BioAssay record AID 164064 submitted by ChEMBL: Antibacterial activity against gram-negative bacteria Pseudomonas aeruginosa ATCC 27853; No effect.

Functional analysis of genes responsible for the synthesis of the B-band O antigen of Pseudomonas aeruginosa serotype O6 lipopolysaccharide Academic Article ...

Cystic fibrosis (CF) lung disease begins in the first few months of life and follows a course of recurrent lower airway bacterial infection and inflammation and progression of disease over years and decades at a variable pace. With the development of chronic lung infection, obstructive disease progressively worsens, ultimately leading to respiratory failure. Pseudomonas aeruginosa (Pa) is the most important pathogen infecting the CF lower airways, and its acquisition early in life is associated with a pro-inflammatory effect, lower lung function, poor nutritional outcomes, and decreased survival.. Pseudomonas aeruginosa (Pa) infection of the cystic fibrosis (CF) airway typically proceeds from early infection to chronic infection. Although some studies have shown that a minority of individuals with CF spontaneously clear early Pseudomonas aeruginosa (Pa) infection, data from multiple studies suggest that antibiotics are superior to no treatment in clearing Pseudomonas aeruginosa (Pa) from ...

Many of the virulence factors produced by the opportunistic human pathogen Pseudomonas aeruginosa are quorum-sensing (QS) regulated. Among these are rhamnolipids, which have been shown to cause lysis of several cellular components of the human immune system, e.g. monocyte-derived macrophages and polymorphonuclear leukocytes (PMNs). We have previously shown that rhamnolipids produced by P. aeruginosa cause necrotic death of PMNs in vitro. This raises the possibility that rhamnolipids may function as a biofilm shieldin vivo, which contributes significantly to the increased tolerance of P. aeruginosa biofilms to PMNs. In the present study, we demonstrate the importance of the production of rhamnolipids in the establishment and persistence of P. aeruginosa infections, using an in vitro biofilm system, an intraperitoneal foreign-body model and a pulmonary model of P. aeruginosa infections in mice. Our experimental data showed that a P. aeruginosa strain, unable to produce any detectable ...

The opportunistic human pathogen Pseudomonas aeruginosa is the predominant micro-organism of chronic lung infections in cystic fibrosis patients. P. aeruginosa colonizes the lungs by forming biofilm microcolonies throughout the lung. Quorum sensing (QS) renders the biofilm bacteria highly tolerant t …

Pseudomonas aeruginosa and Aspergillus fumigatus are common opportunistic bacterial and fungal pathogens, respectively. They often coexist in airways of immunocompromised patients and individuals with cystic fibrosis, where they form biofilms and cause acute and chronic illnesses. Hence, the interactions between them have long been of interest and it is known that P. aeruginosa can inhibit A. fumigatusin vitro We have approached the definition of the inhibitory P. aeruginosa molecules by studying 24 P. aeruginosa mutants with various virulence genes deleted for the ability to inhibit A. fumigatus biofilms. The ability of P. aeruginosa cells or their extracellular products produced during planktonic or biofilm growth to affect A. fumigatus biofilm metabolism or planktonic A. fumigatus growth was studied in agar and liquid assays using conidia or hyphae. Four mutants, the pvdD pchE, pvdD, lasR rhlR, and lasR mutants, were shown to be defective in various assays. This suggested the P. aeruginosa ...

Pseudomonas aeruginosa lung infections are a major cause of death in cystic fibrosis and hospitalized patients. Treating these infections is becoming difficult due to the emergence of conventional antimicrobial multiresistance. While monosaccharides have proved beneficial against such bacterial lung infection, the design of several multivalent glycosylated macromolecules has been shown to be also beneficial on biofilm dispersion. In this study, calix[4]arene-based glycoclusters functionalized with galactosides or fucosides have been synthesized. The characterization of their inhibitory properties on Pseudomonas aeruginosa aggregation, biofilm formation, adhesion on epithelial cells, and destruction of alveolar tissues were performed. The antiadhesive properties of the designed glycoclusters were demonstrated through several in vitro bioassays. An in vivo mouse model of lung infection provided an almost complete protection against Pseudomonas aeruginosa with the designed glycoclusters.. ...

The opportunistic human pathogen Pseudomonas aeruginosa is the predominant micro-organism of chronic lung infections in cystic fibrosis patients. P. aeruginosa colonizes the lungs by forming biofilm microcolonies throughout the lung. Quorum sensing (QS) renders the biofilm bacteria highly tolerant to otherwise lethal doses of antibiotics, and protects against the bactericidal activity of polymorphonuclear leukocytes (PMNs). It has been previously demonstrated that QS is inhibited by garlic extract. In this study, the synergistic effects of garlic and tobramycin, and PMNs activities have been evaluated. P. aeruginosa was grown in vitro in continuous-culture once-through flow chambers with and without garlic extract. The garlic-treated biofilms were susceptible to both tobramycin and PMN grazing. Furthermore, the PMNs showed an increase in respiratory burst activation, when incubated with the garlic-treated biofilm. Garlic extract was administered as treatment for a mouse pulmonary infection model. Mice

Bacterial resistance to conventional antibiotics combined with an increasing acknowledgement of the role of biofilms in chronic infections has led to a growing interest in new antimicrobial strategies that target the biofilm mode of growth. In the aggregated biofilm mode, cell-to-cell communication systems involved in the process known as quorum sensing regulate coordinated expression of virulence with immune shielding mechanisms and antibiotic resistance. For two decades, the potential of interference with quorum sensing by small chemical compounds has been investigated with the aim of developing alternative antibacterial strategies. Here, we review state of the art research of quorum sensing inhibitors against the opportunistic human pathogen Pseudomonas aeruginosa, which is found in a number of biofilm-associated infections and identified as the predominant organism infecting the lungs of cystic fibrosis patients ...

TY - JOUR. T1 - Genome‐wide identification of novel small RNAs in Pseudomonas aeruginosa. AU - Gómez Lozano, María. AU - Marvig, Rasmus Lykke. AU - Molin, Søren. AU - Long, Katherine. PY - 2012. Y1 - 2012. N2 - Bacterial small regulatory RNAs (sRNAs) function in post‐transcriptional control of gene expression and control a variety of processes including metabolic reactions, stress responses and pathogenesis in response to environmental signals. A variety of approaches have been used previously to identify 44 sRNAs in the opportunistic human pathogen Pseudomonas aeruginosa. In this work, RNA sequencing (RNA‐seq) is used to identify novel transcripts in P. aeruginosa involving a combination of three different sequencing libraries. Almost all known sRNAs and over 500 novel intergenic sRNAs are identified with this approach. Although the use of three libraries increased the number of novel transcripts identified, there were significant differences in the subset of transcripts detected in ...

Phytopathology 102:575-587...Phytopathology 102:575-587...Effect of Overexpressing rsmA from Pseudomonas aeruginosa on Virulence of Select Phytotoxin-Producing Strains of P. syringae...Hye Suk Kong, Daniel P. Roberts, Cheryl D. Patterson, Sarah A. Kuehne, Stephan Heeb, Dilip K. Lakshman, and John Lydon...

Data of the study: Direct and indirect impact of the bacterial strain Pseudomonas aeruginosa on the dissolution of synthetic Fe(III)- and Fe(II)-bearing basaltic glasses

Introduction: Surgical wound infection is a serious problem, especially with metallo-beta lactamases (MBLs)- producing gram-negative bacteria as Pseudomonas aeruginosa. The main objective of this work was to evaluate for the first time in Minia- Upper Egypt, the incidence of imipenem-resistant Pseudomonas aeruginosa infection of surgical wounds particularly that mediated by MBL production.. Methodology: P. aeruginosa was isolated from infected wounds by swabs and underwent full microbiological identification and Antibiotic Susceptibility testing. MBL production was tested by E-test and PCR was used for imipenemase (blaIMP) and Verona integron-encoded metallo-beta-lactamase (blaVIM) gene detection.. Results: Out of 200 pus samples collected from surgical site infections, P. aeruginosa had the prevalence rate of 35%. Imipenem resistance was found in 28.57% of the isolated Pseudomonas aeruginosa. The prevalence of MBL-producing isolates among Imipenem-resistant P. aeruginosa (IRPA) was 85 % by ...

Cheats are a pervasive threat to public goods production in natural and human communities, as they benefit from the commons without contributing to it. Although ecological antagonisms such as predation, parasitism, competition, and abiotic environmental stress play key roles in shaping population biology, it is unknown how such stresses generally affect the ability of cheats to undermine cooperation. We used theory and experiments to address this question in the pathogenic bacterium, Pseudomonas aeruginosa Although public goods producers were selected against in all populations, our competition experiments showed that antibiotics significantly increased the advantage of nonproducers. Moreover, the dominance of nonproducers in mixed cultures was associated with higher resistance to antibiotics than in either monoculture. Mathematical modeling indicates that accentuated costs to producer phenotypes underlie the observed patterns. Mathematical analysis further shows how these patterns should ...

