In-Vivo Expression Profiling of Pseudomonas aeruginosa Infections Reveals Niche-Specific and Strain-Independent Transcriptional Programs

Pseudomonas aeruginosa is a threatening, opportunistic pathogen causing disease in immunocompromised individuals. The hallmark of P. aeruginosa virulence is its multi-factorial and combinatorial nature. It renders such bacteria infectious for many organisms and it is often resistant to antibiotics. To gain insights into the physiology of P. aeruginosa during infection, we assessed the transcriptional programs of three different P. aeruginosa strains directly after isolation from burn wounds of humans. We compared the programs to those of the same strains using two infection models: a plant model, which consisted of the infection of the midrib of lettuce leaves, and a murine tumor model, which was obtained by infection of mice with an induced tumor in the abdomen. All control conditions of P. aeruginosa cells growing in suspension and as a biofilm were added to the analysis. We found that these different P. aeruginosa strains express a pool of distinct genetic traits that are activated under particular infection conditions regardless of their genetic variability. The knowledge herein generated will advance our understanding of P. aeruginosa virulence and provide valuable cues for the definition of prospective targets to develop novel intervention strategies

Novel capsaicin (VR1) and purinergic (p2X3) receptors in Hirschsprung's intestine

Background/Purpose: Studies Of Hirschsprung's Disease (Hscr) Have Shown That Hypertrophic Nerves In Aganglionic Bowel Are Mainly Of Extrinsic Origin And May Contain Sensory Elements. Recent Advances Have Shown A Specific Capsaicin Receptor Vr1 (Vanilloid Receptor-1), And An Atp-Gated Ion Channel P2x3, Which Are Expressed By Sensory Neurons. Methods: This Study Investigated, For The First Time, The Distribution Of Vr1- And P2x3-Immunoreactivity In Normal Adult, Infant, And Hscr Large Intestine, Using Specific Anti-Bodies For Immunohistochemistry. Results: Vr1-Immunoreactive Fibers And Nerve Fascicles, But Not Somata, Were Detected In All Regions Of The Bowel In Controls With Few Weakly Immunostained Fibers In The Mucosa/Lamina Propria. Hypertrophic Nerve Bundles In Hypoganglionic And Aganglionic Bowel Showed Intense Vr1-Immunoreactivity, Whereas Normoganglionic Regions Of Hscr Were Similar To Controls. P2x3-Immunoreactive Neuronal Cell Bodies, In Some Instances With Long Axonal Processes, Were Detected In The Myenteric And Submucous Plexuses In Control Infant, Adult, And Ganglionic Hscr Samples. Aganglionic Samples Showed Weak P2x3-Immunoreactivity In Hypertrophic Nerve Fasciculi In The Submucous And Myenteric Plexuses. Conclusions: The Presence Of Vr1- And P2x3-Immunoreactivities In Aganglionic Hscr Bowel Indicates That Sensory Nerves May Form A Significant Proportion Of Its Hypertrophic Innervation. The Functional Significance Of P2x3 And Vr1 Receptors In Enteric Nerves Deserves Further Investigation. Copyright © 2001 By W.B. Saunders Company.link_to_subscribed_fulltex

Novel capsaicin (VR1) and purinergic (p2X3) receptors in Hirschsprung's intestine

Background/Purpose: Studies Of Hirschsprung's Disease (Hscr) Have Shown That Hypertrophic Nerves In Aganglionic Bowel Are Mainly Of Extrinsic Origin And May Contain Sensory Elements. Recent Advances Have Shown A Specific Capsaicin Receptor Vr1 (Vanilloid Receptor-1), And An Atp-Gated Ion Channel P2x3, Which Are Expressed By Sensory Neurons. Methods: This Study Investigated, For The First Time, The Distribution Of Vr1- And P2x3-Immunoreactivity In Normal Adult, Infant, And Hscr Large Intestine, Using Specific Anti-Bodies For Immunohistochemistry. Results: Vr1-Immunoreactive Fibers And Nerve Fascicles, But Not Somata, Were Detected In All Regions Of The Bowel In Controls With Few Weakly Immunostained Fibers In The Mucosa/Lamina Propria. Hypertrophic Nerve Bundles In Hypoganglionic And Aganglionic Bowel Showed Intense Vr1-Immunoreactivity, Whereas Normoganglionic Regions Of Hscr Were Similar To Controls. P2x3-Immunoreactive Neuronal Cell Bodies, In Some Instances With Long Axonal Processes, Were Detected In The Myenteric And Submucous Plexuses In Control Infant, Adult, And Ganglionic Hscr Samples. Aganglionic Samples Showed Weak P2x3-Immunoreactivity In Hypertrophic Nerve Fasciculi In The Submucous And Myenteric Plexuses. Conclusions: The Presence Of Vr1- And P2x3-Immunoreactivities In Aganglionic Hscr Bowel Indicates That Sensory Nerves May Form A Significant Proportion Of Its Hypertrophic Innervation. The Functional Significance Of P2x3 And Vr1 Receptors In Enteric Nerves Deserves Further Investigation. Copyright © 2001 By W.B. Saunders Company.link_to_subscribed_fulltex