of the animals inoculated with either bacterial strain at this inoculum (8.1 +/- 0.6 x 10(5) and 9.4 +/- 1.0 x 10(5) for the rough and smooth Pseudomonas, respectively). When PMN differences were abolished in C5-deficient mice, 10(4) rough were cleared less efficiently than smooth Pseudomonas. The relatively poor clearance of rough Pseudomonas could not be explained by in vitro differences in PMN killing or BAL toxicity or by intrinsic growth rates.

Animals↗
PubMed1994

Pseudomonas stimulates interleukin-8 mRNA expression selectively in airway epithelium, in gland ducts, and in recruited neutrophils.

Neutrophils may play important roles in chronic airway diseases. Pseudomonas is a common pathogen in some chronic airway diseases, and expression of the neutrophil chemoattractant interleukin-8 (IL-8) is induced by Pseudomonas in various cells in vitro. Here we examine the localization of IL-8 mRNA expression after incubating human and dog bronchi with Pseudomonas supernatant in vitro. To examine IL-8 expression in recruited neutrophils, we also superfused the dog bypassed tracheal segment with Pseudomonas supernatant in vivo and measured neutrophil number and IL-8 concentration in luminal fluid; simultaneously, we introduced Pseudomonas supernatant by catheter in a peripheral airway. After 6 h, we analyzed IL-8 mRNA expression and localization in removed tissue. Unincubated bronchi showed no IL-8 mRNA expression, but incubation with Pseudomonas supernatant in vitro resulted in IL-8 mRNA expression in surface epithelial, gland duct, and a subpopulation of serous gland cells. In vivo, introduction of Pseudomonas supernatant into dog trachea and peripheral airways caused IL-8 mRNA expression in epithelial and gland duct cells but also in the recruited neutrophils. Pseudomonas lipopolysaccharide alone was without effect in vitro and in vivo. We conclude that Pseudomonas products, but not lipopolysaccharide, stimulate IL-8 expression in airways and that this expression occurs primarily in surface epithelial and gland duct cells, thus bringing the chemoattractant to the bacterial site. Furthermore, IL-8 expression in recruited neutrophils provides a potential mechanism for positive feedback of this protective antibacterial response.

Adult↗
PubMed1974

Increased sheep lung vascular permeability caused by pseudomonas bacteremia.

In awake sheep, we compared the responses of lung lymph flow and lymph and plasma protein concentrations to steady state elevations of pulmonary vascular pressures made by inflating a left atrial balloon with those after an intravenous infusion of 10(5)-10(10)Pseudomonas aeruginosa. Lymph flow increased when pressure was increased, but lymph-plasma protein concentration ratios always fell and lymph protein flow (lymph flow x lymph protein concentration) increased only slightly. After Pseudomonas, sheep had transient chills, fever, leukopenia, hypoxemia, increased pulmonary artery pressure and lymph flow and decreased left atrial pressure and lymph protein concentration, 3-5 h after Pseudomonas, when vascular pressures and lymph protein concentrations had returned to near base line, lymph flow increased further to 3-10 times base line and remained at a steady level for many hours. During this steady state period, lymph-plasma protein concentration ratios were similar to base line and lymph protein flow was higher than in the increased pressure studies. Two sheep died of pulmonary edema 7 and 9 h after Pseudomonas, but in 16 studies, five other sheep appeared well during the period of highest lymph flow and all variables returned to base line in 24-72 h. Six serial indicator dilution lung water studies in five sheep changed insignificantly from base line after Pseudomonas. Postmortem lung water was high in the two sheep dead of pulmonary edema and one other, but six sheep killed 1-6 h after Pseudomonas had normal lung water. Because of the clear difference between the effects of increased pressure and Pseudomonas on lymphplasma protein concentration ratios and lymph protein flow, we conclude that Pseudomonas causes a prolonged increase in lung vessel permeability to protein. Because we saw lung lymph flow as high as 10 times base line without pulmonary edema, we conclude that lung lymphatics are a sensitive high-capacity mechanism for removing excess filtered fluid. An equivalent pore model of sheep lung vessels suggests that the changes we saw after Pseudomonas could result from small changes in the structure of exchanging vessel walls.

