COMPARATIVE MICROBIAL ASSESSMENT OF RAIN WATER COLLECTED FROM THE ROOFS OF SOME HOUSES

ABSTRACT

Roof-harvested rain water (RHRW) has been considered as an effective alternative source of water for domestic use, as public source of water are not always available and consistent. However, the most significant issue in relation to using untreated (RHRW) for domestic purposes is the potential public health risks associated with microbial pathogens. This study focuses on comparative microbial assessment of roofs harvested rain water. A total of eighteen (18) water samples were collected and analyzed using microbiological standard method. The bacteria species implicated from the study are; Staphylococcus aurues, Escherichia coli, Bacillus spp, Streptococcus spp, Enterococcus spp and Shigella spp. The bacteria load ranges from 4.5x104 cfu/ml to 1.56x105 cfu/ml with thatch roof water sample having the highest bacteria load and stone coated roof having the least bacteria load. There was variation in the occurrence of the different bacteria species in the water samples studied. Staphylococcus aureus and Bacillus had the highest occurrence (33.3% to 100%), while shigella spp had the least occurrence of 0% to 33.3%.The prevalence of the microorganisms was highest in thatched roof water and least in the open air rain water. From the recorded observations in this study, it was concluded that rain waters from different roofs in and around Umudike are of low microbiological quality. Therefore, it was recommended that the roofs harvested rain water should not be drunk without treatment. Simple thermal treatment like boiling is suggested as well as filtration of the water.

TABLE OF CONTENTS

Title Page ﾿   ﾿ i

Certification ﾿ iii

Dedication ﾿ iv

Acknowledgements ﾿ v

Table of Contents ﾿ vi

List of Tables ﾿ vii

List of Figure ﾿ viii

Abstract ﾿ ix

CHAPTER ONE

Introduction ﾿ 1

1.1 ﾿ Aim and Objectives ﾿ 5

CHAPTER TWO

2.0 ﾿ Literature Review ﾿ 6

2.1 ﾿ Fecal Indicators and Pathogens in Roof-Harvested Rainwater ﾿ 6

2.1.1 ﾿ Fecal Indicators ﾿ 6

2.2 ﾿ Bacterial Pathogens ﾿ 9

2.3 ﾿ Protozoan Pathogens ﾿ 11

2.4 ﾿ Correlation between Fecal Indicators and Pathogens in Roof-Harvested 

﾿ Rainwater ﾿ 12

2.5 ﾿ Roof-Harvested Rainwater and Associated Health Risks ﾿ 13

2.6 ﾿ Management of the Risk of Infections Associated with the 

﾿ Use of Roof-Harvested Rainwater ﾿ 18

CHAPTER THREE

3.0 ﾿ Material and Methods ﾿ 20

3.1 ﾿ Study Area

3.2 ﾿ Materials ﾿ 20

3.3 ﾿ Sample Collection ﾿ 20

3.4 ﾿ Media Used ﾿ 20

3.5 ﾿ Sterilization of Materials ﾿ 20

3.6 ﾿ Processing of Samples ﾿ 21

3.7 ﾿ Media Preparation and Isolation of Microorganism ﾿ 21

3.7.1 ﾿ Media Preparation ﾿ 21

3.7.2. ﾿ Sample Inoculation and Enumeration of Bacteria Load ﾿ 21

3.7.3 ﾿ Total Coliform Count ﾿ 22

3.8 ﾿ Microbial Characterization and Identification ﾿ 23

3.8.1 ﾿ Identification of Bacterial Isolates ﾿ 23

3.8.1.1 ﾿ Gram Staining ﾿ 23

3.8.2 ﾿ Biochemical Tests ﾿ 23

3.8.2.1 ﾿ Indole Test ﾿ 23

3.8.2.2 ﾿ Carbohydrate Utilization Analysis ﾿ 23

3.8.2.3 ﾿ Catalase Test ﾿ 24

3.8.2.4 ﾿ Oxidase Test ﾿ 24

3.8.2.5 ﾿ Coagulase Test ﾿ 24

3.8.2.6 ﾿ Citrate Utilization Test ﾿ 24

3.8.2.7 ﾿ Motility Test ﾿ 24

3.9 ﾿ Statistical Analysis ﾿ 25

3.10 ﾿ Determination of Occurrence ﾿ 25

CHAPTER FOUR

4.0 ﾿ Results ﾿ 26

CHAPTER FIVE

5.0 ﾿ Discussion, Conclusion and Recommendation ﾿ 32

5.1 ﾿ Discussion ﾿ 32

5.2 ﾿ Conclusion ﾿ 34

5.3 ﾿ Recommendations ﾿ 34

﾿ References