Immunological, Haematological and Biochemical Responses of Bata (Labeo bata), Naturally and Experimentally Infected withAphanomyces invadans

Abstract

The effect of the oomycete, Aphanomyces invadans, on immunological, haematological and biochemical responses of bata (Labeo bata) was investigated in the present study. The oomycete, recovered from naturally infected ulcerated bata, was used for experimental infections in apparently healthy bata. Intramuscular injection using a zoospore dose of 1×105 spores/ml produced lesions at 5 days post-infection (p.i.) and by 8-9 days p.i., all the lesions became necrotic. Cohabitation of epizootic ulcerative syndrome-affected and apparently healthy bata produced lesions 7 days p.i. Immunological parameters, including superoxide anion production, nitric oxide production, leucocyte proliferation and lysozyme activity, showed significantly higher values in the infected groups than the apparently healthy bata. Among the haematological parameters, red blood cell count, haemoglobin and packed cell volume values were significantly lower than the healthy bata, while white blood cell counts were significantly higher. Biochemical parameters including total serum protein, serum glutamate pyruvate transaminase and serum glutamate oxaloacetate transaminase activity, showed significantly higher values in the infected groups, whereas the serum alkaline phosphatase activity was higher but statistically non-significant. The results suggest that there was a strong physiological response against A. invadans infection in bata.