Anisakidae nematodes isolated from the flathead grey mullet fish (Mugil cephalus) of Buenaventura, Colombia

Abstract

Anisakiasis is a parasitic infection caused by larval stages of nematodes of the genus Anisakis, Pseudoterranova and Contracaecum, of the Anisakidae family. The lifecycle of these nematodes develops in aquatic organisms and their final hosts are marine mammals. However, humans can act as accidental hosts and become infected with infective stage larvae (L3) by consuming raw or undercooked fish or shellfish carrying the parasite. Of this group of parasites, the genus Anisakis is the most studied: its presence in humans is associated with non-specific gastrointestinal symptoms or allergic responses that can trigger anaphylactic shock. The lack of studies in anisakiasis and Anisakis in Colombia has resulted in this infection being little-known by medical practitioners and therefore potentially underreported. The objective of this study was to identify anisakid nematodes in the flathead grey mullet fish (Mugil cephalus), caught by artisanal fishing methods and commercialized in Buenaventura. Morphological identification was carried out by classical taxonomy complemented by microscopy study using the histochemical technique Hematoxylin-Eosin. Nematodes of the genus Anisakis were found in the host M. cephalus. The Prevalence of Anisakis larvae in flathead grey mullet fish was 33%. The findings confirm the presence of Anisakis sp. in fish for human consumption in the Colombian Pacific region, a justification for further investigation into a possible emerging disease in this country.

Keywords: Allergy; Anisakiasis; Anisakis; Emerging diseases; Mullet fish.

Graphical abstract

Fig. 1

Larva (L3) Type II de Anisakis sp. isolated from M. cephalus. A. Front end, 10x, B. Front end 40x C. Medium portion 4x, D. Back end 40x dc. cuticular tooth e. esophagus v. ventricle i. intestine tc. conical termination, pa. anal pore.

Fig. 2

Sectioned larvae (L3) of anisakid nematodes. H.E. A. and B. Cross-sections 40x, C. 40x, D. Longitudinal sections 10x c. cuticle, h. hypodermis, cm. muscular layer, cn. nerve cord.