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

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 elastase structural gene (lasB) from Pseudomonas aeruginosa PAO1 has been previously cloned on an 8-kilobase (kb) DNA fragment. The lasB gene, cloned in both orientations in pUC18, produced elastase in Escherichia coli, indicating that its promoter and translation initiation sites are functional in E. coli. Deletion analysis further defined the location of the lasB gene to a 3.0-kb EcoRI-KpnI fragment (pRB1803). Elastase prepared from E. coli TB1 (pRB1803) corresponded in molecular weight to mature P. aeruginosa extracellular elastase (33,000). The lasB gene directed the synthesis of 54- and 50-kilodalton (kDa) proteins in a bacterial cell-free transcription-translation system. The 33-, 50-, and 54-kDa proteins reacted with elastase-specific antiserum. To further characterize the lasB gene, the nucleotide sequence of the 3.0-kb EcoRI-KpnI fragment was determined. This DNA fragment contained a 1,491-base-pair open reading frame encoding 498 amino acids, corresponding to a predicted molecular ...

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

Author Summary The human pathogen Pseudomonas aeruginosa and other bacteria communicate with each other using quorum sensing (QS). This is important for their growth, virulence, motility and the formation of biofilms. Furthermore, eukaryotic cells

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 ...

Cells in bacterial biofilms are often less susceptible to host immune responses and antibiotics than cells grown in suspension (18). Biofilms may also provide a protective environment for pathogens, which, when released from the biofilm, may result in contamination of drinking water and medical fluids in delivery devices such as dialysis machines, venous catheters, dental water lines, and airway ventilators. Life-threatening infection caused by Pseudomonas aeruginosa in cystic fibrosis patients is a well-known example (8). Since biofilm formation in itself can be considered a virulence factor, it is important to understand the mechanisms which influence biofilm accumulation, structure, and behavior. Both hydrodynamics and cell signaling have been found to influence the structure of P. aeruginosa PAO1 biofilms. Stoodley et al. (27) reported that, under conditions of low-shear laminar flow, the biofilm consisted of a monolayer of cells with mound-shaped circular microcolonies but under high-shear, ...

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]...

PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Objective(s): Bacterial biofilm formation causes many persistent and chronic infections. The matrix protects biofilm bacteria from exposure to innate immune defenses and antibiotic treatments. The purpose of this study was to evaluate the biofilm formation of clinical isolates of Pseudomonas aeruginosa and the activity of zinc oxide nanoparticles (ZnO NPs) on biofilm. Materials and Methods: After collecting bacteria from clinical samples of hospitalized patients, the ability of organisms were evaluated to create biofilm by tissue culture plate (TCP) assay. ZnO NPs were synthesized by sol gel method and the efficacy of different concentrations (50- 350 µg/ml) of ZnO NPs was assessed on biofilm formation and also elimination of pre-formed biofilm by using TCP method.Results:The average diameter of synthesized ZnO NPs was 20 nm. The minimum inhibitory concentration of nanoparticles was 150- 158 μg/ml and the minimum bactericidal concentration was higher (325 µg/ml). All 15 clinical isolates of ...

Gilead is developing a broad spectrum combination antibiotic (FTI) consisting of fosfomycin (an antibiotic with activity against gram-positive and gram-negative bacteria) and tobramycin (an aminoglycoside antibiotic with potent gram-negative activity) for treatment of patients with CF. FTI offers a potential option for treatment of CF lung infections. It is important to note that the concentration of tobramycin in FTI is lower than that of the approved dose of inhaled tobramycin alone, thereby demonstrating the potential of FTI to minimize long-term toxicity from repeated exposure to aminoglycosides like tobramycin. This study will evaluate the safety and efficacy of 2 dose combinations of fosfomycin/tobramycin for inhalation (FTI), following a 28-day course of Aztreonam for Inhalation (AZLI) in patients with cystic fibrosis and Pseudomonas aeruginosa lung infection ...

TY - JOUR. T1 - Peptide-conjugated phosphorodiamidate morpholino oligomers retain activity against multidrug-resistant pseudomonas aeruginosa in vitro and in vivo. AU - Moustafa, Dina A.. AU - Wu, Ashley W.. AU - Zamora, Danniel. AU - Daly, Seth M.. AU - Sturge, Carolyn R.. AU - Pybus, Christine. AU - Geller, Bruce L.. AU - Goldberg, Joanna B.. AU - Greenberg, David E.. N1 - Funding Information: This work was supported by NIH grants RO1 AI141102 and R33 AI105980 to D.E.G. We wish to acknowledge the UT Southwestern Live Cell Imaging Facility (Kate Luby-Phelps, Director) for use of the Perkin-Elmer spinning disk confocal microscope. We also thank the Texas Advanced Computing Center (http://www.tacc.utexas.edu) at the University of Texas, Austin, Texas, for data storage of microscopy files. B.L.G. and D.E.G. are listed on numerous patents involving PPMOs.. PY - 2021. Y1 - 2021. N2 - Most antimicrobials currently in the clinical pipeline are modifications of existing classes of antibiotics and are ...

