3. • They are large, elongated slender and cork screw like
organism.
• Sizeries from 5-12 mu m X 0.1-0.6 mu m.
• Spirochetes which are pathogenic to humans are divided
into
– Treponema
– Leptospira
– Borrelia
9. PATHOGENESIS
• Syphilis is a chronic infectious disease
caused by the spirochaete Treponema
pallidum.
• The disease is transmitted during sexual
contact or can be transmitted congenitally.
10. • So that it is divided into,
1. ACQUIRED SYPHILLIS
2. CONGENITAL SYPHILLIS
11. ACQUIRED SYPHILIS
• It is mainly transmitted because of unprotected
sexual contacts.
• The organism penetrates the mucous surface and
multiplies at the site of entry.
• Incubation period is 2-4 weeks and it ranges from
10-100 days.
12. • During the incubation period the organism
invades the regional lymph nodes(inguinal
in males & pelvic in females) and leads to
lymphadenitis
• From the lymph nodes the organism
spreads to the body parts through the
blood.
13. • Clinically syphilis is divided into 4stages,
• 1. primary syphilis or primary stage
• 2. secondary syphilis or secondary stage
• 3. latent syphilis or latent stage
• 4. tertiary syphilis or tertiary stage
14. PRIMARY SYPHILIS OR
PRIMARY STAGE
• In this stage the papule appears in the
genital area that ulcerates and forming a
primary lesion called “chancre” or “hard
chancre”.
• It is characterized by red, flat, painless and
indurated ulcer with 1-2 cm in diameter.
15. • This lesion is also called as hunterian
chancre, which is most frequently appears
in the external genitalia(penis,labia,vagina)
• Occasionally the chancre may appear on
mouth, lips, cheeks and nipples.
21. SECONDARY SYPHILIS OR
SECONDARY STAGE
• The secondary stage is characterized by
appearance of widespread papular skin
rashus particularlly on trunk and extrimities
and mucous patches in the oropharynx.
22. • There may be enlargement of lymph
nodes will occur in the second stage.
• Other features are retinitis, arthritis,
periostitis and meningitis.
27. LATENT SYPHILIS OR
LATENT STAGE
• After disappearance of the secondary
lesions 30% of cases will get cured without
any treatment.
• Remaining 30% will continue without
producing any symptoms and that can
lead to tertiary syphilis.
28. LATENT SYPHILIS OR
LATENT STAGE
• This stage is slowly progressive and the
lesions may be formed anywhere in the
body and may affect any organ.
• The granulomatous nodules will be formed
in the skin, mucous membrane, bones,
tongue, liver and myocardium.
29. CONGENITAL SYPHILLIS
• The organism is capable of crossing the
placenta and leading to congenital
syphilis.
• Transmission can be occur from the 10th
week until the late in pregnancy.
• The infected feces may die and resulting
in miscarriage.
30. LABORATORY DIAGNOSIS
• Hematological investigations
• Bacteriological investigations
– Direct demonstration of treponema
• Microscopic studies
• Direct fluorescent antibody staining for T.Pallidum
• Tissue biopsy
– Serological diagnosis
• Non treponemal or standard test
• Treponemal tests
31. Hematological investigations
• In acute cases the leucocytes will be
increased and in chronic cases the
lymphocytes will be elevated.
32. Bacteriological investigations
• Microscopic studies
When the specimen is observed
under a dark ground microscope after
covering the specimen by a cover slip, the
organism appears as spiral, slender with
flexion and extension movements.
33. Direct fluorescent antibody
staining for T.Pallidum(DFA-TP)
• The smears made from the exudates can
be directly stained with fluorescein labelled
antitrponemal antibody.
• This is also called as fluoroscein labelled
antibody test.
34. Tissue biopsy
• The organism can be demonstrated in
tissues by silver staining or by
immunofluorescence.
35. SEROLOGICAL TESTS
• Serological tests are the most effective
diagnostic method for syphilis.
• Two types of antibodies are produced in this
disease, specific anti-treponemal antibody &
non-specific reagin antibody.
• Therefore two types of antigen are used in the
serological studies which include treponemal
antigen and non-treponemal antigen.
36. • Thus depending upon the antigen used,
serological test for syphilis can be two
types,
• Non treponemal or standard test
• Treponemal tests
37. NON TREPONEMAL OR STANDARD TEST
• 1. flocculation test
VDRL test
RPR test
kahn test
• 2. Compliment fixation test
38. TREPONEMAL TEST
• Test using cultivable treponemes as
antigen.
• Tests using pathogenic treponemes as
antigen.
– Test using live T.pallidum
– Test using killed T.palludum
– Test using T.pallidum extract
39. VDRL TEST
• It is a most widely used screening test
which is rapid and economical.
• In VDRL test, 0.05 ml of serum which is
heated at 56degree C for 30 min is taken.
• One drop of freshly prepared cardiolipin
antigen is added over that.
• The slide is rotated at 180 rpm for 4
minutes.
40. • Positive: formation of clumps
• Negative: formation of uniformly disturbed
crystals.
41. RAPID PLASMA REAGIN
(RPR)
• The test is almost similar to VDRL test.
• One drop of patients serum is mixed with
one drop of modified VDRL antigen on a
disposable plastic card with a disposable
stick.
• The card is gently rocked to and fro for 8
minutes and observed under microscope.
42. • Positive: aggregation of carbon particles
occurs in the periphery of the specimen.
• Negative: absence of black aggregation.
