Isolation of Trichinella spiralis Adult Worms

T. spiralis (strain ISS 533) was maintained in female ICR mice. The muscle larvae were recovered from infected mice by digestion of the carcasses in artificial gastric juice (32 (link)). The recovered muscle larvae were used to infect rats orally with 14,000 larvae each. Six days after infection, each rat was euthanized, and the adult T. spiralis worms were collected from intestine. The collected adult worms were washed several times with sterile saline (0.9% NaCl) and cultured in RPMI-1640 (Thermo Fisher, Carlsbad, USA) supplemented with 200 U penicillin/ml and 200 μg streptomycin/ml (Caisson labs, Logan, USA) at 3000 worms/ml at 37°C, 5% CO₂, for 48 h. Cultured medium containing AES products was collected and concentrated buffer-exchanged to PBS using a centrifugal filter (Millipore Amicon Ultra-15, NMWL: 3000, USA), and buffer-exchanged to PBS (32 (link)). Protein concentration in AES was determined using the BCA protein assay (Merck, Darmstadt, Germany).