Difference between revisions of "Chlamydia and Chlamydophila species"

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*Only grow in presence of living eukaryotic cells
 
*Only grow in presence of living eukaryotic cells
 
*Unable to synthesis ATP therefore require intermediates from host cells
 
*Unable to synthesis ATP therefore require intermediates from host cells
*
+
*Grow in embyonated eggs and McCoy cells as well as animal tissues
 +
*Not stained by Gram stain
 +
*Kosters (modified Ziehl-Neelson, small red rods) or fluorescent antibody stain required for detection
 +
*Blue inclusions in cytoplasm of Giemsa-stained cels
 +
*Antigen detection kits for diagnosis from swabs
  
  
Line 30: Line 34:
 
*Reticulate body has un-crosslinked peptidoglycan, which is cross-linked to form elementary bodies
 
*Reticulate body has un-crosslinked peptidoglycan, which is cross-linked to form elementary bodies
 
*Elementary bodies released from dying host cells to infect other cells
 
*Elementary bodies released from dying host cells to infect other cells
 +
*Persistent infections
 +
*Many infections subclinical due to intracellular existence of ''chlamydia'' preventing inflammatory reactions
 +
*Clinical infections occur in non-natural host species
 +
 +
 +
===''Chlamydophila psittaci''===
 +
 +
*Causes notifiable psittacosis in birds
 +
 +
 +
===''Chlamydophila abortus''===
 +
 +
*Ovine enzootic abortion
 +
*Contagious ovine abortion in late pregnancy
 +
*Infection via ingestion or inhalation causes a bacteraemia
 +
*Bacteria localise in placenta and cause placentitis, leading to abortion
 +
*Abortion rates may reach 30%
 +
*Fertility not impaired
 +
*Survival of elementary bodies in faeces and wild birds are a source of infection from one lambing season to the next
 +
*Ewes may be carriers for several years
 +
*Venereal transmission from infected rams
 +
*Some immunity develops after infection, protecting ewes from subsequent disease
 +
*Vaccines prevent infection but will not clear infection from persistently-infected animals
 +
*Vaccination of ewe lambs
 +
 +
 +
===''Chlamydophila felis''===
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 +
*Host adapted species in cats
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*Feline interstitial pneumonia and conjunctivitis
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*Diagnosis by antigen detection in ocular/nasal secretions - ELISA, PCR, Kosters, fluorescent antibody test
 +
*Vaccine
  
  
===Clinical infections===
 
  
  

Revision as of 09:36, 18 May 2008

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Chlamydophila psittaci involved in feline rhinotracheitis together with herpes virus 1 C.psittaci more frequently infects the conjunctival epithelium -> chronic conjunctivitis, see feline chlamydiosis

Overview

Characteristics

  • Obligate intracellular bacteria
  • Gram negative bacteria with outer membrane, LPS, ribosomes, DNA and RNA
  • Peptidoglycan cell wall resistant to lysozyme
  • Only grow in presence of living eukaryotic cells
  • Unable to synthesis ATP therefore require intermediates from host cells
  • Grow in embyonated eggs and McCoy cells as well as animal tissues
  • Not stained by Gram stain
  • Kosters (modified Ziehl-Neelson, small red rods) or fluorescent antibody stain required for detection
  • Blue inclusions in cytoplasm of Giemsa-stained cels
  • Antigen detection kits for diagnosis from swabs


Pathogenesis and pathogenicity

  • Elementary body, the infective form, phagocytosed and internalised into host epithelial cells
  • Transformation into larger reticulate body
  • 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
  • Elementary bodies released from dying host cells to infect other cells
  • Persistent infections
  • Many infections subclinical due to intracellular existence of chlamydia preventing inflammatory reactions
  • Clinical infections occur in non-natural host species


Chlamydophila psittaci

  • Causes notifiable psittacosis in birds


Chlamydophila abortus

  • Ovine enzootic abortion
  • Contagious ovine abortion in late pregnancy
  • Infection via ingestion or inhalation causes a bacteraemia
  • Bacteria localise in placenta and cause placentitis, leading to abortion
  • Abortion rates may reach 30%
  • Fertility not impaired
  • Survival of elementary bodies in faeces and wild birds are a source of infection from one lambing season to the next
  • Ewes may be carriers for several years
  • Venereal transmission from infected rams
  • Some immunity develops after infection, protecting ewes from subsequent disease
  • Vaccines prevent infection but will not clear infection from persistently-infected animals
  • Vaccination of ewe lambs


Chlamydophila felis

  • Host adapted species in cats
  • Feline interstitial pneumonia and conjunctivitis
  • Diagnosis by antigen detection in ocular/nasal secretions - ELISA, PCR, Kosters, fluorescent antibody test
  • Vaccine



Diagnosis

Treatments