Molecular survey on the parasitic nematode Contracaecum spp. in fish (Planiliza abu) destined for human consumption

• Published in: Veterinarski glasnik p. 9
• Main Authors: Alali, Firas, Hussein, Muayad, Jawad, Marwa
• Format: Journal Article
• Language: English
• Published: 2024
• ISSN: 0350-2457; 2406-0771
• DOI: 10.2298/VETGL231221009A

Contracaecum spp. is a parasitic nematode belonging to the Anisakidae family
and which has a significant potential zoonotic effects on different hosts.
Anisakiasis in humans is caused due to consumption of raw infected or
undercooked seafood that contains nematode larvae. In this study, the
prevalence of Contracaecum spp. nematodes in the fish, Planiliza abu, was
determined over eight months from June 2022 to January 2023. The source of
fish was Razzaza Lake, while the specimens of Planiliza abu were purchased
from the local market, Karbala city, Iraq. The Contracaecum spp. nematodes
were examined by morphological and molecular techniques.The total prevalence
was 32%, as 133 of 416 fish were infected in the viscera by Contracaecum
spp. third stage (L3) larvae. Molecular diagnosis of the COX-2 gene in
Contracaecum spp. from P. abu was used to confirm the infection and to study
their population biology. In the parasitology laboratory of the Veterinary
Medicine College at Kerbala University, we confirmed the nematodes
morphologically and molecularly as Contracaecum spp. The infection rates in
September and November were greater than in October 2022. The results showed
a significant positive correlation between the length of the fish and the
number of nematodes per fish. This study detected the presence of
Contracaecum spp. using analysis of mitochondrial cytochrome c oxidase II
(COX-2 gene). In conclusion, molecular genotyping might be an effective
method for detecting the Contracaecum L3 larval species, determining the
biology of the life-cycles, population structures, transmission methods, and
intermediate hosts types.