Bacterial motility: Bacterial motility is facilitated by Flagella. Flagella are the dominant means by which bacteria express motility; there are some exceptions, for example gliding. When viewed directly under a microscope, bacterial motility is usually described in terms of run and tumble. This movement describes bacterial movement as facilitated by the movement and rest periods of flagella.
Mycoplasmas: Mycoplasmas do not have cell walls and maintain some rigidity in their cell membrane with sterols.
Pathogenic Bacteria: Bacteria that are capable of causing disease are known as Pathogenic
Relationship between bacteria and disease: Robert Koch developed a set of postulates that are used to establish the cause and effect relationship between bacteria and disease. Koch’s Postulates are used to demonstrate, through a multi-step process, that a specific bacterium causes a specific disease.