MICROBIAL EVALUATION OF SLICED Citrullus lanatus (WATER MELON) AND Ananas comosus (PINEAPPLE) SOLD BY HAWKERS IN UMUDIKE, MOUAU

ABSTRACT

Fresh fruits may harbour a wide range of microbial contaminants due to several factors which may be of public health significance. This study was conducted to evaluate the microbial quality of sliced watermelon and pineapple sold in Umudike, MOUAU. Evaluation of the possible bacteria and fungi on the fruit samples was carried out based on standard microbiological methods. A total of seven species of bacteria and five species of fungi were isolated from twenty samples of fresh cut pineapple and water melon fruits analyzed. This work revealed the Total Viable Count (TVC) and Total Fungal Count (TFC) for both Pineapple and Watermelon collected from different locations. 5.2×108 and 1.1×107 (CFU/ml) represented the highest and lowest Total Viable Count (TVC) respectively while 2.4×107 and 0.2×107 represented the highest and lowest Total Fungal Count (TFC) respectively for Pineapple. The Total Viable Count (TVC) and Total Fungal Count (TFC) for Watermelon collected from different locations were 5.2×107 and 1.0×107 (CFU/ml) representing the highest and lowest Total Viable Count (TVC) respectively while 5.5×107 and 0.1×107 represented the highest and lowest Total Fungal Count (TFC) respectively. It was observed that almost all the fruits examined had bacterial counts above the acceptable limit and is therefore microbiologically unacceptable. Pineapple appeared to have the highest bacterial count which may be due to its high carbohydrate content needed for the growth of bacteria. From this, the percentage occurrence of the different bacterial isolates for both Pineapple and Watermelon, S. epidermidis had the highest percentage occurrence (31.9%) followed by Staphylococcus aureus 19.1%, Bacillus sp 17%. Pseudomonas aeruginosa 14.9%, Enterobacter 8.5%, Proteus 6.4% while E. coli had the lowest percentage occurrence (2.1%). The percentage occurrence of fungal isolates revealed that Aspergillus sp had the highest percentage occurrence (40%) followed by Mucor sp 25%, Botrypdiplodia sp 15%, while Fusarium sp and Penincillum sp had the lowest percentage occurrence (10%) respectively. The commonest genera of fungi that were isolated and identified included Aspergillus sp, Mucor, Penicillum sp, Fusarium sp, and Botrypdiplodia sp. There is need for urgent improvement in the hygienic condition of preparation and handling of fresh cut fruits, especially when organisms like S. aureus, E. coli, and Bacillus species occur in high numbers. E. coli count in fruits is widely used and accepted as indicators of feacal contamination.

TABLE OF CONTENT

Title Page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

Table of Contents ﾿ v

List of Table ﾿ viii

Abstract ﾿ ix

CHAPTER ONE

1.0 ﾿ Introduction ﾿ 1

1.1 ﾿ Aim and Objectives of the Study ﾿ 3

1.1.1 ﾿ Aim of the Study ﾿ 3

1.1.2 ﾿ Objectives of the Study ﾿ 3

CHAPTER TWO

2.0 ﾿ Literature Review ﾿ 5

2.1 ﾿ Water Melon (Citrullus Lanatus) ﾿ 5

2.2 ﾿ Pineapple (Ananas Comosus) ﾿ 9

2.2.1 ﾿ Nutritional Value ﾿ 11

2.3 ﾿ Pathogens of Greatest Concern in Fruits ﾿ 13

2.3.1 ﾿ Shigella Species ﾿ 13

2.3.2 ﾿ Escherichia Coli ﾿ 14

2.3.3 ﾿ Campylobacter Species ﾿ 15

2.3.4 ﾿ Yersinia Enterocolitica ﾿ 15

CHAPTER THREE

3.0 ﾿ Materials and Methods ﾿ 17

3.1 ﾿ Sample Collection ﾿ 17

3.2 ﾿ Media Used ﾿ 17

3.3 ﾿ Sterilization ﾿ 17

3.4 ﾿ Enumeration of Bacteria ﾿ 17

3.5 ﾿ Identification and Characterization of Isolates ﾿ 18

3.5.1 ﾿ Gram Staining ﾿ 18

3.5.2 ﾿ Spore Staining Technique ﾿ 18

3.5.3 ﾿ Motility Test ﾿ 19

3.6 ﾿ Biochemical Cultural Characteristics ﾿ 19

3.6.1 ﾿ Catalase Test ﾿ 19

3.6.2 ﾿ Coagulase Test ﾿ 19

3.6.3 ﾿ Citrate Test ﾿ 19

3.6.4 ﾿ Indole Test ﾿ 20

3.6.5 ﾿ Oxidase Test ﾿ 20

3.6.6 ﾿ Urease Test ﾿ 20

3.6.7 ﾿ Methyl Red Test ﾿ 21

3.6.8 ﾿ Voges-Proskaeur Test ﾿ 21

3.7 ﾿ Sugar Fermentation Test ﾿ 22

3.8 ﾿ Identification of Fungi ﾿ 22

CHAPTER FOUR

4.0 ﾿ Results ﾿ 23

CHAPTER FIVE

5.0 ﾿ Discussion, Conclusion Recommendation ﾿ 30

5.1 ﾿ Discussion ﾿ 30

5.2 ﾿ Conclusion ﾿ 33

5.3 ﾿ Recommendations ﾿ 34

REFERENCES

Table ﾿ Title ﾿ Page

4.1 ﾿ Total Viable Count (TVC) and Total Fungal Count (TFC) of Pineapple from different location in CFU/ml ﾿ 24     

4.2 ﾿ Total Viable Count (TVC) and Total Fungal Count (TFC) of Water from different location in CFU/ml ﾿ 25

4.3 ﾿ Percentage occurrence of bacteria isolates from Pineapple and Watermelon ﾿ 26

4.4 ﾿ Percentage occurrence of Fungi isolated from Water melon and Pineapple ﾿ 27

4.5 ﾿ Cultural Characteristics of Fungal Isolates ﾿ 28

4.6 ﾿ Morphological and Biochemical Identification of Isolates ﾿ 29

LIST OF TABLES