No its False.
Taste and smell are not strong signs of food safety. Some bacteria that produce food borne illness do not have off-flavors connected with them. It can occur in other foods stored inappropriately. Furthermore, the toxin designed by Staphylococcus is useless and can cause typically short-term but obnoxious symptoms. If you can only see a living thing with a microscope, that means it is a microorganism. These are spotted everywhere. Some of them, like yeast, is helpful. And some of them are dangerous and disease causing, like bacteria.