Cytotoxicity and immunological impact of Trypanosoma sp. infection on blood parameters of wild African catfish, Clarias gariepinus

Abstract

Fish trypanosomiasis is a common blood parasitic disease transmitted by aquatic invertebrates, such as leeches. This study aims to shed light on the cytotoxicity of Trypanosoma sp. on erythrocytes and its impacts on the innate immune response (serum lysozyme activity, nitric oxide production, phagocytic activity, serum total protein, and globulin) in wild African catfish, Clarias gariepinus. One hundred catfish were examined using blood smears stained with Giemsa and confirmed with PCR. The prevalence of infection was found to be 10% by microscope detection and 15% by PCR. The morphological identification of Trypanosoma as Trypanosoma mukasai was determined. Additionally, this study included previously undescribed features of Trypanosoma, such as the width of the anterior and posterior body, the length of the posterior pale region, and the number of folds. Various alterations in erythrocytes were observed, totaling 54.57%. Nuclear abnormalities, including fragmented nuclei, eccentric nuclei, and micronuclei, were also reported. Infected fish showed a reduction in serum total protein and globulin levels, while nitric oxide production, lysozyme activity, and phagocytic activity exhibited a significant increase compared to non-infected fish. We believe that our findings will contribute valuable data to the morphological and molecular identification of Trypanosoma sp. in African catfish, as well as their cytotoxic impact.

Blood-Chemistry Parameters Comparison among Different Age Stages of Chinese Sturgeon Acipenser sinensis

“…Healthy fish typically maintain normal levels of blood globulin. Various stressors, such as chronic starvation, parasitic infections, and exposure to toxic compounds, have been shown to adversely affect fish globulin [18,21,22]. In the context of immune-related studies, all parameters exhibit an age-related increase, suggesting that the Chinese sturgeon's immune capacity and visceral synthesis and storage functions improve with age.…”