Clinical trial: Efficacy & Tolerability of Tobramycin Podhaler in Bronchiectasis Patients With Chronic Pseudomonas Aeruginosa Infection

TY - JOUR. T1 - Proteomic profile of cystic fibrosis sputum cells in adults chronically infected with Pseudomonas aeruginosa. AU - Pattison, SH. AU - Gibson, DS. AU - Johnston, E. AU - Peacock, S. AU - Rivera, K. AU - Tunney, MM. AU - Pappin, DJ. AU - Elborn, JS. N1 - UIR Compliant dates from UIR added to PURE link. Replaced manuscript as QUB front cover was on original uploaded version. PY - 2017/7/5. Y1 - 2017/7/5. N2 - Lung disease is the main cause of morbidity and mortality in cystic fibrosis (CF) andinvolves chronic infection and perturbed immune responses. Tissue damage ismediated mostly by extracellular proteases, but other cellular proteins may alsocontribute to damage through their effect on cell activities and/or release into sputumfluid by means of active secretion or cell death.We employed Multidimensional Protein Identification Technology to identify sputumcellular proteins with consistently altered abundance in adults with CF, chronicallyinfected with Pseudomonas aeruginosa, ...

A simple, reproducible model of fatal Pseudomonas aeruginosa sepsis in mice during immunosuppression was developed. Mice were rendered leukopenic (less than or equal to 800 leukocytes per mm3 of blood) for a period of 5 days by multiple injections of cyclophosphamide. Mice were challenged at the onset of leukopenia by instilling the bacteria onto a 0.5-mm incision made into the back. The mean lethal dose (LD50) for P. aeruginosa PA220 and M-2 was less than 20 bacteria. The mean time to death for these strains ranged from 46 to 59 h. Leukopenic mice were comparatively resistant when challenged with Klebsiella pneumoniae (LD50 = 1.5 x 10(6)) or Staphylococcus aureus (LD50 greater than 10(6)). Infection with P. aeruginosa was characterized by rapid bacterial multiplication in the skin at the site of infection, producing ecthyma gangrenosum. Bacteremia and colonization of the liver were pronounced 21 h postinfection. This model should prove to be a useful tool for studying the pathogenesis of P. ...

TY - JOUR. T1 - Acquisition of 16S rRNA methylase gene in Pseudomonas aeruginosa. AU - Yokoyama, Keiko. AU - Doi, Yohei. AU - Yamane, Kunikazu. AU - Kurokawa, Hiroshi. AU - Shibata, Naohiro. AU - Shibayama, Keigo. AU - Yagi, Tetsuya. AU - Kato, Haru. AU - Arakawa, Yoshichika. PY - 2003/12/6. Y1 - 2003/12/6. N2 - Background: Bacteria develop resistance to aminoglycosides by producing aminoglycoside-modifying enzymes such as acetyltransferase, phosphorylase, and adenyltransferase. These enzymes, however, cannot confer consistent resistance to various aminoglycosides because of their substrate specificity. Notwithstanding, a Pseudomonas aeruginosa strain AR-2 showing high-level resistance (minimum inhibitory concentration ,1024 mg/L) to various aminoglycosides was isolated clinically. We aimed to clone and characterise the genetic determinant of this resistance. Methods: We used conventional methods for DNA manipulation, susceptibility testing, and gene analyses to clone and characterise the ...

A novel series of thiepine derivatives were synthesized and evaluated as potential antimicrobials. All the synthesized compounds were evaluated for their antimicrobial activities in vitro against the fungi Candida albicans (ATCC 10231), C.parapsilosis (clinical isolate), Gram-negative bacterium Pseudomonas aeruginosa (ATCC 44752), and Gram-positive bacterium Staphylococcus aureus (ATCC 25923). Synthesized compounds showed higher antifungal activity than antibacterial activity, indicating that they could be used as selective antimicrobials. Selected thiepines efficiently inhibited Candida hyphae formation, a trait necessary for their pathogenicity. Thiepine 8-phenyl[1]benzothiepino[3,2-c]pyridine (16) efficiently killed Candida albicans at 15.6g/mL and showed no embryotoxicity at 75g/mL. Derivative 8-[4-(4,5-dihydro-1H-imidazol-2-yl)phenyl][1]benzothiepino[3,2-c]pyridine (23) caused significant hemolysis and in vitro DNA interaction. The position of the phenyl ring was essential for the... ...

