Spirochetes

• Borrelia spp.


  Helically coiled bacteria transmitted through arthropod vectors
• Borrelia spp.


  • Flexible twisted organisms resembling stretched spiral
  • Lice and ticks are vectors
• Borrelia recurrentis


  Agent of Louse-borne relapsing fever
• Borrelia hermsii/Borrelia parkeri


  Agents of Tick-borne relapsing fever
• Borrelia burgdorferi


  Agent of Lyme Disease
• Lyme Disease


  1. Appearance of lesion; erythema chronicum migrans (bull's eye rashes)

  2. Dissemination through blood; bones, CNS, heart, and liver

  3. Neurological abnormalities, arthritis, and skin lesion (chronic stage)
• Kelly's medium


  Culture medium for Borrelia
• Barbour Stoenner-Kelly's (BSK)


  Culture medium for Borrelia
• ELISA


  Serological test for Borrelia
• Western blot


  Gold standard serological test for Borrelia
• Treponema spp.


  Tightly twisted organism resembling cork screw
• Treponema pallidum subsp. pallidum


  Agent of syphilis (sexually transmitted infection)
• Syphilis


  1. Primary syphilis: hard chancre

  2. Secondary syphilis: condylomata lata (wart-like lesions)

  3. Latent syphilis: absence of clinical symptoms

  4. Tertiary syphilis: gummas, neurosyphilis
• Dark field microscope


  Used for direct microscopic examination of Treponema
• Penicillin


  Drug of choice for treatment of syphilis
• Jarisch-Herxheimer reaction


  Large quantities of toxins are released as the bacterium dies during treatment process
• Treponema pallidum subsp. pertenue


  Agent of yaws (chronic nonvenereal disease of skin and bones)
• Treponema pallidum subsp. endecume


  Agent of Bejel [Non-vereal syphilis and endemic syphilis]
• Treponema carateum


  Agent of pinta (ulcerative skin disease)
• Leptospira spp.


  Tightly twisted with one or both ends bent into a hook
• Leptospira interrogans


  Agent of leptospirosis (human and animals)
• Leptospirosis


  • Zoonosis
  • Shed in urine of animals
  • Transmission: direct contact with urine of animals
  • Infection may involve kidney, liver, and central nervous system
  • Weil's disease: severe form of leptospirosis
• Leptospira interrogans serovariants


  • icterohemorrhagiae – Weil's Disease
  • canicola – Infectious Jaundice
  • autumnalis – Fo'rt Bragg or Pretibial Fever
  • grippotyphosa – Marsch Fever
  • hebdomadis – 7-day Fever
  • mitis/Pomona – Swine-herd's disease
• EMJH Medium


  Culture medium for Leptospira
• Fletcher's and Stuart's


  Culture media for Leptospira (6-8 weeks)
• Chlamydia spp.


  • Formerly Bedsonia ("large virus")
  • Obligate intracellular bacteria – similar with Tropheryma whipplei
  • Gram (-) like CW; binary fission
  • Infectious particle – Elementary Bodies
• Chlamydia psittaci


  Agent of psittacosis or ornithosis (disease of birds, parrots, parakeets, and cockatoos)
• Chlamydia pneumoniae


  Associated with mild respiratory tract infections
• Chlamydia trachomatis subtypes


  • A, B, Ba, C: endemic trachoma
  • Inclusion conjunctivitis
  • D-K: Urethritis, cervicitis, pelvic inflammatory disease, epididymitis, infant pneumonia
  • L1, L2, L3: Lymphogranuloma venereum [STI]
• McCoy's cell


  Used for culture of Chlamydia
• FREI's Test


  Delayed hypersensitivity skin test for Lymphogranuloma venereum
• Mycoplasma spp.


  • Smallest free-living organisms (gram negative)
  • Found in plants and animals
  • Formerly known as pleuropneumonia-like organisms (PPLOs)
• Mycoplasma pneumoniae


  • Eaton's agent
  • Cause of community-acquired pneumonia and tracheobronchitis in children and young adults
  • Primary atypical pneumonia or walking pneumonia
• Mycoplasma hominis and Ureaplasma urealyticum


  • Genital mycoplasmas
  • Colonize adults asymptomatically
  • Cause of nongonococcal urethritis in males
  • M. hominis: Agent of salpingitis and postpartal fever in females
• Shepard's/A7B/ε-Agar


  Culture media for Mycoplasma
• Cold agglutinin (Anti-I)


  Serological test for Mycoplasma
• Rickettsia, Ehrlichia, Coxiella, and Rochalimaea

  Genera of Rickettsiae
• Coxiella


  Cannot survive outside animal host or insect vector EXCEPT C. burnetti
• Afipia felis


  • Associated with cat-scratch disease (CSD)
  • Despite its rare isolation, indirect evidence suggests that the organism may be more commonly linked to CSD than is currently appreciated
  • Due to lack of appropriate laboratory methods for detection