Isolation And Identification Of Biofilms Forming Bacteria In Mouau Fish Pond

  ABSTRACT

A  biofilm is a complex aggregation of microorganism growing on a solid substrate. It act as defensive role for microorganism during various stress conditions. The proposed work was carried out to study the biofilm forming ability of microorganisms specifically  Escherichia coli, Staphylococcus aures, Streptococcous spp, Bacillus,  Pseudomonas,  Enterobacter,  Salmonella  and Listeria from fish pond in MOUAU. The bacteria were isolated using selective media morphological and biochemical characterization of isolates were carried out. All eight (8) isolates were found to be Gram positive and Gram negative pathogens bacteria. Biofilm forming ability was studied by Congo red agar method (CRA) Staphylococcus aureus, Bacillus and Pseudomonas occurrence at 100% (6) each are strong biofilm producer based on black colonies appearance on (CRA) While Streptococcus, Escherichia coli and Listeria spp are moderate biofilm producers occurrence at 66.7% (4) each and non-biofilm producers are Enterobacter and Salmonella spp. Occurrence at 50%(3) each. This present study will help to understand the biofilm formation of fish pond.

TABLE OF CONTENTS

Title page ﾿ i

Dedication ﾿ ii

Acknowledgement ﾿ iii

Certification ﾿ iv

Declaration

Table of contents ﾿ v

List of tables ﾿ vii

Abstract ﾿ x

CHAPTER ONE

1.0 Introduction  ﾿ 1-2

1.1 Background of study ﾿ 2

1.2 Aim and objective of the study ﾿ 3

CHAPTER TWO

2.0 Literature review ﾿ 4 ﾿

2.1 General concept of biofilms ﾿ 4

2.2Mechanism for the formation of biofilms  ﾿ 4 ﾿

2.3 Different places where biofilms can be formed        ﾿ 5                   

2.4 Biofilms and infectious diseases ﾿ 6 ﾿

2.5 Biofilms in the food industry ﾿ 7 ﾿ 2.6 Bacteria associated with farmed fish ﾿ 8 ﾿

2.6.1 Vibrio Paraheamotyticus and other vibrios: ﾿ 9-10

2.6.2 Escherichia coli ﾿ 10-11

2.6.3 Salmonella Spp: ﾿ 11

2.6.4 Staphylococcus Aureus: ﾿ 11 ﾿

2.6.5 Listeria Monocytogenes: ﾿ 12 ﾿

2.6.6 Clostridium botulinum: ﾿ 13 ﾿

2.6.7 Pseudomonas Aeruginosa: ﾿ ﾿ 13 ﾿

26.8 Aeromonas Species: ﾿ 14 ﾿  

2.6.9 Citrobacter Freundii: ﾿ 14-15

2.7 Factors contributing to fish contamination ﾿ 16-17

CHAPTER THREE ﾿

3.0 Materials and methods ﾿ 18 ﾿ 3.1 Collection and preparation of the fish pond water sample ﾿ 18 ﾿

3.2 Preparation of media ﾿ 18 ﾿

3.3 Isolation of biofilm producing bacteria ﾿ 18 ﾿

3.4 Characterization and identification of isolates ﾿ 19

3.4.1 Gram Staining ﾿ 19 ﾿

3. Biochemical Tests ﾿ ﾿ 20 ﾿

3.5.1 Catalase Test ﾿ 20

3.5.2 Urease Test  ﾿ 20

3.5.3 Indole Test

3.5.4 Methyl Red-Voges Proskauer Test      ﾿ 20-21                                                                                             

3.5.5 Citrate Utilization Test ﾿ 21 ﾿ ﾿

3.5.6 Sugar Fermentation Tests ﾿ 21 ﾿

CHAPTER FOUR ﾿

4.0 Results ﾿ 22-24 ﾿

CHAPTER FIVE

5.1 Discussion ﾿ 25 ﾿

5.2 Conclusions ﾿ 26 ﾿

Reference ﾿ 28-29