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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
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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
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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
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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
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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 responseneonatal 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
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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
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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
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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
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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
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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
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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
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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
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Orienta tsutsgamushi - Disease, transmission, ID, treatment
- disease: scrub tyhus
- trans: mites (chiggers) of rodents
- ID: serology, symptoms
- treat: tetracycline, avoid chiggers
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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 formreplicates 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
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