Clinical And Treatment Outcomes in Clarias gariepinus Experimentally Infected With Single And Mixed Escherichia coli And Salmonella gallinarium Strains

ABSTRACT

Catfish is an important fresh water fish and is an excellent source of protein. However, it can be susceptible to microbial infection. This study therefore, was designed to determine the clinical and treatment outcomes in African Catfish experimentally infected with E. coli and S. gallinarium strains. A total of 160 juvenile African catfish were used for this study and they were randomly assigned into four groups (A, B, C, and D) of 40 fish each. Clinical isolates of E. coli and S.gallinarium were sourced from the Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka. Fishes in groups A, B, C were infected by immersing them in water containing 1x108 colony forming units/ml of each test isolate while the fish in group D served as uninfected control. Fishes in group A were infected with E. coli alone, those in group B with S. gallinarium, those in group C with E .coli and S. gallinarium, while fishes in group D were uninfected. Haematological and biochemical parameters were measured on weeks 1 and 2 post infection. The fish were monitored daily for signs of illhealth and mortality. Body weight change and vital physicochemical properties (dissolved oxygen, ammonia and pH) of water was also determined and recorded. Treatment was instituted five weeks post infection with amoxicillin by immersion for five consecutive days. Sluggish movement, curdling together, emaciation, poor growth rate, anorexia, high morbidity and mortality were the signs of ill health observed in fishes in the experimental groups. The clinical signs were more pronounced in groups A and C when compared to group B. The uninfected control showed no obvious clinical manifestation. The body weight of the fish in groups A (51.25±4.25) and C (58.25±4.11) were significantly (p0.05) improvement in weight changes post treatment in groups A and C. Haematology showed significant (p0.05) different from 17 groups C (2.28±0.14) and D (2.22±0.13). There was also a significant (p