43. Kahn test
• Also known as khan tube test
• In this test 0.15ml of serum which is
heated at 56degree C for 30 minutes is
added to three test tubes containing
0.05,0.025, and 0.0125 ml of freshly
prepared cardiolipin antigen.
• Shake the tube for 3-4 minutes.
44. • Presence of floccules indicates a positive
test.
• Absence of floccules indicates a negative
test.
45. Compliment fixation test
• Otherwise known as wassermann
reaction.
• In this study serum which is heated at 56
degree C for 30 minutes is mixed with the
cardiolipin antigen.
• Then add 2 units of serum from guinea pig
to the mixture.
• The mixture is intubated at 37 degree C
for one hour.
46. • The absence of hemolysis indicates a
positive test.
• The presence of hemolysis indicates a
negative test.
47. TREPONEMAL TEST
• Test using cultivable treponemes as
antigen.
Test using reiter’s treponeme:
in this test the antigen used
is derived from reiters strain of T.pallidum
and most probably derived from the
endoflagella of the organism.
48. • The antigen is protein in nature hence the
test is also called as Reiter protein
compliment fixation test.
• The procedure and the results are same
as that of compliment fixation test.
49. Tests using pathogenic
treponemes as antigen.
Test using live T.pallidum:
1. Treponema pallidum immobilization test:
In this study the suspected
serum is incubated anaerobically. if antibodies are
present, the immobilized organism can be found
under dark ground microscope.
50. • REACTIVE: more than 50% are
immobilized
• NON-REACTIVE: less than 20% are
immobilized
• DOUBTFUL TEST: 20-50% are
immobilized
51. Test using killed T.pallidum:
1. Treponama pallidum immune adherence test:
in this test the serum is mixed with
inactivated treponemes.
Fresh heparinized whole blood of a normal
individual is added to the above mixture.
The mixture is incubated.
If antibodies are present in the patients serum,
the treponemes will adhere to the erythrocytes.
If no antibodies are present, no such adherence
will occur.
52. 2. Treponema pallidum agglutination test:
In this method the serum is mixed with
T.pallidum and the mixture is intubated.
Under dark ground microscope, the
organism is found agglutinated only if the
serum contains specific antibodies.
53. 3. Fluorescent treponemal antibody test:
In this test smears of T.pallidum are made
on slides and fixed with acetone.
The patients serum is added to the mixture
and incubated for the presence of
antibodies that will react with treponemes
in the smear.
The excess serum is washed off and the
antibodies that binds to the organisms in
smear are detected by treating the smear
with fluorescein labelled antihuman
immunoglobin.
54. The slide is again incubated and washed
and examined under microscope.
The organism shows fluorescence in
positive cases.
55. 4. Fluorescent treponemal antibody adsorption
test:
In the test the patients serum is first absorbed
by non-pathogenic treponemal antigen(Reiter’s
strain) to remove group specific treponemal
antibody present in the serum.
The test can detect both IgG & IgM antibodies
present in patients serum.
56. Test using T.pallidum extract
Trponema pallidum haemagglutination test:
in this test the T.pallidum
antigen is coated into the suface of red blood
cells.
Then this RBC is mixed with patients serum.
The formation of clumps indiacates the
positive study.
57. TREATMENT
• Early stages
benzathine benzyl penicillin-single dose
doxycycline- twice for 5 days
• Late stages
benzathine benzyl penicillin- once in a
week for 3 weeks.
58.
59. • THE IMPORTANT SPECIES COMING
UNDER THIS GENUS IS……
Leptospira icterohemorrhagica
60.
61.
62. CULTURAL
CHARACTERISTICS
• They are aerobic and grows well in the
temparature of 25-30 degree C at the pH
of 7.2-7.5.
• The organism can be cultivated in the
enrichment media which contains rabbit
serum.
63. PATHOGENESIS
The disease caused by the micro organism
is known as leptospirosis (weils disease/
infectious jaundice)
Leptospires are believed to enter the host
through the following:
• Abrasions in healthy skin
• Animal and rodent bites
• Mucous membranes or conjunctiva
• The placenta during pregnancy
64. • Wild rats are the reservoir of the micro
organism.
• The organism localize in the kidneys and
colonizing in the convoluted tubules of the
rats.
• Humans acquires infection when the
ingestion of contaminated food or water
occur which is infected with the rats urine.
65. • Incubation period is 1-8 weeks.
• After that the organism is spreading to
whole body through the circulating blood
and causes severe leptospirosis.
67. LABORATORY DIAGNOSIS
• Hematological studies
– Increased number of leucocytes, ESR and
polymorphous cells.
– Blood urea and serum bilirubin level
increased.
68. • Bacteriological investigations
– Microscopy:
under dark ground microsopy can
observe coiled, motile spirochetes.
– Culture studies:
the specimen is placed in stewart or
korthof’s medium. Then the bottles are
incubated at 30 degree C for 2days- 2weeks.
Under microscope can observe the micro
organism.
76. PATHOGENESIS
• The organism is primarily a parasite of small
mammals like rats and rodents.
• Then it is transmitted to man the bite of ixodid
tick which carries these spirochetes.
77. • Incubation period is 2-3 weeks and the
disease is known as lyme disease or lyme
arthritis.
• The features are fever, head ache, stiff
neck, myalgia, arthralgia,
lymphadenopathy and rashus or lesions.
• These rashus/lesions is known as
erythema chronium migrans.
