Medicine and Health Sciences Commons^™

Comparative Study On The In Vitro Effects Of Pseudomonas Aeruginosa And Seaweed Alginates On Human Gut Microbiota, Shaofeng Bai, Huahai Chen, Liying Zhu, Wei Liu, Hongwei Yu, Xin Wang, Yeshi Yin

Hongwei Yu

Alginates pertain to organic polysaccharides that have been extensively used in food- and medicine-related industries. The present study obtained alginates from an alginate overproducing Pseudomonas aeruginosa PAO1 mutant by screening transposon mutagenesis libraries. The interaction between bacterial and seaweed alginates and gut microbiota were further studied by using an in vitro batch fermentation system. Thin-layer chromatography (TLC) analysis indicated that both bacterial and seaweed alginates can be completely degraded by fecal bacteria isolated from study volunteers, indicating that a minor structural difference between bacterial and seaweed alginates (O-acetylation and lack of G-G blocks) didn’t affect the digestion of alginates by …

Antibiogram Of Multidrug-Resistant Isolates Of Pseudomonas Aeruginosa After Biofield Treatment, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Mayank Gangwar, Snehasis Jana

Mahendra Kumar Trivedi

Comparative Transcriptome Analyses Of Pseudomonas Aeruginosa, Deepak Balasubramanian, Kalai Mathee

Kalai Mathee

One of the hallmarks of bacterial survival is their ability to adapt rapidly to changing environmental conditions. Niche adaptation is a response to the signals received that are relayed, often to regulators that modulate gene expression. In the post-genomic era, DNA microarrays are used to study the dynamics of gene expression on a global scale. Numerous studies have used Pseudomonas aeruginosa--a Gram-negative environmental and opportunistic human pathogenic bacterium--as the model organism in whole-genome transcriptome analysis. This paper reviews the transcriptome studies that have led to immense advances in our understanding of the biology of this intractable human pathogen. Comparative …

Truncation Of Type Iv Pilin Induces Mucoidy In Pseudomonas Aeruginosa Strain Pao579, T. Ryan Withers, F. Heath Damron, Yeshi Yin, Hongwei D. Yu

Hongwei Yu

Pseudomonas aeruginosa is a Gram negative, opportunistic pathogen that uses the overproduction of alginate, a surface polysaccharide, to form biofilms in vivo. Overproduction of alginate, also known as mucoidy, affords the bacterium protection from the host's defenses and facilitates the establishment of chronic lung infections in individuals with cystic fibrosis. Expression of the alginate biosynthetic operon is primarily controlled by the alternative sigma factor AlgU (AlgT/σ22). In a nonmucoid strain, AlgU is sequestered by the transmembrane antisigma factor MucA to the cytoplasmic membrane. AlgU can be released from MucA via regulated intramembrane proteolysis by proteases AlgW and MucP causing the …

Effects Of Pseudomonas Aeruginosa Virulence Factor Pyocyanin On Human Urothelial Cell Function And Viability, Catherine Mcdermott, Russ Chess-Williams, Gary Grant, Anthony Perkins, Amelia Mcfarland, Andrew Davey, Shailendra Anoopkumar-Dukie

Russ Chess-Williams

Purpose: We determined the effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell viability and function in vitro. Materials and Methods: RT4 urothelial cells were treated with pyocyanin (1 to 100 μM) for 24 hours. After exposure the treatment effects were measured according to certain end points, including changes in urothelial cell viability, reactive oxygen species formation, caspase-3 activity, basal and stimulated adenosine triphosphate release, SA-β-gal activity and detection of acidic vesicular organelles. Results: The 24-hour pyocyanin treatment resulted in a concentration dependent decrease in cell viability at concentrations of 25 μM or greater, and increases in reactive …

Effects Of Pseudomonas Aeruginosa Virulence Factor Pyocyanin On Human Urothelial Cell Function And Viability, Catherine Mcdermott, Russ Chess-Williams, Gary Grant, Anthony Perkins, Amelia Mcfarland, Andrew Davey, Shailendra Anoopkumar-Dukie

Catherine M. McDermott

Purpose: We determined the effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell viability and function in vitro. Materials and Methods: RT4 urothelial cells were treated with pyocyanin (1 to 100 μM) for 24 hours. After exposure the treatment effects were measured according to certain end points, including changes in urothelial cell viability, reactive oxygen species formation, caspase-3 activity, basal and stimulated adenosine triphosphate release, SA-β-gal activity and detection of acidic vesicular organelles. Results: The 24-hour pyocyanin treatment resulted in a concentration dependent decrease in cell viability at concentrations of 25 μM or greater, and increases in reactive …

