1. Syphilis Gavin Hensley

2. What is syphilis?  Treponema pallidum subsp. pallidum – obligate intracellular bacterium  Spirochete (corkscrew- shaped)  Affects wide variety of tissue/organ types  Unusually small genome

3. Biological mechanisms  Endoflagella within the periplasmic space allow corkscrew-like motility  Attach to ECM components via adhesins  Able to penetrate junctions in between endothelial cells  Antigenic variation in TprK

4. Transmission  Sexually transmitted disease  Occurs through contact with chancre (syphilitic sore)  There is risk of congenital syphilis infection in cases of pregnant women positive for the disease.

5. Epidemiology  Estimated 12 million people infected annually  90% of cases occur in the developing world  Epidemiological shift from heterosexual men and women to MSM cases  Racial and ethnic minorities more greatly affected (MSW) In the US

6. Symptoms  Syphilis is characterized by primary, secondary, latent, and tertiary stages  Chancres  Skin rashes, lesions, gummas  Internal organ damage at late stage  Neurosyphilis

7. Diagnosis  Dark-field microscopy (primary syphilis)  Nontreponemal and treponemal blood tests  Treponemal detects antibodies specific for the bacterium while nontreponemal is more generic and broad

8. Prevention  Condoms! Practice safe sex.  Know your partner’s sexual history.

9. Treatment  Intramuscular injection of long-acting Benzathine penicillin G  Bacterium is very sensitive, no resistance has developed

10. Proteolytic activity of pallilysin

11. References  http://en.wikipedia.org/wiki/Syphilis  http://www.cdc.gov/std/syphilis/STDFact-Syphilis- detailed.htm  Houston, Simon, Rebecca Hof, Lisa Honeyman, Julia Hassler, and Caroline E. Cameron. "Activation and Proteolytic Activity of the Treponema Pallidum Metalloprotease, Pallilysin." Ed. Jenifer Coburn. PLoS Pathogens 8.7 (2012): E1002822. Web.  Lafond, R. E., and S. A. Lukehart. "Biological Basis for Syphilis." Clinical Microbiology Reviews 19.1 (2006): 29- 49. Web.