This document discusses Treponema pallidum, the spirochete bacteria that causes syphilis. It describes the morphology and pathogenic species of Treponema, focusing on T. pallidum. The stages of syphilis and correlation with test results are outlined. Antibodies produced during syphilis infection and their development are explained. Treatment of syphilis and its effects on test results are also summarized. Related diseases caused by other Treponema species like yaws are briefly mentioned.

1. Sexually Transmitted
Infection
BOND KING (SUNIL)
NITISH
RAHUL CHAUDHARY

2. Morphology of Treponema pallidium
 Member of the order Spirachaetales family Treponemateceae genus -
Treponema
 Darkfield illumination
 Three genera :- Borelia, Treponema, Leptospira
 Genus treponema has four principal pathogenic species

3. PATHOGENIC SPECIES
1)T. Pallidum – responsible for human syphilis.
2)T. Pertenue – Etiologic agent for Yaws and Pinta.
3)T. Carateum - same as pertenue
4)T. Cuniculi – responsible for rabbit syphilis.

4. 1) T. Pallidum
 Close- colied, thin regular spiral organism
 6-15 u, 8-24 coils width is seldom more than 0.25 u
 Periplast or capsular structure
 Multiplies by transverse fission, active phase occurs
about every 30 hrs.

5.  In aqueous media, young treponemas spins vigorously in more viscous
media, they propel themselves in a tissue they show flexibility.
 Cork screw motility is due to the internal periplasmic flagella.
 Extremely susceptible to a variety of physical and chemical agents which
rapidly destroy them.
 Viable or motile up to 15 days when kept at 35 degree celcius under
anaerobic condition containing serum albumin CHON,CO2.

6.  Cannot be recovered in blood , serum or plasma stored at 4 degree celcius
more than 48 hrs.
 May remain alive for 5 days in tissue specimens from diseased animals.
 Suspension of treponemes frozen at (-70 degree celcius) or lower frozenin
glycerol is viable for years.
 Both humoral and cell-mediated immune responses are involved.

7.  Antitreponemal anticardiolipin antibodies are
product
 Inflammatory response is initated (lymphocytes,
macrophages, plasma cells)
 Immune complexes are formed, the organism is
walled off in lesions ,the disease has atendency or
remission stage.

8. WassermannAntigen(compliment fixn. Test, non-
treponemal
 The original forth of wassermann test an extract of liver containing many
treponemes from human fetuses with congenital syphilis was used as antigen.
 The ligand was isolated from carrdiac muscle and identified as a phospholipid,
diphosphatidglycerol called cardiolipin which is normal constituents of host
tissue.
 Free cardiolipin is a hapten and must be bound to a suitable carrier to be
antigenic.
 The microbial cell a foreign carrier and the bound cardiolipin is the
immunologic determinant.

9. Treponemal Antigens
 In treponemes, two classes of Ag have been recognized
1. Those restricted to one or more species
2. Those shared by many different spirochetes.
Reiter treponeme
 Reiter treponeme a spirochete reputed to be cultivable
non virulent variant of T. Pallidum can be used as Ag.

10. Stages of syphilis (correlation with test results)
 Syphilis in human is ordianarily transmitted by sexual contact.
 Infected males, T. Pallidum are present in lesions on the penis or discharged
from deeper genitourinary sites along with the seminal fluid.
 Infected females, the lesions are commonly located in the perianal region or
the labia, vaginal wall or cervix.
 In some cases the primary infection is extragenital usually in or about the
mouth.

11. 1. Primary stage (early)
 T. Pallidum enter the skin through small breaks capable of passing through
intact mucous membranes which is carried by the blood stream to every
organ of the body.
 Chancre develops at the site of entrance within 10- 60 days.
 Chancre usually begins as a papule, breakdown to form a superficial ulcer.
 Chancre in males occurs at the sulcus of penis or inside the urethra.

12.  In females the chancre occurs at the labia majora or
minora, fourchette, clitoris, cervix, uterus or urethral
orifice.
 Persists for 1- 5 week, positive result is between the
1st and 3rd week after the appearance of chancre.

13. 2. Secondary stage
 Usually occurs from 6-8 weeks after the appearance of the primary chancre.
 About 1/3 of the cases it occurs before the chancre disappears.
 Symptoms are generalized rash( involving the mucus membrane)
 Lesions may develop in the eyes ,joints or CNS
 Lesions subsides spontaneously after 2-6 weeks.
 Serologic test are invariably positive.
 In some cases the primary and secondary stages go unnoticed.

14. 3.The late latent stage
 Occurs after the 2nd year of infection.
 Disease is contagious(communicable disease) at this stage.
 There are no clinical signs and symptoms positive serologic test.
 May lost for many years or even for the rest of patient’s life.
 For more than 4 years it is rarely communicable except between mother
and fetus.

15. 4. Tertiary stage
 Lesions are usually seen from 3-10 years after the primary stage.
 The lesions (gummata) usually located on the skin, mucous membranes,
subcutaneous and sub mucous tissues, joints, muscles and ligaments
 Serious manifestations when lesions are present in the nervous system
(causing general paralysis) cardiovascular system(aortic aneurysm) eyes
(permanent blindness)
 In about ¼ of untreated cases this stage is asymptomatic.

