Atypical Organisms

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

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

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

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

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

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

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

Chlaymdia Intracellular parasite No cell wall 2 forms during development –Elementary bodies (EB) Dormant, infective –Reticulate bodies Intracellular inclusions Species –C. trachomatis –C. pneumoniae –C. psittaci

Chlamydia trachomatis Reportable STI 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

Chlamydia pneumoniae Community acquired Droplet transmission CS –Sinusitis –Bronchitis –Chronic cough –Pneumonia –+/- atherosclerosis Dx: FA Tx: AB

Chlamydia psittaci Zoonotic Parrot fever Aerosolized EB in feces CS –Flu like symptoms –Pneumonia Dx: serology Tx: AB Pv: husbandry Quarantine

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

Treponema Human pathogen Obligate intracellular parasite T. pallidum pallidum Fastidious – CH2O use –Host: FA, Protein, enzymes Double membrane –2 flagella –Lack of surface proteins STI (STD) Tx : AB [penicillins] Syphilis

CS/Stages –1 : Primary Active Blister –2 : Disseminated Latent Rash –3 : Tertiary CV (aneurysms) NS (meninges) Skin/Bone (Gummas) –4: Congenital Fetus (stillborn) 3 12

Treponema pallidum … T. p endemicum –“Bejel” –MM –gummas T. p pertenue –“Yaws” –Skin: granular, draining tracts T. carateum –“Pinta” –Skin papules  flat  Hyper & depigmentation

Borrelia Spirochete –Endoflagella –Extracellular parasite Species and Strains –B. burgdorferi B. andersoniii B. japonica B. valaisiana –B. lonestari –B. turcica –B. recurrentis Genetics –Linear chromosome –Plasmids Zoonotic Arthropods –Ticks –Fleas –Lice Dx: IF, serology, organism in blood

B. burgdorferi GN spirochete Deer mice host, deer Hard tick (Ixodes) spread (3x) Lyme’s disease CS –Bull’s eye rash –Myalgia –Neuropathy –Arthralgia  Chronic Arthritis »MO  IL-1, IL-6  TH 17 cells Dx: serology Tx: AB Pv: tick control, repellent

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

Leptospira Spirochete Zoonotic Species –L. interrogans (humans) –L. …….. Transmission –Contam Urine  water –Primary Hosts Rats Mice Moles –Secondary Hosts Dogs Deer Rabbits Raccoons Skunks Opossums

Leptospirosis CS –N/V/F/headache –Pneumonia –Migrates through tissues Renal Meningitis Liver failure (Weil’s Ds) Respiratory distress Dx: –Giemsa stain –titers Tx: –AB – fluids Pv: vaccinate animals NA Epidemic ~1620 (Pilgrims) Out breaks: Civil War, WWI, WWII

Questions?