Course # DL-982: Chlamydiae And Their Role In Human Disease
by Lucy Treagan, Ph.D. - Prof. Biol. Emerita - University of San Francisco
Approved for 2.0 CE
Level of Difficulty: Intermediate
Long considered a unique group of intracellular bacteria containing a few pathogenic species, the chlamydiae have recently been shown through molecular studies to represent a highly diverse group of ubiquitous organisms. In addition to well known human pathogens there is an abundance of environmental chlamydiae symbiotic in free-living amoebae and in other hosts. These symbionts are obligate intracellular parasites. Phenotypic comparison of newly described chlamydial groups suggests that all have descended from a common ancestor that replicated intracellularly within eukaryotic host cells. The minor phenotypic differences observed among chlamydial groups depend on small genomic differences.
The divergence of environmental and pathogenic chlamydiae is thought to have taken place about 700 million years ago. The common ancestor of diverse chlamydial groups was already adapted to intracellular survival in early eukaryotic cells and contained many virulence factors found in modern pathogenic chlamydiae. Recent molecular studies of environmental chlamydiae have identified three families: Simkaniaceae, Parachlamydiaceae, and Waddliaceae.
After completing this course the participant will be able to:
1. Discuss the principal characteristics of chlamydiae, including their intracellular life cycle and their classification.
2. Contrast the classic chlamydiae species with the newly described Para- chlamydiaceae.
3. Outline the pathogenesis of chlamydial infections.
4. Discuss human diseases caused by chlamydiae, including emerging chlamydial infections.
5. Describe the possible role of chlamydia in chronic diseases.
6. Summarize current diagnostic methods and treatment options.