The extent of the transfer of the adenosine 5-diphosphate ribose (ADPR) moiety of nicotinamide adenine dinucleotide onto elongation factor 2 (EF-2) catalyzed by Pseudomonas aeruginosa exotoxin A (PA-toxin) was dependent upon the presence of a reducing agent, dithiotheritol (DTT). The reaction requires DTT in low concentration (1 to 10 mM) and in the absence of DTT less product, ADPR-EF 2, was formed. PA-toxin was fully activated by treatment with a denaturing agent, sodium dodecyl sulphate (SDS), in conjunction with DTT. In the presence of activated toxin, the maximum transfer of ADPR onto EF-2 was observed when EF-2 had been previously reduced with DTT. Denaturation of EF-2 prior to reduction did not produce a further increase in its ability to act as a substrate for PA-toxin ...

Stuart, R K. and Pollack, M, Pseudomonas aeruginosa exotoxin a inhibits proliferation of human bone marrow progenitor cells in vitro. (1982). Subject Strain Bibliography 1982. 3514 ...

TY - JOUR. T1 - Aerosolization of respirable droplets from a domestic spa pool and the use of MS-2 coliphage and Pseudomonas aeruginosa as markers for Legionella pneumophila. AU - Moore, Ginny. AU - Hewitt, Matthew. AU - Stevenson, David. AU - Walker, Jimmy T.. AU - Bennett, Allan. N1 - Publisher Copyright: © 2015, American Society for Microbiology.. PY - 2015. Y1 - 2015. N2 - Legionnaires disease can result when droplets or aerosols containing legionella bacteria are inhaled and deposited in the lungs. A number of outbreaks have been associated with the use of a spa pool where aeration, a high water temperature, and a large and variable organic load make disinfectant levels difficult to maintain. Spa pool ownership is increasing, and the aim of this study, using two surrogate organisms (MS-2 coliphage and Pseudomonas aeruginosa [a natural contaminant]), was to assess the potential risk to domestic users when disinfection fails. A representative entry level domestic spa pool was installed in ...

The Pseudomonas exotoxin (or exotoxin A) is an exotoxin produced by Pseudomonas aeruginosa. It inhibits elongation factor-2. It does so by ADP-ribosylation of EF2. This then causes the elongation of polypeptides to cease. (The mechanism of the toxin is similar to that of Diphtheria toxin.) It has been investigated as a treatment for hepatitis B and cancer. Yates SP, Taylor PL, Jørgensen R, et al. (February 2005). Structure-function analysis of water-soluble inhibitors of the catalytic domain of exotoxin A from Pseudomonas aeruginosa. Biochem. J. 385 (Pt 3): 667-75. doi:10.1042/BJ20041480. PMC 1134741 . PMID 15458385. Yates SP, Merrill AR (May 2004). Elucidation of eukaryotic elongation factor-2 contact sites within the catalytic domain of Pseudomonas aeruginosa exotoxin A. Biochem. J. 379 (Pt 3): 563-72. doi:10.1042/BJ20031731. PMC 1224111 . PMID 14733615. Hafkemeyer P, Brinkmann U, Brinkmann E, Pastan I, Blum HE, Baumert TF (May 2008). Pseudomonas exotoxin antisense RNA selectively kills ...

Pseudomonas aeruginosa bloodstream infection (BSI) is predominantly acquired in the hospital setting. Community-onset infection is less common. Differences in epidemiology, clinical features, microbiological factors and BSI outcomes led to the separation of bacterial community-onset BSI into the categories of healthcare-associated infection (HCAI) and community-acquired infection (CAI). Community-acquired P. aeruginosa BSI epidemiology is not well defined in the literature. In addition, it is also not clear if the same factors separate CAI and HCAI BSI caused by P. aeruginosa alone. A retrospective multicentre cohort study was performed looking at P. aeruginosa BSI from January 2008 to January 2011. Strict definitions for HCAI and CAI were applied. Extensive epidemiological, clinical and outcome data were obtained. Thirty-four CAI episodes and 156 HCAI episodes were analysed. The CAI group could be characterised into seven distinct categories based on comorbidities and clinically suspected ...

Caspase-1 and IL-1β have been postulated to have deleterious effects for the host in acute P. aeruginosa-infections. Schultz et al. found that IL-1R deficiency had a protective effect in response to pulmonary infection with P. aeruginosa (36). In another study, neutralization of IL-1β with antibodies protected acid sphingomyelinase-deficient mice from lethal P. aeruginosa pneumonia (37). In addition, Thakur et al. found in a P. aeruginosa keratitis model, that caspase-1 deficiency results in less corneal damage (38). However, it remains unclear from these studies if the adverse effects mediated by IL-1β and caspase-1 are caused by inflammatory damage or lack of control of bacterial replication. In contrast to these studies, IL-1R-deficient mice had greater colonization with P. aeruginosa compared with WT mice after oral exposure to the pathogen in drinking water (39). We show that the IPAF-inflammasome plays an important role in host defenses against P. aeruginosa. IPAF-deficiency resulted in ...

