ABSTRACT

To access the role of biocide in the environment and the impact of biocide resistance, a panel of biocides was evaluated for antimicrobial activity and biocide resistance patterns.  Equally, plants with traditionally acclaimed biocidal activities were accessed. The samples were subjected to Disc susceptibility testing, minimum inhibitory concentration (MIC) and time-kill determination. Majority of the population use household commercial biocides including benzalkonium chloride, sodium hypochlorite, sodium carbonate, chlorophenol, choroxylenol and ammonium as well as isoprppyl alcohol and other respective combinations.  Preliminary data on zone of inhibition at 1mg/L(v/v) against standard   E. coli and S. aureus strains for benzalkonium (Harpic®), sodium hypochlorite( Jik®), chloroxylenol (Dettol®) and chlorophenol (Ivy fectant®) were all resistant at < 19mm S. aureus except dettol and Izal, including Izal towards E. coli >17mm respectively. Xylopia was the only botanical that showed biocidial activity against E.coli >18mm. Xylopia, Azadiracha and Vernonia only showed moderate antistaphylococcal activity at high MIC value (1,024mg/L). Comparatively, Izal B had the highest  to moderate inhibition effect against E. coli  in the following manner Izal> Harpic > Dettol > Jik at 0 hr, while Ivy detergent didnt show biocidal activity at 0 hr contact both at MIC or double MIC value. The double MIC biocide-bacterial time-kill effects were very pronounced and consistent among all the biocides suggesting that higher effect of biocides could only be enjoyed at higher concentrations and longer time contact with the oragnism. This suggests that when applying household biocide, high concentration and more time factor is needed in other to act on the applied area and to achieve inhibition of bacterial growth. The fact that biocides are used extensively in many different products and concentration contribute largely to its efficacy, while at lower dosage usage and less time contact, it remain inactive allowing the organisms to overcome the effect and thereby  contribute to bacterial resistance.

TABLE OF CONTENTS                 

Title Page           i

Certification           ii

Dedication           iii

Acknowledgement           iv

Table of Contents           v 

List of Tables           vi

List of Figures           vii

Abstract           viii

CHAPTER ONE                                                                                                                 1                                                                                            

1.0   INTRODUCTION            1

1.1 Examples showing links between Antibiotic and Biocide Resistance 2

1.2What is Biocide?                                                                                                               6

1.3 What is Resistance?                                                                                                         6

1.4 What is biocide resistance?                                                                                              6

1.5 Mechanisms of biocide resistance                                                                                    7

1.6 Mechanisms of intrinsic bacterial resistance to biocide                                                   8

1.7 Mechanism of acquired bacterial resistance to biocides                                                  10

1.8 Common resistance mechanism of both biocide and Antibiotic                                     11

1.1.1 Research Justification                                                                                                    13

1.1.2   Aim and Objectives of the study                                                                                 14

CHAPTER TWO                         15

2.0 Literature Review                                                                                                             15

2.1 chemicals used as ingredient in biocide                                                                         16                    

2.2 Jik                                                                                                                                      17

2.3 Dettol                                                                                                                                18

2.4 Nittol                                                                                                                                 18

2.5 Harpic Active fresh                                                                                                           19

2.2.1 Ivy’s Antiseptic                                                                                                              20

2.2.2 Dettol hand sanitizer and Mum and me hand gel                                                          21

2.2.3 Izal (Z Germicie)                                                                                                            21

2.2.4 Botany of plants investidated for biocidal activity                                                        22

2.2.5 Ricinus communis                                                                                                          22

2.2.6 Jatrophy curcas L.                                                                                                          23

2.2.7Azadirachta indica (Neem)                                                                                             24

2.2.8 Vernonia amydalina                                                                                                       26

2.2.9 Piper guineense                                                                                                              27

2.3 Xylopia aethiopica                                                                                                           28

2.4 Cassia alata                                                                                                                       28

2.5Thinlayer chromatography 29                                                                                              

CHAPTER THREE        31

3.0   MATERIALS AND METHODS                    31

3.1 Study Area      31 

3.2 Biocide/ Plant collection and identification 31

3.3 Preparation of extracts 31

3.4 Preparation of Biocides 32

3.5 Diameter zone of inhibition determination of the biocides 33

3.6 Preparation of test organism 33                                                                                     

3.7 Minimum inhibitory concentration (MIC) determination 33

3.8 Determination of Time – kill curve method 34

3.9 Thin layer chromatography 35

CHAPTER FOUR 36

4.0   RESULT 36

4.1 Antimicrobial activity of the household biocide                                                              36

4.2 Result of MIC determination of biocides and plant extracts 40

4.3 Effect of time- kill determination of the biocides                                                             42

4.4 Thin layer chromatography (TLC) 44

CHAPTER FIVE 47

5.0 DICUSSION AND CONCLUSION                                                                              47

5.1 Discussions 47

5.2 Conclusion 49

5.3 Recommendation 51

 References

 Appendix: Abstract and certificate of scientific presentation