ISOLATION OF METHICILLIN-RESISTANT Staphylococcus aureus FROM THE NOSTRILS OF STUDENTS OF MICHAEL OKPARA UNIVERSITY OF AGRICULTURE, UMUDIKE

ABSTRACT

Methicillin-resistant Staphylococcus aureus (MRSA) has evolved as a major health care-acquired pathogen worldwide into one that can be found in the community. This study was carried out to determine the carriage rate of MRSA in the nostrils of students of Michael Okpara University of Agriculture, Umudike. Of the 100 samples analysed, 65(65 of 100) were positive for S. aureus, Some of the S. aureus isolates that showed resistance to many antimicrobial agents were found to be methicillin-resistant. The prevalence of MRSA nasal carriage was 9.2% (6 of 65) detected by oxacillin disk diffusion methods. MRSA was identified in 3.1% (2 of 65) of males and 6.1% (4 of 65) of females. All the MRSA isolates showed multi-drug resistance to at least four antibiotics tested. However, MRSA strains were highly sensitive to Levofloxacin. The highest rates of resistance were observed for Amoxicillin and Ampicillin.

TABLE OF CONTENTS

Title Page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgements ﾿ iv

Table of Contents ﾿ v

List of Tables and Figures ﾿ viii

Abstract ﾿ ix

CHAPTER ONE

Introduction

1.1 ﾿ Introduction ﾿ 1

1.2 ﾿ Aim and Objectives ﾿ 3

CHAPTER TWO

Literature review

2.1 ﾿ Staphylococcus aureus ﾿ 4 ﾿

2.1.1 ﾿ Pathogenesis of S. aureus ﾿ 4

2.1.2 ﾿ Mode of transmission of S. aureus ﾿ 5

2.1.3 ﾿ The role of nasal carriage of S.aureus in Staphylococcus aureus

﾿ Infections ﾿ 6

2.1.4 ﾿ Virulence factors in S. aureus ﾿ 6

2.1.5 ﾿ Mode of reproduction of S. aureus ﾿ 8

2.1.6 ﾿ Antibiotic susceptibility and resistance of S. aureus ﾿ 9

2.2 ﾿ Methicillin-resistant Staphylococcus aureus ﾿ 10

2.2.1 ﾿ Hospital-acquired and Community-Acquired MRSA ﾿ 11

2.2.2 ﾿ Clinical implications of MRSA ﾿ 12

2.2.3 ﾿ Mechanism of methicillin resistance ﾿ 12

2.2.4 ﾿ Mode of transmission ﾿ 13

2.2.5 ﾿ Risk factors for CA-MRSA ﾿ 13

2.2.6 ﾿ Prevention and control of CA-MRSA ﾿ 15

CHAPTER THREE

Materials and methods

3.1 ﾿ Study Location and design ﾿ 16\

3.2 ﾿ Sample collection ﾿ 16

3.3 ﾿ Sterilization of materials ﾿ 16

3.4 ﾿ Preparation of culture media ﾿ 17

3.5 ﾿ Inoculation of the nasal sample ﾿ 17

3.6 ﾿ Identification of Staphylococcus aureus ﾿ 17

3.7 ﾿ Preparation of turbidity standard equivalent to McFarland 0.5 ﾿ 18

3.8 ﾿ Antibiotic Susceptibility test ﾿ 19

3.9 ﾿ Detection of methicillin resistance ﾿ 19

CHAPTER FOUR

Results ﾿ 20

CHAPTER FIVE

Discussion, Conclusion and Recommendation ﾿

5.1 ﾿ Discussion ﾿ 29

5.2 ﾿ Conclusion ﾿ 30

5.3 ﾿ Recommendation ﾿ 31

REFERENCES

APPENDIX

LIST OF TABLES AND FIGURES

Table ﾿ Title ﾿ Page

1 ﾿ Characterization and identification of S. aureus ﾿ 21

2 ﾿ Incidence of S. aureus among the sampled population ﾿ 22

3 ﾿ Sex distribution and antibiotic susceptibility profile of the Staphylococcus aureus isolates ﾿ 23

4 ﾿ Antimicrobial susceptibility profile of Staphylococcus aureus from the nasal passages of students ﾿ 25

5 ﾿ Sex distribution and diameter zone of inhibition of oxacillin ﾿ 26

6 ﾿ Percentage of isolates resistant to oxacillin ﾿ 27

Figure ﾿ Title ﾿ Page

1 ﾿ Susceptibility pattern of identified MRSA ﾿ 28