Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2002 Pathogenic mechanisms of Photobacterium damselae subspecies piscicida in hybrid striped bass Ahmad A. Elkamel Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Veterinary Pathology and Pathobiology Commons Recommended Citation Elkamel, Ahmad A., "Pathogenic mechanisms of Photobacterium damselae subspecies piscicida in hybrid striped bass" (2002). LSU Doctoral Dissertations. 773. https://digitalcommons.lsu.edu/gradschool_dissertations/773 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. PATHOGENIC MECHANISMS OF PHOTOBACTERIUM DAMSELAE SUBSPECIES PISCICIDA IN HYBRID STRIPED BASS A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Pathobiological Sciences by Ahmad A. Elkamel B.V. Sc., Assiut University, 1993 May 2002 DEDICATION This work is dedicated to the people in my life who encouraged each step of my academic career. My mother was anxious as I was for each exam or presentation. I have been always looking to my Dad as a model, and trying to follow his footsteps in academic career. My wife stood by me like no other one in the world, and her love and support helped me see one of my dreams come true. ii ACKNOWLEDGMENTS I thank God for answering prayers and helping me to achieve my dreams. There are several extraordinary people who guided me through my doctoral experience and without their help and support I could have not finished my project. I am and forever will be grateful to my advisor Dr. Ronald Thune for his advice, encouragement over years, insightful guidance, “tireless editing”, and most importantly for always being willing to listen. I feel extremely fortunate to be counted as one of his students. I would like to offer my deepest thanks to my minor advisor Dr. John Hawke for his assistance and help in my project. I would like also to offer my everlasting gratitude to all of my committee members, Dr. David Horohov, Dr. Philip Elzer, and Dr. Richard Cooper for their aid, guidance, and advice throughout this long, and sometimes difficult, process. To those of you in Dr. Thune’s lab, Denise Fernandez, Ron Miller, Heather Harbottle, Pat Bohannon, Maria Smith, Ericka Judice, Karen Plant, Tara Landrum, Kim Mayer, Jim Sellers, and Jennifer Benoit, I owe you a lot for all the help, encouragement, and friendship you gave to me, and for making the graduate school an experience I will never forget (it goes both ways). I am uniquely and foremost grateful to my wife, Ghada, for her support, motivation, and understanding that sustained me to complete this work. Her contribution throughout my study is beyond words of recognition. I am eternally grateful for my Mom and Dad, Mr. and Mrs. Elkamel, my sister Abeer, my brother in law Basem, and all of my family. iii Finally, I thank the Egyptian Cultural and Educational Bureau for the financial support of my research. Also, I would like to thank Wally Landry for providing fish for my research. And thanks for all who I might forget to mention their name, but offered me any kind of support. iv TABLE OF CONTENTS DEDICATION.................................................................................................................... ii ACKNOWLEDGMENTS .................................................................................................iii LIST OF TABLES...........................................................................................................viii LIST OF FIGURES ........................................................................................................... ix ABSTRACT....................................................................................................................... xi INTRODUCTION .............................................................................................................. 1 CHAPTER I. LITERATURE REVIEW......................................................................... 6 Striped Bass and Its Hybrids................................................................................... 6 Hybridization .............................................................................................. 7 Production of Striped Bass and Its Hybrids................................................ 8 Broodstock and Hatchery Phase ..................................................... 9 Phase I Culture.............................................................................. 10 Phase II Culture............................................................................. 11 Phase III Culture ........................................................................... 12 Fish Photobacteriosis ............................................................................................ 13 Geographic Distribution and Epizootics................................................... 13 Species Susceptibility ............................................................................... 15 Clinical Signs............................................................................................ 15 Acute Disease................................................................................ 15 Chronic Disease ............................................................................ 16 Histopathology.............................................................................. 17 Photobacterium damselae subspecies piscicida ....................................... 18 Taxonomy ..................................................................................... 18 Morphology................................................................................... 19 Culture Characteristics.................................................................. 20 Biochemical Characteristics.......................................................... 20 Serological Characteristic ............................................................. 21 Pathogenicity................................................................................. 21 Virulence Mechanisms of Photobacterium damselae .......................................... 23 Factors That Promote Colonization and Invasion of Host Surfaces......... 24 Flagella.......................................................................................... 24 Adhesion ....................................................................................... 24 Invasion......................................................................................... 30 Iron Acquisition ............................................................................ 37 Outer Membrane Proteins............................................................. 39 Serum Resistance.......................................................................... 40 Capsule.......................................................................................... 41 Lipopolysaccharide....................................................................... 43 v Plasmids ........................................................................................ 43 Surviving Macrophage Killing ..................................................... 46 Intracellular Replication................................................................ 64 Apoptosis ...................................................................................... 66 Factors That Cause Damage to the Host................................................... 76 Bacterial Toxins and ECP............................................................. 76 Treatment and Prevention of Photobacteriosis ..................................................... 78 Chemotherapy........................................................................................... 78 Vaccination ............................................................................................... 80 Study Objectives ................................................................................................... 82 CHAPTER II. PHOTOBACTERIUM DAMSELAE SUBSPECIES PISCICIDA IS CAPABLE OF REPLICATING IN HYBRID STRIPED BASS MACROPHAGES . 84 Introduction........................................................................................................... 84 Materials and Methods.......................................................................................... 86 Fish............................................................................................................ 86 Macropahge Media ................................................................................... 86 Macrophage Isolation................................................................................ 87 Lysing Macrophages................................................................................. 88 Bacterial Strains........................................................................................ 89 Determination of Optimum Gentamicin Concentrations.......................... 91 Killing Assay ...........................................................................................