Atypical Organisms

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Atypical Organisms
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Mycoplasmas

• Characteristics
• Lack cell walls
• Pleomorphic (fried egg)
• NM
• FA-Obligate anaerobes
• Examples
• M. genitalium
• M. pneumoniae
• M. hominis
• Diseases
• Pneumonia
• Urogenital infections

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Rickettsias

• GN (very little PG)
• Intracellular parasites
• Aerobic
• Slow reproduction
• Cell lysis for release
• Arthropod vectors
• Species
• R. rickettsii
• R. typhi
• R. prowazekii

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RMSF

• R. rickettsii
• Dermacentor tick
• STD for ticks
• Salivary gland ? host blood
• Humans, rodents
• Damage endothelium
• CS
• F/N/V/myalgia
• Spotted rash, pettechiae
• Gangrene, paralysis
• Encephalitis, death
• Dx IFA, agglutination
• Tx AB, remove tick

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Epidemic Typhus

• R. prowazekii
• Pediculis louse
• Human host
• CC/CS
• Fever, depression
• Rash
• Dx IFA
• Tx AB
• Pv hygeine, sanitation

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Murine (Endemic) Typhus

• R. typhi
• Flea (rat, cat)
• Rodent (murine) reservoir
• Human exposure to fleas
• CC/CS
• Fever, headache, myalgia
• Rash on trunk and chest
• Dx IFA
• Tx AB
• Pv Flea control

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Scrub Typhus

• Orientia tsutsugamushi
• Red Mites (chiggers)
• Rodents and Humans
• Pacific
• Asia, Japan
• Australia
• CS
• Fever, headache
• Myalgia, lymphadenopathy
• Rash on trunk
• Tx Ab
• Pv mite control, repellent

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Ehrlichia and Anaplasma

• Emerging disease (1987)
• Intracellular parasite in WBC
• Hard Ticks
• Lone Star (Ambylomma)
• Deer (Ixodes)
• Dog (Dermacentor)
• Species
• E. chaffeensis
• E. equi (Anaplasma)
• CC/CS
• Fever, rash, leukopenia
• Dx IFA
• Tx AB
• Pv Tick control

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Chlaymdia

• Intracellular parasite
• No cell wall
• 2 forms during development
• Elementary bodies
• Dormant, infective
• Reticulate bodies
• Intracellular inclusions
• Species
• C. trachomatis
• C. pneumoniae
• C. psittaci

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Chlamydia trachomatis

• Reportable STD
• Human cells with EB receptors
• Respiratory
• Female repro
• Lower GI (rectum)
• CS
• Ocular lesions (trachoma) ? scar cornea ?
  blindness
• or
• Lymphogranuloma ?
• Buboes ?
• Genital sores ?
• Urethritis, vagninitis, proctitis
• Dx Giemsa stain, culture
• Tx AB
• PV safe sex

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Chlamydia pneumoniae

• Community acquired
• Droplet transmission
• CS
• Sinusitis
• Bronchitis
• Chronic cough
• Pneumonia
• /- atherosclerosis
• Dx FA
• Tx AB

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Chlamydia psittaci

• Zoonotic
• Parrot fever
• Aerosolized EB in feces
• CS
• Flu like symptoms
• Pneumonia
• Dx serology
• Tx AB
• Pv husbandry
• Quarantine

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Spirochetes

• GN, helical/coiled
• Endoflagella
• Corkscrew shape
• Genera
• Treponema
• Borrelia
• Leptospira

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Treponema

• Human pathogen
• Obligate intracellular parasite
• T. pallidum pallidum
• Fastidious
• STD
• Tx AB
• Syphilis
• 4 stages (3 active)
• 1) Chancre at site blister
• Spreads via blood
• 2) Malaise, rash
• Latent (hyper immune)
• 3) Gummas

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Treponema pallidum

• T. p endemicum
• Bejel
• MM
• gummas
• T. p pertenue
• Yaws
• Skin granular, draining tracts
• T. carateum
• Pinta
• Skin papules

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Borrelia

• GN spirochete
• B. burgdorferi
• Deer mice host, deer
• Hard tick (Ixodes) spread (3x)
• Lymes disease
• CS
• Bulls eye rash
• Myalgia
• Neuropathy
• Arthralgia ? Chronic Arthritis
• MO ? IL-1, IL-6 ? TH 17 cells
• Dx serology
• Tx AB
• Pv tick control, repellent

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Relapsing Fever

• Borrelia recurrentis
• Arthropod vector
• Lice (human)
• Soft Tick
• Rodent reservoir
• Humans
• CS fever, malaise
• Dx Blood smear
• Tx AB
• Pv vector control

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Leptospira

• Spirochete
• Zoonotic
• Species
• L. interrogans (humans)
• L. ..
• Transmission
• Contam Urine ? water
• CS
• Migrates through tissues
• Renal
• Dx Giemsa stain, titers
• Tx AB, fluids
• Pv vaccinate animals

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Questions?