Comparative efficacy of Allium sativum and levofloxacin on histopathological alterations in experimentally induced Escherichia coli infection in broilers

Abstract

The present study evaluated the effect of Allium sativum bulb powder on induced E. coli infection in broiler birds by analyzing gross and histopathological alterations. A total of 150 Vencob broiler birds were divided into six groups (T1-T6) and subjected to different treatments. Birds in group T1 were fed a plain diet (control), while those in group T2 were administered E. coli broth (0.5 ml, 1x10⁹ CFU/ml) orally on the 8th day. Groups T3, T4, T5, and T6 received different combinations of E. coli broth, garlic powder (1.5 gm/kg of feed), and Levofloxacin (1gm/10 kg of body weight). Gross and histopathological changes were examined on the 7th, 14th, and 21st day post-infection. Severe gross pathological changes in group T2 included tracheal congestion, lung edema, thickened air sacs, fibrinous pericarditis, perihepatitis, hemorrhagic kidneys, splenomegaly, and catarrhal exudation in the intestine. Birds in group T4 exhibited milder gross lesions with focal lung consolidation and liver necrosis, while minimal changes were observed in groups T5 and T6. By the 21st day post-infection, no significant gross abnormalities were detected in any treatment groups except T2. Histopathologically, birds in group T2 showed marked catarrhal inflammation, desquamation of the tracheal mucosa, fibrinous bronchopneumonia, fibrinous airsacculitis, and pericarditis. Liver sections revealed fatty changes, focal coagulative necrosis, and fibroproliferative changes. Kidney sections showed hydropic degeneration, vacuolar changes, and proteinaceous casts, while spleen sections indicated lymphocyte depletion. Birds in group T4 showed mild inflammatory changes, while minimal histoarchitectural alterations were noted in groups T5 and T6. The results demonstrated that garlic and its combination with Levofloxacin exhibited significant therapeutic potential by reducing gross and histopathological lesions in E. coli-infected broiler birds. The study highlights the antibacterial and protective effects of garlic, attributed to its high allicin content.