Background: Sparganosis is caused by the invasion of Spirometra sparganum into various tissues/organs. Subcutaneous sparganosis can be diagnosed by biopsy, while visceral/cerebral sparganosis is not easy to be diagnosed. The diagnosis de-pends largely on the detection of specific anti-sparganum antibodies. The specific-ity of the ELISA could be increased by using S. mansoni sparganum excretory– secretory (ES) antigens, but it also had the cross-reactions with sera of patients with cysticercosis or paragonimiasis. The aim of this study was to identify early specific diagnostic antigens in S. mansoni sparganum ES proteins.
Methods: The sparganum ES proteins were analyzed by two-dimensional electro-phoresis (2-DE) and Western blot probed with early sera from infected mice at 14 days post-infection. The immunoreactive protein spots were characterized by MALDI-TOF/ TOF-MS.
Results: A total of approximately 149 proteins spots were detected with isoelectric point (pI) varying from 3 to 7.5 and molecular weight from 20 to 115 kDa and sev-en protein spots with molecular weight of 23-31 kDa were recognized by the infec-tion sera. Three of seven spots were successfully identified and characterized as the same S. mansoni protein (cysteine protease), and the proteins of other 4 spots were not included in the databases.
Conclusion: The cysteine protease from S. mansoni ES proteins recognized by early infection sera might be the early diagnostic antigens for sparganosis.