title: Strain-dependent effects of environmental signals on the production of extracellular phospholipase by Cryptococcus neoformans.
abstract: Extracellular phospholipase (PL) activities comprising phospholipase B, lysophospholipase and lysophospholipase transacylase have been identified in culture supernatants of Cryptococcus neoformans and contribute to virulence. We found that PL production was optimal after fungal growth at 30 degrees C and secretion at 37 degrees C for all six C. neoformans isolates studied (four C. neoformans var. neoformans and two C. neoformans var. gattii). No increase in PL activity was found in one strain, NU-2, in low iron or tissue culture media, conditions where upregulation of other virulence factors has been reported. The most virulent strains in an intravenous mouse model of infection were best able to produce PL at growth and secretion temperatures of 37 degrees C, in tissue culture media and under assay conditions of pH 7.0.
authors: Centre for Infectious Diseases and Microbiology, Level 3, ICPMR Building, Westmead Hospital, Darcy Rd., NSW, 2145, Australia. lesleyw@icpmr.wsahs.nsw.gov.au
authors: Lesley C
authors: LC
authors: Wright
authors: Sharon C A
authors: SC
authors: Chen
authors: Christabel F
authors: CF
authors: Wilson
authors: Mukoma F
authors: MF
authors: Simpanya
authors: Rebecca
authors: R
authors: Blackstock
authors: Gary M
authors: GM
authors: Cox
authors: Juneann W
authors: JW
authors: Murphy
authors: Tania C
authors: TC
authors: Sorrell
mesh_terms: D002021:Buffers; D003455:Cryptococcus neoformans / Q000201:enzymology* / Q000254:growth & development* / Q000472:pathogenicity; D003470:Culture Media / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005110:Extracellular Space; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000494:pharmacology; D010740:Phospholipases / Q000096:biosynthesis* / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature; D014774:Virulence
chemical_list: D002021:Buffers; D003470:Culture Media; D004791:Enzyme Inhibitors; D007093:Imidazoles; C029899:imidazole; D010740:Phospholipases; D005947:Glucose