ABSTRACT

The antimicrobial effect of some honey samples obtained from National Root Crop Research Institute (NRCRI), Umudike and Mbaise were tested on some fungal pathogens such as Aspergillus niger, Penicillium chrysogenum and Candida albicans. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the honeys were also determined. Results obtained reveal that the honey samples showed varying levels of inhibitory activity at various concentrations against the fungi tested with zones of inhibition increasing with increasing honey concentration. Penicillium chrysogenum was the most sensitive of all the fungal isolates studied, value at 21mm at 100% in honey from National Root Crop Research Institute (NRCRI), Umudike and 22mm at 100% in honey from Mbaise. While C. albicans was the least sensitive, value at 18mm at 100% in honey from National Root Crop Research Institute (NRCRI), Umudike and 19mm in honey from Mbaise. The minimum inhibitory concentration (MIC) value from 40 – 60% concentration while the minimum fungicidal concentration (MFC) value from 20 – 40% concentration. The samples of honey used in the study showed broad spectrum and promising antifungal effect. Nigerian honey can serve as sources of antifungal substances for possible development of antifungal drugs for the treatment of fungal infections.  

TABLE OF CONTENTS

Title page         i

Certification         ii

Dedication         iii

Acknowledgements         iv

Table of contents         v

List of tables         ix

Abstract         x

CHAPTER ONE

1.1 Introduction          1

1.2 Aims and Objectives          2

CHAPTER TWO

2.1 Literature Review           3

2.2 Local test for real Honey           5

2.2.1 Classification of  Honey           5

2.2.2 Extraction           6

2.2.3 Preservation           6

2.3 Properties and active ingredients of honey           7

2.4 Mode of action of some of the antibacterial substances in honey                   8

2.4.1 High osmotic pressure                                                                       8

2.4.2 Low water activity           8

2.4.3 Glucose oxidase enzyme           8

2.4.4 Low pH/ acidic environment           9

2.5 Clinical conditions that respond to treatment with honey                9

2.6 Honey as an antibacterial agent         10

2.6.1 Practical consideration for the clinical use of honey         12

2.6.2 Adverse reaction of honey         12

2.7 Nutritional and health benefits of honey         13 

2.7.1 Health         13

2.7.2 Gastroenterology                     13

2.7.3 Infants         14

2.8 Fungal pathogens                     15

2.8.1 Aspergillus niger         15

2.8.2 Uses of Aspergillus niger         15

2.8.3 Penicillium chrysogenum         15

2.8.4 Uses of Penicillium chrysogenum         16

2.8.5 Candida albicans         16

CHAPTER THREE

3.0 Material and methods         17

3.1 Material         17

3.2 Methods         17

3.2.1 Collection of samples         17

3.2.2 Microorganisms used          17

3.2.3 Honey preparation         18

3.2.4 Media used         18

3.2.5 Preparation of Inoculum         18

3.3 Determination of antifungal activities         18

3.4 Determination of minimum inhibitory concentration (MIC)          19

3.5 Determination of minimum fungicidal concentration (MFC)         19

CHAPTER FOUR

4.1 Results          21

CHAPTER FIVE

5.1 Discussion           26

5.2 Conclusion                28

REFERENCES         29

LIST OF TABLES

TABLES TITLE PAGE

1:  The zone of inhibition on the effect of undiluted honey on some 

        fungal pathogens.         22

2:    Antimicrobial effect of honey sample on the test organisms.         23

3:    Minimum inhibitory concentration of the honey samples

                    against test organisms.         24

4:    Minimum fungicidal concentration of the honey samples

                 against test organisms.         25