Effects of Single and Co-infections of Proteus Mirabilis and Aeromonas Hydrophila on Baseline Hematological, Serological, and Histological Data in Cultured Clarias Gariepinus

Significant mortality and production disruptions in fish culture are brought on by diseases and parasites. The purpose of the current study was to collect baseline data on the effects of single and co-infections of Proteus mirabilis, and Aeromonas hydrophila in Clarias gariepinus.

One hundred and twenty sub-adults of C. gariepinus were divided into control, P. mirabilis, A. hydrophila, and co-infection groups (P. mirabilis X A. hydrophila). Standard methods were used to determine hematology, serology, and histology. Standard microbiology methods were used for microbial analysis.

The single A. hydrophila-infected group had the highest mortality (60% versus 37%) in the co-infected and P. mirabilis groups. A marked decrease was observed in the RBC, hemoglobin, and Packed Cell Volume (PCV) of 2.9×10¹²/L, 32.8 g/L, and 33.5% in the co-infected fish, compared to the control with 3.6×10¹²/L, 35.8 g/L, and 41.0%, respectively. Alanine transaminase, alkaline phosphatase, and aspartate transaminase levels were significantly lower in the co-infected fish (13.8, 236.0, and 66.3, respectively) compared to the A. hydrophila-infected group. Creatinine and urea levels were, however, higher in the co-infected treatment. The kidneys and livers of the A. hydrophila and co-infected groups were more severely damaged than those of the P. mirabilis and control groups. Vacuolation and necrosis of hepatocytes led to the desquamation of tubular and glomerular epithelial cells in the livers and kidneys of infected fish. Fish infected with A. hydrophila had the highest bacterial load count.

It was concluded that an antagonistic association exists between A. hydrophila and P. mirabilis when they are co-infected.