Sequencing the Parasitic Nematode Contracaecum spp. in Edible Fish (Planiliza Abu)

Abstract

Contracaecum rudolphii Hartwich,1 964 (Nematoda: Ascaridoidea, Anisakidae) is a typical anisakid recorded globally. Consumption of undercooked seafood, raw or infected, contains the nematode larvae that cause human anisakidosis . Fish (Planiliza abu) specimens were obtained from a local market in Karbala, Iraq. This type of fish came from the Razzaza Lake. The prevalence of Contracaecum spp. parasites was done over eight months from June 2022 until January 2023, using ITS1, morphological and molecular analysis of the nematodes Contracaecum spp from fish. Out of 395 fish, 124(31.3%) had visceral infections caused by Contracaecum spp. larval type (L3). The morphological and genetic identification of Contracaecum spp. was validated in the parasitology laboratory of the veterinary medicine college at Kerbala University. The result showed the infection rate in January 2023 was (46.6%) and it dropped in 2022, September with a percentage of (20%). With the use of ITS1 gene, the molecular analysis for Contracaecum spp. was to investigate Contracaecum spp. and to confirm it. However, the nematode count, number of infected fish, and length were all substantially different at the P≤0.05. This study detected the isolate=(a1) at the locus=OP787071 and sequencing the parasites. The isolates were confirmed as Contracaecum rudolphii, isolate a1 internal transcribed spacer 1, partial sequence. In conclusion, molecular genotyping might be a useful technique for identifying the Contracaecum L3 larval species., life-cycle biology, transmission methods, and types of intermediate hosts.