Simultaneous Detection and Prevalence of Allergens in Anisakis Species Isolated from Marine Fishes

Anisakis pegreffii Extract Induces Airway Inflammation with Airway Remodeling in a Murine Model System

Exposure of the respiratory system to the Anisakis pegreffii L3 crude extract (AE) induces airway inflammation; however, the mechanism underlying this inflammatory response remains unknown. AE contains allergens that promote allergic inflammation; exposure to AE may potentially lead to asthma. In this study, we aimed to establish a murine model to assess the effects of AE on characteristic features of chronic asthma, including airway hypersensitivity (AHR), airway inflammation, and airway remodeling. Mice were sensitized for five consecutive days each week for 4 weeks. AHR, lung inflammation, and airway remodeling were evaluated 24 h after the last exposure. Lung inflammation and airway remodeling were assessed from the bronchoalveolar lavage fluid (BALF). To confirm the immune response in the lungs, changes in gene expression in the lung tissue were assessed with reverse transcription-quantitative PCR. The levels of IgE, IgG1, and IgG2a in blood and cytokine levels in the BALF, splenocyte, and lung lymph node (LLN) culture supernatant were measured with ELISA. An increase in AHR was prominently observed in AE-exposed mice. Epithelial proliferation and infiltration of inflammatory cells were observed in the BALF and lung tissue sections. Collagen deposition was detected in lung tissues. AE exposure increased IL-4, IL-5, and IL-13 expression in the lung, as well as the levels of antibodies specific to AE. IL-4, IL-5, and IL-13 were upregulated only in LLN. These findings indicate that an increase in IL-4+ CD4+ T cells in the LLN and splenocyte resulted in increased Th2 response to AE exposure. Exposure of the respiratory system to AE resulted in an increased allergen-induced Th2 inflammatory response and AHR through accumulation of inflammatory and IL-4+ CD4+ T cells and collagen deposition. It was confirmed that A. pegreffii plays an essential role in causing asthma in mouse models and has the potential to cause similar effects in humans.

First morphological and molecular identification of third-stage larvae of Anisakis typica (Nematoda: Anisakidae) from marine fishes in Vietnamese water

Anisakid nematodes are parasites of cetaceans, their larval stages live in marine fishes. The third-stage larvae of some Anisakis species are also the etiological agents of human anisakiasis caused by consumption of raw or undercooked infected fish. Thus, identification of Anisakis larvae at the species level is crucial for their ecology and epidemiology. In Vietnam, although Anisakis larvae have been reported, they have not been identified to the species level. The aim of this study was, therefore, to identify third-stage larvae of Anisakis collected from marine fishes in Vietnamese water, based on morphological characteristics and molecular analysis. All Anisakis larvae found in this study were morphologically similar to each other and identical to Anisakis typica. In addition, molecular analysis based on ITS1-5.8S-ITS2 sequences confirmed them as A. typica. Vietnamese A. typica population was genetically close to those from Asian countries and Australia. The third-stage larvae of A. typica were collected from eight fish species from three localities in the South of Vietnam. Among them, seven were recorded as new intermediate hosts of A. typica. This is the first identification of A. typica larvae in Vietnamese water with records of new fish hosts.