Ozer B, Duran N, Onlen Y, Savas L. Efflux pump genes and antimicrobial resistance of Pseudomonas aeruginosa strains isolated from lower respiratory tract infections acquired in an intensive care unit. J Antibiot 2012; 65(1): 9-13. Badamchi, A., Masoumi, H., Javadinia, S., Asgarian, R. and Tabatabaie, A., 2017. Molecular detection of six virulence genes in Pseudomonas aeruginosa isolates detected in children with urinary tract infection. Microb Pathog 107: 44-47. Farra A, Islam S, Stralfors A, et al. Role of outer membrane protein OprD and penicillin-binding proteins in resistance of Pseudomonas aeruginosa to imipenem and meropenem. Int J Antimicrob Agents 2008; 31(5): 427-33. Fazeli H, Havaei SA, Solgi H, et al. Pattern of antibiotic resistance in Pesudomonas aeruginosa isolated from intensive care unit, Isfahan, Iran. Journal of Isfahan Medical School 2013; 31(232): 432-438. Gutierrez O, Juan C, Cercenado E, et al. Molecular epidemiology and mechanisms of carbapenem resistance in Pseudomonas ...

A total of 3,700 Pseudomonas aeruginosa isolates were collected from 17 general hospitals in Japan from 1992 to 1994. Of these isolates, 132 carbapenem-resistant strains were subjected to DNA hybridization analysis with the metallo-beta-lactamase gene (blaIMP)-specific probe. Fifteen strains carrying the metallo-beta-lactamase gene were identified in five hospitals in different geographical areas. Three strains of P. aeruginosa demonstrated high-level imipenem resistance (MIC, , or = 128 micrograms/ml), two strains exhibited low-level imipenem resistance (MIC, , or = 4 micrograms/ml), and the rest of the strains were in between. These results revealed that the acquisition of a metallo-beta-lactamase gene alone does not necessarily confer elevated resistance to carbapenems. In several strains, the metallo-beta-lactamase gene was carried by large plasmids, and carbapenem resistance was transferred from P. aeruginosa to Escherichia coli by electroporation in association with the acquisition of the ...

Bacteria synchronize group behaviors using quorum sensing, which is advantageous during an infection to thwart immune cell attack and resist deleterious changes in the environment. In Pseudomonas aeruginosa, the Pseudomonas quinolone signal (Pqs) quorum-sensing system is an important component of an interconnected intercellular communication network. Two alkylquinolones, 2-heptyl-4-quinolone (HHQ) and 2-heptyl-3-hydroxy-4-quinolone (PQS), activate transcriptional regulator PqsR to promote the production of quinolone signals and virulence factors. Our work focused on the most abundant quinolone produced from the Pqs system, 2,4-dihydroxyquinoline (DHQ), which was shown previously to sustain pyocyanin production and antifungal activity of P. aeruginosa. However, little is known about how DHQ affects P. aeruginosa pathogenicity. Using C. elegans as a model for P. aeruginosa infection, we found pqs mutants only able to produce DHQ maintained virulence towards the nematodes similar to wild-type. In addition,

Haji SH. Detection of Biofilm Formation in Pseudomonas aeruginosa Isolates from Clinical Specimens. Zanco J Pure Appl Sci. 2018; 30[4]:83-89. doi: https://doi.org/10.21271/ZJPAS.30.4.9 Saha S, Devi KM, Damrolien S, Devi KS, . K, Sharma KT. Biofilm production and its correlation with antibiotic resistance pattern among clinical isolates of Pseudomonas aeruginosa in a tertiary care hospital in north-east India. Int J Adv Med. 2018;5[4]:964. doi: http://dx.doi.org/10.18203/2349-3933.ijam20183129 Vallés J, Mariscal D, Cortés P, Coll P, Villagrá A, Díaz E, et al. Patterns of colonization by Pseudomonas aeruginosa in intubated patients: A 3-year prospective study of 1,607 isolates using pulsed-field gel electrophoresis with implications for prevention of ventilator-associated pneumonia. Intensive Care Med. 2004; 30[9]:1768-1775. doi: https://doi.org/10.1007/s00134-004-2382-6. Gales AC, Jones RN, Turnidge J, Rennie R, Ramphal R. Characterization of Pseudomonas aeruginosa Isolates: Occurrence Rates, ...

The success of Pseudomonas aeruginosa in cystic fibrosis (CF) and other chronic infections is largely attributed to its ability to grow in antibiotic-resistant biofilm communities. This study investigated the effects of limiting iron levels as a strategy for preventing/disrupting P. aeruginosa biofilms. A range of synthetic and naturally occurring iron-chelating agents were examined. Biofilm development by P. aeruginosa strain PAO1 and CF sputum isolates from chronically infected individuals was significantly decreased by iron removal under aerobic atmospheres. CF strains formed poor biofilms under anaerobic conditions. Strain PAO1 was also tested under anaerobic conditions. Biofilm formation by this model strain was almost totally prevented by several of the chelators tested. The ability of synthetic chelators to impair biofilm formation could be reversed by iron addition to cultures, providing evidence that these effective chelating compounds functioned by directly reducing availability of iron to P.

An organism of concern, Pseudomonas aeruginosa is a water-loving bacteria that works and builds biofilms with other threatening bacteria. Understanding that disinfection alone will not rid an engineered water system of bacteria means we need to look toward biofilm-resistant material and disinfection at the source of use as opposed to where the water enters the building.. Antibiotic Resistance of Pseudomonas aeruginosa in Pneumonia at a Single University Hospital Center in Germany over a 10-Year Perioddetermines that while P. aeruginosa and MDR P. aeruginosa were resistant to a variety of commonly used antibiotics, they were not resistant to colistin in the few isolates recovered from patients with pneumonia.. Inhibition of Aspergillus fumigatus and Its Biofilm by Pseudomonas aeruginosa Is Dependent on the Source, Phenotype and Growth Conditions of the Bacterium reports that Aspergillus fumigatus (Af) and Pseudomonas aeruginosa (Pa) are leading fungal and bacterial pathogens, respectively, in ...

Cystic fibrosis lung disease is characterized by chronic airway infections with the opportunistic pathogen Pseudomonas aeruginosa and severe neutrophilic pulmonary inflammation. P. aeruginosa undergoes extensive genetic adaptation to the cystic fibrosis (CF) lung environment, and adaptive mutations in the quorum sensing regulator gene lasR commonly arise. We sought to define how mutations in lasR alter host-pathogen relationships. We demonstrate that lasR mutants induce exaggerated host inflammatory responses in respiratory epithelial cells, with increased accumulation of proinflammatory cytokines and neutrophil recruitment due to the loss of bacterial protease-dependent cytokine degradation. In subacute pulmonary infections, lasR mutant-infected mice show greater neutrophilic inflammation and immunopathology compared with wild-type infections. Finally, we observed that CF patients infected with lasR mutants have increased plasma interleukin-8 (IL-8), a marker of inflammation. These findings ...

Prime Journal of Microbiology Research (PJMR) ISSN: 2251-1261. susceptible and P. aeruginosa the least. Antibiotic use is suggested to be a major risk factor for.. chromID ™ P.aeruginosa Chromogenic medium for direct ID of Pseudomonas aeruginosa. Deliver rapid direct identification of Pseudomonas aeruginosa to contribute to.chromID™ P.aeruginosa Chromogenic medium for direct ID of Pseudomonas aeruginosa. Deliver rapid direct identification of Pseudomonas aeruginosa to contribute to.RESEARCH ARTICLE Open Access Screening of Lactobacillus spp. for the prevention of Pseudomonas aeruginosa pulmonary infections Youenn Alexandre1, Rozenn Le Berre1,2*.tetracycline, Tetracycline is an antibiotic used to treat a number of bacterial infections. It is commonly used to treat acne and rosacea. Historically it was.Original article Antibiotic resistance and virulence properties of Pseudomonas aeruginosa strains from mechanically ventilated patients with pneumonia in intensive ...

BioAssay record AID 478497 submitted by ChEMBL: Antibacterial activity against Pseudomonas aeruginosa at 2 mg/ml after 24 hrs by agar diffusion method.

The opportunistic human pathogen Pseudomonas aeruginosa controls virulence, production of secondary metabolites, motility, biofilm formation, growth in anaerobic conditions, intracellular and intercellular signalling and the switch from an acute to a chronic mode of infection at the transcriptional and post-transcriptional levels by modulation of the Gac/Rsm system. Cell density-dependent signal accumulation and environmental stimulators such as pH changes and ion limitation activate the GacS/GacA two-component system which in turn triggers transcription of the small regulatory RNAs RsmY and RsmZ. These sRNAs sequester multiple copies of the RNA-binding protein RsmA, antagonising its function. The RsmA/CsrA proteins act as translational repressors by binding to the GGA-motifs in the untranslated region of target mRNAs and blocking ribosome binding. In this study, the biological function of RsmN, an RsmA homologue with a conserved RNA-binding pocket but a distinct protein folding, the predicted ...

