Spirochetes
Bacteriology
SPIROCHETES • T. pallidum endemicum – endemic syphilis
• Large, heterogeneous group of spiral and (bejel)
motile bacteria • T. carateum – pinta
• Family – Spirochaetaceae HABITAT AND TRANSMISSION
• Order – Spirochaetales • Habitat – human genital tract
• Genera • Transmission
o Borrelia o Sexual contact
o Treponema o Mother to fetus across the placenta
• The other family (Leptospiraceae) includes CLINICAL SYNDROME
one genus of medical PRIMARY SYPHILIS
importance: Leptospira • Occurs approximately 3 weeks after
STRUCTURE infection
• Long, slender, helically coiled, spiral, or
corkscrew-shaped bacilli
• Has an outer sheath or
glycosaminoglycan coating
o Inside the sheath is the outer
membrane
▪ Contains peptidoglycan
▪ Maintains structural
integrity of the organisms
• Endoflagella (axial filaments) – flagella-
like organelles in the periplasmic
space encased by the outer membrane
• Cytoplasmic tubules (body fibrils) – inside
the cell near the inner membrane
• Treponemes reproduce by transverse Chancre
fission • Chancre
Treponema pallidum o A single firm nontender, raised, red
lesion
o Located at the site of treponemal
invasion
▪ Penis
▪ Cervix
▪ Vaginal wall, or
▪ Anus
o Heals with or without therapy
o Spirochetes are plentiful within
the chancre
• Spread via hematologic and lymphatic
• Coiled spirochete
dissemination
• Not seen on Gram-stain – too thin
• Cannot be cultured in-vitro
o Lacks Krebs cycle enzymes
• Microaerophilic
DISEASES
• T. pallidum pallidum – venereal syphilis
• T. pallidum pertenue – yaws
BS BIOLOGY (MICROBIOLOGY TRACK) | 1
Bacteriology
SPIROCHETES • T. pallidum endemicum – endemic syphilis
• Large, heterogeneous group of spiral and (bejel)
motile bacteria • T. carateum – pinta
• Family – Spirochaetaceae HABITAT AND TRANSMISSION
• Order – Spirochaetales • Habitat – human genital tract
• Genera • Transmission
o Borrelia o Sexual contact
o Treponema o Mother to fetus across the placenta
• The other family (Leptospiraceae) includes CLINICAL SYNDROME
one genus of medical PRIMARY SYPHILIS
importance: Leptospira • Occurs approximately 3 weeks after
STRUCTURE infection
• Long, slender, helically coiled, spiral, or
corkscrew-shaped bacilli
• Has an outer sheath or
glycosaminoglycan coating
o Inside the sheath is the outer
membrane
▪ Contains peptidoglycan
▪ Maintains structural
integrity of the organisms
• Endoflagella (axial filaments) – flagella-
like organelles in the periplasmic
space encased by the outer membrane
• Cytoplasmic tubules (body fibrils) – inside
the cell near the inner membrane
• Treponemes reproduce by transverse Chancre
fission • Chancre
Treponema pallidum o A single firm nontender, raised, red
lesion
o Located at the site of treponemal
invasion
▪ Penis
▪ Cervix
▪ Vaginal wall, or
▪ Anus
o Heals with or without therapy
o Spirochetes are plentiful within
the chancre
• Spread via hematologic and lymphatic
• Coiled spirochete
dissemination
• Not seen on Gram-stain – too thin
• Cannot be cultured in-vitro
o Lacks Krebs cycle enzymes
• Microaerophilic
DISEASES
• T. pallidum pallidum – venereal syphilis
• T. pallidum pertenue – yaws
BS BIOLOGY (MICROBIOLOGY TRACK) | 1
