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Table of Contents
Page Number
4.1.2. The CEN recommendations for reporting disinfectant 118
efficacy
4.1.3. The ASTM standards for evaluating disinfectant
119
efficacy
4.1.4. The influence of biofilm models on the efficacy of 120
disinfectant agents
4.1.5. Disinfectants used 121
4.1.6. Neutralizing agents 126
4.1.7. Use of test controls 127
4.1.8. Duration of contact time 128
4.1.9. Survival of Salmonella cells after contact with
128
disinfectant agents
4.2. Method 130
4.2.1. Broth Minimum Inhibitory Concentration Method 130
4.2.2. Disinfectant testing method using the CBR 131
4.3. Results 135
4.3.1. Suspension test to establishing Minimum Inhibitory 135
Concentration (MIC)
4.3.2. Assessing the efficacy of three disinfectants against an 135
established 48 hour biofilm
4.3.3. Assessing the efficacy of disinfectants against an
138
established 168 hour biofilm
4.4. Discussion 141
4.4.1. The log 10 reduction achieved by sodium hydroxide 141
4.4.2. The log 10 reduction achieved by sodium hypochlorite 143
4.4.3. The log 10 reduction achieved by benzalkonium chloride 146
4.4.4. The change in tolerance over an extended period of 147
time
4.4.5. Variability in methods 148
4.5. Summary 150
Chapter 5 – Examining S. enterica biofilm formation using the
microtitre plate based method
5 Abstract 153
5.1. Introduction 154
5.1.1. Colony morphology of biofilm forming strains 154
5.1.2 Previous research using colony morphology 156
5.1.3. Biofilm formation assessed using the microtitre plate 158
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