EDTA has a detrimental effect on the outer membrane permeability of free-living planktonic Proteobacteria (15, 25, 29, 40). By chelating divalent cations from their binding sites in lipopolysaccharide (LPS), EDTA facilitates the release of a significant proportion of LPS from the cell (26). Although prolonged treatments with EDTA are lethal, short treatments increase the permeability of the outer membrane to hydrophobic molecules (25, 29). Thus, there can be synergy between EDTA and other antibacterial agents (2, 8, 24). In this study we report that EDTA not only kills P. aeruginosa planktonic cells but also affects P. aeruginosa biofilms (Fig. 1 and 2).. Exposure of P. aeruginosa biofilms to EDTA killed P. aeruginosa cells and triggered detachment of cells from biofilms (Fig. 3 to 5). CSLM revealed that the majority of the cell population affected by the EDTA treatment resides in the inner regions of the mushroom-like structures. This type of killing or detachment pattern has been observed in ...

Increasing rates of antibiotic resistance among Gram-negative pathogens such as Pseudomonas aeruginosa means alternative approaches to antibiotic development are urgently required. Pyocins, produced by P. aeruginosa for intraspecies competition, are highly potent protein antibiotics known to actively translocate across the outer membrane of P. aeruginosa. Understanding and exploiting the mechanisms by which pyocins target, penetrate and kill P. aeruginosa is a promising approach to antibiotic development. In this work we show the therapeutic potential of a newly identified tRNase pyocin, pyocin SD2, by demonstrating its activity in vivo in a murine model of P. aeruginosa lung infection. In addition, we propose a mechanism of cell targeting and translocation for pyocin SD2 across the P. aeruginosa outer membrane. Pyocin SD2 is concentrated at the cell surface, via binding to the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide (LPS), from where it can efficiently locate its outer

Increasing rates of antibiotic resistance among Gram-negative pathogens such as Pseudomonas aeruginosa means alternative approaches to antibiotic development are urgently required. Pyocins, produced by P. aeruginosa for intraspecies competition, are highly potent protein antibiotics known to actively translocate across the outer membrane of P. aeruginosa. Understanding and exploiting the mechanisms by which pyocins target, penetrate and kill P. aeruginosa is a promising approach to antibiotic development. In this work we show the therapeutic potential of a newly identified tRNase pyocin, pyocin SD2, by demonstrating its activity in vivo in a murine model of P. aeruginosa lung infection. In addition, we propose a mechanism of cell targeting and translocation for pyocin SD2 across the P. aeruginosa outer membrane. Pyocin SD2 is concentrated at the cell surface, via binding to the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide (LPS), from where it can efficiently locate its ...

Pseudomonas aeruginosa ATCC ® 47085D-5™ Designation: Genomic DNA from Pseudomonas aeruginosa strain PAO1-LAC TypeStrain=False Application:

Cluster II che Genes from Pseudomonas aeruginosa Are Required for an Optimal Chemotactic Response: Pseudomonas aeruginosa, a γ-proteobacterium, is motile by mea

Bacterial viruses, or phage, are key members of natural microbial communities. Yet much research on bacterial-phage interactions has been conducted in liquid cultures involving single bacterial strains. Here we explored how bacterial diversity affects the success of lytic phage in structured communities. We infected a sensitive Pseudomonas aeruginosa strain PAO1 with a lytic phage Pseudomonas 352 in the presence versus absence of an insensitive P. aeruginosa strain PA14, in liquid culture versus colonies on agar. We found that both in liquid and in colonies, inter-strain competition reduced resistance evolution in the susceptible strain and decreased phage population size. However, while all sensitive bacteria died in liquid, bacteria in colonies could remain sensitive yet escape phage infection, due mainly to reduced growth in colony centers. In sum, spatial structure can protect bacteria against phage infection, while the presence of competing strains reduces the evolution of resista

Shape (Cocci/Diplococci/Rods) Rods. of a 1% solution of α-naphthol in 95% … Pseudomonas aeruginosa. This enzyme oxidizes di-methyl-p-phenylenediamine in the presence of molecular oxygen and cytochrome c and on the addition of α-naphthol, indophenol blue is formed. After filtration of the sample and a short cultivation step, this test confirms all grown microcolonies, not only a selection as it is the case with classical methods. Negative. Item Number: 01230002. Properties (Pseudomonas aeruginosa) Capsule. Dentalanalyse Pseudomonas Dieser Test untersucht folgende Parameter: Mikrobiologischer Parameter: Pseudomonas aeruginosa Schritt 1: Innerhalb eines Werktages verschicken wir Ihre Bestellung! I got the HI MEDIA Biochemical test results as follows: Citrate test +ve, Lysine +ve, Ornithine +ve, Urease +ve, Phenylalanine deamination -ve, Nitrate reduction -ve, H2S Production +ve, Glucose -ve, Adonitol-ve, Lactose -ve, Arabinose +ve, Sorbitol-ve. Pseudomonas aeruginosa colonies that were ...

Pseudomonas aeruginosa Serotype 2B antibody LS-C538938 is an FITC-conjugated mouse monoclonal antibody to pseudomonas aeruginosa Pseudomonas aeruginosa Serotype 2B. Validated for ELISA.

TY - JOUR. T1 - Dual β-lactam combination therapy for multi-drug resistant Pseudomonas aeruginosa infection. T2 - enhanced efficacy in vivo and comparison with monotherapies of penicillin-binding protein inhibition. AU - Siriyong, Thanyaluck. AU - Murray, Rachael M.. AU - Bidgood, Lucy E.. AU - Young, Simon A.. AU - Wright, Florence. AU - Parcell, Benjamin J.. AU - Voravuthikunchai, Supayang Piyawan. AU - Coote, Peter J.. PY - 2019/6/24. Y1 - 2019/6/24. N2 - The aim of the study was to determine the efficacy of dual β-lactam combination treatments derived from eight approved drugs against Galleria mellonella larvae infected with MDR strains of P. aeruginosa. Carbapenem-resistant P. aeruginosa NCTC 13437 and an unrelated clinical isolate were used to infect G. mellonella larvae and the efficacy of twenty-eight dual β-lactam combination therapies were compared to their constituent monotherapies. For the most potent combinations identified, penicillin-binding protein (PBP) inhibition profiles ...

In the opportunistic pathogen Pseudomonas aeruginosa, quorum sensing (QS) via acyl-homoserine lactone (AHL) signals coordinates virulence gene expression. AHL signals must reach a critical threshold before enough is bound by cognate regulators LasR and RhlR to drive transcription of target genes. In addition, three anti-activator proteins, QteE, QscR, and QslA, sequester QS regulators to increase the threshold for induction and delay expression of QS target genes. It remains unclear how multiple anti-activators work together to achieve the quorum threshold. Here, we employed a combination of mutational, kinetic, phenotypic, and transcriptomic analysis to examine regulatory effects and interactions of the three distinct anti-activators. We observed combinatorial, additive effects on QS gene expression. As measured by reporter gene fusion, individual deletion of each anti-activator gene increased lasB expression and QS-controlled virulence factor production. Deletion of qslA in combination with the

A Pf1-like phage is involved in P. aeruginosa biofilm killing.Electron microscopic examination of the CsCl-purified phage revealed filamentous phage particles that were approximately 1.5 μm long (Fig. 3b). The genome of P. aeruginosa contains a filamentous prophage that is closely related to phage Pf1, and Pf1 genes are known to be upregulated in P. aeruginosa biofilms (66). Moreover, it is known that Pf1 can infect a cell by using T4P (24). Flagella have also been reported to be receptors for filamentous phage (44), and our data suggest that the P. aeruginosa Pf1-like phage may additionally infect a cell through the flagellum. We also carried out PCR with Pf1-specific primers 437F and 437R using DNA extracted from the CsCl-purified phage band. The 894-bp PCR product was sequenced, and the sequence showed 100% identity with the sequence of the Pf1-like prophage from P. aeruginosa. We also hybridized a PCR-labeled, Pf1-specific DNA probe with individual plaques generated from the biofilm ...

A Pf1-like phage is involved in P. aeruginosa biofilm killing.Electron microscopic examination of the CsCl-purified phage revealed filamentous phage particles that were approximately 1.5 μm long (Fig. 3b). The genome of P. aeruginosa contains a filamentous prophage that is closely related to phage Pf1, and Pf1 genes are known to be upregulated in P. aeruginosa biofilms (66). Moreover, it is known that Pf1 can infect a cell by using T4P (24). Flagella have also been reported to be receptors for filamentous phage (44), and our data suggest that the P. aeruginosa Pf1-like phage may additionally infect a cell through the flagellum. We also carried out PCR with Pf1-specific primers 437F and 437R using DNA extracted from the CsCl-purified phage band. The 894-bp PCR product was sequenced, and the sequence showed 100% identity with the sequence of the Pf1-like prophage from P. aeruginosa. We also hybridized a PCR-labeled, Pf1-specific DNA probe with individual plaques generated from the biofilm ...

Looking for Pseudomonas aeruginosa? Find out information about Pseudomonas aeruginosa. An opportunistic pathogen that is the most significant cause of hospital-acquired infections, particularly in predisposed patients with metabolic,... Explanation of Pseudomonas aeruginosa

ABSTRACT. The present work attempts to solve pollution problems in watery surroundings by aromatic compounds such as the phenol and the benzoic acid. Several ways of elimination of these compounds were the object of different research among which is the use of bacteria. In this framework, Pseudomonas aeruginosa bacterium is used to eliminate phenol and the benzoic acid. This made it possible to isolate the Pseudomonas aeruginosa bacterium directly on the nourishing environment containing phenol and benzoic acid as source of energy then the bacteria is incubated at 37˚C during a minimal duration of four days. Furthermore, we studied the influence of the Pseudomonas aeruginosa bacterium on the deterioration of an area exposed to a phenol and the benzoic acid concentration. Results obtained at the time of the different experimentations clearly show that phenol and the benzoic acid were eliminated by the Pseudomonas aeruginosa bacterium. However, it was noted that during the various investigations ...

