Which species causes syphilis?
treponema pallidum, subspecies pallidum
What are the characteristics of primary Syphilis?
- single painless ulcer -> highly infectious
- widespread dissemination
- lymphadenopathy
- often undetectable
- ulcers heal spontaneously but individual is still infected
What is the name for the ulcers found in syphilis?
chancres
What are the characteristics of secondary syphilis?
-3-6 months after initial infection
- widespread mucocutaneous rash
-widespread dissemination of treponema throughout the body -> rash, alopecia, lymphadenopathy (swelling or enlargement of lymph nodes)
What are the characteristics of tertiary syphilis?
-20-40 years after initial exposure
-leads to Gumma: nodular like lesions
- cardiovascular syphilis: aortic aneurism
- neurosyphilis = syphilitic gait caused by tabes gorsalis
What is tertiary syphilis so destructive?
occurs months/ years after contact
1) Has granulomatous lesions that secrete treponema’s = highly infectious
2) destroys skin, tissues, bone, brain and heart
3) cardiovascular syphillis
What are the features of congenital syphilis?
-early onset: 2-10 weeks post delivery of foetus
-sniffles, skin lesions, death, bleeding in the lungs, pulmonary haemorrhage, hepatitis
Describe the causative microorganism behind syphilis:
Treponema
-has 3 periplasmic flagella -> exhibits corkscrew motility
-has limited metabolic capacity, can only grow in vivo and cannot be cultured in the lab
- slow doubling time
-sensitive to antibiotics
Describe the virulence factors for treponema
1) Attachment: Uses Tp0155 (binds to fibronectin) and Tp0483 to bind to surfaces
2) Invasion: Hyaluronidase production = molecular mimicry
3) Motility: corkscrew motion
How can syphilis be diagnosed?
direct microscopy/dark ground microscopy (light is scattered by motile treponema’s) and serological assays
What does Venereal Disease research Laboratory detect?
IgM and IgG antibodies against lipoidal antigens released as a consequence of cell damage from host and bacterium
Which antibodies can be found in serological test samples (VDRL)?
-IgM and IgG antibodies
Describe the Treponema Palladium Haemagglutination Assay
- treponema pallidum antigen coated onto RBC
-haemagglutination = positive result
-buttoning of RBC = negative result
shows amount of treponema in patients blood
Describe fluorescent treponema antibody absorption test
-T.Pallidum is fixed onto the slide with acetone and incubated with patient serum
-Incubated with anti human antibody conjugate FITC AND A SECONDARY ANTIBODY
- detects patients antibodies to treponema
How did they used to treat syphilis before?
mercury and arsenic- 19th/20th century
penicillin- 21st century
