Sunday, July 26, 2009
P73

Phospholipases of Aspergillus fumigatus

Ali, D. Noodeh and Geoff, D. Robson. Faculty of life sciences, University of Manchester, Oxford Road, Stopford Building, Manchester, United Kingdom

 

 

 

Aspergillus fumigatus is an opportunistic pathogen responsible for around 90% of all cases of disseminated Aspergillus infections in immunocompromised patients. Infections normally arise through inhalation of spores which penetrate the alveoli and come into contact with surfactant, composed of around 80% phospholipid. Extracellular phospholipase activity has previously been demonstrated. In the presence of phosphatidylcholine, the colony radial growth rate of A.fumigatus increased two fold by decreasing branching frequency without affecting the overall specific growth rate. Phosphorylcholine, a degradation product of the action of phospholipase C was shown to also significantly increase the colony radial growth rate whereas the breakdown products of other phospholipases did not. Real time PCR revealed a greater level of expression in the presence compared to the absence of phospholipid in the media. The stimulation of surface growth in response to PLC mediated phosphatidylcholine may have implications for colonisation and invasion of lung tissue.