Pseudomonas aeruginosa lectins interact with Escherichia coli strains O86B7 and O128B12, which possess B and H (O) blood group determinants, respectively. The interaction could be demonstrated by specific agglutination of the bacteria, by haemagglutination inhibition tests and by lectin-mediated peroxidase binding to the bacteria. The agglutination of E. coli O86B7 by the Pseudomonas galactose-binding lectin was inhibited by d-galactose and by the lipopolysaccharide extracted from E. coli O86B7. Similarly, the specific agglutination of E. coli O128B12 by the Pseudomonas mannose-binding lectin (which also binds l-fucose, l-galactose and d-fructose) was inhibited by d-mannose, l-fucose, l-galactose and d-fructose, as well as by the lipopolysaccharide extracted from E. coli O128B12. The interaction between E. coli O128B12 and the Pseudomonas mannose-binding lectin was also demonstrated by lectin-mediated peroxidase binding to the bacterial surface. Peroxidase binding was also inhibited by the above

Numerous hits in gapped BLAST to DNA-directed RNA polymerase sequences,e.g.residues 1-1390 are 64% similar to DNA-directed RNA polymerase beta chain from Escherichia coli (gb,AAB18647.1,). Residues 1-1390 are 64% similar to DNA-directed RNA polymerase beta chain from Pseudomonas aeruginosa strain PAO1 (11348463,). Residues 12-1166 are 45% similar to DNA-directed RNA polymerase beta chain from Chlamydia trachomatis serotype D, strain UW3/Cx (gb,AAC67908.1,).Residues 20-963 are 45% similar and residues 839-1389 are 38% similar to DNA-directed RNA polymerase, beta subunit from syphilis spirochete Treponema pallidum (gb,AAC65229.1 ...

Limited research has suggested iron oxide nanoparticles (FeNP) have an inhibitory effect against several different genera of bacteria: Staphylococcus, Bacillus and Pseudomonas spp. In this study we looked at the effect of three different sets of Fe3O4 nanoparticles (FeNPs) on the development of Pseudomonas aeruginosa PAO1 biofilms. Two of the tested NPs were SPIONs (Superparamagnetic Iron Oxide Nanoparticles). Exposure of cells to the SPIONs at concentrations up to 200 μg/ml resulted in an increase in biofilm biomass by 16 h under static conditions and a corresponding increase in cell density in the bulk liquid. In contrast, these biofilms had decreased levels of extracellular DNA (eDNA). Fe(II) levels in the supernatants of biofilms formed in the presence of FeNPs exceeded 100 μM compared with 20 μM in control media without cells. Spent cell supernatants had little effect on Fe(II) levels. Cells also had an effect on the aggregation behavior of these nanoparticles. SPIONs incubated with cells

It is well known that the vast majority of the bacterial skin infections is caused by Staphylococcus intermedius, and if there is immunosuppression or the infection goes deeper other organisms like small rods add to the problem. This interesting publication describes another and new problem: an infection which is only due to Pseudomonas aeruginosa, without S. intermedius. Very interesting!

Flagellar motility is critical for surface attachment and biofilm formation in many bacteria. A key regulator of flagellar motility in Pseudomonas aeruginosa and other microbes is cyclic diguanylate (c-di-GMP). High levels of this second messenger repress motility and stimulate biofilm formation. C-di-GMP levels regulate motility in P. aeruginosa in part by influencing the localization of its two flagellar stator sets, MotAB and MotCD. Here we show that just as c-di-GMP can influence the stators, stators can impact c-di-GMP levels. We demonstrate that the swarming motility-driving stator MotC physically interacts with the transmembrane region of the diguanylate cyclase SadC. Furthermore, we demonstrate that this interaction is capable of stimulating SadC activity. We propose a model by which the MotCD stator set interacts with SadC to stimulate c-di-GMP production in conditions not permissive to motility. This regulation implies a positive feedback loop in which c-di-GMP signaling events cause ...

An improved method is presented for the purification of 8 α-(N1-histidyl)riboflavin, 8 α-(N3-histidyl)riboflavin and their 2′,5′-anhydro forms, which permits the isolation of sizeable quantities of each of these compounds from a synthetic mixture in pure form. Flavin peptides were isolated from the D-gluconate dehydrogenases of Pseudomonas aeruginosa and Pseudomonas fluorescens and from the 2-keto-D-gluconate dehydrogenase of Gluconobacter melanogenus. After conversion into the aminoacyl-riboflavin, the flavin in all three enzymes was identified as 8 α-(N3-histidyl)riboflavin. By sequential treatment with nucleotide pyrophosphatase and alkaline phosphatase, the flavin in each enzyme was shown to be in the dinucleotide form. ...

