PREVALENCE AND ANTIBIOGRAM OF Staphylococcus aureus ISOLATED FROM PIGS AND PIG FARMERS IN MICHAEL OKPARA UNIVERSITY OF AGRICULTURE, UMUDIKE

ABSTRACT

Staphylococcus aureus is an important human pathogen that causes serious infections both in hospitals and communities globally due to its multi-drug resistance tendency. This study was undertaken to determine the prevalence of Staphylococcus aureus  and antibiotic sensitivity pattern among pigs and pig farmers in Michael Okpara University of Agriculture, Umudike (MOUAU). Sixty (60) swab samples were collected from various sites of the pigs of 2 species (Duroc and Large-white) and from the nostrils of the pig farmers. The samples were subjected to standard microbiological techniques to identify Staphylococcus aureus. Resistance to Methicillin was determined by using Cefoxitin (30µg). A total of 48 isolates of Staphylococcus species were recovered representing 80% (48/60) of total isolates and MRSA carriage of 0% (0/48) was obtained showing no prevalence of MRSA. Large white specie of the pigs had a higher prevalence of 70.83% (34/48) compared with the isolates from Duroc pigs which had a lower prevalence of 29.16% (14/48). The antibiotic susceptibility profiles of the isolates to the commonly used drugs showed high resistance to Ceftazidime (95.83%) followed by Erythromycin (47.90%). All isolates were susceptible to Cefuroxime (100%), Ceftriaxone (100%) and Cefoxitin (100%). The prevalence of Staphylococcus aureus was more in the nasal discharge of the pigs (61.54%) than in the pig farmers (38.46%). This should therefore call for urgent intervention because pigs can serve as reservoir through which infections related to Staphylococcus aureus  can spread to other animals, humans and community at large. Therefore, proper hygiene practices, control of indiscriminate use of antibiotics, and frequent screening of this population for  Staphylococcus aureus  related infections, are hereby recommended both for prevention and control of livestock acquired Staphylococcus aureus infections.

TABLE OF CONTENTS

Title page ﾿                 ﾿        i

Certification ﾿                                 ﾿                                ii  

Dedication ﾿                     iii

Acknowledgment ﾿                      iv

Table of contents ﾿                       v

Abstract ﾿                       ix

CHAPTER ONE

1.0 ﾿ INTRODUCTION ﾿ 1

1.1    Aims and objectives of the study ﾿ 3

CHAPTER TWO

2.0 ﾿ LITERATURE REVIEW ﾿ 4

2.1 ﾿ Staphylococcaceae ﾿ 4

v

2.2 ﾿ Staphylococcus aureus ﾿ 5

2.3 ﾿ Morphology and identification of Staphylococcus aureus        ﾿ 5

2.4 ﾿ Biology and pathogenesis of Staphylococcus aureus ﾿ 6

2.5 ﾿ Methicillin Resistant Staphylococcus aureus (MRSA) ﾿ 7

2.6 ﾿ Mechanism of resistance of MRSA ﾿ 9

2.7 ﾿ Historical Background of Methicillin Resistant Staphylococcus aureus (MRSA) ﾿ 10

2.8 ﾿ Epidemiology of MRSA ﾿ 11

2.9 ﾿ MRSA and its association with Pigs ﾿ 12

2.10    ﾿   Antibiotics ﾿ 12

2.10.1 ﾿   Classes of Antibiotics ﾿ 13

2.10.2 ﾿ β-Lactam Antibiotics ﾿ 13

2.11 ﾿ Penicillin ﾿ 14

2.12 ﾿ Methicillin ﾿ 15

2.13 ﾿ Mode of action of β-Lactam Antibiotics ﾿ 16

2.14 ﾿ Mechanism of resistance of β-Lactam antibiotics ﾿ 17

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CHAPTER THREE

3.0 ﾿ MATERIALS AND METHODS ﾿ 18

3.1.1 ﾿ Culture media ﾿ 18

3.1.2     Reagents used ﾿ 18 ﾿

3.1.3    Equipment and materials used ﾿ 18

3.1.4    Antibiotic discs used ﾿ 18

3.2 ﾿ Collection of samples ﾿ 18

3.3 ﾿ Media preparation ﾿ 19

3.4 ﾿ Characterization and identification of the isolates ﾿ 19

3.4.1 ﾿ Growth on Mannitol Salt Agar (MSA) ﾿ 19

3.4.2 ﾿ Growth on blood agar (Sub-culturing of the isolates) ﾿ 20

3.4.3 ﾿ Identification of Staphylococcus aureus ﾿ 20

3.5 ﾿ Gram staining ﾿ 20

3.6 ﾿ Biochemical characterization of isolates ﾿ 21

3.6.1 ﾿ Catalase Test ﾿ 21

3.6.2 ﾿ Coagulase Test ﾿ 21

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3.7 ﾿ Antibiotic Sensitivity Testing ﾿ 22

3.8 ﾿ Detection of MRSA (using disc diffusion method)  ﾿ 22

CHAPTER FOUR

RESULTS ﾿ 23

CHAPTER FIVE

5.0 DISCUSSION AND CONCLUSION ﾿ 32 ﾿

5.1 Discussion ﾿ 32

5.2 Conclusion ﾿ 33

References ﾿ 35