ABSTRACT

The antibacterial effect of Annona muricata linn (sour sop) leaf, bark, and fruit on some selected organisms was investigated using Escherichia coll, Salmonella and Shigella. Different concentrations (IQOmg/ml, 50mg/ml and 25mg/ml) of the aqueous and ethanol extracts of the leaf and bark, and the juice extract of the fruit were used. The Kirby-Bauer disc diffusion method was used for the susceptibility test. The results showed that the ethanol bark extract and the aqueous leaf extract at different concentrations showed little inhibition against the organisms. For ethanol bark extract the zone of inhibition observed against the test organisms were 4mm against Salmonella sp and 3mm against Shigella sp at lOOmg/ml concentrations. For the aqueous extract of the leaf, the zones of inhibition were 4mm for E. coli and 3mm for Shigella sp at lOOmg/ml concentration. The fruit juice extract also did not show any inhibition against all the three organisms tested. The antibiotics used as control (gentamicin and chloramphenicol) showed some degree of inhibition against all the organisms. The result of this study shows that this plant cannot be effectively used to treat infections caused by this test organisms, hence it cannot be recommended for use in their treatment.

TABLE OF CONTENTS

Title page i

Certification ii

Dedication iii

Acknowledgement iv

Table of contents v

List of tables viii

Abstract ix

CHAPTER ONE

1.0      Introduction 1

1.1      Aims and objectives 3

CHAPTER TWO

2.0      Literature review 4

2.1       Annona muricata linn 4

2.2.1    Chemical Compositions of Annona Muricata. 4

2.2.2   Chemical components of the leaf. 4

2.2.3    Medicinal properties of sour sop: 5

2.3       Phytochemical constituents of Annona muricato 8

2.3.1    Steroids 8

2.3.2    Cardiac glycosides: 8

2.3.3    Alkaloids 9

2.3.4    Saponins 9

2.3.5    Tannin 10

2.3.6 Flavonoids 11

2.4    Test organisms 12

2.4.1 Shigella 12

2.4.2 Salmonella 13

2.4.3 Escherichia coll 14

2.5 Antibiotics used 15

2.5.1 Chloramphenicol 15

2.5.2 Gentamicin 16

CHAPTER THREE

3.0 Materials and method 17

3.1 Sample collection 17

3.2 Media used. 17

3.3 Collection of test microorganism 17

3.4 Sterilization of equipments 17

3.5      Biochemical identification/confirmation of bacterial isolates      18

3.5.1 Gram Staining: 18

3.5.2 Catalase test. 18

3.5.3 Citrate Test 19

3.5.4 Indoletest .                                                                               19

3.5.5 Methyl red test 19

3.5.6 Voges-Proskauer test 19

3.5.7 Sugar test 20

3.5.8 Motilitytest 20

3.6      Preparation of plant extracts 21

3.6.1    Ethanol Extract Preparation 21

3.6.2    WaterExtract Preparation 21

3.7       Preparation of paper disc 21

3.8       Agar disc diffusion methods 22

CHAPTER FOUR

4.0       Results 23

CHAPTER FIVE

5.0      Discussion, conclusion, and recommendation 28

5.1       Discussion 28

5.2       Conclusion                                         . 29

5.3       Recommendation 29

References 30

LIST OF TABLES

Table Title                                                            Page

1 Characterization and identification of bacterial isolates.                                          24

2         The antibacterial effect of the ethanol leaf and bark extract against the test

organisms recorded as zones of inhibition (mm), 25

3 The antibacterial effect of the aqueous leaf and bark extract against the test

organisms recorded as zones of inhibition (mm). 26

4         The antibacterial effect of the fruit juice extract against the test organisms

recorded as zones of inhibition (mm).                                                                                27