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DISTRIBUTION OF CULTURABLE VIBRIO SPECIES IN FRESHWATER RESOURCES OF CACADU, OR TAMBO AND CHRIS HANI DISTRICT MUNICIPALITIES BY GAQAVU SISIPHO A dissertation submitted in fulfillment of the requirements for the degree of MASTERS IN MICROBIOLOGY DEPARTMENT OF BIOCHEMISTRY AND MICROBIOLOGY FACULTY OF SCIENCE AND AGRICULTURE UNIVERSITY OF FORT HARE ALICE, SOUTH AFRICA SUPERVISOR: PROF A.I OKOH 2017 DECLARATION I, the undersigned, declare that this dissertation entitled “Distribution of culturable Vibrio species in freshwater resources of Cacadu, OR Tambo and Chris Hani District Municipalities” submitted to the University of Fort Hare for the degree of Masters in Microbiology in the Faculty of Science and Agriculture, School of Biological and Environmental Sciences, and the work contained herein is my original work with exemption to the citations and that this work has not been submitted at any other University in partial or entirely for the award of any degree. Name: Sisipho Gaqavu Signature:............................................................................ Date:………………………………………. i DEDICATION I dedicate my dissertation work to my Lord “Jesus Christ”. Your mercy and faithfulness never cease to amaze me. ii ACKNOWLEDGEMENTS I would like to thank God for giving me the power to finish this project. I wish to express my profound gratitude to my supervisor, Professor Anthony Okoh, for providing me an opportunity of pursuing my Masters Degree, for guiding me throughout my studies. I appreciate his guidance, constructive comments, and constant support all the way through the writing of the dissertation. I am grateful to have him as my supervisor. I would also like to thank Dr Ben Iweriebor, who has been like a father; I want to thank him for his encouragement, mentorship and support. I wish to express my gratitude to the National Research Foundation (NRF) for offering me Bursary/ scholarship award to pursue the Masters degree. I would also like to thank my wonderful colleagues at the Applied Environmental Microbiology Research Group members more especially the cholera group for their support and mentorship. To save the best for last, I am extremely grateful to my parents (Nomawethu Constance Gaqavu and Sithile Alfred Gaqavu). I appreciate your firm support, encouragement, your sacrifices and your prayers. You are the most wonderful gifts from God. To my sisters Amanda and Mihle and my brother Lubabalo, thank you for love and encouragement. To my best friend Zilungele Qolo, you have been a great blessing in my life. iii ABSTRACT Freshwater resources are essential to the survival of all living organisms and are used for numerous purposes such as domestic, industrial, agricultural and recreational activities. Nevertheless they are vulnerable to contamination including by pathogenic organisms. Among the pathogens distributed in water resources, diarrhoea causing pathogens such as Vibrio species are the most frequently encountered, hence, the aim of this study was to evaluate the incidence of pathogenic Vibrio species in freshwater resources in Cacadu, OR Tambo and Chris Hani District Municipalities. Water samples were collected from four rivers located in Cacadu, OR Tambo and Chris Hani District Municipalities in the Eastern Cape Province, South Africa. A total of 6 physicochemical parameterswere measured and includes: temperature, total dissolved solids (TDS), dissolved oxygen, turbidity, pH and electrical conductivity. Samples were collected between March and May 2016and concentrated using the standard membrane filtration technique and plated on TCBS agar. Yellow and green colonies on TCBS agar were enumerated as presumptive Vibrio species and expressed as CFU/100ml for each river. The identification of the presumptive Vibrio species and their antibiogram characteristics were done using both culture based and molecular techniques. The physicochemical qualities ranged as follows: pH (7.0-7.03), temperature (16 - 23 ºC), turbidity (15.6 – 43 NTU), electrical conductivity (61.1 – 835μS/cm), dissolved oxygen (7.34 – 8.73 mg/L), total dissolved solids (39.3 – 533.33 mg/L). Statistical analysis showed that pH, temperature, turbidity, dissolved oxygen were significantly different (P < 0.05), whereas the total iv dissolved solids were not significantly different (P ˃ 0.05) with respect to sampling sites. Vibrio densities ranged between 3.08 ×101-6.96 ×101 with Bloukrans River characterized by high counts compared to other rivers. Two hundred and three (203) positive Vibrio genus isolates were screened for speciation. Of these, the prevalent species found was V. cholerae (29%) followed by V. vulnificus (4%), V. fluvialis (4%) and the least was V. parahaemolyticus (3%). The remaining unidentified 60% were alleged to belong to other Vibrio species not covered within the scope of this study. The antibiotic susceptibility profiles of confirmed Vibrio genus isolates recovered from the four rivers revealed that 83% of Vibrio isolates in this study exhibited resistance againstthree or more antimicrobial agents. The presence of the following Vibrio pathogens V. fluvialis, V. cholerae, V. vulnificus and V. parahaemolyticus in water resources suggests that these water resources are significant reservoirs of Vibrio pathogens. Thus, there is a need for regular contamination monitoring programme of the selected water resources and other areas that might be of interest. In general, the results obtained from this study suggest that the river waters are not suitable for drinking, domestic or recreational use. v Table of Contents DEDICATION .............................................................................................................................................. ii ACKNOWLEDGEMENTS ......................................................................................................................... iii ABSTRACT ................................................................................................................................................. iv LIST OF FIGURES ................................................................................................................................... viii LIST OF TABLES ....................................................................................................................................... ix CHAPTER 1 ................................................................................................................................................. 1 GENERAL INTRODUCTION ..................................................................................................................... 1 1.1 Background of the study ............................................................................................................... 1 1.2 Problem statement ......................................................................................................................... 3 1.3 Hypothesis..................................................................................................................................... 5 1.4 Aim and objectives ....................................................................................................................... 5 CHAPTER TWO .......................................................................................................................................... 6 LITERATURE REVIEW ............................................................................................................................. 6 2.1 Vibrio species ...................................................................................................................................... 6 2.2 Human pathogenic Vibrio species ....................................................................................................... 7 2.2.1 Vibrio parahaemolyticus .............................................................................................................. 9 2.2.2 Vibrio vulnificus ......................................................................................................................... 10 2.2.3 Vibrio fluvialis ........................................................................................................................... 11 2.2.4 Vibrio cholerae .......................................................................................................................... 12 2.3 Epidemiology .................................................................................................................................... 14 2.4 Survival in the environment .............................................................................................................. 16 2.5 Freshwater resources as reservoir of Vibrio species. ........................................................................ 19 2.6 Sources of pollution in freshwater resources .................................................................................... 20 2.6.1 Final effluents of WWTP as one of the largest source of pollution ........................................... 21 2.7 Antibiotic resistance of Vibrio species .............................................................................................. 23 CHAPTER 3 ............................................................................................................................................... 26 MATERIALS AND METHODS ................................................................................................................ 26 3.1 Reconnaissance visit of sampling