i OCCURRENCE AND CHARACTERISTICS OF MYCOTIC AGENTS ISOLATED FROM SKIN LESIONS OF TRADE HORSES AND DONKEYS IN OBOLLO-AFOR, ENUGU STATE, NIGERIA BY ANEKE, CHIOMA INYANG PG/M.Sc/13/65113 DEPARTMENT OF VETERINARY PATHOLOGY AND MICROBIOLOGY FACULTY OF VETERINARY MEDICINE UNIVERSITY OF NIGERIA, NSUKKA FEBRUARY, 2016 ii TITLE OCCURRENCE AND CHARACTERISTICS OF MYCOTIC AGENTS ISOLATED FROM SKIN LESIONS OF TRADE HORSES AND DONKEYS IN OBOLLO-AFOR, ENUGU STATE, NIGERIA BY ANEKE, CHIOMA INYANG PG/M.Sc/13/65113 A RESEARCH DISSERTATION SUBMITTED TO THE DEPARTMENT OF VETERINARY PATHOLOGY AND MICROBIOLOGY, FACULTY OF VETERINARY MEDICINE UNIVERSITY OF NIGERIA, NSUKKA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF MASTER OF SCIENCE (M.Sc) IN VETERINARY MICROBIOLOGY FEBRUARY, 201 iii DECLARATION I declare that the work presented in this thesis entitled “OCCURRENCE AND CHARACTERISTICS OF MYCOTIC AGENTS ISOLATED FROM SKIN LESIONS OF TRADE HORSES AND DONKEYS IN OBOLLO-AFOR, ENUGU STATE, NIGERIA’’ has been carried out by me in the Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Enugu State, Nigeria under the supervision of Prof. K.F Chah and Prof (Mrs) J.I Okafor. The information derived from the literature has been duly acknowledged in the text and a list of references provided. No part of this thesis has previously been presented for another Degree or Diploma at this or any other institution. I declare that the work described in this dissertation is my original work and has not been previously submitted for any degree to any university or similar institution. Name of student: DR. ANEKE, Chioma Inyang Registration Number: PG/M.Sc/13/65113 Signature: Date: iv CERTIFICATION This is to certify that Dr. Aneke, Chioma Inyang, (PG/M.Sc/13/65113) has satisfactorily completed the requirements for the course and research work for the degree of Master of Science (M.Sc) in Veterinary Microbiology. The work embodied in this dissertation is original and has not been submitted in part or full for any other Diploma or Degree of this or any other university. The dissertation has therefore, been approved for award of Master of Science degree in Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka. By __________________________ _________________________________ Prof. K.F Chah Prof. (Mrs) J.I. Okafor (Supervisor) (Supervisor) _____________________________ _________________________________ Dr. W.S. Ezema (External Examiner) (Head of Department) ___________________________________________ Prof. C.O. Nwosu (Dean, Faculty of Veterinary Medicine) v DEDICATION This work is dedicated to my ever loving husband, Engr. Joseph Ogochukwu Aneke for his ceaseless prayers, encouragement and support and to my adorable daughter Daniella Chimamanda for her unimaginable and unexplainable endurance during the course of this work and of course to my wonderful parents, Mr and Dr (Mrs) I.I Ibe. vi ACKNOWLEDGEMENTS This work would not have been a success if not for the steadfast love and mercies of the Almighty God that saw me through; to Him alone be all the glory forever. Many thanks to my handsome and sweetest husband, Jossy; you are a gift from God. Thank you so much for your encouraging words and prayers as well as facilitating my visit to the Obollo Afor horse market. Danny Diamond who was in me and later outside me, you are a true heritage from God to me. My immense gratitude goes to my parents, Mr. and Dr. (Mrs.) I.I Ibe, who strove against all odds to see that I attended University. I remain eternally grateful to both of you and I hope you are proud of me. My sincere and heartfelt gratitude goes to my amiable teacher, mentor, disciplinarian and ever ready supervisor, Prof. Kennedy Chah, whose friendly disposition at all times, constructive criticisms, encouragement and thoroughness inspired me most during the course of my programme. Sir, you are really a blessing to us all. You have made me a better researcher through the wealth of experience, expertise and knowledge shared in this work. This work would have been aborted if not because of the timely intervention and active participation of our erudite, dynamic, scholarly, amiable mummy, Prof. (Mrs.) J.I Okafor. She indeed thought me what Mycology is all about; she nurtured, groomed, counseled and empowered me. Mummy, you are rare and priceless. I am very grateful to you. I must not forget the immense contributions of Prof. S.V.O Shoyinka who volunteered his only office for my reading and research. Prof. your office truly served me all round especially during the periods I was stressed. I do not forget the immense contributions of my senior colleague, Dr. I.K Idika, “thank you a million times”. My profound gratitude also goes to the members