Aspergillosis

Revision as of 19:21, 6 June 2010 by Bara (talk | contribs) (Text replace - 'Intestine Diarrhoea - Pathology' to 'Diarrhoea')


  • Worldwide
  • Common laboratory contaminants
  • Widely found in nature
    • Colonise a wide range of substrates under different environmental conditions
    • Abundant in hay, straw and grain which have heated during storage
  • Pathogenic species include Aspergillus fumigatus, A. flavus, A. nidulans, A.niger and A. terreus
  • May cause primary or secondary disease
    • Infection may be acute, chronic or benign
  • Avians:
    • Diffuse infection of the air sacs
    • Diffuse pneumonic form
    • Nodular form involving the lungs
    • Spores are inhaled
    • Yellow nodules in the lungs and air sacs
    • The acute form usually affects young birds and is rapidly fatal (within 24-48 hours)
      • Signs include diarrhoea, listlessness, pyrexia, loss of appetite and loss of condition
      • Sometimes convulsions may occur
      • Resembles Pullorum disease
    • The chronic form usually occurs in adult birds and is sporadic, presenting with milder clinical signs
  • Cattle:
    • Infection can cause abortion and ocular infections
    • Infections involve the uterus, fetal membranes and fetal skin
    • Lesions are usually up to 2mm in diameter and contain asteroid bodies with a germinated spore in the centre
      • Acute infection causes miliary lesions
      • Chronic infections causes granulomatous and calcified lesions
  • Dogs, cats and sheep:
    • Infections occur, but infrequently
    • lungs and nasal cavity most usually affected
    • Disseminated form with granulomas and infarcts can occur in dogs
    • Pulmonary and intersitital forms can occur in cats
  • Grows on Sabauraud's Dextrose and Blood agar
    • White colonies intitially which turn green, then dark green, flat and velvety
    • Colony colour varies with species
  • Also grows on Czapek-Dox agar and 2% malt extract agar supplemented with antibacterial antibiotics
  • Microscopically:
    • Conidiophores with large terminal vesicles (only visible in the lungs and air sacs where there is access to oxygen)
      • Vesicle shape varies depending on the species
    • Is a common contaminant so repeated tests should be done for a definitive diagnosis
  • Serology:
    • Gel immunodiffusion for canine nasal asper