1. Spirochetes are spiral-shaped, motile bacteria that include pathogens causing syphilis, Lyme disease, and leptospirosis. 2. Treponema pallidum causes syphilis, which has primary, secondary, and tertiary stages and can be transmitted congenitally. Darkfield microscopy and serological tests are used for diagnosis. 3. Other human pathogenic spirochetes include Borrelia burgdorferi, which causes Lyme disease transmitted through tick bites, and Leptospira interrogans, which causes leptospirosis transmitted through contact with infected animal urine.

1. 1
SPIROCHETES

2. 2
Spirochetes
Spirochetes -are elongated motile,
flexible bacteria twisted spirally along the
long axis.
spirochetes contain – endoflegalla which
are polar flagella along the helical
protoplasmic cylinder and situated
between the outer membrane and cell
wall

3. Cell wall
Cytoplasmic
menbrane
Endoflagella
Outer envelope

4. 4
Human pathogens
Genera Treponema
Borreilia
Leptospira

5. 5
How they appear

6. 6
Comparative Morphology of
Spirochetes

7. 7
Genus Species Disease
Treponema pallidum ssp. pallidum
pallidum ssp. endemicum
pallidum ssp. pertenue
carateum
Syphilis
Bejel
Yaws
Pinta
Borrelia burgdorferi
recurrentis
Many species
Lyme disease (borreliosis)
Epidemic relapsing fever
Endemic relapsing fever
Leptospira interrogans Leptospirosis
(Weil’s Disease)
Spirochaetales Associated
Human Diseases

8. 8
What are Treponema
Greek words
Tripos – Turn
Nema Meaning thread
Relatively short and slender
With fine spirals pointed and round
ends
May be pathogenic or commensals
in the mouth

9. 9
Discovery
“Everything” happened mostly
in Germany from 1905 to 1910 !
With a short life of 35 years,
Fritz Schaudinn (1871-1906) and
Paul E. Hoffmann (1868-1959)
discovered Treponema pallidum
in serum in 1905.
Paul Ehrlich,
father of
immunochemistry
and his assistan Hati.
Fritz
Schaudinn

10. 10
Syphilis
Named from poem
published by the Italian
physician and poet
Girolamo Fracastoro –
shepherd [' epərd]fromʃ
Hispaniola named
Syphilis who angered
Apollo and was given
the disease as
punishment

11. 11
Treponema pallidum
Biological Characteristics
Gram-negative spirochetes
Spirochete from Greek for “coiled hair”
Extremely thin and can be very long
Tightly coiled helical cells with tapered
ends

12. 12
Trepanoma pallidum
Biological Characteristics
Motile, sluggish in viscous['v skəs]environmentsɪ
Size: 0.2 μm in width and 5-l5 μm in length
Structure
• Multilayer cytoplasmic membrane
• Flagella-like fibrils
• Cell wall
• Outer sheath (outer cell envelope)
• Capsule-like outer coat

13. 13
Treponema pallidum
Spiral spirochete can
be seen on fresh
primary or secondary
lesions by dark field
microscopy or
fluorescent antibody
techniques

14. 14
Dark field Microscopy

15. T. pallidum in the direct fluorescent antibody test

16. 16
Treponema pallidum
Difficult to culture
※ Nichols strain: virulent, cultured in rabbit testis or
anterior chamber of eye, slow growth (doubling time is
30 hr), if cultured in rabbit testis fragments containing
amino acids, the virulence will be lost and Nichols strain
become to Reiter strain.
※ Reiter strain: non-virulent, infected rabbit testis fragments.

