Download Spirochetes

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Spirochetes
Spiral , motile organism, 3 genera are
pathogenic to man
1. Trepanoma  syphilis , yaws and pinta
2. Borrelia  Relapsing fever and lyme
disease
3. Leptospira  Leptospirosis
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Trepanoma
e.g. Trepanoma pallidum  Syphilis
Morphology
 Spiral filaments , motile
 Seen by dark-field microscopy
 Stained by immune fluorescence
Cultural character
 Not cultured
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Syphilis
 Sexually transmitted disease (venereal
disease) , it has 3 stages
1. Primary stage (chancre):
 6-12 weeks after exposure
 Ulceration of genitalia papule
2. Secondary stage

6-12
weeks
after
appearance
of
chancre

Characterized
by
generalized
manifestation e.g skin rash
 Condylomata of anus and vulve and
mucous patches in the mouth
 T. pallidum found in large number in
the lesion of both stages
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3. Tertiary stage:- if not treated

Appearance
of
gummata
in
the
internal organs years after infection
 General paralysis
Diagnosis:
1. Detection of spirochetes in the lesion:
lesion exudates examined by :
a. Dark field microscopy
b. Direct
IF
stain
antitrepanomal Abs
labeled
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2. Serological
Diagnosis
to
detect
antigen, the most common serological
test:
a. Venereal
disease
research
laboratory (VDRL)
b. Rapid
plasma
Region
(RPR)
 a&b are not specific test and may
give false positive result in case of
e.g. autoimmune disease.
c. Flourescent
trepanomal
antibody
(FTA) test: indirect IF test in which
patient serum is layered on killed
trepanoma
incubation
fixed
then
on
slide
–
flourescein
labeled anti-human gamma globulin
is added  wash  positive or
negative. It is very sensitive test
and specific
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d. Trepanoma
pallidum
haemagglutination
(TPHA)
test:
depend on the ability of Abs in
syphilitic
patient
sera
to
bring
agglutination of sheep RBCs coated
with extract of T. pallidum. This test
is specific and easy to use.
Treatment: Penicillin is a drug of choice
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Borrelia
 Cause Relapsing fever and lyme disease
 Large spiral , stained with gram stain
(Gram negative)
 Cultured in fluid media containing blood
or serum.
Relapsing fever
 Transmitted by lice or ticks
 Rodent are the reservoir
 Causative agent Borrelia recurrentis
 Characterized by repeated attack of
fever, alternating with period of apyrexia
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Pathogenicity
Lice /tick infected by feeding of patient /
rodent blood during bacteremia stage
↓
Borrelia multiplies in insect body
↓
Infection transmit by insect bite
↓
Incubation 3-10 days
↓
Sudden onset of fever for 4 days
↓
Afebrile 3-10 days
↓
Another attack of fever
↓
Organism found in large numbers in blood
during febrile stage
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Diagnosis
1. During
Febrile
stage

blood
film
stained with leishman's stain / Giemsa
stain  large number of spirochetes
2. During afebrile stage  the organism is
scanty in blood and blood film negative
Treatment:
Penicillin
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Lyme disease
 Caused by Borrelia Burgdorferi
 Transmitted to human by tick bite
 Rodent is the animal reservoir
 Disease characterized by early and late
Stage:
1. Early stage Skin lesion, fever, chills ,
muscle pain and headache
2. Late stage  appear week/month later
 arthritis , myocarditis, neurological
disorder
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Diagnosis
1. PCR to detect DNA of B. burgdofferi in
CSF, joint fluid
2. Serology (IgM) or high titer IgG
Treatment : penicillin and tetracycline.