of staff of the Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka for their wonderful support and encouragement. vii TABLE OF CONTENT Page Cover page----------------------------------------------------------------------------------------i Title page -----------------------------------------------------------------------------------------ii Declaration ---------------------------------------------------------------------------------------iii Certification---------------------------------------------------------------------------------------iv Dedication -----------------------------------------------------------------------------------------v Acknowledgements-------------------------------------------------------------------------------vi Table of contents-------------------------------------------------------------------------------- vii-ix List of Tables--------------------------------------------------------------------------------------x List of Plates---------------------------------------------------------------------------------------xi-xii List of Appendix--------------------------------------------------------------------------------- xiii Abstract --------------------------------------------------------------------------------------------xiv-xv CHAPTER ONE: INTRODUCTION 1.1 Background of the study------------------------------------------------------------------- 1 1.2 Statement of the research problem------------------------------------------------------ 4 1.3 Research questions-------------------------------------------------------------------------5 1.4 Aim and objectives of the study---------------------------------------------------------6 CHAPTER TWO: LITERATURE REVIEW 2.1 Brief history of mycology------------------------------------------------------------------7 2.2 Classification of fungi ----------------------------------------------------------------------9 2.3 Characteristics of fungi--------------------------------------------------------------------16 viii 2.4 Dermatomycoses----------------------------------------------------------------------------17 2.4.1 Dermatophytoses-------------------------------------------------------------------------17 2.4.2 Aetiologic agents--------------------------------------------------------------------------18 2.4.2.1 Anamorphs ------------------------------------------------------------------------------18 2.4.2.2 Teleomorphs-----------------------------------------------------------------------------23 2.5 Ecology of dermatophytes-----------------------------------------------------------------23 2.5.1 Geophilic dermatophytes----------------------------------------------------------------24 2.5.2 Zoophilic dermatophytes----------------------------------------------------------------26 2.5.3 Anthropophilic dermatophytes---------------------------------------------------------28 2.6 Epidemiology of dermatophytosis ------------------------------------------------------30 2.6.1 Epidemiology in human ---------------------------------------------------------------30 2.6.2Epidemiology of in animals-----------------------------------------------------------33 2.7 Transmission of dermatophytoses-------------------------------------------------------34 2.9 Other dermatomycoses in horses and donkeys----------------------------------------35 2.10 Laboratory diagnosis of dermatomycosis--------------------------------------------42 2.10 Antifungal therapy-----------------------------------------------------------------------47 2.10.1 Azoles-----------------------------------------------------------------------------------47 2.10.2 Polyenes--------------------------------------------------------------------------------48 2.10.3 Allylamines-----------------------------------------------------------------------------48 2.10.4 Echinocandins--------------------------------------------------------------------------48 2.11 Antifungal susceptibility testing methodologies ----------------------------------49 2.12 Resistance to antifungal drugs---------------------------------------------------------52 2.12.1 Mechanisms of resistance to azoles-------------------------------------------------53 ix 2.12.2 Mechanism of resistance to polyenes ----------------------------------------------53 CHAPTER THREE: MATERIAL AND METHODS 3.1 Study animals-------------------------------------------------------------------------------55 3.2 The study population and sampling -----------------------------------------------------55 3.3 Sample collection ---------------------------------------------------------------------------55 3.4 Materials and reagents ---------------------------------------------------------------------56