ANTIMICROBIAL ACTIVITIES OF MICROORGANISMS ISOLATED FROM NIGERIAN FERMENTED CHEESE WHEY AGAINST DIARRHEA CAUSING BACTERIA

Globally, diarrhea is one of the most important health hazard and is the leading cause of morbidity and mortality in children especially in developing countries, particularly in areas where access to immediate treatment is absent. Despite widespread use of oral rehydration therapies (ORT) and an increased understanding of the pathogenesis of diarrhea, in developing countries, 2.5 million children still die from these illnesses every year. This study therefore tends to investigate antimicrobial activities of microorganisms isolated from Nigerian fermented cheese whey against diarrhea causing bacteria. The study was drawn from patients attending hospitals in Ibadan, Oyo state, Nigeria. One hundred and twenty three children between the ages of three and below feacal samples were obtained for a period of two months and investigated for diarrhea causing bacteria. The samples were processed using standard microbiological methods while the antagonistic effect of the isolated lactic acid bacteria and the conventional antibiotics were determined using agar well and disc diffusion method respectively. Diarrhea causing bacteria isolated from the samples were Escherichia coli 3(2%) Klebsiellaspecies 1(1%) and Morganellamorgannii. The microorganisms isolated from the cheese whey included Lactobacillus sp. and Pediococcus sp. Results of the antagonistic effects of whey isolates against the diarrheic isolates revealed that all the whey isolates showed varying inhition against the diarrhea isolates. The highest inhibition zones (7 and 15mm, 7 to 18mm and 6 to 12mm) were recorded against Morganellamorganii for Pediococcus spp. and Lactobacillus spp. The inhibition was compared favourably with that obtained when conventional antibiotics were tested against the diarrheic isolates. It could be said that the whey isolates produce bioactive constituents against diarrheal pathogens.

TABLE OF CONTENTS

CHAPTER ONE: INTRODUCTION

1.1       Background to the study

1.2       Objective of the study

1.3       Justification of the Study

CHAPTER TWO: LITERATURE REVIEW

2.1       Definition of Diarrhea

2.1.1    The main causative agents of diarrhea

2.1.2    Transmission routes

2.1.3    Types of Diarrhea

2.2       Cheese whey

2.2.1    Cheese whey characterization

2.1.2    Cheese whey treatment

2.1.3    Biological treatment without valorization

2.3       Lactic acid bacteria

2.4       Probiotics

2.5.1    Lactic acid bacteria (LAB) as probiotics

2.5.2    Effects on diarrheal diseases

CHAPTER THREE: MATERIALS AND METHODS

3.1       Equipments used

3.2       Study setting

3.3       Study population

3.4       Collection of samples

3.5       Sterilization of apparatus and working surface

3.6       Media

3.6.1    Preparation of the media used

3.7       Stool sample processing

3.7.1    Microscopy

3.7.2    Culturing

3.8       Characterization and identification of microorganism isolated from stool samples

3.8.1    Gram staining

3.9       Biochemicals for identification of the microorganisms

3.9.1    Indole test

3.9.2    Urease test (urea agar)

3.9.3    Citrate utilization test (Simmon’s citrate agar)

3.10     Isolation of microorganisms from cheese whey

3.10.1 Subculturing

3.11     Characterization and identification of microorganisms isolated fromcheese whey

3.11.1 Catalase test

3.11.2 Glucose fermentation test

3.11.3 Oxidase test

3.11.4 Germ tube test

3.12     Determination of antimicrobial activity of lactic acid bacteriaisolates on diarrhea causing bacteria isolates

3.13     Antimicrobial sensitivity testing

3.13.1 Preparation of turbidity standard equivalent to the Mcfarland Standard 0.5

3.13.2 Agar disc diffusion technique

CHAPTER FOUR: RESULT                                                                                            

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1       Discussion

5.2       Conclusion

5.3       Recommendation

References

Appendix