The early endobronchial inflammation induced by Pseudomonas aeruginosa infection varies in resistant and susceptible strains of mice. Mice of the DBA/2 strain are severely afflicted by the infection, with a high bacterial burden accumulating rapidly following inoculation and a high mortality rate occurring. Mice of the BALB/c strain are resistant to infection and clear the bacteria within 3 to 7 days. Infection of (BALB/c x DBA/2)F1 hybrid mice showed that the resistance to lung P. aeruginosa infection is inherited as a dominant trait. Mice of the A/J and C57BL/6 strains were found to have an intermediate phenotype to Pseudomonas aeruginosa infection when compared with BALB/c and DBA/2 strains. The decrease in the bacterial load seen early after infection coincided with a steady and strong recruitment of inflammatory cells to the bronchoalveolar spaces of mice of the resistant BALB/c strain. On the other hand, the recruitment of inflammatory cells to the lungs of mice of the susceptible DBA/2 ...

TY - JOUR. T1 - Slime production a virulence marker in Pseudomonas aeruginosa strains isolated from clinical and environmental specimens. T2 - A comparative study of two methods. AU - Prasad, S. Vishnu. AU - Ballal, Mamatha. AU - Shivananda, P. G.. PY - 2009/4/1. Y1 - 2009/4/1. N2 - Detection of slime in Pseudomonas aeruginosa can be useful in understanding the virulence of this organism. Here, comparative studies of two phenotypic methods using the tube method and the spectrophotometric method for slime production from 100 clinically and 21 environmentally significant isolates of P. aeruginosa were performed. A total of 68 isolates were positive by either of the tests whereas only 34 were positive by both the tests. The tube method detected slime significantly in more number of isolates than the spectrophotometric method. The tube test was found to be superior to the spectrophotometric method in ease of performance, interpretation and sensitivity. Among the clinical isolates, systemic isolates ...

Background: Pseudomonas aeruginosa is one of the primary pathogens isolated more frequently in cystic fibrosis (CF) and it exhibits innate resistance to a wide range of antibiotics. Purpose: We sought to determine whether the highly prevalent genotypes of P. aeruginosa are specifically linked to CF patients and have any related multidrug antibiotic resistance. Isolates from hospitalized non-CF patients and from environmental sources were also genotypically analyzed. Methods: Collections of P. aeruginosa from lower respiratory secretions (n=45) were genotyped using pulsed-field gel electrophoresis (PFGE). Phenotypic screening for antibiotic susceptibility was performed for the common antimicrobial agents by E-test and automated Phoenix method. Results: P. aeruginosa isolates from CF (n=32), hospitalized non-CF patients (n=13), and environment sources (n=5) were analyzed. The population structure of P. aeruginosa is highly diverse and population-specific. All PFGE results of P. aeruginosa isolates ...

A total of 183 patients were colonized or infected with multidrug-resistant Pseudomonas aeruginosa isolates at a hospital in Spain during 2007-2010; prevalence increased over this period from 2.8% to 15.3%. To characterize these isolates, we performed molecular epidemiologic and drug resistance analysis. Genotyping showed that 104 (56.8%) isolates belonged to a single major clone (clone B), which was identified by multilocus sequence typing as sequence type (ST) 175. This clone was initially isolated from 5 patients in 2008, and then isolated from 23 patients in 2009 and 76 patients in 2010. PCR analysis of clone B isolates identified the bla(VIM-2) gene in all but 1 isolate, which harbored bla(IMP-22). ST175 isolates were susceptible to only amikacin (75%) and colistin (100%). Emergence of the ST175 clone represents a major health problem because it compromises therapy for treatment of P. aeruginosa nosocomial infections ...

One of the major clinical problems regarding Pseudomonas aeruginosa is attributed to metallo-beta-lactamases (MBL). This group of enzymes is a subset of beta lactamases which belong to group B of Ambler classification and cause hydrolysis of carbapenems. Based on epidemiological studies conducted worldwide, it is proved that prevalence of genes coding MBLs in P. aeruginosa species are different in various geographic zones and even in various hospitals. Therefore, according to the clinical importance of organisms generating MBLs, it is necessary to identify and control these bacteria in hospitals for therapeutic purposes.The current study aimed to investigate the Metallo-beta-Lactamase VIM-1, SPM-1, and IMP-1 genes among clinical P. aeruginosa species isolated in Zahedan, Iran.The current study investigated the presence of MBL through phenotypic and genotypic methods and also the pattern of antibiotic resistance in P. aeruginosa species isolated in hospitals. The Minimum Inhibitory Concentration (MIC)

Los mecanismos innatos y adquiridos de resistencia a los antibióticos en Pseudomonas representan un reto para los médicos que buscan una quimioterapia oportuna y eficaz. Esto es par- ticularmente importante en las áreas de cuidados intesnsivos de los hospitales. Este estudio está dirigido a lograr una comprensión a nivel molecular de dos de los más importantes mecanismos de resistencia a los fármacos en Pseudomonas aeruginosa. Cien aislados clínicos de Pseudomonas aeruginosa se obtuvieron de un hospital de tercer nivel en Quito, Ecuador. Se analizó la expresión de ampC y oprD mediante PCR cuantitativa en tiempo real. Se realizó una comparación entre los perfiles de expresión ampC y oprD y los fenotipos obtenidos en la prueba de susceptibilidad antimicrobiana (AST), con más del 50% de los aislados con perfiles concordantes para la expresión ampC y oprD. Nuestros resultados sugieren que la expresión ampC y oprD podría proporcionar información útil sobre mecanismos de resistencia ...

Pseudomonas aeruginosa causes aggressive infection in patients with pre-existing disorders and recurrent pulmonary infections in cystic fibrosis patients. Pathogenesis of P. aeruginosa infections is multifactorial owing to numerous virulence factors. The focus of this thesis research was to investigate whether P. aeruginosa elastase (PE) causes remodeling of the cytoskeleton by increasing the phosphorylation of RhoA GTPase proteins. In addressing our hypothesis, we utilized Small GTPase Immuno-sorbent Activation assays (G-LISA) and Enzyme linked Immuno-sorbent assay (ELISA) to quantitate changes in the total as well as phosphorylated RhoA protein in Calu3 cell lines. Fluorescence microscopy aided in understanding the changes in morphological organization of F-actin. Changes in expression of TJ protein, ZO1, due to PE induced RhoA GTPase activity, was analyzed with SDS PAGE and Western Blot Analysis. Our data from G-LISA and ELISA assays indicate that PE increases the amount of active RhoA protein by 50

Emond et al are reporting in Nat Genetics the identification of DCTN4 as a modifier for P.aeruginosa infection in patients with cystic fibrosis. It is a well-established fact that the majority of patients with cystic fibrosis develop acute and chronic P.aerugonisa infections which are associated with a worse clinical outcome. The authors selected and exome sequenced 91 patients from the EPIC collection with cystic fibrosis and P.aeruginosa and after performing logistic regression adjusted for ancestry and for CFTR mutation risk group identified DCTN4 as the only modifier gene. Dynactin 4 is a component of the dynein-dependent motor that moves autophagosomes along microtubules into lysosomes for degradation as part of the autophagy process which has an essential role in the clearance of P. aeruginosa. The presence of at least one DCTN4 missense variant was significantly associated with both early age of first P. aeruginosaâ€positive culture and with early age at onset of chronic P. aeruginosa ...

The fucose binding lectin LecB affects biofilm formation and is involved in pathogenicity of Pseudomonas aeruginosa. LecB resides in the outer membrane and can be released specifically by treatment of an outer membrane fraction with fucose suggesting that it binds to specific ligands. Here, we report that LecB binds to the outer membrane protein OprF. In an OprF-deficient P. aeruginosa mutant, LecB is no longer detectable in the membrane but instead in the culture supernatant indicating a specific interaction between LecB and OprF.

Author Summary Pathogens face a hostile and often novel environment when infecting a new host, and adaptation to this environment can be critical to a pathogens survival. The genetic basis of pathogen adaptation is in turn important for treatment, since the consistency with which therapies succeed may depend on the extent to which a pathogen adapts via the same routes in different patients. In this study, we investigate adaptation of the bacterium Pseudomonas aeruginosa to laboratory conditions that resemble the lungs of cystic fibrosis patients and to quinolone antibiotics. We find that a handful of genes and genetic pathways are repeatedly involved in adaptation to each condition. Nonetheless, other, less common mutations can play important roles in determining fitness, complicating strategies aimed at reducing the prevalence of antibiotic resistance.

