ABSTRACT

The bacteriological quality and antibiogram of isolates of public health importance from twenty (20) samples of Hamburgers was investigated. The bacteriological quality of the burger samples were performed using standard microbiological method. The mean bacterial load of the samples from the different locations revealed that the counts were within the range of 4.1x105cfu/g to 6.4x105cfu/g. It was observed that the hamburger samples had the following prevalence; Escherichia coli (35%), Salmonella (13%) and Staphylococcus aureus (65%). For the E. coli isolates, 100% were resistant to ceftazidime, 100% to Augmentin and 71.4% to ceftriaxone. All the E. coli isolates were sensitive to Ciprofloxacin and Gentamicin. The results showed that the resistance of S. aureus isolates to Gentamicin, Augmentin, Ceftriaxone and Nitrofurantoin were 23.1%, 84.6%, 46.1% and 38.5% respectively. Percentage susceptibility levels of the S. aureus isolates to ofloxacin and nitrofurantoin were 76.9% and 61.5%, respectively. Multidrug resistant strains of S. aureus as well as the other isolates obtained in this study poses a risk factor for the public health. The results indicate that hamburgers could be a reservoir of E. coli. Since this strain is a food-borne pathogen, inspection of meat products for this bacterium is recommended.

TABLE OF CONTENTS

Title Page

Certification

Dedication

Acknowledgements

Table of Contents

List of Tables

List of Figures

Abstract

Chapter One: Introduction

1.0 Introduction            1

1.1 Aim and Objectives            4

Chapter Two

2.0 Literature Review            5       

2.1 Overview of Hamburgers            5

2.2 History of Hamburger                        5

2.3 Nutritional Attributes of Hamburgers                                7

2.3.1 Preparation and Storage of Burger                                  7

2.4 Microorganisms found in Meat                                  8

2.4.1 Listeria monocytogenes            8

2.4.2 Salmonella                      10

2.4.3 Escherichia coli                  11

2.4.4 Staphylococcus aureus          12

2.5 Contamination during Handling and Processing                            13

2.5.1 Meat as Source of Contamination of Burgers                                      15

2.6 Consequences of Food-Borne Diseases from Microorganisms        19

2.7 Studies on Isolation of Microorganisms from Burgers        21

2.8 Antimicrobial Resistance        23

2.8.1 Transmission between Human and Animal due to Indirect Pathways        24

2.8.2 Direct Pathways                                24

2.8.3 Food-borne Transmission                      25

2.9 Ensuring Food Safety of a Hamburger          26

Chapter Three

3.0 Materials and Methods                      27

3.1 Sample Collection          27

3.2 Sterilization of Equipments          27

3.2.1 Culture Media Preparation          27

3.3 Isolation, Enumeration and Identification              27

3.4 Gram staining          28

3.5 Biochemical Tests          29

3.5.1 Catalase Test          29

3.5.2 Indole Production Test             29

3.5.3 Citrate Utilization Test                    29

3.5.4 Hydrogen Sulfide Production Test             30

3.5.5 Methyl Red Test          30

3.5.6 Voges-Proskauer test          30

3.5.7 Urease Test          30

3.6 Antibiotics Susceptibility testing          30

Chapter Four

4.0 Results          32

Chapter Five

5.0 Discussion and Conclusion          41

5.1 Discussion          41

5.2 Conclusion          44

References          45