Anisakis Antigens Detected in Fish Muscle Infested with Anisakis simplex L3

Abstract

Anisakis simplex is a fish parasite that is a public health risk to those consuming raw or poorly cooked marine fish and cephalopods because of the possibility of becoming infested with live larvae. In humans, penetration of the larvae into the gastrointestinal track can cause acute and chronic symptoms and allergic anisakiasis. Excretion and secretion products released by the larvae are thought to play a role in migration through the tissues and induce an immunoglobulin E-mediated immune response. The aim of this preliminary study was to detect parasite antigens and allergens in fish tissues surrounding the migrating larvae. Hake and anchovy fillets were artificially parasitized with Anisakis larvae and stored in chilled conditions for 5 days. Larvae were evaluated for fluorescence, fish muscle tissue was examined with transmission electron microscopy, and immunohistochemical reactions of two rabbit polyclonal antisera against a parasite crude extract and the allergen Ani s 4 were recorded. Larvae immediately migrated into the fish muscle, and no emission of bluish fluorescence was observed. Fish muscle areas in contact with the parasite showed disruptions in the structure and inclusion of granules within sarcomeres. Both parasite antigens and the Ani s 4 allergen were located in areas close to the larvae and where sarcomere structure was preserved. These findings indicate that parasite antigens and allergens are dispersed into the muscle and might cause allergic symptoms such as dyspnea, vomiting, diarrhea, urticaria, angioedema, or anaphylaxis in some individuals sensitive to A. simplex.

Antigenicity of Anisakis simplex s.s. L3 in parasitized fish after heating conditions used in the canning processing

“…Ani s 4 was detected after all heat treatments applied to experimentally infected fish flesh. These results confirm the presence of allergens in muscle areas where no larvae were observed, as described previously, and also that harsh technological treatments cannot eliminate their allergenicity.…”

“…Immunohistochemical analyses of experimentally infected fish with no heat treatment (Figs a and a) show that A. simplex L3 release Ani s 4 when they migrate into the muscle. These data confirm previous results on identification of allergens in the muscle/parasite contact zone of parasitized fish after 5 days of chilling . Ani s 4 is a component of excretory/secretory products, and these proteins are thought to play a role in the tissue invasion and migration of pathogenic nematodes …”

Experimental comparison of pathogenic potential of two sibling species Anisakis simplex s.s. and Anisakis pegreffii in Wistar rat

“…; Solas et al . ). The scarcity or even absence of distinguishing morphological features in the third larval stage complicates or prevents species differentiation.…”

Anisakis Simplex Antigens in Fresh and Frozen-thawed Muscle of Anchovies in Vinegar

“…Moreover, Anisakis antigens have been detected in fish muscle parasitized by live A. simplex L3 (Solas et al, 2008). It has been reported that live A. simplex L3 larvae release allergens even during a short incubation in diluted acid (Moneo and Caballero, 2002) which suggests that an increase of allergen release may also be produced in parasitized fish treated at low pH.…”