Decreased Pseudomonas aeruginosa biofilm formation on nanomodified endotracheal tubes: a dynamic lung model Mary C Machado,1 Thomas J Webster2 1Center for Biomedical Engineering, Division of Engineering Brown University, RI, USA; 2Department of Orthopaedics, Division of Engineering Brown University, RI, USA Abstract: Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation that has been shown to be associated with increased mortality rates and medical costs in the pediatric intensive care unit. Currently, there is no cost-effective solution to the problems posed by VAP. Endotracheal tubes (ETTs) that are resistant to bacterial colonization and that inhibit biofilm formation could provide a novel solution to the problems posed by VAP. The objective of this in vitro study was to evaluate differences in the growth of Pseudomonas aeruginosa on unmodified polyvinyl chloride (PVC) ETTs and on ETTs etched with a fungal lipase, Rhizopus arrhizus, to create nanoscale surface

Pseudomonas aeruginosa is a gram-negative opportunistic pathogen in patients with neutropenia, cystic fibrosis, and burn wounds (1, 15, 19, 21). The prevalence of multidrug-resistant strains complicates the control ofP. aeruginosa (3), which has prompted studies to define the molecular basis for its pathogenesis. P. aeruginosa possesses an array of virulence factors, which makes it a successful opportunistic pathogen (6), including the ADP-ribosyltransferases, exotoxin A, and exoenzyme S.. Exoenzyme S was identified by Iglewski and coworkers as an ADP-ribosyltransferase of P. aeruginosa (8). Cloning the two forms of exoenzyme S showed that the 53-kDa form of exoenzyme S (now termed exoenzyme T [ExoT]) and the 49-kDa form of exoenzyme S (now termed exoenzyme S [ExoS]) were encoded by separate genes that were located on the P. aeruginosa chromosome (10, 22). While alignment of their primary amino acid sequences showed that ExoS and ExoT possess 76% homology (22), the specific activity of ExoT in ...

Taxobox , color = lightgrey , name = Pseudomonas , image = Pseudomonas aeruginosa 01.jpg , image_width = 280px , image_caption = P. aeruginosa colonies on an [[agar plate]]. , regnum = [[Bacterium,Bacteria]] , phylum = [[Proteobacteria]] , classis = [[Proteobacteria,Gamma Proteobacteria]] , ordo = [[Pseudomonadales]] , familia = [[Pseudomonadaceae]] , genus = Pseudomonas , genus_authority = Migula 1894 , type_species = [[Pseudomonas aeruginosa]] , subdivision_ranks = Species , subdivision = P. aeruginosa group :[[Pseudomonas aeruginosa,P. aeruginosa]] :[[Pseudomonas alcaligenes,P. alcaligenes]] :[[Pseudomonas anguilliseptica,P. anguilliseptica]] :[[Pseudomonas argentinensis,P. argentinensis]] :[[Pseudomonas borbori,P. borbori]] :[[Pseudomonas citronellolis,P. citronellolis]] :[[Pseudomonas flavescens,P. flavescens]] :[[Pseudomonas mendocina,P. mendocina]] :[[Pseudomonas nitroreducens,P. nitroreducens]] :[[Pseudomonas ...

Biofilms have been implicated as an important reservoir for pathogens and commensal enteric bacteria such as Escherichia coli in natural and engineered water systems. However, the processes that regulate the survival of E. coli in aquatic biofilms have not been thoroughly studied. We examined the effects of hydrodynamic shear and nutrient concentrations on E. coli colonization of pre-established Pseudomonas aeruginosa biofilms, co-inoculation of E. coli and P. aeruginosa biofilms, and P. aeruginosa colonization of pre-established E. coli biofilms. In nutritionally-limited R2A medium, E. coli dominated biofilms when co-inoculated with P. aeruginosa, and successfully colonized and overgrew pre-established P. aeruginosa biofilms. In more enriched media, P. aeruginosa formed larger clusters, but E. coli still extensively overgrew and colonized the interior of P. aeruginosa clusters. In mono-culture, E. coli formed sparse and discontinuous biofilms. After P. aeruginosa was introduced to these biofilms, E.

Pseudomonas aeruginosa is an opportunistic pathogen and one of the leading causes of nosocomial infections. Moreover, the species can cause severe infections in cystic fibrosis patients, in burnt victims and cause disease in domestic animals. The control of these infections is often difficult due to its vast repertoire of mechanisms for antibiotic resistance. Phage therapy investigation with P. aeruginosa bacteriophages has aimed mainly the control of human diseases. In the present work, we have isolated and characterized a new bacteriophage, named Pseudomonas phage BrSP1, and investigated its host range against 36 P. aeruginosa strains isolated from diseased animals and against P. aeruginosa ATCC strain 27853. We have isolated a Pseudomonas aeruginosa phage from sewage. We named this virus Pseudomonas phage BrSP1. Our electron microscopy analysis showed that phage BrSP1 had a long tail structure found in members of the order Caudovirales.

TY - JOUR. T1 - Chronic colonization of rat airways with Pseudomonas aeruginosa. AU - Boyd, R. L.. AU - Ramphal, R.. AU - Rice, R.. AU - Mangos, J. A.. PY - 1983/1/1. Y1 - 1983/1/1. N2 - Colonization of the airways of rats by Pseudomonas aeruginosa was established by treating the animals with hexamethylphosphoramide (HMPA) and inoculating with P. aeruginosa. Male Sprague-Dawley rats were given tap water (controls) or HMPA in the drinking water at 2 or 4 mg/ml. The ciliated cells of the airway epithelium were denuded, and microulcerative lesions in the epithelium were induced in the HMPA-treated rats. After 2 weeks of treatment, the rats were inoculated by transoral intratracheal instillation with 5 x 107 CFU of P. aeruginosa obtained from a cystic fibrosis patient. Two weeks after inoculation, P. aeruginosa was cultured from the airways, and scanning and transmission electron microscopy showed bacilli adhering to or invading the injured airway epithelium. P. aeruginosa was present in tracheal ...

Multilocus amplicon sequencing of Pseudomonas aeruginosa cystic fibrosis airways isolates collected prior to and after early antipseudomonal ...

TY - JOUR. T1 - Reverting Antibiotic Tolerance of Pseudomonas aeruginosa PAO1 Persister Cells by (Z)-4-bromo-5-(bromomethylene)-3-methylfuran-2(5H)-one. AU - Pan, Jiachuan. AU - Bahar, Ali Adem. AU - Syed, Haseeba. AU - Ren, Dacheng. N1 - Copyright: Copyright 2013 Elsevier B.V., All rights reserved.. PY - 2012/9/20. Y1 - 2012/9/20. N2 - Background: Bacteria are well known to form dormant persister cells that are tolerant to most antibiotics. Such intrinsic tolerance also facilitates the development of multidrug resistance through acquired mechanisms. Thus persister cells are a promising target for developing more effective methods to control chronic infections and help prevent the development of multidrug-resistant bacteria. However, control of persister cells is still an unmet challenge. Methodology/Principal Findings: We show in this report that (Z)-4-bromo-5-(bromomethylene)-3-methylfuran-2(5H)-one (BF8) can restore the antibiotic susceptibility of Pseudomonas aeruginosa PAO1 persister cells ...

Soluble (S-type) pyocins are Pseudomonas aeruginosa bacteriocins that kill nonimmune P. aeruginosa strains via a specific receptor. The genes coding for pyocin Sa (consisting of a killing protein and an immunity protein) were cloned and expressed in Escherichia coli. Sequence analysis revealed that Sa is identical to pyocin S2. Seventy-nine strains of P. aeruginosa were tested for their sensitivity to pyocins S1, S2, and S3, and their ferripyoverdine receptors were typed by multiplex PCR. No strain was found to be sensitive to both S2 and S3, suggesting that the receptors for these two pyocins cannot coexist in one strain. As expected, all S3-sensitive strains had the type II ferripyoverdine receptor fpvA gene, confirming our previous reports. S1 killed strains irrespective of the type of ferripyoverdine receptor they produced. All S2-sensitive strains had the type I fpvA gene, and the inactivation of type I fpvA in an S2-sensitive strain conferred resistance to the S2 pyocin. Accordingly, ...

Аннотация: The properties of the isolated Pseudomonas aeruginosa bacteriophage phiPMG1 include the lytic infection cycle, and the formation of a broad halo (semi-transparent zone) around the plaques. We consider phiPMG1 as a potential member of therapeutic cocktails of live phages, and as a source of peptidoglycan and lipopolysaccharide degrading enzymes. Partial sequencing of phiPMG1 genome has revealed high similarity with known temperate P. aeruginosa phage D3. An open reading frame encoding lytic transglycosilase was identified in the genome. This enzyme PMG MUR was obtained in recombinant form, and its activity and substrate specificity has been studied. ...

Pseudomonas aeruginosa produce the pigment pyocyanin, which is a secondary metabolite and has antibiotic activity. Pyocyanin is a blue-green pigment that is produced by P. aeruginosa in a media that is devoid of iron content. Pyocyanin producing Pseudomonas aerginosa was isolated from soil sample. Pyocyanin was extracted and purified using chloroform and then characterized using TLC, UV-Vis and FTIR scpectroscopy. The Rf value was found to be 0.79. The UV-Vis Spectrum showed a maximum peak at 277 nm. Pyocyanin has a high antimicrobial activity and can act as a broad-spectrum antibiotic. The inhibition concentrations were found to be as low as 5μg/ml. The extracted pyocyanin showed antibacterial and anti-biofilm activities.. ...