Animals↗
PubMed1991

Pseudomonas and neutrophil products modify transferrin and lactoferrin to create conditions that favor hydroxyl radical formation.

In vivo most extracellular iron is bound to transferrin or lactoferrin in such a way as to be unable to catalyze the formation of hydroxyl radical from superoxide (.O2-) and hydrogen peroxide (H2O2). At sites of Pseudomonas aeruginosa infection bacterial and neutrophil products could possibly modify transferrin and/or lactoferrin forming catalytic iron complexes. To examine this possibility, diferrictransferrin and diferriclactoferrin which had been incubated with pseudomonas elastase, pseudomonas alkaline protease, human neutrophil elastase, trypsin, or the myeloperoxidase product HOCl were added to a hypoxanthine/xanthine oxidase .O2-/H2O2 generating system. Hydroxyl radical formation was only detected with pseudomonas elastase treated diferrictransferrin and, to a much lesser extent, diferriclactoferrin. This effect was enhanced by the combination of pseudomonas elastase with other proteases, most prominently neutrophil elastase. Addition of pseudomonas elastase-treated diferrictransferrin to stimulated neutrophils also resulted in hydroxyl radical generation. Incubation of pseudomonas elastase with transferrin which had been selectively iron loaded at either the NH2- or COOH-terminal binding site yielded iron chelates with similar efficacy for hydroxyl radical catalysis. Pseudomonas elastase and HOCl treatment also decreased the ability of apotransferrin to inhibit hydroxyl radical formation by a Fe-NTA supplemented hypoxanthine/xanthine oxidase system. However, apotransferrin could be protected from the effects of HOCl if bicarbonate anion was present during the incubation. Apolactoferrin inhibition of hydroxyl radical generation was unaffected by any of the four proteases or HOCl. Alteration of transferrin by enzymes and oxidants present at sites of pseudomonas and other bacterial infections may increase the potential for local hydroxyl radical generation thereby contributing to tissue injury.

Apoproteins↗
PubMed2000

Review of the incidence and prognosis of Pseudomonas aeruginosa infections in cancer patients in the 1990s.

In an attempt to determine the actual relevance of Pseudomonas aeruginosa as a target of empiric antimicrobial first-line therapy in febrile cancer patients, 44 reports of clinical trials on antimicrobial treatment regimens and 53 reports on the epidemiology of microbiologically documented infections in cancer patients were reviewed. The incidence of infections due to Pseudomonas aeruginosa was 1-2.5% among all patients presenting with first fever during neutropenia, and 5-12% among patients with microbiologically documented infections. The proportion of Pseudomonas aeruginosa infections among cases of gram-negative bacteremia has not generally declined during the past 2 decades. There were marked local and regional differences regarding the incidence of documented Pseudomonas aeruginosa infections. No clear differences between neutropenic and non-neutropenic cancer patients, between patients with solid tumors and those with hematologic malignancies, or between inpatients and outpatients presenting with fever and neutropenia were detected with respect to the likelihood of Pseudomonas aeruginosa involvement. The mortality rate in patients with Pseudomonas aeruginosa bacteremia, particularly with polymicrobial bacteremia or bacteremic pneumonia with Pseudomonas aeruginosa involvement, is considerably high. The beneficial impact on mortality of an empiric antimicrobial treatment regimen with high antipseudomonal activity has not yet been demonstrated unequivocally. Additional factors such as the quality of intensive care management, effective second-line antimicrobial regimens, local resistance patterns, and patient-related cofactors are very likely to influence the outcome of Pseudomonas aeruginosa infections in cancer patients.

Anti-Bacterial Agents↗
PubMed1999

Ciprofloxacin-resistant Pseudomonas keratitis.

