Index >>Prokaryotes Microbes >> Chlamydiae

Chlamydiae -The chlamydiae (sing.chlamydia) are a group of microorganisms presently classified in Part 18 of BM as a type of rickenttsiae. This is a subgroup of rickettsiae and are among the smallest recognised bacteria that cause diseases in humans and animals. They measure about 0.25 µm in diameter. These were originally through as viruses. However, later it was found that they possess both  DNA and RNA as well as a number of enzymes. They can be treated with some antibiotics. They grow only in living tissues such as fertilised chicken eggs and tissue cultures. They have a complex reproductive cycle that occurs in the cytoplasm of an infected cell

The resulting RB, continue to grow in size and 10-15 hr. after infection binary fission begins. At 20-30 hr. after infection some of the RBs develop a central condensa­tion of cytoplasmic contents decrease in size and become typical EBs. Most of the RBs, however, continue to multiply until the host cell cytoplasm is almost filled by the colony. Little is known about the mechanism of release of organisms. In cell culture, the host cells die and autolyse 40-60 hr. after infection. The process is completed within about 24 hour and the particles may be seen in cells cytoplasm as granule like inclusions. Which are characteristic of chlamydial diseases. They are obligate intracellular parasites. like other rickettsiae.