Question

What bacteria is largest and smallest and what is the harmful disease caused by bacteria and name of the bacteria

Answer 1

The biggest bacterium is Thiomargarita namibiensis, which means "Sulfur Pearl of Namibia", 100 times bigger than the regular bacteria, and is visible to the naked eye. 

The smallest bacterium is Bdellovibrio, which is parasitic to other bacteria. Bdellovibrio appears as a comma-shaped motile rod that is about 0.3-0.5 by 0.5-1.4 µm in size with a barely discernible flagellum.
Staphylococcus aureus may cause minor skin infections such as pimples and boils, but these may become deep-seated, causing abscesses etc.
 
Staphylococcus aureus may cause minor skin infections such as pimples and boils, but these may become deep-seated, causing abscesses etc. 

If it enters the blood it can cause a number of problems in the body: bacteremia and sepsis, toxic shock syndrome (TSS), pneumonia, meningitis, osteomyelitis, endocarditis. 

Answer 2

Answer:

The smallest bacteria is Mycoplasma genitalium, which has a diameter of 200–300 nm. While the largest/longest bacterium is Thiomargarita namibiensis having a diameter of 100–300 micrometers(0.1–0.3millimetres).

Pathogenic bacteria contribute to other globally important diseases, such as pneumonia, which can be caused by bacteria such as Streptococcus and Pseudomonas, and foodborne illnesses, which can be caused by bacteria such as Shigella, Campylobacter, and Salmonella.