17. 17
Cultivation of .. ?
Treponemes cannot be
cultivated in laboratory
media and are maintained
by subculture in
susceptible animals.
TP can cultured in cotton tail
rabbit epithelial cell and
maintain its virulence

18. Histology:Histology:
Treponema pallidumTreponema pallidum grow in Rabbit’s testisgrow in Rabbit’s testis
Brown color stained with Fontana silver impregnation stain

19. 19
Antigenic structure
The Antigens are complex
Infection with Treponema will induce 3
types of Antigens
Reagin (Antibodies ） – STS

20. 20
Second Group Antigen
T.pallidum
Present in T.pallidum
and Nonpathogenic
cultivable treponemes

21. 21
Third Antigen
• Polysaccharide
species specific
• Positive only in
sera of patients
infected with
pathogenic
Treponema

22. 22
The bacteria rapidly enter the
lymphatic's and widely disseminated via
the bloodstream and may lodge in any
organ. The exact infectious dose for man
is not known, but in experimental animals
fewer than ten organisms are sufficient to
initiate infection.
Pathology

23. 23
Penetration:
T. pallidum enters the body via skin and mucous
membranes through abrasions during sexual contact
Also transmitted transplacentally
Dissemination:
Travels via the lymphatic system to regional lymph
nodes and then throughout the body via the blood
stream
Invasion of the CNS can occur during any stage of
syphilis
Pathology

24. Transmission
※ sexual contact
※ congenitally
※ blood transfusion

25. △ Acquired syphilis
※ venereal syphilis
※ syphilis caused by blood transfusion
△ Congenital syphilis

26. venereal syphilis

27. 27
Primary Disease
Chancre: single lesion, non-tender & firm with
a clean surface, raised border & reddish
color
Usually on the cervix, vaginal wall, anal canal
Draining lymph nodes enlarged & non-tender

28. 28
Primary Syphilis- Penile
Chancre
Clinical Manifestations
Source: CDC/ NCHSTP/ Division of STD Prevention, STD Clinical Slides

29. 29
Basic lesion of syphilis
The chancre is
painless and most
frequently on the
external genitalia,
but it may occur on
the cervix, perianal
area, in the mouth
or anal canal.

30. 30
Primary Syphilis - Chancre

31. 31
Primary Syphilis - Chancre

32. Primary stage
※ 3 weeks after infection
※ primary lesion —hard
chancre
※ rich in TP
※ infectious highly
※ 4~8w disease course
※ subside spontaneously

33. 33
The chancre usually heals
spontaneously within 3-6 weeks, and 2-
10 weeks later the symptoms of
secondary syphilis develop. These are
highly variable and widespread but most
commonly involve the skin where macular
or pustular lesions develop, particularly
on the trunk and extremities. The lesions
of secondary syphilis are highly
infectious.
Chancre

34. 34
Secondary Syphilis

35. 35
Secondary Syphilis

36. 36
Secondary Syphilis

37. 37
Secondary syphilis

38. Secondary stage
△ 2~10w after primary stage
※ systemic spread
※ many organisms
※ skin, particularly
△ flu-like symptoms,
rash anywhere on the body
△ rich in TP
△ infectious highly
△ 3w~3m disease course
△ subside spontaneously

39. 39
Relapse of the lesions of secondary
syphilis is common, and latent syphilis is
classified as early (high likelihood of
relapse) or late (recurrence unlikely).
Individuals with late latent syphilis are not
generally considered infectious, but may
still transmit infection to the fetus during
pregnancy and their blood may remain
infectious.
Progress of Disease

40. 40
Following secondary disease, host
enters latent period
•First 4 years = early latent
•Subsequent period = late latent
About 40% of late latent patients
progress to late tertiary syphilitic
disease
Latent Stage Syphilis

41. 41
Affects 2/3 of untreated cases
Gummata: rubbery tumors
Bone deformities
Blindness
Loss of coordination
Paralysis
Insanity
Tertiary Syphilis

42. △ 5~10 years after infection
△ granulomatous lesions in
skin ， bone, and liver
△ degenerative changes in the
central nervous
△ cardiovascular lesions
△ few TP in lesion and blood
Tertiary stage
['ænjər zəm]ɪ

43. Acquired Syphilis
Primary and secondary syphilis also called early syphilis.
△ infectious highly
△ destructive small
Tertiary syphilis also called late syphilis.
△ infectious small
△ long course of disease
△ destructive highly

