Atypical Organisms Mycoplasmas Characteristics Lack cell walls Pleomorphic

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 • Fastidious – CH 2 O use – Host: FA, Protein, enzymes • Double membrane – 2 flagella – Lack of surface proteins • STI (STD) • Tx : AB [penicillins] • Syphilis

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

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 (3 x) 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, WWII

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