Experimental Investigation on Rabbits Following Peritoneal Injection of Bacteria Isolated from Human Keratitis

Abstract

Aim: This work was aimed at studying the pathogenicity of bacteria causing infectious keratitis through experimental infection using different groups of rabbits that were inoculated with clinical isolates and assessed through biochemical and histopathological investigations. Study Design: This study was carried out on Rabbits. Place and Duration of the Study: this experiment was carried out at Med. Labs. Dept, Qassim Univ., in April 2013. Methodology: The isolated bacteria, Pseudomonas aeruginosa and Staphylococcus aureus from clinical corneal scraping swabs of patients suffering from infectious keratitis were experimentally inoculated through intraperitoneal injection in different groups of rabbits (2.0-2.5kg) and were subjected to serum biochemical and histopathological examinations. Results: The experimental rabbits showed alterations in both liver and kidney function parameters that varied with the type of bacteria injected. The level of urea was non-significantly increased to a higher extent in rabbits within 3 and 7 days of infection. There was no marked change in the levels of uric acid and creatinine in all groups of rabbits. Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) showed variable increased values but seemed also within limits of reference in all the groups of rabbits injected with either S. aureus or P. aeruginosa. Histopathologically, the internal organs (liver and kidneys) of the experimental rabbits showed inflammatory reactions with degenerative changes and/or necrosis while the cornea revealed oedema and leukocytic infiltration. The microscopic findings were varied in severity according to the type of the bacteria. Conclusion: Pseudomonas aeruginosa and Staphylococcus aureus experimentally induced infections revealed histopathologic lesions and disturbances in the functions of liver and kidneys of experimental rabbits together with proliferation of corneal epithelium and polymorphonuclear leukocytes infiltration in the corneal stroma. Therefore, strict measures are recommended to control and treat infectious keratitis to avoid visual complications and systemic disturbances among infected patients.