Freezing infective-stage larvae from Anisakis simplex and their produce at -20 degrees C for 24 h does not prevent the occurrence of autonomic imbalance in rat ileum.

UNLABELLED: In the present report, we analyze the efficacy of the sanitary regulations to kill the Anisakis simplex larvae (As L3) (heat or freeze) to avoid the gastrointestinal alterations that it provokes. We studied the effects on intestinal contractility (muscular tone, amplitude, and frequency of the twitches and cholinergic and alpha-adrenergic stimulus) of As L3, their crude extracts (CE) and excretory-secretory products (ESP), untreated or heated (60 degrees C for 15 min) or frozen (-20 degrees C for 24 h) using rat ileum and an isometric system. Carbachol and noradrenaline have been used as cholinergic and alpha-adrenergic stimulus, respectively. We determined that viable As L3, their untreated CE and ESP, as well as all their frozen counterparts, altered the intestinal contractile activity and its autonomic control. In contrast, heated As L3, CE, and ESP were incapable of provoking any change in rat ileum motility, suggesting an inhibitory effect by the heating procedure. IN CONCLUSION: 1) The gastrointestinal alterations provoked by As are not necessarily associated with a prior infection; and 2) the storage of the seafood at -20 degrees C during 24 h does not prevent the intestinal autonomic imbalance provoked by As, whereas, the prior heating at 60 degrees C for 15 min may completely prevent such process.

A new procedure for marinating fresh anchovies and ensuring the rapid destruction of Anisakis larvae.

The consumption of marinated anchovies is the main route of transmission of anisakiasis in Spain. Because this country is one of the world's major tourist destinations, this traditional food also poses a potential health risk to millions of foreign visitors. Anisakis larvae are not destroyed by the traditional marinating procedure, and alternative methods, such as long-term storage in brine, freezing, or hydrostatic pressure treatment, all present major difficulties. In this study, we used high food-grade acetic acid concentrations (10, 20, 30, and 40% [vol/vol] in line with the quantum satis rule) to destroy these larvae rapidly, and we report data on the survival of Anisakis larvae exposed directly to different marinades and when the larvae are placed under the fish musculature. The percentage of salt and acetic acid in the fish tissue water phase was also determined. A marinating procedure is proposed that ensures the rapid death of Anisakis through the use of strong acetic acid concentrations. Posttreatment washes with water reduce these to levels acceptable to consumers. The sensory characteristics of the product were shown to be satisfactory. The actual selection of an acetic acid concentration for marinating depends on costs and the processing time available. The physiological stress of the larvae exposed to the different marinades was determined by measuring the levels of their stress proteins. The latter are good indicators of injury and might reflect the infectivity of larvae. In addition, we also used a rat model to determine the infectivity of larvae considered microscopically dead.

Altered autonomic control in rat intestine due to both infection with Anisakis simplex and incubation with the parasite's crude extract.

Anisakis simplex IgE may bring on allergic responses such as angioedema, vomiting, and urticaria from eating seafood, but it is not the only etiology. Induced cholinergic hyperreactivity or adrenergic blockade in the target tissue can cause these diseases nonimmunologically also. Here we studied the effects on normal intestinal motility of brief A. simplex infections and in vitro exposures to the parasite's extract (CE). Each approach was evaluated according to its ability to induce cholinergic hyperreactivity or adrenergic blockade in rat duodenum (RD), jejunum (RJ), and ileum (RI) in vitro. Additionally, bolus propulsion in RD, RJ, and RI was evaluated with time in vivo utilizing animals infected 4 h previously with A. simplex larvae (L3) vs sham animals. Tissues, after inoculation of 1, 5, 10, and 20 L3, exhibited time- and dose-dependent motility changes after carbachol (Ch) and noradrenaline (NA), justifying our using herein rats from the fourth hour of infection with 20 L3. We observed a persistent, yet differential effect of the infection on RD, RJ, and RI responses to Ch or NA. It caused cholinergic (muscarinic) hyperreactivity in RD only, and adrenergic blockade in all other parts, and consequently increased the transit index in RD, not in RJ or RI. In contrast, exposing RD, RJ, and RI to CE persistently increased both parameters, amplitude of twitches and muscular tone, in all, albeit that, here also, responses to Ch and NA were CE dose dependent. Interestingly, sensitivity to CE was in the order RI > RJ > RD, the reverse situation of that observed during active infection. Thus, previously viable A. simplex L3, after digestion, can exert bystander disturbance in autonomic control in the whole intestine. Our findings demonstrate that A. simplex L3, alive or dead, can induce cholinergic hyperactivity and adrenergic blockade in the whole small intestine and, as a consequence, gastrointestinal symptoms. Significantly, they may do so long before parasite-specific IgE is detectably induced or despite the occurrence of such IgE.

Reacciones cruzadas entre Anizakis simplex y Gymnorhynchus gigas: estudio experimental en ratones NMRI / Cross reactions between Anisakis simplex and Gymnorhynchus gigas: experimental study in NMRI mice

En el presente trabajo se ha realizado el seguimiento de la respuesta inmunitaria humoral que provoca la ingesta de diferentes fracciones y dosis de la larva plerocercoide de Gymnorhynchus gigas, utilizando ratones NMRI como modelo de laboratorio. Para ello y mediante la técnica de ELISA se han determinado los niveles de IgG, M, A y E en suero y mucosa intestinal. Asimismo, se han analizado las posibles reacciones cruzadas que se puedan producir con la L3 de Anisakis simplex, ensayando las reacciones de cada suero y cada mucosa tanto frente a antígenos somáticos, como frente a antígenos de excreción-secreción de la L3 de A: simplex y de la larva plerocercoide de G. gigas, según procedía. Los resultados obtenidos indican que I) G. gigas provoca una respuesta inmunitaria humoral tanto a nivel general como entérico, al producirse un aumento de las Ig en ambos niveles; II) los dos parásitos comparten antígenos, ya que existen reacciones cruzadas entre ambos, y III) esos antígenos actúan como alergenos, al ser capaces de producir un aumento de las IgE. (AU)