44. 44
Passed from
mother to
fetus during
pregnancy
Congenital Syphilis

45. T. pallidum in the pregnant woman
placenta
Blood circulation of the fetus
Systemic infection of the fetus
Abortion or death of
the fetus
Syphilitic newborn infant
Congenital Syphilis

46. △ Hutchinson’s teeth
△ Saddlenosema
△ Periostitis
△ A variety of central nervous system anomalies
△ pyoderma……
Congenital Syphilis
Periostitis

47. 1.Microscopic diagnosis
Exudate from skin
lesions(chancre or rash)
Tissue specimens
△ Dark-field
△ Direct fluorescent
antibody staining
△ Silver stain
Microbiological Diagnosis

48. 48
Dark field Microscopy

49. T. pallidum in the direct fluorescent antibody test

50. Histology:Histology:
Treponema pallidumTreponema pallidum grow in Rabbit’s testisgrow in Rabbit’s testis
Brown color stained with Fontana silver impregnation stain

51. 51
General screening test, can be adapted to
automation.
CANNOT be performed on CSF.
Antigen
VDRL cardiolipin antigen is modified with choline
chloride to make it more stable
attached to charcoal particles to allow macroscopic
reading
antigen comes prepared and is very stable.
Serum or plasma may be used for testing, serum
is not heated.
Rapid Plasma Reagin Test - RPR

52. 52
Every Pregnant women Needs
Screening

53. 53
Biologic False-Positive
Test Results
Positive STS in persons with no
history or clinical evidence of syphilis
Acute BFP: those that revert [r 'v rt]ɪ ɜː
恢复 to negative in less than 6
months
Chronic BFP: persist > 6 months

54. 54
Prevention & Treatment of Syphilis
Penicillin remains drug of choice
•WHO monitors treatment recommendations
•7-10 days continuously for early stage
•At least 21 days continuously beyond the early
stage
Prevention with barrier methods (e.g.,
condoms)

55. 55
Genus Species Disease
Treponema pallidum ssp. pallidum
pallidum ssp. endemicum
pallidum ssp. pertenue
carateum
Syphilis
Bejel
Yaws
Pinta
Borrelia burgdorferi
recurrentis
Many species
Lyme disease (borreliosis)
Epidemic relapsing fever
Endemic relapsing fever
Leptospira interrogans Leptospirosis
(Weil’s Disease)
Spirochaetales Associated
Human Diseases

56. Borrelia burgdorferi
Histopathology showing Borrelia burgdorferi spirochetes
in Lyme disease. Dieterle silver stain.

57. Hard tick

58. Lyme disease rash

59. 59
Genus Species Disease
Treponema pallidum ssp. pallidum
pallidum ssp. endemicum
pallidum ssp. pertenue
carateum
Syphilis
Bejel
Yaws
Pinta
Borrelia burgdorferi
recurrentis
Many species
Lyme disease (borreliosis)
Epidemic relapsing fever
Endemic relapsing fever
Leptospira interrogans Leptospirosis
(Weil’s Disease)
Spirochaetales Associated
Human Diseases

60. 60
Leptospirosis

61. 61
Scientific Beginning
It was first described by Adolf Weil in
1886 when he reported an "acute
infectious disease with enlargement of
spleen, jaundice and nephritis".
Leptospira was first observed in 1907
from a post mortem renal tissue slice.

62. 62
Leptospirosis - Zoonosis
[zo ' n s s]ʊ ɒ ə ɪ
Leptospirosis is an acute arthropod-
zoonotic[ zo ə'no t k] infection of worldwideˌ ʊ ʊ ɪ
significance caused by spirochete Leptospira
interrogans
World: 25 serogroups ， 273
serotypes
China: 19 serogroups ， 161
serotypes

63. 63
Leptospirosis also called as Weil’s
Disease after its inventor
.