A 15-month, single-masked, randomised study including 35 patients was conducted in a tertiary university hospital. Following the isolation of Pseudomonas aeruginosa and a 14-day intravenous treatment with Ceftazidime and Tobramycin, patients received 300 mg nebulised Tobramycin twice daily or placebo during 3 months, and were followed up for 12 months thereafter ...

p,The bifunctional enzyme methylenetetrahydrofolate dehydrogenase – cyclohydrolase (FolD) is identified as a potential drug target in Gram-negative bacteria, in particular the troublesome ,em,Pseudomonas aeruginosa,/em,. In order to provide a comprehensive and realistic assessment of the potential of this target for drug discovery we generated a highly efficient recombinant protein production system and purification protocol, characterized the enzyme, carried out screening of two commercial compound libraries by differential scanning fluorimetry, developed a high-throughput enzyme assay and prosecuted a screening campaign against almost 80,000 compounds. The crystal structure of ,em,P. aeruginosa,/em, FolD was determined at 2.2 Å resolution and provided a template for an assessment of druggability and for modelling of ligand complexes as well as for comparisons with the human enzyme. New FolD inhibitors were identified and characterized but the weak levels of enzyme inhibition suggest ...

TY - JOUR. T1 - Gene cloning and characteristics of the RND-type multidrug efflux pump MuxABC-OpmB possessing two RND components in Pseudomonas aeruginosa. AU - Mima, Takehiko. AU - Kohira, Naoki. AU - Li, Yang. AU - Sekiya, Hiroshi. AU - Ogawa, Wakano. AU - Kuroda, Teruo. AU - Tsuchiya, Tomofusa. PY - 2009. Y1 - 2009. N2 - muxA-muxB-muxC-opmB (formerly PA2528-PA2527-PA2526-opmB), encoding a putative resistance nodulation cell division (RND)-type multidrug efflux pump system, was cloned from Pseudomonas aeruginosa PAO1. Introduction of muxABC-opmB into P. aeruginosa YM64, a drug-hypersusceptible strain, led to elevated MICs of aztreonam, macrolides, novobiocin and tetracycline. Since muxB and muxC, both of which encode RND components, were essential for function, MuxABC-OpmB is thought to be a drug efflux pump with four components. One novobiocin-resistant mutant, PMX725, isolated from P. aeruginosa PMX7 showed elevated resistance not only to novobiocin but also to aztreonam, macrolides and ...

In contrast to Escherichia coli, a model organism for chemotaxis that has 5 chemoreceptors and a single chemosensory pathway, Pseudomonas aeruginosa PAO1 has a much more complex chemosensory network, which consists of 26 chemoreceptors feeding into four chemosensory pathways. While several chemoreceptors were rigorously linked to specific pathways in a series of experimental studies, for most of them this information is not available. Thus, we addressed the problem computationally. Protein-protein interaction network prediction, coexpression data mining, and phylogenetic profiling all produced incomplete and uncertain assignments of chemoreceptors to pathways. However, comparative sequence analysis specifically targeting chemoreceptor regions involved in pathway interactions revealed conserved sequence patterns that enabled us to unambiguously link all 26 chemoreceptors to four pathways. Placing computational evidence in the context of experimental data allowed us to conclude that three ...

Molecular Plant-Microbe Interactions 15:1147-1156...Kris Audenaert , 1 Theresa Pattery , 2 Pierre Cornelis , 2 and Monica Höfte 1...© 2002 The American Phytopathological Society...The rhizobacterium Pseudomonas aeruginosa 7NSK2 produces secondary metabolites such as pyochelin (Pch), its precursor salicylic acid (SA), and the phenazine compound pyocyanin. Both 7NSK2 and mutant KMPCH (Pch-negative, SA-positive) induced resistance to Botrytis cinerea in wild-type but not in tra...

In view of the large outbreaks of infection by Acinetobacter baumannii and Pseudomonas aeruginosa, researchers sought to determine risk factors for the occurrence and appropriate infection control measures. They observed that Acinetobacter outbreaks were mainly reported from intensive care units, after use of

Pseudomonas aeruginosa (P. aeruginosa) produces a suite of virulence factors that are coordinated by Quorum Sensing (QS) contributing to its disease-causing ability in aquaculture. The present study is first of its kind to obtain information regarding the presence and distribution of five QS genes, three virulence genes viz: lasI, lasR, rhlI, rhlR, rhlAB, toxA, aprA and plcH and seven of the Extended-spectrum βlactamases (blaVEB, blaPER, blaTEM,, blaSHV, blaCTX-M1, blaCTX-M2 and blaCTX-M3) of Pseudomonas species isolated from fish meat by direct PCR. Bacterial identification was based mainly on conventional biochemical techniques using the Vitek 2, automated system. Phenotypic sensitivity of antibiotics was established by the agar disc diffusion technique through 16 various antimicrobial drugs. Quantification of their in vitro production of numerous virulence genes outside the cell that are QS dependent namely, pyocyanin, elastase, alkaline protease, biofilm and cytotoxicity of Vero cell was as

