atypicals

• medically important atypical microorganisms

  • Chlamydiaceae
  • Chlamydia trachomatis
  • Chlamydophila pneumoniae
  • Mycoplasma
  • Mycoplasma pneumoniae
  • Legionella pneumophila
• chlamydia trachomatis

  • intracellular microorganism
  • causes chlamydia
  • most common STD in US
  • site of infection
  • urogenital (nongonococcal urethritis) --> in some cases can involve cervicitis, endometritis
  • transmission: sexual
  • most pts are asymptomatic
  • diagnosis: PCR in urine (usually in combination w/ gonorrhea)
• chlamydophila pneumoniae

  • intracellular microorganism
  • causes respiratory infections (sinusitis, bronchitis, pneumonia) - usually either asymptomatic or mild resp symptoms
  • known as an atypical microogranism when talking about covering for respiratory pathogens (together w/ Mycoplasma pneumoniae and Liognella pneumophila)
  • diagnosis: PCR (resp sample)
• mycoplasma pneumoniae

  • smallest free-living bacteria, pleomorphic
  • do not have a cell wall --> no gram-stain
  • diagnosis: PCR
  • M. pneumoniae
  • causes bronchitis and atypical pneumonia
• legionella pneumophila

  • intracellular bacteria commonly found in water or moist environment
  • multiply in alveolar macrophages, monocytes, and alveolar epithelial cells in humans
  • transmission: inhalation of aerosols
  • contaminated water systems (hot tubs/spas, large plumbing systems, hot water tanks, etc.)
  • rising incidence but still relatively uncommon
• legionella pneumophila (cont.)

  • causes a mild respiratory illness (Pontiac fever) or a more severe pneumonia (Legionnaire's disease)
  • severe disease usually in elderly, COPD, smokers, immunocompromised pts
  • diagnosis: urine antigen test --> detects Legionella serogroup 1 - specific LPS