OBJECTIVE: To determine ciprofloxacin resistance of corneal isolates of Pseudomonas and to review the clinical response to topical therapy in cases of ciprofloxacin-resistant Pseudomonas keratitis, where medical therapy was begun with 0.3% ciprofloxacin. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Medical and microbiology records of 141 culture-proven cases of Pseudomonas keratitis, examined between January 1991 and June 1998, were reviewed retrospectively. METHODS: All isolates of the Pseudomonas species from corneal scrapings were tested for their susceptibility to routinely used antibiotics by the Kirby-Bauer disc-diffusion method. The minimum inhibitory concentration of ciprofloxacin was determined by the agar-dilution method for most of the isolates found resistant to ciprofloxacin. Clinical response to initial therapy with 0.3% ciprofloxacin was determined in cases of keratitis caused by ciprofloxacin-resistant Pseudomonas. MAIN OUTCOME MEASURES: Resistance of Pseudomonas isolates to ciprofloxacin and clinical response to initial therapy with 0.3% ciprofloxacin. RESULTS: By use of the in vitro antimicrobial susceptibility test, 22 cases of keratitis caused by ciprofloxacin-resistant Pseudomonas were identified. The minimum inhibitory concentration of ciprofloxacin for these isolates was > or =16 microg/ml (mean = 43 microg/ml). Gentamicin resistance occurred in 63.6% of isolates also, but 90.9% ciprofloxacin-resistant isolates were susceptible to amikacin. Fifteen (76.7%) of 19 patients who initially received ciprofloxacin did not show any clinical improvement even after 3 days of intensive medical therapy. The infiltrate resolved in all 8 cases where the antibiotic therapy was modified on the basis of susceptibility test. Four eyes were subjected to penetrating keratoplasty, and three were eviscerated following failure of treatment with ciprofloxacin. CONCLUSION: True resistance to ciprofloxacin is emerging in ophthalmology even among Pseudomonas isolates; therefore, the empiric treatment of infectious keratitis with ciprofloxacin monotherapy must be critically reviewed at this time.

Adolescent↗
PubMed2000

Pseudomonas spp. complications in patients with HIV disease: an eight-year clinical and microbiological survey.

Two hundred and twenty-four episodes of Pseudomonas spp. complications that occurred in 179 consecutive patients with HIV infection were retrospectively reviewed. Pseudomonas spp. organisms were responsible for 11.6% of 1933 episodes of non-mycobacterial bacterial diseases (5.4% of 1072 episodes of sepsis), observed over an 8-year period; 20.7% of patients experienced disease relapses (45 episodes). These complications mostly involved lower airways (66 cases), urinary tract (53 episodes), and blood (34 cases), with Pseudomonas aeruginosa isolated in 161 episodes, and other Pseudomonas spp. in the remaining 63 cases. An advanced HIV disease was frequently present (as expressed by a prior diagnosis of AIDS, a low CD4+ lymphocyte count, and leukopenia-neutropenia). Indwelling intravascular and urinary catheters were often associated with bacteremia and urinary tract involvement, respectively. More than 60% of patients were given antibiotics and/or cotrimoxazole in the month preceding the onset of Pseudomonas spp. disease. Bacterial strains isolated from our HIV-infected patients showed a favorable sensitivity to piperacillin, ceftazidime, imipenem, amikacin, tobramycin, and ciprofloxacin. An adequate antimicrobial treatment led to clinical and microbiological cure in 73.2% of patients at the first episode, and in 22.3% more subjects after one or more relapses. A lethal outcome occurred in only eight patients of 179 (4.5%), suffering from a far advanced HIV disease; P. aeruginosa infection directly contributed to death in four cases (sepsis, and/or pneumonia). Nosocomial disease occurred in 46.4% of the 224 episodes, and was significantly related to a previous diagnosis of AIDS, concurrent neutropenia, the occurrence of sepsis or urinary tract infection, disease relapses, the involvement of non-aeruginosa Pseudomonas spp., and a lethal outcome, compared with community-acquired infection. Our experience (the largest reported to date) confirms that Pseudomonas spp. (including non-aeruginosa Pseudomonas spp. organisms) is responsible for remarkable morbidity and mortality among patients with HIV infection, and may pose relevant problems to clinicians and microbiologists involved in the care of HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1992

Analysis of IgA antibody to Pseudomonas aeruginosa in sera and sputa of patients with chronic airway diseases.

