Definition
The genus *Chlamydia* consists of Gram-negative bacteria that are obligate intracellular parasites. These bacteria must live and reproduce inside host cells. *Chlamydia* species cause various diseases, including sexually transmitted infections (STIs), trachoma (an eye infection), and pneumonia. Think of them as tiny invaders that hijack cells to survive and replicate. Understanding *Chlamydia* is crucial for diagnosing, treating, and preventing these infections. The most well-known species is *Chlamydia trachomatis*.