BACTERIOLOGICAL EXAMINATION OF SELECTED SLICED FRUITS SOLD IN UMUAHIA METROPOLIS

Abstract

Fresh cut fruits processed by peeling, slicing or trimming with or without further processing or cooking before consumption are often contaminated with Microorganisms. Fresh cut fruits collected from different stationary vendors and hawkers in Umuahia metropolis were analyzed to determine their bacteriological safety. The fruit samples were analyzed using MacConkey agar, blood agar and nutrient agar, by streaking method, the agar plates were inoculated with dilutions of 10-2, 10-5 and the original sample. All samples were contaminated with bacteria. The bacteria count ranged from 3.0×103 cfu/g _4.1×105 cfu/g for cut watermelon, 1.0×105 cfu/g _5.0×102 cfu/g for cut pawpaw and 1.0×104 cfu/g _8.0×103 cfu/g for cut pineapples. The bacteria isolates were identified as Staphylococcus aureus, pseudomonas aeruginosa, Escherichia coli, Proteus species, Klebsiella species and Streptococcus species. The results obtained suggest that fresh cut fruits sold in Umuahia are often contaminated with bacteria.

TABLE OF CONTENTS

Title page ﾿ i ﾿

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

List of Tables ﾿ v

Abstract ﾿ vi

CHAPTER ONE 

1.0 ﾿ Introduction ﾿ 1

1.1 ﾿ Aim and Objectives ﾿ 2

CHAPTER TWO: LITERATURE REVIEW

2.1 ﾿ Processed Fresh Fruits ﾿ 3

2.2 ﾿ Nutritional Value of Fruits ﾿ 4

2.2.1 ﾿ The Uses of Fruits ﾿ 4

2.3 ﾿ Recent Trends in Disease Outbreak Due to Consumption of Contaminated 

      ﾿ Ready-To-Eat Fruits ﾿ 5

2.4 ﾿ Sources of Fruits Contamination ﾿ 6

2.5 ﾿ Factors that Enhance Microbial load in Some Sliced Fruits ﾿ 7

2.5.1 ﾿ Intrinsic Factors ﾿ 7

2.5.2 ﾿ Extrinsic Factors ﾿ 8

2.6 ﾿ Food Borne Diseases ﾿ 9

2.6.1 ﾿ Staphylococcal Food Borne Infections ﾿ 10 ﾿

2.6.2 ﾿ Cholera ﾿ 10

2.6.3 ﾿ Botulism ﾿ 10

2.6.4 ﾿ Listeriosis ﾿ 11

2.6.5 ﾿ Escherichia Coli 0157 and other Related Enterotoxigenic Producing 

Escherichia coli Infections ﾿ 12

2.6.6 ﾿ Bacillus spp Related Infections ﾿ 12

2.6.7 ﾿ Shigellosis ﾿ 13

2.6.8 ﾿ Campylobacter spp Related Food-borne Infections ﾿ 13

2.7 ﾿ Benefits Associated with Some Sliced Fruits ﾿ 14

2.8 ﾿ Safety Regulations for the Growing, Preparation and Storage of fruits. ﾿ 15

CHAPTER THREE: MATERIALS AND METHODS

3.1 ﾿ Study Area and Sample Collection. ﾿ 16

3.2 ﾿ Sample Collection ﾿ 16

3.3 ﾿ Materials Used ﾿ 16

3.3.1 ﾿ Media ﾿ 16

3.3.2 ﾿ Laboratory Equipments ﾿ 16

3.4 ﾿ Media Preparation ﾿ 16

3.5    ﾿ Methods ﾿ 17

3.5.1     Streak Plate Procedure ﾿ 17

3.5.2     Determination of Total Bacteria Counts. ﾿ 17

3.5.3     Purification of Isolates ﾿ 17

3.6 ﾿ Characterization and Identification of Bacterial Isolates ﾿ 18

3.7      ﾿ Gram Stain ﾿ 18

3.8    ﾿ Biochemical Test ﾿ 18

3.8.1    Catalase Test ﾿ 19

3.8.2    Coagulase Test ﾿ 19

3.8.3   Citrate Test ﾿ 19

3.8.4     Motility, Indole, Urease Test (MIU) ﾿ 20

3.8.5    Triple Sugar Iron (TSI) Test ﾿ 20

3.8.6   Oxidase test ﾿ 21

Chapter four

4.0         Result ﾿ 22

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION

5.1       Discussion ﾿ 31

5.2       Conclusion ﾿ 33

5.3 ﾿ Recommendation ﾿ 33

REFERENCE

LIST OF TABLES

   4.1 ﾿      Sources of fruits used in the study      ﾿                        23                            

   4.2 ﾿      Characteristics of the isolates ﾿ 24

   4.3 ﾿      Biochemical characteristics of the isolates ﾿ 25

   4.4 ﾿      Total bacteria isolate from fruits ﾿ 26

   4.5 ﾿       Bacterial load of isolates from watermelon                                      ﾿ 27

  4.6          Bacterial load of isolates from pawpaw                                              ﾿ 27

   4.7         Bacterial load of isolates from pineapple                                          ﾿ 28

    4.8        Distribution of bacterial isolates in fruit samples ﾿ 29

   4.9 ﾿      Viable counts of bacteria in pawpaw ﾿ 30

   4.10 ﾿      Viable counts of bacteria in watermelon ﾿ 30

   4.11 ﾿      Viable counts of bacteria in pineapple ﾿ 30