Unit 5: Bacteria and Human Disease
Ever since Louis Pasteur first theorized that microorganisms were the source of infectious diseases, scientists have labored to learn more about the causes of disease and, more generally, the field of microbiology as a whole. As a result, the majority of microbiology research has focused on human disease and immunology (the study of the immune system). The following unit will discuss microorganisms and the diseases that they cause.
We will begin with bacteria, learning that they are mainly classified as cocci, bacilli, or spiral shaped. They are also differentiated via gram staining procedures, which indicate the amount of peptidoglycan present in a cell wall. If a bacterium contains a lot of peptidoglycan in its cell wall, it will take up the primary gram stain (crystal violet) and will appear purple (gram positive). However, if the bacterium contains a small amount of peptidoglycan and an outer membrane, it will not take up the primary stain. It will instead take up the secondary stain (safranin) and will appear red (gram negative). Each of the classes listed below has been selected for its importance to modern microbiology; take the time to learn all of their names!
Completing this unit should take you approximately 22 hours.
5.2: Gram Positive and Negative Cocci
5.3: Gram-Positive Bacilli
5.3.4: Mycobacterium and Corynebacterium
5.3.5: Actinomyces and Nocardia
5.4: Gram-Negative Bacilli
5.4.3: Bordetella and Legionella
5.4.4: Escherichia, Salmonella, Shigella, and Yersinia
5.5: Other Bacteria
5.5.1: Treponema and Leptospira
5.5.2: Vibrio and Campylobacter