SPIROCHETES

• Borrelia burgdorferi is the causative agent of Lyme disease.
• Lyme disease can be transmitted by ticks, causing skin lesions called "erythema migrans."
• Borrelia spp.


  Helically coiled bacteria transmitted through arthropod vectors
• Borrelia spp.


  • Flexible twisted organisms resembling stretched spiral
• Borrelia recurrentis


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

  Tick-borne relapsing fever
• Borrelia burgdorferi


  Agent of Lyme Disease
• Borrelia burgdorferi


  1. 3 stages:

  2. I: appearance of lesion; Erythema chronicum migrans (bull's eye rashes)

  3. II: dissemination through blood; bones, CNS, heart & liver

  4. III: neurological abnormalities, arthritis & skin lesion (chronic stage)
• Borrelia spp. Laboratory diagnosis

  • Culture: Kelly's medium, Barbour Stoenner-Kelly's (BSK)
  • Serological tests: ELISA, Westernblot: gold standard
• Treponema spp.


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


  Agent of venereal syphilis
• Treponema pallidum subsp. pallidum Transmission


  Sexual contact, direct transmission & transplacental route (baby is affected/vertical transmission)
• Congenital syphilis


  Hutchinsonian Triad: Notched teeth, Keratitis, Eczema
• Treponema pallidum subsp. pallidum Stages (in adults)

  • Primary syphilis: hard chancre (painless & firm)
  • Secondary syphilis: condylomata lata (wart-like lesions)
  • Latent syphilis: absence of clinical symptoms (+ serologic tests)
  • Tertiary syphilis: gummas, neurosyphilis (CNS)
• Treponema pallidum subsp. pallidum Laboratory diagnosis

  Direct microscopic examination using Dark field microscope, Serological tests
• Treponema pallidum subsp. pallidum Treatment

  Heavy metals: Arsenic, Arsphenamine, Salvarsan, Drug of choice: Penicillin, Jorisch-Herxheimer reaction
• Treponema pallium subsp. pertenue


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


  Agent of Bejel (lesion in oral cavity, oral mucosa, skin, bones & nasopharynx)
• Treponema carateum


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


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


  Non-pathogenic, Found in water & soil
• Leptospira interrogans


  Agent of leptospirosis (human and animals)
• Leptospira interrogans Transmission


  Direct contact with urine of animals
• Principal leptospiral diseases


  • Icterohemorrhagiae: Weil's disease
  • canicola: Infectious jaundince
  • autumnalis: Fo'rt Bragg or Pretibial fever
  • grippotyphosa: Marsch fever
  • hebdomadis: 7-day fever
  • mitis/Pomona: Swine-herd's disease
• Leptospira interrogans Culture


  Specimen: Blood (early infection); Urine (2nd week), Media: Ellinghausen-McCullough-Johnson-Harris, Fletcher's & Stuart's (6-8 weeks), Usually use serologic tests and clinical findings
• Chlamydia spp.


  Formerly Bedsonia ("large virus"), Obligate intracellular, Gram (-) like CW; binary fission, Infectious particle: Elementary bodies
• Chlamydia psittaci


  Agent of Psittacosis or Ornithosis (disease of birds, parrots, parakeets & cockatoos)
• Chlamydia pneumoniae


  Associated with mild respiratory tract infections, TWAR (Taiwan Acute Respiratory) strain
• Chlamydia trachomatis Subtypes


  • A, B, Ba, C: Endemic trachoma (multiple/ persistent infections that leads to blindness)
  • D-K: Urethritis, cervicitis, pelvic inflammatory disease, epididymitis, infant pneumonia
  • L1, L2, L3: Lymphogranuloma venereum
• Chlamydia trachomatis Laboratory diagnosis

  Culture: McCoy's cell, FREI's test: delayed hypersensitivity skin test for LGV
• Mycoplasma spp.


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


  Eaton's agent, Cause of community-acquired pneumonia & tracheobronchitis in children and young adults, Primary atypical pneumonia/ Walking pneumonia
• Mycoplasma hominis & Ureaplasma urealyticum

  Genital mycoplasmas, Colonize adults asymptomatically, Cause of nongonococcal urethritis in males, M. hominis: Agent of salpingitis & postpartal fever in females
• Mycoplasma spp. Laboratory diagnosis

  Culture: Shepard's/ A7B/ E-Agar ("fried egg" colonies), Serologic tests: Cold agglutinin (Anti-I)
• Ricketssiae


  Genera: Rickettsia, Ehlichia, Coxiella & Rochalimea, Gram (-) obligate intracellular bacteria, Vector transmitted (lice, fleas & ticks), Coxiella: cannot survive outside animal host or insect vector EXCEPT C. burnetti
• Rickettsial diseases


  • Spotted Fever, Typhus, Scrub typhus, Q fever, Ehrlichiosis
• Bartonella spp.


  Organism, Habitat, MOT, Infection
• 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