Chlamydiae

Chlamydiae

1. characteristics

   • Gm - cocci
   • obligate intracellular pathogen
   • 2 cellular forms
     • Elementary bodies
       • .25um
       • infectious/ invasive form
       • EXTRACELLULAR
       • no division
     • reticulate bodies
       • .6-.8um
       • cell division -> binary fission
       • non infectious
     • unique dev. cycle
   • invasive
   • lack peptidoglycan cell wall, but have the genes for peptidoglycan
   • non motile
   • v small
     • .25-.8um
   • small genomes
     • 1-1.2mbp
   • autotrophic for 3/4 nucelotide triphosphates and several amino acids
   • old disease
     • caused eye infections
     • New disease as STD in 1970
       • the STD involved from the eye infection
         • reported to CDC in 1989

2. animal, human, bird hosts

3. C. trachtomatis

   • most common bacterial STI
     • 2nd most common -> gonn
   • cause STD, eye infection, resp infections
   • infects mucosal membranes
     • cervix, rectum, urethra throat, eye
   • transmission
     • sex w/ secretions
     • during birth
       • baby pneumonia
     • infected secretion from genitals to eye
   • trachoma
     • leading case of blindness
       • 50 mil cases, 3-10 mil are blind
       • 15-20 yrs after infection
     • common in Africa, Middle East, Asia
   • most studied
   • virulence factors
     • type III secretion
     • translocated actin recruiting protein
       • use actin to move
     • chlamydial protease like activity factor (CPAF)
     • major outer membrane protein (MOMP)
     • putative autotransporter proteins
   • diagnostics
   • treatment
     • antibiotics
       • doxycycline
       • ofloxacin
       • erythromycin
       • azithromycin
         • 1 dose, 7 day abstinence
   • symptoms
     • women
       • discharge
       • dysuria
       • pelvic pain
       • bleeding
       • 75% asymptomatic
     • men
       • discharge
       • dysuria
       • red tip
       • 50% asymptomatic

4. 2 genus

   • chlamydia
   • chlamydophila

5. prevalence

   • 92 mil cases in 1999
   • current est 140mil
   • trachoma (eye infection) not included

6. Chlamydia psittaci

   • causes human psittacosis
     • zoonotic pneumonia
     • 100-200 cases/yr in US
   • diagnosis
     • blood based assay
   • treatment
     • doxycycline
     • tetracycline
     • azithromycin
     • erythromycin