CLS06 - Parasitic Bacteria

  1. Mycoplasma general - unique characteristics, cultural considerations, habitat
    • unique: smallest known free-living organisms
    • NO CELL WELL (sterols provide shape)
    • culture: fastidious growth requirements
    • habitat: colonize mucosa of resp and urogen
    • *must be on the surface of the cell to grow
  2. Mycoplasma pneumoniae - diseases, transmission, colony morph,  ID, treatment
    • disease: asymptomatic, upper resp infection in children (mild), lower resp infection in adults (mild, but 1/3 progress to pneumonia)
    • may have rarely cause complications (arthritis, myocarditis, etc)
    • "walking pneumoniae" outbreaks (mild symptoms allow people to spread)
    • transmission: spread by aeresol droplets
    • colony: fried-egg morphology
    • media must be selective (normal resp flora will overgrow)
    • ID: PCR, serology
    • will grow on modified NYC agar (confused for N. gonnorhoaea)
    • treat: antibiotics that do not target cell wall
  3. Mycoplasma hominis and Ureaplasma urealyticum - diseases, treatment
    • diseases: Symptomatic in neonates (meningitis, abscess, chronic lung disease)
    • invasive disease in immunocomp (bacteremia, arthritis, would inf, pneumonia)
    • urogenital inf (prostatis, PID, urethritis, bacterial vaginosis) 
    • *women often asymp carriers
    • treatment: antibiotic that does not target cell wall
  4. Chlamydia general - unique char, treatment, life cycle
    • unique: obligate intracellular organisms (need our ATP)
    • cell wall less toxic
    • treat: susceptible to antibiotics
    • life cycle...
    • elementary body (EB) - infectious stage ( doesn't replicate), enters host cell then differentiates
    • reticulate body (RB) - binary fission within vacuoles, vacuoles enlarge and become inclusions, differentiate back to EB which exocytose to infect more cells (no harm)
    • *most damage from host response
  5. Chlamydia trachomatis - diseases, epidemiology, ID, treatment
    • diseases: trachoma - leading cause of preventable blindness, caused by different serovars than cause genital disease
    • urethritis/PID - frequent in women 15-24, damage is exacerbated by host inflammatory response
    • neonatal pneumonia/oculogenital infection - caused from mother with active infection during birth
    • *no scarring as in trachoma
    • lympogranuloma venerum - infection in lymph nodes (may become systemic)
    • *not in N. America
    • contributes to infertility and ectopic pregnancy
    • asymptomatic (50% men, 80% women!)
    • epidemiology: 60% of nongonococcal urethritis
    • contributes to infertility and ectopic pregnancy
    • ID: Genprobe (aptima) is most common method now (can be done with urine)
    • Giemsa stain cytology
    • culture similar to viral (labor intensive)
    • serology
    • treatment: antibiotics, avoid contact, public health monitors and contacts partners
  6. Chlamydia pneumoniae - disease, habitat, transmission, ID
    • disease: pneumonia, cold-like symptoms, atherosclerotic syndromes
    • habitat: human pathogen (no reservoirs)
    • 30-45% of population is infected
    • transmission: aerosolized droplets
    • ID: serology, direct cultivation from oropharynx
  7. Chlamydia psittaci - disease, habitat, transmission, ID, treatment
    • disease: Psittacosis ("parrot fever")
    • untreated fatalities 20%
    • aerosol in lung can disseminate through reticuloendothelial system
    • habitat: pathogen of birds, man is accidental host
    • transmission: infected birds -> diarrhea -> aerosolization
    • ID: serology, must be cultivated at biosafety 3
    • treatment: antibiotics, treat/quarantine infected birds
  8. Coxiella, Ehrlichia, Orientia, Rickettsia general - unique, treatment, habitat, virulence factors
    • unique: obligate intracellular parasites so small once thought to be viruses!
    • treat: antibiotics (tetracycline)
    • habitat: die quickly outside host cell (EXCEPT COXIELLA)
    • vir: intracellular growth protects from host resp
  9. Coxiella, Ehrlichia, Orientia, Rickettsia - arthropod vectors
    • tick - R. Ricketsii, E. chaffeensis, E. phagocytophilia, E. ewingii
    • mite - R. akari, O. tsutsugamushi
    • lice - R. prowazekii, R. quintana
    • flea - R. typhi
    • none - C. burnetii
  10. Rickettsia ricketsii - disease, transmission, epidemiology, ID, treatment
    • disease: Rocky mount spotted fever - replicates in endothelial cells leading to vasculitis, leaky vessels, hypovolemia, and potential organ failure (lack of blood delivery)
    • transmission: tick bite
    • epidem: most common Rickettsial pathogen in US
    • distr in W. hemisphere (SE atlantic and SC states)
    • ID: serology/Ag (can't plate)
    • treatment: tetracycline, avoid tick areas, no vaccine
  11. Rickettsia prowazekii - disease, transmission, epidemiology, ID, treatment
    • disease: epidemic typhus - fever, 40% have petichial rash, MORTALITY UP TO 66%
    • trans: human body louse (feces, not bite)
    • *unsanitary conditions favor spread (war, famine, etc)
    • epid: rare in US
    • ID: IFA
    • Treatment: tetracycline, louse control, vaccine available outside US
  12. Rickettsia typhi - disease, transmission, ID, treatment
    • disease: endemic typhus (low # in US)
    • trans: rat or cat flea
    • ID: IFA
    • treat: tetracycline, rodent control, no vaccine
  13. Orienta tsutsgamushi - Disease, transmission, ID, treatment
    • disease: scrub tyhus
    • trans: mites (chiggers) of rodents
    • ID: serology, symptoms
    • treat: tetracycline, avoid chiggers
  14. Coxiella bernetti - disease, unique char, habitat, transmission, ID, treatment
    • disease: Q fever - HIGHLY INFECTIOUS
    • abrupt onset (fever, chills, myalgia), chronic resp disease or other syndromes (myocarditis, hepatitis)
    • unique: morphology depends on life cycle stage
    • intracellular pathogen w/ extracellular form
    • replicates in acid env (lysosomes)
    • habitat: extracellular form extremely stable (soil)
    • reservoirs in multiple mammals, birds worldwide (except NZ)
    • trans: inhalation of aerosols OR contaminated milk
    • ID: serology (NO CULTURE)
    • treatment: tetracycline, stay away from infected animals, vaccine for humans and animals
Card Set
CLS06 - Parasitic Bacteria
CLS06 - Parasitic Bacteria