64. 64
Epidemiology
Rainfall; Contaminated environment;
Poor Sanitation; Inadequate drainage facilities;
Presence of rodents, cattle & stray dogs;
Walking/ working bare foot poses high risk
Difficult to pinpoint the source of infection
Any person can get infected, if exposed to
contaminated and environment

65. 65
Epidemiology
Leptospirosis causes several animal infections
Most wide spread zoonotic infection in Nature
Human infections are accidentally associated with
contamination of water, other materials contaminated
with excreta and animal flesh.
Animal carriers often excrete upto 100 million
leptospira per ml of urine

66. 66
Epidemiology - Occupation
Certain occupational
groups such as
agriculture workers
in rice and cane
fields, miners and
sever cleaners are
potential victims

67. 67
How Man gets Infected
• Water the great source
Drinking
Swimming
Bathing, as the urine of
rodents chronically
contaminate water
sources
Children get infected
when in contact with
infected Dogs

68. 68
Walking in Flood Waters can Infect
• With the rats comes
the threat of illnesses
such as Weil's
Disease, which is
transmitted to
humans via
contaminated water
and is carried by up to
30 percent of the
rodent population.

69. — natural focus infection disease
△ Susceptible population ：
— fieldworker ， farmer, stock 家畜
man ，
youngsters in countryside△ Epidemic season ：
— summer and autumn

70. 70
Leptospirosis – A Major Zoonotic Infection
Weil's disease is comparatively rare, though
'mild' cases of leptospirosis happen everywhere.
It is believed that leptospirosis is one of the
most common zoonotic infections in the world.
Millions of people are infected each year, but
information and treatment can be limited,
especially in the developed world where cases
are considered 'rare' by the medical community.

71. 71
Leptospirosis 2011

72. 72
Reservoirs
Wild and domestic animals rodents,
livestock (cattle, horses, sheep, goats),
canines['ke na n], and wild mammals areɪ ɪ
the reservoir for leptospirosis. Many
animals have prolonged leptospiruria
without suffering from the disease
themselves.

73. 73
What causes Leptospirosis
Leptospirosis is a bacterial disease that
affects humans and animals. Leptospira
bacteria are found worldwide and there are
many different types or serovars capable of
causing disease. Disease caused by Leptospira
bacteria is most common in temperate or
tropical climates .

74. 74
Morphology
• The Leptospira appear
tightly coiled thin flexible
Spirochetes 5 – 15
microns long.
• Fine spiral of 0.1 – 0.2
microns
• One end appears bent
forms a hook.
• Actively motile
• Seen best with dark field
Microscopy.

75. 75
Greater Understanding with Electron
Microscopy
• Electron Microscopy
show thin axial
filament and a
delicate membrane
• In dark field it may
appear as chain of
miniature cocci.

76. 76
Animals spread Leptospirosis
Rats, Mice, Wild Rodents,
Dogs, Swine, Cattle are
principle source of infection
The above animals excrete
Leptospira both in active
infection and Asymptomatic
stage
The Leptospira survive and
remain viable for several
weeks in stagnant water.

77. 77
Modes of Transmission
1. Direct contact with urine or tissue of infected animal
Through skin abrasions, intact mucus membrane
2. Indirect contact
Broken skin with infected soil, water or vegetation
Ingestion of contaminated food & water
3. Droplet infection
Inhalation of droplets of infected urine

78. 78
Transmission
Environment Human
polluti
on
Survive
Urine
Tissue
Feces
Infection
Animal Source
Human infection is accidental
No human to human transmission

79. 79
Pathogenic Strains x Non pathogenic
Leptospirosis
There are several species of Leptospira only
few are pathogenic to Humans, rest to some
Animals and Many in Nature as saprophytes
Leptospira Interrogans is Pathogenic there are
200 serovars.
Leptospira biflexa( 双曲） Non Pathogenic
there are 60 serovars
Further classifications are made on shared
antigens

80. 80
Culturing of Leptospira
• Leptospira grows best under
aerobic [e'ro b k] conditions atʊ ɪ
28 to 30 best demonstrated in℃ ℃
Semi Solid agar media

Optimal growth after 1 – 2 weeks

81. Leptospirosis
3.Disease:
meningitis
hepatic dysfunction
renal dysfunction
rash
1. Entry (broken
or nomal skin or
mucosa)
2. Spread
4.Exit

