The document discusses several genera of bacteria including Spirochetes, Treponema, Borrelia, Leptospira, Mycoplasma, Rickettsia and Chlamydia. Spirochetes are long, spiral shaped bacteria that can be pathogenic, causing diseases like syphilis, relapsing fever, and Lyme disease. Treponema pallidum causes syphilis in humans. Borrelia recurrentis causes relapsing fever. Leptospira interrogans can cause leptospirosis.
2. Spirochetes
x Gram negative, motile, x Heterogenous group
long helical corkscrew of motile organisms
appearance
x Contains one outer
x spirochete flagella - sheath of
endoflagella glycosaminoglycans
x aerobic & facultative x Contains series of
anaerobes cytoplasmic tubules
x reproduce by transverse (body fibrils)
fission
Microbiology HTL
3. Spirochetes
x Family Spirochaaetaceae ( free living, large
spiral organisms )
x Family Treponemataceae
– Genus Treponema – T. pallidum
– Genus Borrelia – B. recurrentis
– Genus Leptospira – L. interrogans
Microbiology HTL
5. Characteristics of Treponema
x 0.2 um in diameter up to 15 um in length
x Actively motile, rotating steadily around
their endoflagella even after attaching to
cells
x Spirals are thin and only seen in
immunofluorescent stain or darkfield
microscopy
x Can be stained with silver impregnation mtd
Microbiology HTL
6. Culture
x Has never been cultured continuously on
artificial media, in fertile eggs, or in tissue
culture
x Nonpathogenic treponemes ( Reiter Stain )
can be cultured anaerobically in vitro
x They are saprophytic
Microbiology HTL
7. Growth characteristics
x Microaerophilic organism
x Survives best with 1-4% oxygen
x Grows in a defined medium with 11 amino
acids, vitamins, salts & serum albumin
x Remain motile 3-6 days at 25 degrees, and
in whole blood remain viable for at least 24
hours at 4 degrees clinical significance
in blood transfusion
Microbiology HTL
8. Reactions & antigens
x Killed by drying or temperature elevation
(42 degrees)
x Immobilized and killed by trivalent arsenic,
mercury & bismuth
x Slow killing time with penicillin, sometimes
tolerance is demonstrated
x Not culturable = hard to characterize
antigens = more than 100 antigens
Microbiology HTL
9. Syphillis
x Acquired Syphillis
x Congenital Syphillis – 10th to 15th fetal week
x Nontreponemal antigen Test – (VDRL)
x Treponemal Antibody test
– Fluorescent Treponemal Antibody (FTA-ABS)
– Particle Agglutination test – TP-PA
Microbiology HTL
10. Trivia
x Most common type of Syphilis is “Rabbit
Syphilis” caused by T.cuniculi
x Natural STD in rabbits producing minor
lesions in the genitalia
x Moral of the story: Doesn’t pay to be too
sexually active like the rabbit! ( Hooray for
bugs bunny )
Microbiology HTL
12. Borrelia
x B. reccurrentis causes relapsing fever in
epidemic form
x Transmitted by the human body louse
x Highly flexible and move by rotation &
twisting
x Stain readily with blood stains ( Wright’s &
Giemsa stain )
Microbiology HTL
13. Culture & Growth
x Cultured in media containing blood, serum,
tissue
x Rapidly loses pathogenicity for animal after
repeated culture in vitro
x Multiplication is quick in chick embryo
x Can survive at 4 degrees in infected blood
or culture
Microbiology HTL
14. B. burgdorferi
x Causes lyme disease ( named after the place
Lyme, CT )
x Isolated in children and transmitted thru the
bite of a small ixodes tick
x Characteristic skin lesion, erythema
migrans, along with flu like symptoms with
late manifestations often with arthritis
Microbiology HTL
16. Leptospira & leptospirosis
x L. interrogans causes leptospirosis which is
a zoonosis of worldwide distribution
x Contains more than 260 serotypes
x Tightly coiled spirochete and not easily
stainable ( silver impregnation)
x No traditional method of classification due
to high heterogeneity
Microbiology HTL
17. Culture, growth & antigens
x Grow best under aerobic conditions at
28-30 degrees in serum containing semi-
solid media ( Fletcher’s or Stuarts media )
x Derives energy from oxidation of long
chain FA & cannot use aminoacids and
carbohydrates
x Mainstream antigens are called serovars
(many) with rodents & canine urine as main
source
Microbiology HTL
19. Mycoplasma
x lack of cell wall x also causes rhinitis -
x obligate intracellular nose of chickens &
parasites & fermenters turkeys
x colonies : fried egg x due to absence of cell
appearance wall can squeeze thru
x long spiral to perfectly small openings ,not
round cocci filterable.
x Mycoplasma pneumoniae – Penicillin &
- atypical Streptomycin Ab
Microbiology HTL
21. Rickettsia & Chlamydia: (1)
x Gram(-) bacteria which x R. typhi - endemic
used to be grouped w/ typhus
virus because of its size x R. rickettsi - Rocky
x Chlamydia - 0.2 -0.7 u mountain spotted fever
x Rickettsia - 0.3 - 1.0 u x Coxiella burnetti - Q
x obligate intracellular fever
parasites x Rickettsial diseases are
x R. prowazekii - epidemic all systemic
typhus x C. trachomatis -
Microbiology HTL trachoma ( blindness)
22. Rickettsia & Chlamydia: (2)
x C. psittaci - psittacosis x Chlamydia has 2 cell
(parrot fever) types:
x Rickettsial pathogens are – Chlamydiospore-
carried by arthropods elementary body
(lice, ticks, mites) – Vegetative cell -
x chlamydia are from reticulate body
human to human x most important
x rickettsia reproduce by substance needed by
simple division both from host is
Microbiology HTL
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