Equis ISSN 2398-2977

Aspergillus spp

Contributor(s): Susan Dawson, Richard Walker

Introduction

Classification

Taxonomy

  • Genus:Aspergillus.
  • Fungi imperfecti(no perfect state has been found).

Etymology

  • Latin:aspergere- to sprinkle.

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Clinical Effects

Epidemiology

Habitat

  • Soil, vegetation, feedstuffs, especially fermented plant material.

Transmission

  • Inhalation or ingestion of fungus or preformed toxin from the environment.

Pathological effects

  • Depends on impaired defenses in host to assume pathogenic role.
  • Infected animals may develop circulating antibodies, but these have no protective role.
  • Resistance may rely on cell-mediated immunity.
A. fumigatus and other invasive species
  • Produces hemolysins, proteolytic enzymes and other toxic factors but their role in pathogenesis is not known.
  • Horses: guttural pouch mycosis   Guttural pouch: mycosis  , nasal granulomas, placentitis   Placenta: placentitis - bacterial  , pulmonary infections, keratomycosis   Aspergillosis  . Allergens may be implicated in recurrent airway obstruction   Lung: recurrent airway obstruction (RAO)  .
  • Dogs: chronic rhinitis, systemic infections.
  • Cattle: abortion, pneumonia, mastitis.
  • Birds: pneumonia, tracheitis, air sacculitis, neurologic disease.
  • Humans: local infection, generalized infection and allergic reactions. (Often affects immunocompromised patients.)
  • Cats: rare, pneumonia.
    Mycotoxin-producing species
  • Mycotoxins (including alfatoxins), are secondary fungal metabolites which cause a range of clinical symptoms.
  • Alfatoxins are hepatotoxic, teratogenic, mutagenic and carcinogenic.
  • Clinical effects include immunosuppression, nervous system signs, decreased food conversion and decreased milk yield.

Other Host Effects

  • Opportunistic pathogens or production of mycotoxins.

Control

Control via chemotherapies

Vaccination

  • Not available.

Other countermeasures

  • Prevention of contamination at all stages of food production, eg by rapid drying of harvested crops and use of preservatives.
  • Keep out of dusty, enclosed environment.
  • Avoid feeding hay and silage that has deteriorated or appears moldy.
  • Decontaminate feedstuffs by physical removal, thermal inactivation, irradiation, microbial degradation and chemical treatment.

Diagnosis

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Tremaine W H, Clarke C J & Dixon P M (1999) Histopathological findings in equine sinonasal disorders. Equine Vet J 31 (4), 296-303 PubMed.
  • McGorum B C, Dixon P M & Halliwell R E (1993) Evaluation of intradermal mold antigen testing in the diagnosis of equine chronic obstructive pulmonary disease. Equine Vet J 25 (4), 273-275 PubMed.
  • Greet T R (1987) Outcome of treatment of 35 cases of guttural pouch mycosis. Equine Vet J 19 (5), 483-7 PubMed.

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