Spiro

• Spirochetes


  Tightly coiled organisms, unlike rods and spheres
• Spirochetes

  • Have unusual morphologic features
  • Exhibit various types of motility patterns
  • They have fibrils or axial filaments which are flagella-like organelles that wrap around the bacterial cell wall and facilitate motility
• Genera of Spirochetes

  • Borrelia
  • Leptospira
  • Treponema
• Treponema


  The name of the genus came from the Greek words trepein, which means "to turn" and nema, which means "thread", that when combined means turning thread
• Treponema

  • Species are difficult to visualize with brightfield microscope but can be best observed with darkfield microscope
  • Most species stain poorly with gram staining (faintly gram negative)
  • Negative staining: staining the background
  • Reproduction: transverse fission
• Treponema pallidum subsp. pallidum


  • Etiologic agent of syphilis
  • It is microaerophilic
  • Remains viable in whole blood or plasma for at least 24 hours, which is of potential importance in blood transfusion
  • Appears white against dark background and long with fine spirals that have 10 – 13 coils and three fibrils/ periplasmic flagella
• Treponema pallidum subsp. pallidum is the etiologic agent of syphilis (French Disease/ Italian Disease/ The Great Pox)
• Syphilis


  • A disease of the blood vessels and perivascular areas
  • It is also known as the "great imitator" because it can copy and assume many clinical manifestations
• Transmission of syphilis

  • Sexual contact
  • Congenital (vertical) transmission
  • Skin contact with an active lesion
  • primary lesion: chancre
  • secondary lesion: condylomata lata
  • Transfusion of fresh blood
  • Injuries from contaminated needle sticks
  • Handling of specimens
• Stages of Syphilis

  • Primary Syphilis
  • Secondary Syphilis
  • Latent Stage
  • Tertiary or Late Syphilis
• Primary Syphilis


  • Characterized by the appearance of hunterian or hard chancre, which is an infectious primary lesion that is painless and usually seen at the site of inoculation (most commonly on genitalia)
  • Develops 10 – 90 days after infection
  • No systemic signs or symptoms are evident at this stage
• Secondary Syphilis


  • Develops 2 – 12 weeks after the appearance of chancre
  • All lesions that are observed/seen in this phase are highly infectious
  • The chancre heals but the organisms are still disseminated in various tissues via the bloodstream
  • Symptoms: fever, sore throat, weight loss, headache, and rashes (palms and soles)
• Latent Stage


  • A period in which the disease becomes subclinical but not necessarily dormant
  • Occurs within more than a year of infection
  • Diagnosis can be made only by serological tests
• Tertiary or Late Syphilis


  • The tissue-destructive phase
  • Appears 10 – 25 years after initial infection
  • Individuals are not usually infectious
  • Complications: Neurosyphilis, Cardiovascular abnormalities, Eye disease, Granuloma-like lesions (Gummas)
• Laboratory Diagnosis of Syphilis

  • Direct visualization: Dark field microscopy – corkscrew motility
  • Special stains: Fontana Tribondeau, Levaditi Silver Impregnation
  • Serological test: Non-specific (VDRL, RPR, USR), Specific (TPI, TPA, FTA-ABS)
• Treponema pallidum subsp. pertenue


  • Etiologic agent of yaws or frambesia tropica
  • Acquired by direct contact through skin breaks with an infected lesion
  • Yaws is non-venereal infection that is characterized by random bodily chronic ulcerative sores which eventually lead to tissue and bone destruction and then to crippling if left untreated
  • Affects the skin, bones, cartilages, and joint
  • The most visible effect of this disease is the lesions in the skin
• Treponema pallidum subsp. endemicum


  • Etiologic agent of endemic non-venereal syphilis or bejel
  • Transmitted by direct contact with active lesions and contaminated fingers and utensils
  • Bejel is non-venereal syphilis that is characterized by the appearance of a primary lesion usually on or near the mouth followed by the development of pimple-like sores on the trunk, arms, and legs
• Treponema carateum


  • Etiologic agent of pinta or carate
  • Acquired by contact with infected skin
  • Pinta is an infection of the skin that is characterized by the appearance of a primary lesion or a gradually enlarging papule with enlargement of the regional lymph node
• T. pertenue, T. endemicum, and T. carateum infections are mostly on African countries – Risk factors: far-flung areas (difficult access to medical attention), lack of education
• Borrelia

  • Slow growing spirochetes that multiply by binary fission
  • Composed of 3 – 10 loose coils and is actively motile
  • They have 15 – 20 axial filaments
  • They stain well with Giemsa stain, and can be visualized by using brightfield microscopy
• Borrelia recurrentis


  • Etiologic agent of Louse-born / epidemic / European relapsing fever
  • Vector: Louse (Pediculus humanus)
  • Reservoir: Humans
• Borrelia burgdorferi


  • Etiologic agent of Lyme disease
  • Transmission: Bite of Ixodes ticks
  • 3 stages of Lyme Disease:
  • Appearance of lesion (erythema chronicum migrans), "bull's eye' rashes
  • Dissemination through blood
  • Neurological abnormalities, arthritis, and skin lesion
• Laboratory Diagnosis of Borrelia

  • Microscopic examination (Giemsa or Wright's stain)
  • Culture (Barbour Stoenner Kelly Medium or Chick Embryo)
  • Slow grower: 7 - 14 days at 35 C
  • Serodiagnosis (ELISA and IFA)
• Leptospira


  • Thin, flat, flexible, tightly coiled spirals with one or both ends are bent to form a hook
  • Transmitted through contact with urine of infected rats
  • Thrives in polluted water
• Leptospira interrogans serovars

  • icterohemorrhagiae (Weil's disease)
  • canicola (Infectious jaundice)
  • automnalis (Fort Bragg/ Pretibial fever)
  • hebdomadis (7 day fever)
  • mitis/pomona (Swine herd disease)
• Leptospira culture


  Fletchers / Stuart medium, Ellinghausen-McCullough-Johnson-Harris culture medium
• • Non-specific serological test: using cardiolipin, lecithin antigen to detect Ab
  • VDRL: suggested for neurosyphilis using CSF as sample
  • RPR: rapid plasma reagin
  • USR: unheated serum reagin; based on flocculation test to detect anti-lipoidal antibodies in human serum
• • Specific serological test: organisms are used as antigens
  • TPI – Treponema pallidum immobilization test
  • TPA – Treponema pallidum antibodies
  • FTA-ABS – Fluorescent Treponema Antibody – Absorption test