ABSTRACT

This study was conducted to ascertain the occurrence and antibiotics susceptibility pattern of Staphylococcus aureus present in exposed powered milk. The research was carried out in Umuahia North local Government area, Abia State. A total of 160 exposed milk samples were collected such as Miksi, Cowbell and Dano milk were collected from four different market located in Umuahia North local Government Area. The samples were collected under aseptic precautions and were enriched in peptone water (PW) followed by direct plating on selective media (Mannitol Salt Agar). The presumptive Staphylococcus aureus isolates were identified by biochemical tests. Antibiogram pattern of Staphylococcus aureus to antimicrobial agents were evaluated by disk diffusion method. The analysis of the result showed that out of 160 samples of exposed powdered milk resulted in the isolation of 10 isolates (12.5%) of 100 milk samples. The staphylococcus aureus showed the highest sensitivity towards Cephalexin (100%), Co-trimoxazole (100%) Oxacillin (70%), streptomycin (60%) and ampicillin (60%). Results clearly suggested a possibility of potential public health threat of S. aureus resulting from contaminating of exposed powdered milk with pathogenic bacteria is mainly due to unhygienic processing handling and unhygienic environment. 

TABLE OF CONTENT

Certification ii

Dedication iii

Acknowledgement iv

Table of content v

List of tables vi

Abstract vii

CHAPTER ONE

1.1 Introduction 1

1.2 Aim and Objectives of the study 3

CHAPTER TWO: LITERATURE REVIEW

2.1 Biology and Characteristics of S. aureus 4

2.2 The mechanisms of antibiotic resistance 7

2.3 Food contamination by S. aureus 8

2.4 Exposed powdered handling practices 11

2.5 Milk pasteurization as a preservation technique 13

CHAPTER THREE: MATERIALS AND METHODS

3.1 Study Area 17

3.1.1 Sample collection 17

3.1.2 Isolation and Identification of Staphylococcus aureus 17

3.1.3 Morphological characteristics 18

3.1.4 Biochemical examination 18 

3.1.5 Antibiogram pattern of the isolated Staphylococcus aureus to  some antimicrobial

         agents 18

3.2 Biochemical tests 19

3.2.1 Identification of Staphylococcus aureus by catalase test 19

3.2.2 Identification of Staphylococcus aureus by coagulase test 19

3.2.3 Antimicrobial sensitivity test 20

3.2.4 Determination of products with the highest level of contamination 22

CHAPTER FOUR

Results

CHAPTER FIVE

5.1 Discussion          28

5.2 Conclusion          29

REFERENCES

LIST OF TABLES

Table 1: Recovery frequency of S.aureus from sample in various sampling 

             location 24

Table 2.1: identification and characterization of Staphylococcus aureus

                isolate                                                                                                       25

Table 2.2. Morphological and culture characteristics of S.aureus                        26

Table 4: Antimicrobial Susceptibility pattern of S.aureus  isolated (n=10) from 

               the exposed powered milk           27