The cytochrome cd1 nitrite reductases are enzymes that catalyse the reduction of nitrite to nitric oxide (NO) in the bacterial energy conversion denitrification process. These enzymes contain two different redox centres: one covalently bound c-haem, which is reduced by external donors, and one peculiar d1-haem, where catalysis occurs. In the present paper, we summarize the current understanding of the reaction of nitrite reduction in the light of the most recent results on the enzyme from Pseudomonas aeruginosa and discuss the differences between enzymes from different organisms. We have evidence that release of NO from the ferrous d1-haem occurs rapidly enough to be fully compatible with the turnover, in contrast with previous hypotheses, and that the substrate nitrite is able to displace NO from the d1-haem iron. These results shed light on the mechanistic details of the activity of cd1 nitrite reductases and on the biological role of the d1-haem, whose presence in this class of enzymes has to ...

Carbapenems are critically important antimicrobials as a last line of defense against multidrug-resistant Gram-negative bacterial infections (1, 2). As such, the increasing prevalence of carbapenemase-producing isolates in animal husbandry is of great concern. While the metallo-β-lactamase (MBL)-producing bacteria have been commonly identified from food animals (3-7), blaMBL-carrying Pseudomonas spp. are rarely reported in animal husbandry or the surrounding environment. Although we have reported the high prevalence of NDM in Enterobacteriaceae isolates from poultry production in Shandong Province (7), carbapenemase-producing non-Enterobacteriaceae isolates have not been identified in the same region. Here, we report four chromosome-borne VIM-positive Pseudomonas isolates: one Pseudomonas aeruginosa isolate from a swallow (Yanornis martini), one Pseudomonas putida isolate from a fly, and two P. putida isolates from chickens. The blaVIM-2 gene was identified in the P. aeruginosa isolate, but 27 ...

Antimicrobial activity of ceftazidime-avibactam, ceftolozane-tazobactam and comparators tested against Pseudomonas aeruginosa and Klebsiella pneumoniae isolates from United States medical centers in 2016-2018. by Sader HS, Carvalhaes CG, Streit JM, Doyle TB and Castanheira M. published in Microb. Drug Resist.: in press, 2020.. View publication. ...

Pseudomonas species are opportunistic pathogens with implications in a wide range of diseases including cystic fibrosis and sickle cell anaemia. Because of their status as multidrug resistant (MDR) and extremely drug resistant (XDR) bacteria Pseudomonas species represent a threat to public health. Prevalence, antibiogram and associated antibiotic resistant genes of Pseudomonas species isolated from freshwater and mixed liquor environments in the Eastern Cape Province of South Africa were assessed. Polymerase chain reaction (PCR) based technique was used to identify the isolates and screen for antibiotic resistant genes. The result shows occurrence of Pseudomonas spp. in freshwater and mixed liquor as follows: 71.42% and 37.5% (P. putida), 14.28% and 31.25% (P. flourescens), 7.14% and 6.25% (P. aeruginosa) and 7.14% and 25% for other Pseudomonas species respectively. Disk diffusion antibiogram of the Pseudomonas isolates from the two locations showed 100% resistance to penicillin, oxacillin, clindamycin,

Bilateral Pseudomonas Aeruginosa Endogenous Endophthalmitis in an Immune-competent Patient with Nosocomial Urosepsis Following Abdominal Surgery. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

Li, Yan, Zhong, Wenhe, Koay, Ann Zhufang, Ng, Hui Qi, Nah, Qianhui et al. 2019. Backbone resonance assignment for the full length tRNA-(N1G37) methyltransferase of Pseudomonas aeruginosa. Biomolecular NMR Assignments, 13 (2 ...

How do you kill Pseudomonas aeruginosa naturally? In summary, we demonstrate here that cassia, Peru balsam, and red thyme essential oils are more

TY - JOUR. T1 - Detection of bacteriophage particles containing antibiotic resistance genes in the sputum of cystic fibrosis patients. AU - Brown-Jaque, Maryury. AU - Oyarzun, Lirain Rodriguez. AU - Cornejo-Sánchez, Thais. AU - Martín-Gómez, Maria T.. AU - Gartner, Silvia. AU - de Gracia, Javier. AU - Rovira, Sandra. AU - Alvarez, Antonio. AU - Jofre, Joan. AU - González-López, Juan J.. AU - Muniesa, Maite. PY - 2018/5/1. Y1 - 2018/5/1. N2 - © 2018 Brown-Jaque, Rodriguez Oyarzun, Cornejo-Sánchez, Martín-Gómez, Gartner, de Gracia, Rovira, Alvarez, Jofre, González-López and Muniesa. Cystic fibrosis (CF) is a chronic disease in which the bacterial colonization of the lung is linked to an excessive inflammatory response that leads to respiratory failure. The microbiology of CF is complex. Staphylococcus aureus is the first bacterium to colonize the lungs in 30% of pediatric CF patients, and 80% of adult patients develop a chronic Pseudomonas aeruginosa infection, but other microorganisms ...

