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Chlamydia and Chlamydophila species (view source)
Revision as of 09:49, 18 May 2008
, 09:49, 18 May 2008no edit summary
*Blue inclusions in cytoplasm of Giemsa-stained cels
*Blue inclusions in cytoplasm of Giemsa-stained cels
*Antigen detection kits for diagnosis from swabs
*Antigen detection kits for diagnosis from swabs
*Two morphological forms
**Elementary body, the infective extracellular form, which is small, metabolically inert and osmotically stable; surrounded by cytoplasmic membrane, outer membrane with LPS, but no peptidoglycan
**Retiuculate body: larger, metabolically active, osmotically fragile
===Pathogenesis and pathogenicity===
===Pathogenesis and pathogenicity===
*Elementary body, the infective form, phagocytosed and internalised into host epithelial cells
*Elementary body enters host epithelial cells by receptor-mediated endocytosis
*Transformation into larger reticulate body
*Transformation into larger reticulate body within endosome; known as an inclusion
*Reticulate body divides by binary fission to form many new chlamydia cells
*Reticulate body divides by binary fission to form many new chlamydia cells
*Reticulate body has un-crosslinked peptidoglycan, which is cross-linked to form elementary bodies
*Reticulate bodies mature and condense to form elementary bodies
*Elementary bodies released from dying host cells to infect other cells
*Elementary bodies released from dying host cells after about 72 hours to infect other cells
*Persistent infections
*Persistent infections can occur if replication delayed by environmental conditions
*Many infections subclinical due to intracellular existence of ''chlamydia'' preventing inflammatory reactions
*Many infections subclinical due to intracellular existence of ''chlamydia'' preventing inflammatory reactions
*Clinical infections occur in non-natural host species
*Clinical infections occur in non-natural host species