Obligate Intracellular Bacteria: Chlamydia, Mycoplasma, Rickettsia

Coxiella burnetii

-Aerosol transmission (EASY TO TRANSMIT) ---Animal to human -Ingestion -Q FEVER ---Fever, pneumonia, hepatitis, skin eruptions, encephalitis, meningitis, myocarditis, pericarditis...severity ranges from asymptomatic to fatal

Rickettsia

-Diagnoses though clinical manifestations and patient history -Biosafety Level 3 - HIGHLY INFECTIOUS TO LAB STAFF -HIGHLY AEROSOLIZED -ID by Weil-Felix reaction -detects antibodies in serum, not specific (antibody - antigen test) -Confirm ID by microimmunofluorescence -PCR

Chlamydia and Chlamydophila

-Diseases: ---Chlamydia trachomatis -----Trachoma (eye) - LEADING PREVENTABLE CUASE OF BLINDNESS, congenital transmission ------NGU (Non gonococcal urethritis), epididymitis, cervicitis, endometritis, salpingitis (PID/pelvic inflammatory disease), sexual transmission ---Chlamydophila pneumoniae ------Mild pneumonia, pharyngitis, bronchitis ------Can lead to cardiovascular disease ---Chlamydophila psittaci ------Psittacosis (resp) human disease associated with birds (seen in parrots)

Rickettsia spp. and Orienta Transmitted by arthropod vector

-Diseases: (Focus on what organism causes what disease) ---R. rickettsia ------ROCKY MOUTIAN SPOTTED FEVER ------DOG TICKS (vector) ---R. typhi (Warm and humid climates) ------MURINE TYPHUS, ENDEMIC TYPHUS ------FLEAS ---R. prowazekii ------Brill-Zinsser disease, epidemic typhus ------Louse feces ---O. tsutsugamushi (Asian countries) ------Scrub typhus

ID of C. burnetii

-Does not Gram stain -cell cultures (DANGEROUS) -Immunodiagnostic procedures, IFA, molecular

Chlamydia

-Entry ---Extracellular form "Elementary body" (EB) binds to receptors on epi's ---Spread/multiplication ------Exits cell in reproductive form "reticulate body" (RB) ------Replicates by fission -RB replicates within the vacuole to form new RBs -Later in infection, RBs redifferentiate into EBs, which then infect more cells -EB form is not active, but INFECTIOUS -RB form (inside cell) not infectious, but ACTIVE

Ehrlichia and Anaplasma

-GNR -Invade bone marrow-derived cells ---"Intraleukocytic" pathogens -Diseases: ---E. chaffeensis: Human monocytic ehrlichiosis ---A. phagocytophilum: anaplasmosis aka. Human granulocytic ehrlichiosis -TICKBORN

Mycoplasma hominis and Ureaplasma urealyticum

-Genitourinary tract -Colonization can occur due to sexual contact -Can colonize infants at birth -CAN CAUSE NEONATAL PNEUMONIA -Culture ---A7 media ------M. hominis - fried-egg ------U. urealyticum - bird's nest -M. hominis, M. genitalium ---NGU -Non gonococcal urethritis ------Usually caused by C. trachomatis ------Neonatal respiratory infection

Morula

-In Ehrlichia and Anaplasma ---Elementary bodies form a pleomorphic inclusion that matures into a compact cluster of cells called a morula

ID of Ehrlichia an Anaplasma

-Leukocyte cell culture -Immunodiagnostic methods (Best Way) -Indirect Fluorescent AB (IFA) ---Detects antibodies in patient serum -PBS or buffy coat preparations -Diagnosis based on patient history

Obligate Intracellular Bacteria: Chlamydia, Mycoplasma, and Rickettsia

-Must live within host cells -Cannot be grown on artificial media ---Chicken eggs, animal models, cell cultures -Chlamydia -Chlamydophila -Mycoplasma/Ureaplasma -Rickettsia -Orienta -Ehrlichia -Anaplasma -Coxiella

Chlamydia

-Obligate intracellular parasites ---Classified as bacteria ---Gram-negative-like cell wall -Contain DNA and RNA -Utilizes host ATP for energy

Rickettsiae

-Obligate intracellular pathogen -Rickettsia, Ehrlichia, Coxiella, Rochalimaea ---All share same antigenic properties and similar pathogenesis ------Induce endothelial cells of host's blood vessels to engulf them and then are carried into cytoplasm ------Multiply in cytoplasm and cause cell injury/death ------Lead to vascular lesions and damage throughout body ---All except for Coxiella cannot survive extracellularly

Mycoplasma

-Pleomorphic due to LACK OF CELL WALL -Contain DNA and RNA -Ferment glucose -Hydrolyze urea -Utilize arginine -Several species exist ---Very few infect humans -Simple small bacteria -Requires complex enriched media for growth -Found in mucous membranes of the genital tract and respiratory tracts

Rickettsia and Orienta spp.

-Presence of a rash -Arthropod-borne

Diagnosis of Chlamydia

-Require cell cultures for growth -Staining for chlamydial inclusions ---Iodine: glycogen light to dark brown ---Giemsa: purple inclusions ---Fluoroscein-labeled serum -ELISA -GenProbe, ProbeTec -(PCR testing is best way)

C. trachomatis

-Serotypes ---A - C ------Conjunctivitis and trachoma ---D - K ------Urethritis, cervicitis, endometritis, infertility, infant conjunctivitis and pneumonia (STD) ---L1 - 3 ------Lymphgranuloma venereum (LGV) ---------Initially painless genital ulcer ---------Followed by lymphadenopathy and buboes ---------Goes systemic

Mycoplasma pneumoniae

-Spread through direct respiratory contact -Impairs ciliary function -Primary ATYPICAL PNEUMONIAE ---Dry cough ---"WALKING PNEUMONIAE" ------Patchy infiltrates, mono cells in gram stain -Pharyngitis, ear infections -Difficult to culture ---E-agar - FRIED EGG -Cold-agglutinins ---Non-specific antibodies produced in response to infection -ELISA -Fluorescent antibody testing -A7 media -Di-phasic liquid media (flask with agar and liquid) ---Incubate upside down (to increase humidity) -Takes a long time to grow -Have to look at colony under microscope

Treatment of Chlamydia

-Tetracycline -Fluoroquinolones -C. trachomatis - sulfonamides also -GOOD PROGNOSIS IF TREATED

Chlamydia

-Unique developmental cycle ---Elementary bodies ------Metabolically inactive and infectious ------Can survive extracellularly ---Reticulate bodies ------Metabolically active and noninfectious ------Cannot survive extracellularly

Chlamydia

-Virulence ---Binds to epi cells ---Host immune response responsible for inflammation and scarring