Isolation Of Coliforms And Differences Among Coliform Bacteria

ABSTRACT

This study investigated the differences in growth and susceptibility pattern of coliform bacteria isolated from fish pond, stream and borehole waters. This was done by determining the presence of coliform bacteria as Escherichia coli, Klebsiella spp and Enterobacter spp, Citrobacter and their antibiotic susceptibility profile using commercially prepared antibiotic discs. Results showed that Escherichia coli 17% was more predominant borehole waters than the stream and fish pond waters. The growth of colifroms at different temperatures depict that E. coli and Citrobacter grew very well at temperature range between 30oC to 45oC whereas Enterobacter sp and Klebsiella sp grew fairly well at thermophilic temperature of 45oC. The susceptibility profile of the isolates to ten antimicrobial agents indicated that majority of the isolates showed little susceptibility and was highly resistant to the following antimicrobial agents (nitrofurantoin, amoxycillin, ampicillin, ciprofloxacin, tetracycline, norbactin/norfloxacin, ofloxacin, cefuroxime and gentamicin). This showed that they exhibit multi-drug resistance pattern which is a common feature of medically important coliform bacteria. None of the water sources met the WHO microbiological standards for drinking water and thus pose a serious health risk to its consumers and users if not properly treated. This study suggests that more check should be put in place in order to maintain the WHO standards for borehole water drilling which recommends that boreholes should be located at least 30m away from latrines and 17m from septic tanks as most of the faecal contamination of pipe waters is caused by the seepage of faecal materials into leaking pipes.

TABLE OF CONTENTS

Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgement ﾿ iv

Table of contents ﾿ v

List of tables ﾿ vii

Abstract ﾿ viii

CHAPTER ONE: INTRODUCTION ﾿ ﾿ 1

1.2 ﾿ Water quality changes ﾿ 1 ﾿

1.3 ﾿ Water quality challenges ﾿ 4

1.4 ﾿ Biological indicators of water quality ﾿ 6

1.5 ﾿ Aims and objectives ﾿ 7

CHAPTER TWO: LITERATURE REVIEW ﾿ 8

2.1 ﾿ Coliform ﾿ 8

2.2 ﾿ Coliform bacteria ﾿ 8

2.3 ﾿ Environmental significance ﾿ 16

CHAPTER THREE: MATERIALS AND METHODS ﾿ 19

3.1 ﾿ Collection of water samples ﾿ 19

3.2 ﾿ Growth media used ﾿ 19

3.3 ﾿ Sterilization ﾿ 19

3.4 ﾿ Enumeration of bacteria ﾿ 20

3.5 ﾿ Identification of bacterial isolates ﾿ 20 ﾿

3.6 ﾿ Gram staining ﾿ 20

3.7 ﾿ Biochemical cultural characteristics ﾿ 21

3.7.0 ﾿ Coagulase test ﾿ 21

3.7.1 ﾿ Citrate test ﾿ 21

3.7.2 ﾿ Motility, indole, urease test (MIU) ﾿ 20

3.7.3 ﾿ Triple sugar iron test ﾿ 22

3.7.4 ﾿ Oxidase test ﾿ 22

 3.8 ﾿ Antibiotic susceptibility studies ﾿ 22

CHAPTER FOUR: RESULTS ﾿ 24

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATION ﾿

5.1 ﾿       Discussion ﾿ 31

5.2 ﾿ Conclusion ﾿ 33

5.3 ﾿ Recommendation ﾿ 33

References    ﾿ 35