OCCURRENCE OF SALMONELLA SPECIES IN FRESH EGGS PURCHASED FROM UMUAHIA METROPOLIS.

ABSTRACT      

The egg content and shell of each sample were purchased from Ndume, Ndoru, Umudike and Ahiaeke and were analysed for possible occurrence of Salmonella bacteria. The overnight grown cultures on buffered peptone water was then inoculated into freshly prepared MCA and SSA plates for isolation of Salmonella species. The shell of each sample was swabbed with a swab stick and inoculated onto the same media. Out of the 70 samples analysed, 18 isolates were recovered from the egg content representing 25.7% while 25(35.7%) was recovered from the egg shells. SSA proved a better media for the isolation of Salmonella as it yielded 61.1% and 40% of the isolates from the egg content and shell respectively while MacConky agar accounted for 38.9% and 60.0% respectively for egg content and shell. The result of this study indicates that chicken eggs harbour some amount of Salmonella bacteria and stringent measures like proper cooking of eggs should be carried out before consumption.

TABLE OF CONTENT ﾿   

Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

Table of contents ﾿ v

List of tables ﾿ vii

Abstract ﾿ viii

CHAPTER ONE.

1.0 ﾿ Introduction ﾿              1

1.1 Aims and objectives ﾿                         1

CHAPTER TWO

2.0 Literature review      ﾿     ﾿              4

2.0.1 Egg structure and defence mechanism ﾿   5

2.0.2 Defence mechanism in eggs ﾿              6

2.0.3 Egg production ﾿              7

2.1 Public health outcomes ﾿              8

2.2 Chicken as reservoir of salmonella ﾿              9

2.3 Mechanism of egg contamination ﾿              11

2.3.1 Primary contamination ﾿              12

2.3.2 Secondary contamination ﾿              13

2.4 The pathogen: Salmonella ﾿              13

2.5 Salmonellosis ﾿              15

CHAPTER THREE

3.0 Materials and methods ﾿   17

3.1 Materials        ﾿              17

3.2 Methods ﾿              17

3.2.1 Sample collection ﾿   17

3.2.2 Media preparation ﾿   17 

3.3 Sample inoculation/isolation ﾿              18

3.4 Sub-culture and purification ﾿              18

3.5 Characterization and identification ﾿              19

3.6 Gram stain ﾿              19

3.7 Biochemical tests ﾿              19

3.7.1 Catalase test ﾿              19

3.7.2 Urease test ﾿              20

3.7.3 Citrate test ﾿              20

3.7.4 Indole test ﾿              20

3.7.5 Methylred test ﾿              21

3.7.6 Voges-proskauer test ﾿              21

3.7.7 Hydrogen sulphide test ﾿              21

CHAPTER FOUR

Results ﾿              28

CHAPTER FIVE

5.0 DISCUSSION AND CONCLUSION ﾿              29

5.1 Discussion ﾿ 29

5.2 Conclusion    ﾿             ﾿              31 ﾿

REFERENCES