During the course of infection, cultures became negative in both cases and there was a gradual decrease in microbial load (bacteria and fungi). The perception of the patients was very positive, with the therapy being subjectively assessed as very effective and painless. The only side effect reported was the intense blue coloration of the treated area and, occasionally, of urine.. Discussion and Conclusion. PDT with MB was effective in the management of 2 non-healing ulcers superinfected with Fusarium species, Pseudomonas and other difficult-to-treat bacteria. The 2 patients achieved healing and epithelization of the ulcers without the need for costly therapies that are not free of interactions and adverse effects and that may require parenteral administration.. The presence of Fusarium species in both cases and of P aeruginosa in the first patient represents a paradigm of microorganisms that are difficult to treat with anti-microbial agents. P aeruginosa in particular is currently a therapeutic ...

Cyclic-diguanylate (c-di-GMP) is a widespread bacterial signal molecule that plays a major role in the modulation of cellular surface components, such as exopolysaccharides and fimbriae, and in the establishment of a sessile life style. Here, we report that intracellular c-di-GMP levels influence cupA-encoded fimbriae expression in Pseudomonas aeruginosa. In an autoaggregative P. aeruginosa small colony variant (SCV) CupA fimbriae and the intracellular c-di-GMP concentration were found to be enhanced as compared with the clonal wild-type. The SCV morphology and the expression of CupA fimbriae were dependent on a functional PA1120 and morA gene both encoding a GGDEF domain. Overexpression of the GGDEF domain protein PA1120 complemented the PA1120 and the morA mutant with respect to CupA fimbriae expression. In agreement with these findings, overexpression of the EAL domain containing phenotypic variance regulator (PvrR) in the SCV resulted in a decreased intracellular level of c-di-GMP, a reduced ...

In relation to emerging multiresistant bacteria, development of antimicrobials and new treatment strategies of infections should be expected to become a high-priority research area. Quorum sensing (QS), a communication system used by pathogenic bacteria like Pseudomonas aeruginosa to synchronize the expression of specific genes involved in pathogenicity, is a possible drug target. Previous in vitro and in vivo studies revealed a significant inhibition of P. aeruginosa QS by crude garlic extract. By bioassay-guided fractionation of garlic extracts, we determined the primary QS inhibitor present in garlic to be ajoene, a sulfur-containing compound with potential as an antipathogenic drug. By comprehensive in vitro and in vivo studies, the effect of synthetic ajoene toward P. aeruginosa was elucidated. DNA microarray studies of ajoene-treated P. aeruginosa cultures revealed a concentration-dependent attenuation of a few but central QS-controlled virulence factors, including rhamnolipid. ...

Objectives: to compare the in vitro elution characteristics of tobramycin impregnated beads made of polycaprolactone (PCL) and polymethylmethacrylate (PMMA). Design: Six-millimeter PCL and PMMA beads with 6% tobramycin were formed and placed in phosphate-buffered saline or newborn calf serum and incubated at room temperature or 37°C. Aliquots were taken at intervals for eight weeks. Tobramycin levels were determined by fluorescent assay and antibacterial efficacy was assessed by measuring the zones of inhibition against Staphylococcus aureus and Pseudomonas aeruginosa on agar diffusion plates. Results: Tobramycin elution rates at room temperature were similar up to three weeks. At three weeks, elution rates from PCL beads were twice those from PMMA beads, and at eight weeks, elution from PCL was quadruple that from PMMA. At 37°C, tobramycin elution rates from PCL were eight times greater than those from PMMA by eight weeks. Total tobramycin eluted from PCL beads was 38.9% and 20% in PMMA beads. All

Abstract This work presents antibacterial potential and anatomical investigation of Calotropis procera (Aiton) Dryand. Populations from different areas of Mirpur (Azad Jammu & Kashmir), Pakistan. In the research, three different areas (viz: Jarikus, Khaliqabad and Jatlan) were selected for population sampling (leaf parts) having no symptom of disease. Leaf powder was macerated in two solvents and tested against four pathogenic bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa). The methanolic extract depicted highest zone of inhibition (ZI) values with 14.67±1 mm against Pseudomonas aeruginosa (PA) while aqueous extract showed good ZI (14±1 mm) against this bacterium. Extract from Jatlan sample showed highest ZI values for methanolic fraction against Staphylococcus aureus and least effect against Bacillus subtilis (13±1 mm). Against E. coli methanol showed 14.7±0.8 mm and aqueous showed 11±0.5 mm zone of inhibition. Against Pseudomonas ...

