Anisakis pegreffii Larvae in Sea Eels (Astroconger myriaster) from the South Sea, Republic of Korea

Abstract

Anisakis simplex sensu stricto (s.s.), Anisakis pegreffii, Anisakis berlandi (=A. simplex sp. C), and Anisakis typica are the 4 major species of Anisakis type I larvae. In the Republic of Korea (Korea), A. pegreffii, A. berlandi, and A. typica larvae in fish hosts has seldom been documented. In this study, molecular analysis was performed on Anisakis larvae from the sea eels (Astroconger myriaster), the major source of human anisakiasis in Korea, collected from Tongyeong City, a southern coastal area of Korea. All 20 sea eels examined were infected with Anisakis type I larvae (160 larvae; 8 per fish). Their species were analyzed using PCR-RFLP patterns and nucleotide sequences of internal transcribed spacers (ITS1, 5.8 subunit gene, and ITS2) and mitochondrial cytochrome c oxidase 2 (cox2). Most (86.8%; 112/129) of the Anisakis type I larvae were A. pegreffii, and 7.8% (10/129) were A. typica. The remaining 5.4% (7/129) was not identified. Thus, A. pegreffii is the major species of anisakid larvae in sea eels of the southern coast of Korea.

Keywords: Anisakis pegreffii; ITS1; PCR-RFLP; cox2; sea eel.

Fig. 1.

(A) PCR-RFLP patterns of the rDNA region spanning the ITS-1, 5.8S, and ITS-2, for A. pegreffii and A. typica from the sea eels. M, 100-bp ladder. Lanes 1 and 3, gDNA from Anisakis spp.; lane 2, A. pegreffii (370, 300, and 250 bp); lane 4, A. typica (350 and 620 bp). (B) The infection status of the sea eels with different species of Anisakis larvae (n=129).

Fig. 2.

Neighbor-Joining trees of Anisakis spp. based on (A) ITS region (274 bp) and (B) cox2 gene (511 bp) exploring the relationships among Anisakis spp. available in GenBank and Anisakis larvae collected from the sea eels in Korea.