Immunization against trichinellosis using microwaved larvae of Trichinela spiralis

The present study evaluated the effect of microwave irradiation on infective larvae of Trichinella spiralis (T. spiralis) by the ultrastructure changes of the microwaved larvae (ML) using scanning electron microscope (SEM). The ML tested the ability to immunize mice against a challenge infection with T. spiralis. For the optimal dose and the best route of immunization inducing protection against challenge infection, two doses were used; 300 & 600 ML as one or two-dose regimen, each dose was given orally and intraperitoneally (IP). SEM revealed tegumental damage of the ML in the form of distortion, loss of normal fold pattern and depressions or papillae protruded from their outer surface. After administration of the ML (orally or IP) to the non-infected control mice, neither adults nor larvae were detected in the intestines or muscles respectively. This indicated loss of larvae infectivity after exposure to the microwave irradiation. Also, a significant protection against challenge infection with T. spiralis was demonstrated in experimental mice immunized by ML, orally or IP. This was assessed by a statistically significant decrease in adult and muscle larval count, compared with the non-immunized infected control. Complete protection against both adults and larvae (100%) was achieved by IP injection of two doses of 600 ML, two weeks apart. The results suggested the feasible application of the microwave irradiation on meat for its decontamination from T. spiralis larvae. Such a method might be a promising a prophylaxis vaccine against trichinellosis in animals and/or humans.