The compound 2-mercaptoacetyl-L-phenylalanyl-L-leucine (HS-Ac-Phe-Leu) is a potent and specific inhibitor of Pseudomonas aeruginosa elastase, effectively inhibiting the elastase activity both, in vitro and within the rabbit cornea. This inhibitor was therefore evaluated as an adjunct to antibiotics (gentamicin) treatment in experimentally induced Pseudomonas keratitis in rabbits. Twenty eight hours after infection, the eyes that received both, gentamicin and HS-Ac-Phe-Leu showed significantly less corneal melting than those treated with the antibiotics alone, demonstrating the beneficial effect of the inhibitor. Forty eight hours after infection, the difference in clinical appearance between the two treatment groups diminished and was statistically insignificant. No adverse effects were noted in the eyes that received the inhibitor in spite of its frequent application. The protective effect of HS-Ac-Phe-Leu, seen on the first day of the experiment suggests further exploration of the therapeutic ...

TY - JOUR. T1 - Pseudomonas aeruginosa potentiates the lethal effect of intestinal ischemia-reperfusion injury. T2 - The role of in vivo virulence activation. AU - Fink, David. AU - Romanowski, Kathleen. AU - Valuckaite, Vesta. AU - Babrowski, Trissa. AU - Kim, Moses. AU - Matthews, Jeffrey B.. AU - Liu, Donald. AU - Zaborina, Olga. AU - Alverdy, John C.. PY - 2011/12/1. Y1 - 2011/12/1. N2 - Background: Experimental models of intestinal ischemia-reperfusion (IIR) injury are invariably performed in mice harboring their normal commensal flora, even though multiple IIR events occur in humans during prolonged intensive care confinement when they are colonized by a highly pathogenic hospital flora. The aims of this study were to determine whether the presence of the human pathogen Pseudomonas aeruginosa in the distal intestine potentiates the lethality of mice exposed to IIR and to determine what role any in vivo virulence activation plays in the observed mortality. Methods: Seven- to 9-week-old ...

AIMS: To establish the ability of the rhamnolipids biosurfactants from Pseudomonas aeruginosa, in the presence and absence of caprylic acid and ascorbic acid, to disrupt bacterial biofilms, compared with the anionic alkyl sulphate surfactant Sodium dodecyl sulphate (SDS). METHODS AND RESULTS: Pseudomonas aeruginosa ATCC 15442 biofilms were disrupted by rhamnolipids at concentrations between 0·5 and 0·4 g l(-1) and with SDS at 0·8 g l(-1) . The combination of rhamnolipids 0·4 g l(-1) and caprylic acid at 0·1 g l(-1) showed a remarkable effect on biofilm disruption and cell killing. After 30 min of treatment most of the biofilm was disrupted and cell viability was significantly reduced. Neither caprylic acid nor ascorbic acid has any effect on biofilm disruption at 0·1 g l(-1) . SDS is an effective antimicrobial agent; however, in the presence of caprylic acid its effect was neutralized. CONCLUSIONS: The results show that rhamnolipids at low concentration in the presence of caprylic acid are ...

TY - JOUR. T1 - Resistance emergence mechanism and mechanism of resistance suppression by tobramycin for cefepime for Pseudomonas aeruginosa. AU - Drusano, G. L.. AU - Bonomo, Robert A.. AU - Bahniuk, Nadzeya. AU - Bulitta, Juergen B.. AU - VanScoy, Brian. AU - DeFiglio, Holland. AU - Fikes, Steven. AU - Brown, David. AU - Drawz, Sarah M.. AU - Kulawy, Robert. AU - Louie, Arnold. N1 - Copyright: Copyright 2012 Elsevier B.V., All rights reserved.. PY - 2012/1. Y1 - 2012/1. N2 - The panoply of resistance mechanisms in Pseudomonas aeruginosa makes resistance suppression difficult. Defining optimal regimens is critical. Cefepime is a cephalosporin whose 3′ side chain provides some stability against AmpC β-lactamases. We examined the activity of cefepime against P. aeruginosa wild-type strain PAO1 and its isogenic AmpC stably derepressed mutant in our hollow-fiber infection model. Dose-ranging studies demonstrated complete failure with resistance emergence (both isolates). Inoculum range studies ...

Cystic fibrosis (CF) is a complex inherited disease which affects many organs, including the pancreas and liver, gastrointestinal tract and reproductive system, sweat glands and, particularly, the respiratory system. Pseudomonas aeruginosa is the main cause of chronic airway infection. In order to reduce morbidity and mortality due to lung infection by P. aeruginosa, aerosol antibiotics have been used to achieve high local concentrations in the airways and to reduce systemic toxicity. In the course of this review, the current treatments to control CF lung infections by P. aeruginosa are presented. Some innovative aerosol formulations such as liposomes and microspheres are herein reviewed, which may improve the efficiency of anti-pseudomonal agents, and ensure patients compliance to treatments, by reducing dosing frequency and/or drug dose, while maintaining therapeutic efficacy, preventing the occurrence of bacterial resistance and/or reducing adverse effects due to their controlled-release ...

Pseudomonas aeruginosa bacteriophage 11 ATCC ® 14205-B1™ Designation: Phage 11 TypeStrain=False Application: Phage therapy research Ref

The incidence of Pseudomonas aeruginosa bacteraemia (PAB) has remained stable over the last few decades.1-3 Although it is still primarily a nososcomial infection, the number of cases of community-acquired bacteraemia caused by this organism has increased, notably affecting patients with AIDS4,5 and neutropenic patients treated for neoplastic disease who received outpatient management.6 Predisposing conditions for PAB include compromised immunity, neutropenia, intensive care, surgical procedures, central venous and urinary catheters and previous cephalosporin therapy.1,3-5,6 Common factors predictive of a fatal outcome reported in the literature are septic shock, neutropenia, immunocompromised state, severe underlying disease, and in the elderly pneumonia, septic metastases, previous therapy and inappropriate choice of antimicrobial drugs for definitive treatment.1,6,7. P. aeruginosa has also emerged as an important bacteraemic pathogen in immunocompromised children,6,8,9 including ...

The incidence of Pseudomonas aeruginosa bacteraemia (PAB) has remained stable over the last few decades.1-3 Although it is still primarily a nososcomial infection, the number of cases of community-acquired bacteraemia caused by this organism has increased, notably affecting patients with AIDS4,5 and neutropenic patients treated for neoplastic disease who received outpatient management.6 Predisposing conditions for PAB include compromised immunity, neutropenia, intensive care, surgical procedures, central venous and urinary catheters and previous cephalosporin therapy.1,3-5,6 Common factors predictive of a fatal outcome reported in the literature are septic shock, neutropenia, immunocompromised state, severe underlying disease, and in the elderly pneumonia, septic metastases, previous therapy and inappropriate choice of antimicrobial drugs for definitive treatment.1,6,7. P. aeruginosa has also emerged as an important bacteraemic pathogen in immunocompromised children,6,8,9 including ...

SE «Dnepropetrovsk Medical Academy, Ministry of Health of Ukraine», Dnepr, Ukraine The article based on the literature demonstrated a role in the development of cellular immune reactions in response pneumonia caused by Pseudomonas aeruginosa. The mechanisms described of recruitment and activation of pro-inflammatory immune cells, killing the bacterial processes that ensure effective sanogenesis infection by Pseudomonas aeruginosa and prevent the formation of a chronic inflammatory process. Key words: pneumonia, Pseudomonas aeruginosa, bacterial killing, immune cells References 1. Abaturov AE. 2009. Meaning metallosvyazyvayuschih nonspecific proteins in protection of the respiratory tract. 1. Lactoferrin. Child Health. 4(19): 125-128. 2. Abaturov AE, Volosovets AP, Yulish EI. 2013. The role of prooxidant and antioxidant systems in inflammatory diseases of the respiratory. Kharkov, Planet Print: 496. 3. Abaturov AE, Gerasimenko ON, Vysochina IL, Zavgorodnyaya NJ. 2011. Defensins and ...

TY - JOUR. T1 - Inhaled aztreonam lysine for chronic airway Pseudomonas aeruginosa in cystic fibrosis. AU - McCoy, Karen S.. AU - Quittner, Alexandra L.. AU - Oermann, Christopher M.. AU - Gibson, Ronald L.. AU - Retsch-Bogart, George Z.. AU - Montgomery, A. Bruce. PY - 2008/11/1. Y1 - 2008/11/1. N2 - Rationale: The effectiveness and safety of aztreonam lysine for inhalation (AZLI) in patients with cystic fibrosis (CF) on maintenance treatment for Pseudomonas aeruginosa (PA) airway infection was evaluated in this randomized, double-blind, placebo-controlled study. Objectives: To evaluate the safety and efficacy of inhaled aztreonam lysine in controlling PA infection in patients with CF. Methods: After randomization and a 28-day course of tobramycin inhalation solution (TIS), patients (n = 211; ≥6yr; ≥3 TIS courses within previous year; FEV1 ≥25% and ≤75% predicted values) were treated with 75 mg AZLI or placebo, twice or three times daily for 28 days, then monitored for 56 days. The ...