The change of IgA system for Pseudomonas infection was examined by enzyme-linked immunosorbent assay of the system in sera and sputa of patients with chronic airway diseases. The anti-Pseudomonas total IgA antibody titers in both sera and sputa were not elevated in group I with no infection (mainly chronic bronchitis) and group II infected with bacteria other than Pseudomonas, but were elevated in group III colonized transiently with Pseudomonas [diffuse panbronchiolitis (DPB) and bronchiectasis] and group IV colonized persistently with Pseudomonas (mainly DPB). The elevation in the sera and sputa were mainly due to monomeric IgA and polymeric IgA (S-IgA), respectively, and values were significantly higher in group III than in group IV only in the sera. These results indicate that the IgA system is enhanced in advanced DPB and bronchiectasis complicated by Pseudomonas infection, and that the anti-Pseudomonas IgA antibody titer in serum is more useful than that in sputum for the diagnosis of respiratory Pseudomonas infection.

Adult↗
PubMed1980

Use of Pseudomonas aeruginosa lipopolysaccharide immunoadsorbents to prepare high potency, mono-specific antibodies.

Potent, mono-specific anti-Pseudomonas immunoglobulins were isolated from serum and lung lavage fluid from patients with cystic fibrosis using immunotype specific Pseudomonas aeruginosa lipopolysaccharide (LPS) substituted immunoadsorbent gel. Iodinated monovalent Pseudomonas LPS somatic antigens, Fisher immunotypes, were used as ligands for two different insoluble gel matrices. LPS iodination, using the water insoluble chloroglycoluril reagent, permitted quantitation of the percent LPS bound as a ligand. The coupling efficiencies of epoxy-activated and cyanogen bromide-activated Sepharose matrices for various Pseudomonas immunotype specific LPS preparations were compared. Although each of the 7 LPS somatic antigens produced an equivalent amount of coupling, higher percentages of coupling were found using the cyanogen bromide-activated gel when compared to the epoxy-activated gel. IgG fractions prepared from cystic fibrosis sera and lung lavage fluid were passed through the LPS affinity gels, and Pseudomonas LPS immunotype specific antibodies were eluted. The presence of specific antibody activity against individual Pseudomonas immunotypes was determined with a passive micro-hemagglutination assay. Bronchial lavage fluid seemed to be as effective as serum as a source of Pseudomonas specific antibody. Use of such a LPS substituted gel permits direct recovery of Pseudomonas monospecific antibodies suitable for physical-chemical analyses and for biologic functional assays.

Antibodies, Bacterial↗
PubMed1989

Combined treatment with Pseudomonas aeruginosa toxin and interferon on mouse and human cells.

The combined biological effect of Pseudomonas toxin and beta-interferon on mammalian cells was studied on two cell lines. The first was a virus-producing clone derived from NIH/3T3 mouse fibroblasts transformed by Moloney murine sarcoma virus. The second was a clone derived from human amnion cells. The parameters examined were either retrovirus release from the mouse cells or the rate of protein synthesis in both cell lines. When applied together with Pseudomonas toxin, interferon inhibits virus release even at a Pseudomonas toxin concentration that by itself does not exhibit any biological effect on NIH/3T3 cells. This enhancement phenomenon is both Pseudomonas toxin and interferon dose-dependent. Likewise, the combined treatment of either mouse or human cells with Pseudomonas toxin and the appropriate species-specific interferon, inhibits protein synthesis to a much greater extent than either of these agents alone. The kinetics of the inhibition of virus release is different from that seen with protein synthesis indicating that the enhancement phenomenon observed on virus release is not a result of the inhibition of total cellular protein synthesis. Interferon potentiates the effect of Pseudomonas toxin in a species-specific manner, thus suggesting that this process does not occur at the level of cell receptors but is a consequence of a subsequent intracellular event. It is concluded that the enhancement phenomenon does not reflect a direct interaction between interferon and Pseudomonas toxin, since Pseudomonas incubated together with interferon retained its normal biological activity as indicated by the ability of the toxin molecule to transfer the adenine diphosphoribose (ADP-ribose) moiety of nicotinamide-adenine dinucleotide (NAD) onto elongation factor 2 (EF-2).

ADP Ribose Transferases↗
PubMed1987

The effect of enzymatic contact lens cleaning on adherence of Pseudomonas aeruginosa to soft contact lenses.

