[Anti-Trichinella antibody level in muscle juice of experimentally infected mice].
OBJECTIVE
To detect the anti-Trichinella antibody level in muscle juice of experimentally infected mice and their correlation with serum antibodies.


METHODS
Two hundred and eighty-eight Kunming mice were randomly divided into 3 groups (96 mice each), each mouse was inoculated with 100, 300 or 500 muscle larvae of T spiralis, respectively. Anti-Trichinella antibodies in serum and muscle juice taken weekly up to 18 weeks post-infection (wpi) were detected by ELISA using T. spiralis muscle larval excretory-secretory (ES) antigens. Thirty mice were inoculated with T. spiralis muscle larvae(500 larvae each). The muscle samples taken in 6 wpi were kept in plastic containers and conserved at 4 degrees C for 7 days or at -20 degrees C for 20 weeks for detecting anti-Trichinella antibodies later.


RESULTS
Anti-Trichinella antibodies in muscle juice of the mice infected with 100, 300 or 500 larvae were detected in 4, 3 and 3 wpi, with antibody positive rate of 87.5%, 50% and 87.5% respectively. In the three groups of mice, the antibody positive rate of muscle juice increased gradually after infection and up to 100% in 6, 4 and 4 wpi, and the antibody level reached its peak in 8 wpi with an absorbance value of 0.43, 0.49 and 0.52 respectively. Thereafter, the antibody level decreased slightly, but the positive rate was still 100% and lasted to 18 wpi when the experiment was ended. The antibody level in muscle juice showed significant positive correlation with serum antibodies at different time intervals after infection in three groups (r100=0.940, r300=0.970, r500=0.983, P<0.05). The absorbance value of muscle samples conserved at 4 degrees C for 7 d and 1 d was the same (0.53) (F=0.250, P>0.05), and those conserved at -20 degrees C for 8 wk and 1 wk was 0.46 and 0.50 respectively, showing that the antibody level in muscle juice did not decreased considerably after the muscle samples were frozen at -20 degrees C for 8 weeks (F=2.273, P>0.05). The absorbance value of Trichinella-infected muscle conserved at -20 degrees C for 10 wk decreased to 0.43, with significant difference from that conserved at -20 degrees C for 1 wk, but the positive rate was also 100%, and antibodies were detected in all muscle samples conserved at -20 degrees C for 20 weeks when the experiment was ended.


CONCLUSIONS
When animals died or were slaughtered and serum samples could not be collected, muscle juice can be collected from fresh, cool and frozen meat and used as a substitute sample for detecting anti-Trichinella antibodies.
Wang
Zhong-quan
ZQ
Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, China. wangzq@zzu.edu.cn
Lai
Li-hong
LH
Cui
Jing
J
D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis* / Q000097:blood; D000947:Antigens, Helminth / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005513:Food Inspection / Q000379:methods; D007814:Larva / Q000254:growth & development / Q000276:immunology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009132:Muscles / Q000469:parasitology*; D011897:Random Allocation; D014234:Trichinella / Q000254:growth & development* / Q000276:immunology; D014235:Trichinellosis / Q000097:blood / Q000469:parasitology*
D000909:Antibodies, Helminth; D000947:Antigens, Helminth