colony forming unit nonhuman Article 15 controlled study 13 human 7 Humans 5 chemistry 5 Escherichia coli 4 Staphylococcus aureus 4 antibacterial activity 4 bacterial colonization 4 bacterium culture 4 drug effect 4 microbiology 4 Animals 3 Bacillus subtilis 3 Biofilms 3 Candida albicans 3 animal 3 bacterium isolation 3 biofilm 3 cell viability 3 minimum inhibitory concentration 3 oxidative stress 3 radiation response 3 scanning electron microscopy 3 spectrophotometry 3 zone of inhibition 3 Anti-Bacterial Agents 2 Antimicrobial activity 2