Length of most of the bacteria of medical impoance are about?

The limit of resolution with the unaided eye is about 200 microns bacteria being much smaller can be visualized only under magnification. Bacteria of medical impoance generally measures 0.2-1.5 um in diameter and about 3-5 um in length Ref: Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 10