Antimicrobial, immunological and biochemical effects of florfenicol and garlic (Allium sativum) on rabbits infected with Escherichia coli serotype O55: H7.

Florfenicol (FFC) is a synthetic broad-spectrum antibiotic and garlic has a bactericidal action against coliforms. This study was carried out to compare the antimicrobial, immunological and biochemical effects of florfenicol and garlic, for their ability to treat enteropathogenic Escherichia coli serotype O55: H7 infection in rabbits. Four groups (G1-G4) were included. G1 group was the negative control; G2 group was the infected with a field-isolated strain of E. coli and untreated; G3 group was the infected+treated with FFC for 5 days; and G4 group was the infected+treated with garlic tablets for 14 days. The rabbits were observed for clinical signs, growth performance and mortality rates. Garlic-infused disks had a larger clear zone of inhibition than other antibiotic disks. Garlic treatment improved growth performance, biochemical parameters, and immunological response and reduced the fecal shedding and histopathological lesions in E. coli O55: H7 infected rabbits compared to the other groups. Colonization of E. coli more rapidly declined in G3 & G4 than in G2. Hepatic and intestinal gene expressions; tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly elevated in G2 compared to the other groups, and their levels were elevated more in G3 than in G4. Serum interferon-gamma (IFN-γ) and phagocytic activity were significantly elevated in G4 compared to G3. G3 revealed macrocytic hypochromic anaemia that was confirmed histopathologically by moderate haematopoiesis of the bone marrow. In conclusion, garlic powder can reduce rabbit colibacillosis, like FFC, and can enhance the immune status of rabbits.