Pharmacokinetics of streptomycin sulfate in Staphylococcus aureus-infected Clarias gariepinus (Burchell 1822)

Most bacteria causing fish diseases in Nigeria have been observed to be susceptible to aminoglycosides like streptomycin. However, route of administration for effective therapy has been a challenge due to the reported poor intestinal absorption, hence a need to study its kinetics. Clarias gariepinus were divided into four groups of 14 fish each. Fish in A were Staphylococcus aureus-infected while those in B were uninfected and both received streptomycin by bath at 70 mg/l, while it was 70 mg/kg via gastric gavage for groups C which were Staphylococcus aureus-infected and D which were uninfected. Blood and tissue collection was done between 1 and 120 h post exposure to streptomycin. Samples were analyzed by ELISA, while some portions of tissues of infected fish were fixed for histopathology. Sum of area under curve values for serum and kidney (AUC0–8h) were 5876.5 μg h/l and 399,287 μg h/kg; 4519.3 μg h/l and 183,474 μg h/kg; 27,771.2 μg h/l and 82,539 μg h/kg; as well as 18,768.4 μg h/l and 33,252.5 μg h/kg respectively for groups A, B, C and D. Microscopically the lesions were localized and extensive hepatic coagulative necrosis with diffuse tubular necrosis. Possible systemic therapeutic value is suggested, depending on increased distribution of streptomycin and levels of streptomycin in kidneys of diseased fish at corresponding times being higher than in sera