ABSTARCT

This study was designed to assess the microbiological quality of indoor and outdoor air of Microbiology laboratory of Michael Okpara University of Agriculture, Umudike. A total of six (6) air samples from the laboratory were collected and cultured on Nutrient Agar, MacConkey Agar, Nutrient Agar, Sabouraud Dextrose Agar and Salmonella-Shigella Agar using sedimentation techniques. From this study, a total of thirty (30) microbial species were isolated and identified as Bacillus sublitis, Staphylococcus aurues, Escherichia coli, Klebsilla spp, Streptococcus species, Aspergillus niger, Mucor alternaria and Aspergilus fumigates. This study showed that, Microbiology laboratory Umudike, Umuahia, Outdoor (afternoon) had the highest viable mean bacteria count (11.1x104), followed by Outdoor (morning) 10.5x104, Indoor (evening) 7.7x104, Outdoor (evening) 5.3x104, Indoor (afternoon) 5.2x104, while the least viable mean bacteria count was recorded on Indoor (morning) 3.8x104. The total viable mean fungal plate count showed that Outdoor air sample (afternoon) had the highest viable mean fungi count (13.2 x104), while Indoor (afternoon) air sample had the least viable fungi count (2.3 x104). The contamination rate and percentage distribution accessed on the Indoor laboratory Air samples in Microbiology laboratory revealed that, among the indoor air isolates Escherichia coli and Staphylococcus aureus are the most frequently occurring isolates, with a high percentage occurrence of 3(23.1%) each, while among the outdoor air isolates, Escherichia coli, Staphylococcus aureus and Bacillus spp and are the most frequently occurring isolates with a high percentage occurrence of 3(17.6%) each. However, there were slight variations in the fungi population, with Mucor alternaria 2(15.3%) being most predominant and occurring isolates, while from the outdoor laboratory air sample, Aspergillus fumagatus was the most predominant and occurring isolate at 2(11.8%). Therefore, the present work shows that the outdoor laboratory air is heavily contaminated with bacteria and fungi loads than the indoor air sample.

TABLE OF CONTENTS

Title Page   i

Certification

Dedication iv

Acknowledgements v

Table of Contents vi

List of Tables

Abstract ix

CHAPTER ONE

1.0 Introduction

1.2 Aim and Objectives 3

CHAPTER TWO

2.0 Literature Review 5

2.1 Assessment of Airborne Bacteria and Fungi in an Indoor and Outdoor 

Environment

2.2 Microbiological Indoor and Outdoor Air Quality of Selected Places in India 7

2.3 Microbiological Indoor and Outdoor Air Quality of Two Major 

Hospitals in Benin City, Nigeria 9

2.4 Microorganisms Associated with Airborne Contaminations 10

2.4.1 Bacteria Example 11

2.4.2 Fungi Example 11

2.4.3 Virus Example 11

2.5 Factors that Affect Indoor and Outdoor Air Quality 11

2.5.1 Temperature

2.5.2 Relative Humidity 12

2.5.3 Microbes 13

2.5.4 Chemicals 13

2.5.5 Radiation 13

2.5.6 Oxygen, OAFs, and Ions 14

CHAPTER THREE

3.0 Materials and Methods 16

3.1 Study Area

3.2 Materials 16

3.3 Media Preparation 16

3.4 Sterilization of Materials 16

3.5 Sampling Techniques 16

3.6 Identification of the Isolates 17

3.7 Gram Staining

3.8 Biochemical Tests 18

3.8.1 Catalase Test

3.8.2 Indole Test

3.8.3 Citrate Utilization Test 18

3.8.4 Hydrogen Sulphide (H2S) Production Test 19

3.8.5 Starch Hydrolysis 19

3.8.6 Motility, Indole, Urease (MIU) 19

3.8.7 Coagulase Test 20

3.8.8 Oxidade

3.9 Identification of Fungal Isolates 20

3.9.1 Wet Preparation 20

3.9.2 Colonial Morphology 21

CHAPTER FOUR

4.0 Results 22

CHAPTER FIVE

5.0 Discussion, Conclusion and Recommendations 30

5.1 Discussion 30

5.2 Conclusion

5.3 Recommendations 36

References 

LIST OF TABLES

TABLE TITLE PAGE NO

1 Mean Microbial Counts on the Indoor and Outdoor Air in Microbiology Laboratory 24

2 Identification and characterization of Bacterial Isolates from Indoor and Outdoor Air in Microbiology Laboratory 25

3 Cultural Morphology and Microscopic Characteristics Fungal Isolates from Indoor and Outdoor Air Samples in Microbiology Laboratory 26

4 Distribution of Bacterial and Fungal Isolates from Indoor and Outdoor Air Samples in Microbiology Laboratory 27

5a Percentage Occurrence of the Various Isolates from Indoor Air Samples in Microbiology Laboratory 28

5b Percentage Occurrence of the Various Isolates from Outdoor Air Samples in Microbiology Laboratory 29