Spirochetes are a phylum of distinctive, helically coiled bacteria that includes important human pathogens. They have long, thin cells enclosed by an outer membrane and inner periplasmic space containing endocellular flagella. Well-known pathogenic genera include Treponema, which causes syphilis, yaws, and bejel; Borrelia, which causes Lyme disease; and Leptospira, which causes leptospirosis. Spirochetes can infect humans through contact with contaminated body fluids or ticks/lice and cause symptoms ranging from skin sores and rashes to neurological, cardiac, and liver problems if untreated.

1. Mhelvin P. Andir
II BS BIOLOGY

2. Kingdom: Bacteria
Sub-Kingdom: Negibacteria
Phylum: Spirochaetae
Class: Spirochaetes
Order: Spirochaetales
Families: Spirochaetaceae
Leptospiraceae

3.  A spirochaete or spirochete
is a member of the phylum
Spirochaetae which contains
distinctive double-
membrane; gram negative
bacteria, most of which have
a long, helically coiled
(corkscrew-shaped or
spiraled) cells.
 They are regarded as
free-living bacteria but
most of them are highly
pathogenic to humans.
Though they are
sensitive to antibiotics.

4.  Spirochetes is a large heterogeneous group of bacteria.
Some are commensals, symbionts and harmless to animals.
 A spirochete, just like other bacteria, uses their long flagella
to move, however, the spirochetes enclose their flagella in
the periplasm, the narrow space between the inner and
outer membranes.
 Rotation of the flagella in the periplasm causes the entire
cell body to rotate and/or undulate, making the organism to
move vigorously.

6.  There size range from 3 to 500 μm (1 m = 0.001 mm) long
and diameters around 0.09 to at least 3 μm .

7.  Spirochetes are unique in that they have
endocellular flagella (axial fibrils, or axial filaments), which
number between 2 and more than 100 per organism,
depending upon the species.
 Each axial fibril attaches
at an opposite end and
winds around
the cell body, which is
enclosed by an
envelope.

8.  Spirochetes are characteristically found in a liquid environment (e.g.,
mud and water, blood and lymph), soil, decaying organic matter,
plants, animals, and even humans. They are typically thriving in
anaerobic (oxygen-deprived) environments (ex. Treponema pallidum)
Borrelia burgdorferi, a bacterial specie of
spirochaetes class that causes Lyme disease
in humans
Treponema pallidum is a spirochaete
bacterium with various subspecies that
cause the diseases syphilis, bejel, and yaws

9. Borrelia duttoni, Borrelia hermsii, and Borrelia
parkerii, the spirochete species that cause the tick-
borne relapsing fever (TBRF) that is transmited by ticks
and body lice.
Leptospira are spiral-shaped bacteria that are 6-20 μm
long and 0.1 μm in diameter with a wavelength of
about 0.5 μm. One or both ends of the spirochete are
usually hooked. Because they are so thin, live
Leptospira are best observed by darkfield microscopy.

10.  They reproduce asexually by transverse binary fission
(cytokinesis takes place along the transverse axis. e.g.
in ciliate protozoans like Paramecium)
 Contains one outer sheath of glycosaminoglycans

11. The Spirochaetaceae family includes four
genera: Spirochaeta, Cristispira, Treponema, and Borrelia.
Two of these genera—Spirochaeta and Cristispira—are
considered free-living and commensal, respectively.
The other three genera—Treponema, Borrelia, and
Leptospira—contain pathogenic species.

13. Syphilis
Relatively few diseases are as recognized and carry such a
stigma as syphilis, the sexually-transmitted form of which is
caused by subspecies pallidum. Venereal
syphilis is primarily acquired either through sexual intercourse
with an individual in the primary or secondary stages of the
disease or congenitally, being transmitted from a mother to the
unborn fetus .

14. These are the primary
manifestations of syphilis on
the human body. Some
sores will develop around
the mouth and groin area.
Also, red swells will appear
on penis and vagina. Once
left untreated, the sores will
ulcerate and this is so
painful, accompanied by a
foul smell.

15. Secondary syphilis will take place right
after the incubation period of the
bacteria. Skin rashes will scatter all round
the body. Also, it can be accompanied by
hepatitis, meningitis, fever, swollen
lymph glands, sore throat, patchy hair
loss, headaches, weight loss, muscle
aches, and fatigue.
The last stage of syphilis would be life-
threatening as majority of the individuals
would experience neurosyphilis,
cardiovascular syphilis and gummatous
syphilis. The person would lose it’s
insanity and it’s skull will undergo
necrosis (degeneration of the sull).
Granulomatous lesions in the skin, bones,
and liver and onset of aneurysms and
aortic valve regurgitation. The final would
be death.

16. Adolf Hitler, the leader of the Nazi Party and one of the powerful and most notorious
dictator of the 20th century, was confirmed to suffered from tertiary syphilis from being a
prostitute on his early 20’s. Later he was re-infected on WW1 and the disease slowly
progressed until he develop terminal syndrome.
Sources: National Library of Medicine,
National Center for Biotechnology
Information & PunMed.gov

17. Other subspecies of cause the related diseases of
yaws (pertenue) and endemic syphilis (also known as bejel or
non-venereal syphilis and caused by the subspecies
endemicum). A related species, , causes pinta .
These diseases are all transmitted through non-sexual contact
and include skin lesions. Endemic syphilis also includes
inflammation of the leg bones and, in later stages, gum as of
the nose and soft palate . Late stage (tertiary) yaws often
includes widespread bone, joint, and soft tissue damage.

18. YAWS
A chronic infectious disease caused
by a bacterium Treponema pallidum
perteneu. It affects the skin, bones,
cartilages and joints.

19. BEJEL
PINTA
a rare infectious tropical disease affecting
the skin that is caused by the bacterium
Treponema carateum, which is
transmitted by direct, nonsexual contact.
also called endemic syphilis, chronic
infection characterized by eruptions
initially in the mouth and on the skin
and typically later involving the bones.
Bejel is a nonvenereal form of syphilis.

20. Periodontitis
and have been shown to cause
proinflammatory cytokine release. Oral spirochetes in
periodontal diseases release toxic substances and enzymes
that are important in development of periodontitis. These
products damage to tissue by activating immune responses

21. Lyme disease
Lyme disease is caused by the
bacterium
and rarely,
. It is transmitted to
humans through the bite of infected blacklegged ticks.
Typical symptoms include fever, headache, fatigue, and a
characteristic skin rash called erythema migrans. If left
untreated, infection can spread to joints, the heart, and the
nervous system.

22. Leptospirosis
Leptospirosis is a bacterial disease that
affects humans and animals. It is caused by
bacteria of the genus . In
humans, it can cause a wide range of
symptoms, some of which may be mistaken
for other diseases. Some
infected persons, however, may have no symptoms at all.
Without treatment, Leptospirosis can lead to kidney damage, meningitis
(inflammation of the membrane around the brain and spinal cord), liver
failure, respiratory distress, and even death.