82. 82
Pathogenesis
Leptospira are present in the water bodies
Enter through breaks in the skin ( cuts and abrasions ) and
mucous membranes
Enters through Mouth – Nose – Conjunctive
Rarely enters though ingestion.
Incubation period 1 – 2 weeks
When it multiples in blood stream produces fever.
May establish organ involvement in Kidney and Liver,
May produce hemorrhage and necrosis in the tissues
and initiates dysfunction of these organs

83. 83
PATHOGENESIS
leptospira
skin, mucosa
Initial stage leptospiremia toxic symptoms
(1~3days) three symptoms:
fever, myalgia, fatigue;
three signs:
conjunctival suffussion;
muscle tenderness;
enlargement of lymphonodes;

84. Clinical Illnesses
Types Anicteric (common 95% recover)
Icteric ( Weil’s Syndrome) (rare, fatal)
Hepato-renal syndrome
Hemorrhagic syndrome with ARF
Atypical pneumonia syndrome
Aseptic meningo-encephalitis
Myocarditis, Chronic uveitis

85. 85
Clinical Presentation
Anicteric
Common, mild
< 2% Mortality
Icteric
Rare, Severe
15% Mortality
90%ofCases
10%ofCases

86. 86
Presenting with Jaundice is significant and
Important, serious manifestation

87. 87
Weil’s Syndrome
Weil's syndrome is a severe form of leptospirosis
that causes a continuous fever, stupor, and a
reduction in the blood's ability to clot, which leads
to bleeding within tissues. Blood tests reveal
anaemia. By the third to sixth day, signs of kidney
damage and liver injury appear. Kidney
abnormalities may cause blood in the urine and
painful urination. Liver injury tends to be mild and
usually heals completely.

88. 88
May present as
Atypical Pneumonia

89. 89
Hepatitis - Leptospirosis
• Hepatitis is the frequent
complication
• Elevation of serum
creatine phospholipase
enzyme raise
differentiates from Viral
hepatitis where the
enzyme is not raised

90. Specimens ：
Microbiological Diagnosis
△ Blood (the first week of illness)
△ Urine (the second week of illness)
△ CSF (the patient with meningeal irritation sign)

91. Etiological [ i t ' ləd ] examinationsˌ ː ɪ ɒ ʒɪ
△ Direct microscopy
◎ Dark-ground microscopy
◎ Silver stain
◎ Fluoresent antibody staining
△ Culture isolation and identification ： Korthof
liquid medium
△ Animal test
△ Molecular diagnostics

92. 92
Leptospira under the Microscope
Long, Thin, Highly Coiled
Dark Field Microscopy FL

93. Serological examinations
Paired serum
△ Microscopic agglutination test （ MAT ）
△ Indirect agglutination test
△ Complement fixation test
△ IFA
△ ELISA

94. 94
Treatment
Antibiotic of choice is Benzyl Penicillin
given by injection in doses of 5 mega units in
a day, for 5 days.

95. 95
Control of Leptospirosis
• Rodent control is
most important.
• Human’s should avoid
contact with water
contaminated by
animals.

96. 96
Vaccination in humans
Vaccination for humans is justified where they
cannot be separated from animal sources or where the
animals cannot be immunized successfully
Necessity of human vaccinated will arise where
people live and work in proximity [pr k's m ti]toɑː ɪ ə
rodents in wet, tropical conditions, in wet rice planting
and harvesting, in military operations, or working in
sewers 阴沟 .
Yet no universally accepted vaccine
is available for humans

97. 97
Vaccination of Animals
Vaccinating animals have a dual purpose
1 Protecting animals
2 Protecting humans who may contract
['k ntrækt]leptospirɑː a from them
It is probably true as that immunization of
animals will prevent leptospirosis in people in
contact with them.
Several other vaccines in use to suit local
needs.

98. Exercises:
Reagin Gummata
1.What are the 3 major groups of SPIROCHETES that
cause human disease?
2.What is the PATHOGENESIS of the TREPONEMA?
a) Incubation? b) Primary lesion? c) Secondary lesion?
d) Tertiary lesion?
3.What’s the pathgenicity of Leptospira?