Clearance of neutrophils from inflamed sites is critical for resolution of inflammation, but pathogen-driven neutrophil apoptosis can impair host defenses. We previously showed that pyocyanin, a phenazine toxic metabolite produced by Pseudomonas aeruginosa, accelerates neutrophil apoptosis in vitro. We compared wild-type and pyocyanin-deficient strains of P. aeruginosa in a murine model of acute pneumonia. Intratracheal instillation of either strain of P. aeruginosa caused a rapid increase in bronchoalveolar lavage neutrophil counts up to 18 h after infection. In wild-type infection, neutrophil numbers then declined steadily, whereas neutrophil numbers increased up to 48 h in mice infected with pyocyanin-deficient P. aeruginosa. In keeping with these differences, pyocyanin production was associated with reduced bacterial clearance from the lungs. Neutrophil apoptosis was increased in mice infected with wild-type compared with the phenazine-deficient strain or two further strains that lack ...

Dive into the research topics of Molecular monolayers and interfacial electron transfer of Pseudomonas aeruginosa azurin on Au(111). Together they form a unique fingerprint. ...

Understanding how the folding of proteins establishes their functional characteristics at the molecular level challenges both theorists and experimentalists. The simplest test beds for confronting this issue are provided by electron transfer proteins. The environment provided by the folded protein to the cofactor tunes the metals electron transport capabilities as envisioned in the entatic hypothesis. To see how the entatic state is achieved one must study how the folding landscape affects and in turn is affected by the metal. Here, we develop a coarse-grained functional to explicitly model how the coordination of the metal (which results in a so-called entatic or rack-induced state) modifies the folding of the metallated Pseudomonas aeruginosa azurin. Our free-energy functional-based approach directly yields the proper nonlinear extra-thermodynamic free energy relationships for the kinetics of folding the wild type and several point-mutated variants of the metallated protein. The results agree ...

The crude ethyl acetate extract of the leaves of Cornus macrophylla showed antibacterial activity against Pseudomonas aeruginosa, a leading cause of illness in immunocompromised individuals. Bioactivity-guided separation led to the isolation of kaempferol 3-O-α-L-rhamnopyranoside (afzelin). The structure was determined based on evaluation of its spectroscopic (UV, MS, and NMR) data. The minimum inhibitory concentration (MIC) of afzelin against Pseudomonas aeruginosa was found to be 31 µg/mL. In addition, the results indicated that a hydroxyl group at C3 of the C-ring of the flavone skeleton and the rhamnose group may act as a negative factor and an enhancing factor, respectively, in the antibacterial activities of afzelin.

TY - JOUR. T1 - Lipopolysaccharide-free Escherichia coli OmpF and Pseudomonas aeruginosa protein P porins are functionally active in lipid bilayer membranes. AU - Parr, T. R.. AU - Poole, K.. AU - Crockford, G. W.K.. AU - Hancock, R. E.W.. PY - 1986/1/1. Y1 - 1986/1/1. UR - http://www.scopus.com/inward/record.url?scp=0022466549&partnerID=8YFLogxK. U2 - 10.1128/jb.165.2.523-526.1986. DO - 10.1128/jb.165.2.523-526.1986. M3 - Article. C2 - 3003028. AN - SCOPUS:0022466549. VL - 165. SP - 523. EP - 526. JO - Journal of bacteriology. JF - Journal of bacteriology. SN - 0021-9193. IS - 2. ER - ...

BACKGROUND Pseudomonas aeruginosa bacteremia (PAB) is associated with high mortality and morbidity rates, but the outcome for patients with PAB has not been recently well evaluated. METHODS Between 1997 and 1999, all episodes of PAB at the Hôtel-Dieu de France University Hospital, Lebanon, were analyzed to evaluate the outcome for patients with PAB. RESULTS Fifty-five episodes of PAB in 53 patients (26 episodes in men and 29 in women) were analyzed. The mean age of the patients in the cohort was 60.7 years (range: 18-89 years). The mean time between the onset of hospitalization and the first episode of PAB was 21 days (range: 0-77 days). Most of the tested isolates showed favorable in vitro susceptibility to ceftazidime (85%), amikacin (77%) and imipenem (67%). The overall in-hospital cumulative survival was 89% at one week and 49% at 2 months. Among the variables analyzed, four were statistically associated with a higher mortality rate: prior use of antimicrobials (85% vs 54%), use of systemic

Pseudomonas aeruginosa is a nosocomial pathogen that causes severe infections in immunocompromised patients. Biofilm plays a significant role in the resistance of this bacterium and complicates the treatment of its infections. In this study, the effect of lyticase and β-glucosidase enzymes on the degradation of biofilms of P. aeruginosa strains isolated from cystic fibrosis and burn wound infections were assessed. Moreover, the decrease of ceftazidime minimum biofilm eliminating concentrations (MBEC) after enzymatic treatment was evaluated. This study demonstrated the effectiveness of both enzymes in degrading the biofilms of P. aeruginosa. In contrast to the lyticase enzyme, β-glucosidase reduced the ceftazidime MBECs significantly (P | 0.05). Both enzymes had no cytotoxic effect on the A-549 human lung carcinoma epithelial cell lines and A-431 human epidermoid carcinoma cell lines. Considering the characteristics of the β-glucosidase enzyme, which includes the notable degradation of P. aeruginosa

The structural gene (lipA) coding for the extracellular lipase of Pseudomonas aeruginosa PAO1 has been cloned on plasmid pSW118. Nucleotide sequence analysis revealed a gene of 936 bp. lipA codes for a proenzyme of 311 amino acids including a leader sequence of 26 amino acids. The mature protein was predicted to have a M r of 30134, an isoelectric point of 5.6, and a consensus sequence (IGHSHGG) typical of lipases. Furthermore it is highly homologous (>60%) to other lipases from various pseudomonads. The lipA gene failed to hybridize detectably with genomic DNA from other Pseudomonas species except P. alcaligenes, even under relaxed stringency. Located 220 bp downstream of the lipA gene, is an open reading frame (ORF2, lipH) which encodes a hydrophilic protein (283 amino acids; M r 33587) that shows some homology to the limA gene product of P. cepacia. In complementation tests of lipase-defective mutants, lipH was shown to be necessary for expression of active extracellular lipase in P. aeruginosa

BACKGROUND: Extensively drug-resistant (XDR) Pseudomonas aeruginosa and Acinetobacter baumannii are a threat to hospitalized patients. We evaluated the effects of antimicrobial combinations on XDR P. aeruginosa and A. baumannii isolates.. METHODS: P. aeruginosa and A. baumannii isolates, which were resistant to all antibiotics except colistin (CL), were collected from eight hospitals in Korea. Genes encoding metallo-β-lactamases (MBLs) and OXA carbapenemases were detected by PCR in eight P. aeruginosa and 30 A. baumannii isolates. In vitro synergy of antimicrobial combinations was tested by using the checkerboard method.. RESULTS: Minimum inhibitory concentrations of β-lactams, aminoglycosides, and fluoroquinolones were very high, while that of CL was low for majority of XDR P. aeruginosa and A. baumannii isolates. Antimicrobial combinations including Imipenem (IPM)-CL, ceftazidime (CAZ)-CL, and rifampin (RIF)-CL exerted only additive/indifferent effects on majority of XDR P. aeruginosa ...

TY - JOUR. T1 - Stimulus-permeability coupling in rat pulmonary macrophages challenged by Pseudomonas aeruginosa - An X-ray microanalysis study. AU - Smith, Nancy K.R.. AU - Lewinski, Andrzej K.. AU - Mangos, John A.. AU - Lee Boyd, R.. PY - 1985/5/1. Y1 - 1985/5/1. N2 - Electron probe X-ray microanalysis (XRMA) of freeze-dried ultrathin sections provides the capability of measuring intracellular elemental content. This methodology was used to investigate the stimulus-permeability coupling responses associated with phagocytosis of Pseudomonas aeruginosa by cultured pulmonary alveolar macrophages (PAMs) of rats. PAMs were challenged with P. aeruginosa suspended in Geys buffer at a bacteria to PAM ratio of 50:1 for 1 h at 37° C. A 1-mm3 pellet of the unchallenged control PAMs, challenged PAMs and P. aeruginosa alone was quench-frozen in nitrogen-cooled, liquid propane, and 0.1-μm cryosections were cut at -100° C. X-ray spectra were collected for nucleus and cytoplasm of 39 control PAMs, 36 ...

Fluorescently labelled latex microbeads were used to study the interaction of particles with Pseudomonas aeruginosa biofilms in a continuous flow annular reactor. Beads were readily distinguished and enumerated in both intact and disaggregated biofilm samples. The fraction of beads that attached to biofilm during a 24 h period ranged from 0.001 to 0.01 and was proportional to biofilm cell carbon and to the standard deviation of biofilm thickness. Microbeads added to biofilm of steady state thickness (30 μm) were observed to be located throughout the entire biofilm depth in 24 h. Many of the microbeads that attached to biofilm shortly after bacterial inoculation (thickness of 2 μm) remained near the substratum as cells grew past and covered them. Microbeads were observed near the biofilm-substratum interface for up to 5 days after bead addition. Beads formed aggregates on biofilms, but not in bulk water. Beads captured by biofilm remained in the reactor system longer than beads that never ...

