Title
Production of Scedosporium boydii CatA1 and SodC recombinant proteins: another step towards a standardized test for serodiagnosis of Scedosporium infections. 

Objectives
Scedosporium species are worldwide recognized pathogenic fungi causing a wide variety of infections ranging from localized infections such as subcutaneous mycetoma to disseminated infections in severely immunocompromised patients, particularly in chronically colonized CF patients who underwent lung transplantation. Serodiagnosis of these infections is limited to some specialized laboratories, and is mainly based on counter-immunoelectrophoresis using crude antigenic extracts. Therefore, it may be hampered by variations from one batch of the antigenic extract to another, and cross-reactions with other human pathogenic fungi including the aspergilli because of the numerous protein and polysaccharide antigens that are shared between these pathogens. To overcome these limitations, we investigated, using recombinant proteins, the antibody response in several groups of patients with or without an Aspergillus fumigatus or a Scedosporium infection, and evaluated their value as serodiagnostic tools to discriminate Aspergillus and Scedosporium infections and to differentiate between an airway colonization by Scedosporium species and a respiratory infection.
Methods
Recombinant proteins mimicking Scedosporium boydii catalase A1 (rCatA1) or cytosolic superoxide dismutase (rSodC) or S. apiospermum alkaline potease (rAlp1) or dipeptidylpeptidase V (rDPPV) were produced in Escherichia coli. Four groups of sera were used to investigate the value of these proteins in the serodiagnosis of Scedosporium infections by enzyme-linked immunosorbent assay. 
Results
The results showed that only rCatA1 and rSodC allowed the detection of Scedosporium infection, and the differentiation with an Aspergillus infection. Combination of the results showed a sensitivity of 88.2% and a specificity of 97%, with a positive predictive value of 100% and a negative predictive value of 98.2%.
Conclusion
These recombinant proteins therefore may be useful tools for the development of a standardized serological test for serodiagnosis of Scedosporium infections. Using these recombinant proteins, the differentiation between Scedosporium and Aspergillus infections, as well as between colonization and infection, may be particularly helpful for clinicians, to guide them in their therapeutic decision.

2 / Production of Scedosporium boydii CatA1 and SodC recombinant proteins: another step towards a standardized test for serodiagnosis of Scedosporium infections