Liver transplant patients are a population at risk for invasive aspergillosis. Aspergillus fumigatus is the most responsible species. However, other non-fumigatus species can be involved with reduced sensitivity to antifungal drugs. Accurate identification, based mainly on molecular biology, is thus essential to adapt the therapy. We report an invasive pulmonary aspergillosis due to Aspergillus pseudodeflectus in a liver transplant patient. To our knowledge, this is the first reported case of invasive aspergillosis due to this species.
In May 2013, a 64 year-old woman was admitted in surgical intensive care for monitoring after a liver transplantation for cirrhosis post-hepatitis C. Six weeks after transplantation, CT scan showed a right pulmonary opacity associated with an increase of galactomannan antigen and β-D-glucan. A BAL was then performed. Direct examination of BAL showed Aspergillus-like branching hyphae. Several colonies of a white to brown filamentous fungus with a velvety appearance were obtained in culture on Sabouraud media at 30° and 37°C. Microscopic examination of the colonies showed Aspergillus biseriate conidial heads with curved conidiophores. A molecular identification was done, based on partial β-tubulin and calmodulin genes. A BLAST search in GeneBank and MycoBank revealed a sequence identity to 99,78% to the A. pseudodeflectus reference sequence CBS 596.65. This species belongs to Aspergillus section Usti and is very close to Aspergillus calidoustus previously reported in human pathology. The antifungal susceptibility tests revealed low MICs to echinocandines and amphotericin B but high MICs to azoles. After these results, the patient, initially treated with voriconazole was switched for amphotericin B. Unfortunately she died one month after diagnosis.
We diagnosed an invasive pulmonary aspergillosis in a liver transplant patient due to a new species A. pseudodeflectus described in human pathology. This species showed less susceptibility to azoles. This highlights the significance of molecular identification of Aspergillus species regarding the reduce susceptibility profile.