16. Antibodies in syphilis
Development
 Individuals infected with T. Pallidum produce specific and non specific
antibodies.
 Specific Abs. are directed against the pathogen T. Palladum / Treponemal
Abs.
 Non-treponemal Abs./Non-specific Abs. are directed against
CHON(protein) Ag. Group common to pathogenic spirochetes.

17.  Specific antibodies in early or untreated early latent syphilis are
predominantly IgM and 23% in untreated late latent stage.
 IgG levels are devoted in the secondary stage.
 Non-specific IgA antibodies increase significantly during the course of
untreated syphilis.

18. Production of Immunity
 Resistance to reinfection increases 3 months after infection.
 Termination of the disease by treatment renders the individual susceptible to
reinfection.
 Protective immunity against syphilis can be induced by vaccines containing
nonviable T. Palladum but the need for high volume dosage and the
difficulties in the production of sufficient quantities of T.Palladum hampers
the use of vaccines
 It is possible that there is no complete immunity to T. Palladum.

19. Treatment of syphilis(correlation with test
result)
 If infected patients are treated before the appearance of the primary chancre, it
is probable that the serologic test will remain non-reactive.
 If the treatment is given before the appearance of reagin the test is usually
negative.
 After the appearance of reagin the test usually become negative 6 months after
treatment.

20.  In the secondary stage of disease test usually become non-reactive within
12- 18 months after treatment.
 After secondary stage treatment has variable effects on serologic test result
 If patient is treated 10 yrs or more after the onset of disease results can be
expected to change a little.
 Individuals who are allergic to penicillin and usually treated with
tetracycline.
 Pregnant women are treated with erythromycin.

21. Syphilis and blood transfusion
 It may be transmitted by blood transfusion when fresh blood is used.
 Blood stored at 4 degree Celsius for 4 days or more is unlikely to transmit
syphilis.
 STS are standard procedures for all blood donation.

22. Neurosyphilis (syphilis of CNS)
A. Asymptomatic Neurosyphilis
 Reactive serologic test for syphilis.
 No sign/symptoms of CNS involvement
 Examination of CSF reveals as increase in cell, total CHON (protein) positive
reagin test.
B. Meningovascular Neurosyphilis
 There are definite sign and symptoms of CNS damage
 CSF is always abnormal increase in cell and total CHON and a positive reagin
test.
 Meningeal or vascular involvement.

23. C. Parechymatous Neurosyphilis
 Presents paresis (incomplete paralysis) or tabes dorsalis (degeneration) of
dorsal columns of the spinal cord and of sensory nerve trunks with wasting.

24. Conginital syphilis
 Acquired fetal life from the maternal circulation through the placental
passage of T.Palladum.
 More likely to occur when the mother is suffering from early syphilis.
 Adequate treatment of the mother before the 18th weak of pregnancy
prevents infections of the fetus because penicillin will cross the placenta
in adequate amount.

25.  Lesions of the 1st 2 year of life are infectious and resemble those of
secondary syphilis in the acquired form of the disease.
 Late lesions appearing from the 3rd year onward are mostly of gummatous
type and are non-infectious.
 The stigmata are the scars or deformities resulting from early or late lesions
that have healed.

26. Disease related to syphilis
1. YAWS
 Caused by T. pertenue indistungishable from T.palladum the only different
in the disease is character of the lesions (more persistent).
 Scar formation develops at the site of secondary infection.
 Lesions are granulomatous or wart-like, tertiary stage is characherized by
modular or ulcerative necrosis
 Can be treated by penicillin
 Non- venereal transmission by direct contact.

27. 2. PINTA
 Caused by T. carateum, nonvenereal disease endemic in central and south
america.
 Usually occurs in childhood and is contracted through skin contact.
 Initial lesion is commonly found in the legs, starts with a papulae soon
forms a circular scaly patch known as pintid.
 Penicillin is effective in treatment

28. 3. BEJEL
 Nonvenereal syphilis
 No primary lesions seen
 Secondary lesions contact consists of generalized popular and
papulosquamous eruptions.
 Tertiary lesions may be observed in subcutaneous tissue, skin and bones.
 Penicillin is effective in treatment unless cotraindication by allergy.

29. 4. RABBIT SYPHILIS
 T.cuniculi is the causative agent.
 A natural venereal infection of rabbits.
 Producing minor lesions of the genetalia.

30. Serologic test for syphilis
PRINCIPLES
 Infection of human with T. palladum provokes in the host a complex Ab
response
 Based on the detection of one or more of the Abs.
* 2 known types of Antibodies
1. Non-treponemal Abs or reagin which reacts with lipid Ag (antigen)
2. Treponemal Abs which react with T. palladum and closely related strains.

31. Reagin test for syphilis
 VDRL (Venereal Disease Research Laboratory ) slide test
- nonspecific antigen
- cardiolipin is used
 PCT (plasmacrit)
 RPR ( rapid plasma reagin test)
 Unhealed serum reagin test
 RPRC (rapid plasma reagin circle card)

32. Treponemal test
 TPI (Treponema palladum inhibition test)
 TPCF (treponema palladum complement fixation test)
 RPCF (reiter CHON(protein) complement fixation test)
 FTS-ABS- specific to T. palladum.