Aspergillosis, a Natural Infection in Poultry: Mycological and Molecular Characterization and Determination of Gliotoxin in Aspergillus fumigatus Isolates

Avian Dis. 2017 Mar;61(1):77-82. doi: 10.1637/11496-092016-Reg.

Abstract

Aspergillosis affects all types of birds; it causes the loss of specimens with high ecologic value and also leads to significant economic losses within the poultry industry. The main etiologic agent is Aspergillus fumigatus , a filamentary fungus with multiple virulence factors, such as gliotoxin (GT), which is an immunosuppressive epipolythiodioxopiperazine molecule. Necropsy was performed on 73 poultry from different provenances, all of which presented with a respiratory semiology compatible with aspergillosis. A mycological culture was performed on the injured lungs of diseased birds, as was chloroform extraction of the GT, a thin-layer chromatography analysis (TLC), and a histopathology analysis with hematoxylin-eosin and Grocott stainings. The A. fumigatus identification was confirmed by PCR, where the ITS 1 5.1-5.8S-ITS 2 fragment of the rDNA complex was amplified. The in vitro GT production was studied by TLC in the recovered isolates from A. fumigatus . Seven isolates of A. fumigatus were obtained and in six of them, GT-like compounds were detected. In a lung sample, a compound with the same retention time (RF) as the reference GT was detected; whereas RF compounds different from the GT standard were observed in three lung samples.

Keywords: Aspergillus fumigatus; avian aspergillosis; gliotoxin.

MeSH terms

  • Animals
  • Aspergillosis / microbiology
  • Aspergillosis / pathology
  • Aspergillosis / veterinary*
  • Aspergillus fumigatus / classification
  • Aspergillus fumigatus / genetics
  • Aspergillus fumigatus / isolation & purification*
  • Aspergillus fumigatus / metabolism*
  • Chickens
  • Gliotoxin / metabolism*
  • Lung / pathology
  • Lung / virology
  • Poultry Diseases / microbiology*
  • Poultry Diseases / pathology

Substances

  • Gliotoxin