In recent years, prevalence of multidrug resistance (MDR) in Pseudomonas aeruginosa (P. aeruginosa) has been noticed with high morbidity and mortality. Aim of the present study was to determine the impact of Mr. Trivedis biofield treatment on MDR clinical lab isolates (LS) of P. aeruginosa. Five MDR clinical lab isolates (LS 22, LS 23, LS 38, LS 47, and LS 58) of P. aeruginosa were taken and divided into two groups i.e. control and biofield treated. Control and treated group were analyzed for antimicrobial susceptibility pattern, minimum inhibitory concentration (MIC), biochemical study and biotype number using MicroScan Walk-Away® system. The analysis was done on day 10 after biofield treatment as compared with control group. Antimicrobial sensitivity assay showed 60% alteration in sensitivity of tested antimicrobials in MDR isolates of P. aeruginosa after biofield treatment. MIC results showed an alteration in 42.85% tested antimicrobials out of twenty eight after biofield treatment in five isolates

Rhamnolipid biosurfactants were continuously produced with Pseudomonas aeruginosa on the pilot plant scale. Production and downstream processing elaborated on the laboratory scale were adapted to the larger scale. Differences in performance resulting from the scale-up are discussed. A biosurfactant concentration of approximately 2.25 g liter-1 was achieved. The biosurfactant yield on glucose was 77 mg g-1 h-1, and the productivity was 147 mg liter-1 h-1, corresponding to a daily production of 80 g of biosurfactant. The first enrichment step consisted of an adsorption chromatography which was followed by an anion-exchange chromatography. The resulting product was 90% pure, and the overall recovery of active material was above 60% with the downstream processing used. ...

Pseudomonas aeruginosa is an opportunistic pathogen associated with life-threatening nosocomial and community-acquired infections. Antibiotic resistance is an immediate threat to public health and demands an urgent action to discovering new antimicrobial agents. One of the best alternatives for pre-clinical tests with animal models is the greater wax moth Galleria mellonella. Here, we evaluated the antipseudomonal activity of silver nanoparticles (AgNPs) against P. aeruginosa strain UCBPP-PA14 using G. mellonella larvae. The AgNPs were synthesized through a non-toxic biogenic process involving microorganism fermentation. The effect of AgNPs was assessed through characterization and quantification of the hemocytic response, nodulation and phenoloxidase cascade. On average, 80% of the larvae infected with P. aeruginosa and prophylactically treated with nanoparticles survived. Both the specific and total larvae hemocyte counts were restored in the treated group. In addition, the nodulation process and the

Ceftazidime treatment of chronic Pseudomonas aeruginosa respiratory tract infection in cystic fibrosis.: Two open randomized cross-over studies were undertaken

Nitrate respiration is a widespread mode of anaerobic energy generation used by many bacterial pathogens, and the respiratory nitrate reductase, Nar, has long been known to reduce chlorate to the toxic oxidizing agent chlorite. Here, we demonstrate the antibacterial activity of chlorate against Pseudomonas aeruginosa, a representative pathogen that can inhabit hypoxic or anoxic host microenvironments during infection. Aerobically grown P. aeruginosa cells are tobramycin sensitive but chlorate tolerant. In the absence of oxygen or an alternative electron acceptor, cells are tobramycin tolerant but chlorate sensitive via Nar-dependent reduction. The fact that chlorite, the product of chlorate reduction, is not detected in culture supernatants suggests that it may react rapidly and be retained intracellularly. Tobramycin and chlorate target distinct populations within metabolically stratified aggregate biofilms; tobramycin kills cells on the oxic periphery, whereas chlorate kills hypoxic and anoxic ...

Barsoukov E. and J.R. Macdonald (eds). 2005. Impedance Spectroscopy: Theory, Experiment and Applications, 2nded. John Wiley & Sons, Inc., Hoboken, NJ, USA.. Ben-Yoav H., A. Freemanb, M. Sternheimc and Y. Shacham-Dia-manda. 2011. An electrochemical impedance model for integrated bacterial biofilms. Electrochim. Acta. 56:7780-7786.. Bjarnsholt T., K. Kirketerp-Møller, P.Ø. Jensen, K.G. Madsen, R. Phipps, K. Krogfelt, N. Høibyand and M. Givskov. 2008. Why chronic wounds will not heal: a novel hypothesis. Wound Rep. Reg. 16:2-10.. Dominguez-Benetton X., S. Sevda, K. Vanbroekhovena. and D. Panta. 2012. The accurate use of impedance analysis for thestudy of microbial electrochemical systems. Chem. Soc. Rev. 41:7228-7246.. Flemming H., J. Wingender and U. Szewczyk (eds). 2008. Biofilm Highlights. Springer Series on Biofilm Vol. 5. Springer-Verlag, Berlin, Heidelberg.. Ge Y., T. Deng and X. Zheng. 2008. Dynamic monitoring of changes in endothelial cell-substrate adhesiveness during leukocyte adhesion ...

The gram-negative bacterium Pseudomonas aeruginosa catalyzes the conversion of ricinoleic acid into a novel trihydroxy fatty acid, 7, 10, 12-trihydroxy-8(E)-octadecenoic acid (TOD), that has a potent antifungal activity against important crop pathogens, including Magnaporthe grisea the causative agent of rice blast disease. Natural crop-protecting agents such as TOD offer several advantages over synthetic agents, including improved ecological compatibility and environmental safety. Unfortunately, because many naturally occurring crop-protecting agents are produced only in trace amounts, it has been difficult to isolate large enough quantities of these antimicrobial agents to be economically feasible. Thus, a bacterium such as P. aeruginosa that is genetically amenable and produces an antifungal agent is ideal for genetic manipulation to achieve improved TOD production. The long-term goal of this research is to develop efficient processes for improving production of TOD from P. aeruginosa to ...

This is the largest US claims database study of healthcare costs and outcomes for ICU patients with a diagnosis of S. aureus or P. aeruginosa pneumonia. Our findings highlight the comprehensive economic consequences attributed to S. aureus and P. aeruginosa pneumonia and can permit policy makers, payers, and healthcare providers to assess the effect of prevention or therapeutic efforts on the cost and morbidity of these ICU infections.. In our study, ICU patients with pneumonia had substantially higher healthcare costs during the index admission: , $213,000 for P. aeruginosa pneumonia and , $146,000 for with S. aureus pneumonia versus ,$33,000 for patients without pneumonia. Increased utilization continued after index hospitalization discharge, with total healthcare costs through 90 days post discharge of , $17,000 for patients with S. aureus pneumonia and , $22,000 for patients with P. aeruginosa pneumonia versus , $10,000 for patients without pneumonia. Patients with S. aureus or P. aeruginosa ...

IL-1β is a potent proinflammatory cytokine produced in response to Pseudomonas aeruginosa infection. While it is appreciated that IL-1β is a critical modulator of the host response to P. aeruginosa infection, the host and bacterial determinants of IL-1β production during both acute and chronic infections are less well understood. This thesis is focused on the determinants of the IL-1β response to P. aeruginosa. The effects of bacterial phenotypic changes during chronic infection, such as loss of flagellar motility, on the IL-1β response are poorly understood. Bacterial flagellar motility is a fundamental mechanism, which enables bacterial association with leukocytes. Therefore, we hypothesized that loss of bacterial flagellar motility would facilitate evasion of contact-dependent inflammasome activation and IL-1β production. In support of this hypothesis, we demonstrate that bacterial flagellar motility contributes to inflammasome activation and correspondingly, nonmotile P. aeruginosa ...

Exoenzyme S (ExoS) is a mono-ADP-ribosyltransferase secreted by the opportunistic pathogen Pseudomonas aeruginosa. ExoS requires a eukaryotic factor, the 14-3-3 protein, for enzymatic activity. Here, two aspects of the activation of the ADP-ribosyltransferase activity of ExoS by 14-3-3 proteins are …

Most microbial pathogens have a metabolic iron requirement, necessitating the acquisition of this nutrient in the host. In response to pathogen invasion, the human host limits iron availability. Although canonical examples of nutritional immunity are host strategies that limit pathogen access to Fe(III), little is known about how the host restricts access to another biologically relevant oxidation state of this metal, Fe(II). This redox species is prevalent at certain infection sites and is utilized by bacteria during chronic infection, suggesting that Fe(II) withholding by the host may be an effective but unrecognized form of nutritional immunity. Here, we report that human calprotectin (CP; S100A8/S100A9 or MRP8/MRP14 heterooligomer) inhibits iron uptake and induces an iron starvation response in Pseudomonas aeruginosa cells by sequestering Fe(II) at its unusual His6 site. Moreover, under aerobic conditions in which the Fe(III) oxidation state is favored, Fe(II) withholding by CP was enabled ...

Conclusion: Positive microbiology and genomic DNA typing results proved that the contaminated trypan blue solutions were the source of infection in this outbreak. Postoperative endophthalmitis caused by Pseudomonas aeruginosa is often associated with a poor visual prognosis despite prompt treatment with intravitreal antibiotics. PMID: 31660104 [PubMed]...

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