The medical world can be a confusing place. Patients and their families might feel overwhelmed by the large vocabularies and complicated explanations they get from their health care providers. Students entering health care also struggle to grasp the complexity of health sciences, and are forced to memorize huge amounts of information. We hope to make understanding the medical world a bit easier. Look around! These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read or seen in any video.
Everyday we come into contact with thousands of bacterial cells. We are colonized with lots of different types of bacteria which live on us, and inside of us; everywhere from the grooves of your fingerprint, to the nooks and crannies of your intestines. If you count up all of the bacteria, they actually outnumber us (by "us" we mean our human cells) about 10 to 1. To stay healthy, we need to maintain a healthy ecosystem of bacteria, called normal flora (not all bacteria is bad!), while selectively getting rid of the harmful, “pathogenic” bacteria which can cause an infection.
When bacterial cells replicate, there is a small chance the new bacterial cell will not be exactly the same as the original bacterial cell. We call these errors in the copied cell a mutation. In one bacterial cell, the cell wall could be slightly different, in another an enzyme works poorly, and so on. Mutations are key to the idea of evolution, and all of the diversity you can see in nature came from a series of many mutations over hundreds of thousands of years. In animals, it can take centuries or millennia for a species to adopt a mutation which helps it survive (and sometimes these mutations create entirely new species). It takes this long in animals because it takes years for most animals to grow up and reproduce.