Which bacteria are known to cause highly contagious diseases, such as syphilis?

Spirilla are a group of bacteria characterized by their spiral or corkscrew shape. They are known to include species that are associated with highly contagious diseases, including syphilis, which is caused by the bacterium Treponema pallidum, a type of spirochete within the larger category of spirilla. The spiral shape of these bacteria allows them to move in a manner that can facilitate their spread in the human body, which is significant in the context of sexually transmitted infections like syphilis.

The other types of bacteria listed, such as streptococci, staphylococci, and diplococci, have their own associations with various infections but are not typically the cause of syphilis. Streptococci are often linked to throat infections, staphylococci to skin infections, and diplococci are known for diseases like gonorrhea rather than syphilis. Understanding the characteristics and classifications of these bacteria helps clarify their pathogenic roles in different diseases.