Pyocyanin-Induced Toxicity In A549 Respiratory Cells Is Causally Linked To Oxidative Stress, Lee Gloyne, Gary Grant, Anthony Perkins, Katie Powell, Catherine Mcdermott, Peter Johnson, Gregory Anderson, Milton Kiefel, Shailendra Anoopkumar-Dukie

Catherine M. McDermott

Pyocyanin, a virulence factor produced by Pseudomonas aeruginosa, has many damaging effects on mammalian cells. Several lines of evidence suggest that this damage is primarily mediated by its ability to generate ROS and deplete host antioxidant defence mechanisms. However, a causal role for oxidative stress has not yet been demonstrated conclusively. Parallel measures of ROS production, antioxidant levels and cytotoxicity provide convincing evidence that pyocyanin-induced cytotoxicity in A549 respiratory cells is mediated by acute ROS production and subsequent oxidative stress. Pyocyanin increased ROS levels in A549 cells as measured by the fluorescent H2O2 probes Amplex Red and DCFH-DA. These effects …

Immune Responses In Cystic Fibrosis: Are They Intrinsically Defective?, Dmitry Ratner, Christian Mueller

Christian Mueller

Cystic fibrosis (CF), the most common lethal single-gene disorder affecting Northern Europeans and North Americans, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Cftr is a chloride channel and a regulator of other ion channels, and many aspects of the CF phenotype are directly related to ion channel abnormalities attributable to CFTR mutation. Lung disease is the most common limitation to the quantity and quality of life for patients with CF. One aspect that continues to be enigmatic is the observed alterations in innate and adaptive immune responses to certain pathogens. Altered responses to Pseudomonas …

Functional Characterization Of A Recombinant Adeno-Associated Virus 5-Pseudotyped Cystic Fibrosis Transmembrane Conductance Regulator Vector, Jeffrey Sirninger, Christian Mueller, Sofia Braag, Qiushi Tang, Hungwen Yue, Carol Detrisac, Thomas Ferkol, William Guggino, Terence Flotte

Christian Mueller

Despite extensive experience with recombinant adeno-associated virus (rAAV) 2 vectors in the lung, gene expression has been low in the context of cystic fibrosis (CF) gene therapy, where the large size of the cystic fibrosis transmembrane conductance regulator (CFTR) coding sequence has prompted the use of compact endogenous promoter elements. We evaluated the possibility that gene expression from recombinant adeno-associated virus (rAAV) could be improved by using alternate AAV capsid serotypes that target different cell-surface receptors (i.e., rAAV5) and/or using stronger promoters. The relative activities of the cytomegalovirus (CMV) Rous sarcoma virus (RSV) promoter, the CMV enhancer/beta-actin (CB) promoter combination, …

N-Glycosylation Augmentation Of The Cystic Fibrosis Epithelium Improves Pseudomonas Aeruginosa Clearance, Ashley Martino, Christian Mueller, Sofia Braag, Pedro Cruz, Martha Campbell-Thompson, Shouguang Jin, Terence Flotte

Christian Mueller

Chronic lung colonization with Pseudomonas aeruginosa is anticipated in cystic fibrosis (CF). Abnormal terminal glycosylation has been implicated as a candidate for this condition. We previously reported a down-regulation of mannose-6-phosphate isomerase (MPI) for core N-glycan production in the CFTR-defective human cell line (IB3). We found a 40% decrease in N-glycosylation of IB3 cells compared with CFTR-corrected human cell line (S9), along with a threefold-lower surface attachment of P. aeruginosa strain, PAO1. There was a twofold increase in intracellular bacteria in S9 cells compared with IB3 cells. After a 4-hour clearance period, intracellular bacteria in IB3 cells increased twofold. Comparatively, …

In Vitro And In Vivo Functional Characterization Of Gutless Recombinant Sv40-Derived Cftr Vectors, Christian Mueller, M. Strayer, Jeffrey Sirninger, Sofia Braag, Francisco Branco, Jean-Pierre Louboutin, Terence Flotte, David Strayer

Christian Mueller

In cystic fibrosis (CF), respiratory failure caused by progressive airway obstruction and tissue damage is primarily a result of the aberrant inflammatory responses to lung infections with Pseudomonas aeruginosa. Despite considerable improvement in patient survival, conventional therapies are mainly supportive. Recent progress toward gene therapy for CF has been encouraging; however, several factors such as immune response and transduced cell turnover remain as potential limitations to CF gene therapy. As alternative gene therapy vectors for CF, we examined the feasibility of using recombinant SV40-derived vectors (rSV40s), which may circumvent some of these obstacles. To accommodate the large cystic fibrosis transmembrane …