Most organisms which colonize are harmless commensals and are best left alone. They may, in fact, prevent invasion by pathogens. This happens by competition for nutrition and by producing inhibitory metabolic products. Some commensals can nevertheless invade if they have an opportunity. It is important to remember that most pathogenic organisms set up colonization first and switch to an invasiv...

ated, he proposed that the life cycle of D. folliculorum mites was about 14.5 days. He also demonstrated that all life stages of these mites were negatively phototaxic, that is they were more mobile in a dark environment and relatively inert when bright light was shone on them. However, until optimal in vitro culture techniques and conditions allow Demodex proliferation in the laboratory, the t...

ated, he proposed that the life cycle of D. folliculorum mites was about 14.5 days. He also demonstrated that all life stages of these mites were negatively phototaxic, that is they were more mobile in a dark environment and relatively inert when bright light was shone on them. However, until optimal in vitro culture techniques and conditions allow Demodex proliferation in the laboratory, the t...