Previous studies have demonstrated that Pseudomonas aeruginosa adheres more readily to soft contact lenses with a mucin coating than to unworn contact lenses. The mucin coatings that develop on soft contact lenses may, therefore, play a significant role in the pathogenesis of contact lens-associated Pseudomonas corneal ulceration. We tested the ability of a variety of enzymatic contact lens cleaners and other enzyme solutions to decrease the adherence of Pseudomonas to mucin-coated soft contact lenses. Of the commercially available solutions that were tested, cleaning with Optizyme and Extenzyme significantly reduced the adherence of Pseudomonas to the lenses, whereas cleaning with the Softmate Weekly Cleaning System had no effect. Optizyme and Extenzyme were as effective as a 10% solution of acetylcysteine and more effective than a 0.25% trypsin solution. Neuraminidase at pH 5 was the most effective solution at reducing the adherence of Pseudomonas to the lenses, supporting the finding that sialic acid is a specific receptor for Pseudomonas aeruginosa. Soft contact lenses should be cleaned frequently with an effective enzymatic cleaner to reduce the likelihood of Pseudomonas adhering to the lens and thereby reduce the incidence of Pseudomonas corneal ulceration in soft contact lens wearers.

Acetylcysteine↗
PubMed1999

Pseudomonas libanensis sp. nov., a new species isolated from Lebanese spring waters.

The taxonomic position of eight fluorescent Pseudomonas isolates, from two Lebanese spring waters, which were previously recognized by numerical analysis as members of a new subcluster (subcluster Vb) was examined. Except for one strain, the new subcluster exhibited internal DNA hybridization values of 76-100%, and 9-53% hybridization was measured with the type or reference strains of other Pseudomonas species. The highest DNA binding value was found with Pseudomonas marginalis strains (37-53%). The G+C content of the DNA of the type strain was 58 mol%. A comparison of 1322 nt of the 16S rRNA gene sequence of the strain representing subcluster Vb (CFML 96-195T) with the sequence of other strains of the genus Pseudomonas revealed that strain CFML 96-195T was part of the 'Pseudomonas fluorescens intrageneric cluster'. On the basis of the results of phenotypic, DNA-DNA and phylogenetic analyses, a new Pseudomonas species, Pseudomonas libanensis sp. nov., is proposed for the seven strains of subcluster Vb. The type strain is P. libanensis CFML 96-195T and has been deposited in the Collection de l'Institut Pasteur (Paris, France) as CIP 105460T. The P. libanensis strains are phenotypically and genotypically homogeneous and can be differentiated from most other fluorescent species by several phenotypic features. Differentiation of P. libanensis and Pseudomonas aeruginosa is based mainly on pyocyanin production; P. libanensis can be differentiated from P. fluorescens (all biovars) by alpha-aminobutyrate assimilation. The clinical significance of P. libanensis is unknown.

Bacterial Typing Techniques↗
PubMed2002

Pseudomonas extremorientalis sp. nov., isolated from a drinking water reservoir.

On the basis of phenotypic and genotypic characteristics and 16S rDNA sequence analysis, a novel species belonging to the genus Pseudomonas sensu stricto was identified. The saprophytic, fluorescent bacterium, designated KMM 3447(T), was isolated from a drinking water reservoir near Vladivostok City, Russia. The novel organism was a Gram-negative, aerobic, rod-shaped bacterium that produced a cyclic depsipeptide with surface-active properties. It degraded casein, but did not degrade gelatin, starch, agar or Tween 80. The bacterium was also haemolytic. Growth of the novel bacterium occurred between 4 and 35 degrees C. The predominant cellular fatty acids of the novel pseudomonad were C16:0, C16:1(n-7), C18:1(n-7) and C17.0 cyclo; branched fatty acids were only found in trace amounts. The G+C content of the novel bacterium was 61.0 mol%. 16S rDNA sequence analysis indicated that the novel bacterium had a clear affiliation with Pseudomonas fluorescens and species closely related to this recognized pseudomonad. DNA-DNA hybridization experiments showed that the novel bacterium bound at low levels (27-53%) with the DNA of the type strains of its nearest phylogenetic relatives, namely Pseudomonas tolaasii, Pseudomonas veronii, Pseudomonas orientalis and Pseudomonas rhodesiae, indicating that the novel bacterium represented a novel species within the genus Pseudomonas, for which the name Pseudomonas extremorientalis is proposed; the type strain is KMM 3447(T) (= LMG 19695(T)).

Base Composition↗