Of the many functions of poly P (1, 2, 28-30), our studies with E. coli suggest that regulatory controls are among the most significant (3, 4, 31). The E. coli mutant lacking PPK, and thus diminished in poly P, fails to activate the major regulatory gene rpoS that encodes the sigma factor that prepares cells to survive in the stationary phase (31). The mutant, deficient in adapting to nutritional stringencies and environmental stresses, fails to survive (3). In some bacterial pathogens, a defect in swimming motility is also manifested in ppk mutants lacking poly P (21). We have extended those observations to demonstrate that poly P and/or PPK control the swarming and twitching as well as the swimming motility of P. aeruginosa.. Two forms of surface motility (swimming by a polar monotrichous flagellum and twitching by polar multitrichous pili) are well-documented in P. aeruginosa (26, 32). Swarming, another form of flagella-dependent surface motility, has been described in Proteus mirabilis, ...

Purpose: : We previously showed that TLR5 recognized Pseudomonas aeruginosa flagellin and triggers the expression and/or release of proinflammatory cytokines in human corneal epithelial cells (HCECs). In the present study we sought to determine whether activation of HCECs by flagellin-TLR5 results in tolerance as manifested by decreased cytokine production and hyporesponsiveness to subsequent P. aeruginosa infection. Methods: : HUCL, a telomerase-immortalized HCEC line, and primary culture of HCECs were pretreated with low dosages of P. aeruginosa (PA01) flagellin for a period of 12 to 24 h to induce tolerance. The flagellin-tolerized HCECs were then challenged either with higher dose of flagellin or live P. aeruginosa at MOI of 50-100. The activation of NF-ΚB and MAPKs (p38, JNK, ERK) was assessed by Western blotting using phosphor-specific antibodies. RT-PCR was used to detect the changes in mRNA levels of negative-regulators of TLR-signaling pathways such as Tollip, SIGIRR, IRAK-M, IRAK1, ...

We screened the nonredundant PA14 transposon mutant library for mutants defective in growth on GB to identify genes involved in the GB catabolic pathway in P. aeruginosa. We identified a putative GB demethylase, encoded by gbcA and gbcB, based on phenotypic data that indicated that the ΔgbcA-gbcB mutant could not grow on GB but could use DMG as a carbon and nitrogen source (Table 2 and data not shown). Furthermore, when the the ΔgbcA-gbcB mutant was fed choline, GB accumulated in the cells (Fig. 4). The gbcA and gbcB transcript levels increased in response to GB and DMG in a GbdR-dependent manner. The transcript accumulation was mirrored in a proteomics analysis, in which the GbcB protein was shown to be more abundant in P. aeruginosa grown in the presence of GB as the sole carbon source (11). We also identified a putative DMG demethylase, encoded by the dgcAB genes, which is necessary for conversion of DMG to sarcosine. Experiments with 13C-labeled choline confirmed that DMG accumulated in ...

This site uses Akismet to reduce spam. 2. In many cases, Pseudomonas infections are preventable. Septicaemia People with existing lung diseases sometimes carry the bacteria in their lungs without causing infection. A doctor may also prescribe an antibiotic called polymyxin. Certain symptoms depend on the site at which the disease occurs. Produce acid from xylose. Pseudomonas bacteria are generally harmless. These include ear infections and skin rashes, especially after exposure to water. Although it rarely causes disease in healthy individuals, it is a significant threat to hospitalized patients, especially those with severe underlying conditions such as cancer and burns. Of the many different types of Pseudomonas, the one that most often causes infections in humans is called Pseudomonas aeruginosa, which can cause infections in the blood, lungs (pneumonia), or other parts of the body after surgery. It is a widespread free-living bacterium and is found in most moist environments such as skin ...

Canadian Journal of Infectious Diseases and Medical Microbiology is a peer-reviewed, Open Access journal that publishes original research articles, review articles, and clinical studies related to infectious diseases of bacterial, viral and parasitic origin. The journal welcomes articles describing research on pathogenesis, epidemiology of infection, diagnosis and treatment, antibiotics and resistance, and immunology.

Against the biofilm-forming cells, levofloxacin showed a strong bactericidal activity; however, ciprofloxacin, ceftazidime, and gentamicin were hardly effective. There are two main reasons that the latter antibacterial agents are not as effective on biofilm-forming cells as they are on planktonic cells. One is that the biofilm-forming cells are slow- or nongrowing (29). Another is a reduction in antibacterial penetration through the biofilm layer, because alginate, the main constituent of the biofilm, plays a barrier role (6, 9, 10). The bactericidal activity of levofloxacin against nongrowing cells of P. aeruginosa was as strong as that of ciprofloxacin but superior to that of gentamicin. Ceftazidime hardly showed bactericidal activity against nongrowing cells. However, the diffusion rate of levofloxacin through the alginate layer was not as high as that of ceftazidime but slightly higher than that of ciprofloxacin. The diffusion rate of gentamicin was below the limit of detection. These ...