S. aureus is responsible for Bumblefoot and septic arthritis in broilers and layers. The present work is designed to investigate and evaluate the most common bacterial causes of bumblefoot disease and their hematological, biochemical and immunological effects in broiler chicks. For bacteriological examination, one hundred and twenty foot swabs were collected from diseased chicks and investigated for the bacterial causes. Also, blood samples were collected from the same cases for hematological, biochemical and immunological analysis. In this study, S. aureus was isolated in 45.8% of diseased broilers. It was isolated either in pure form (18.18%); or in a mixed form with other species like: E. coli (58.18%), Proteus mirabilis (14.67%) and Pseudomonas aeruginosa(9.1%). Molecular characterization of Coaand Spagenes of S. aureus isolates were detectedwith PCR in 70% and 80%, respectively. Levofloxacin was the highest sensitive antibiotic drug against the isolated speciesfollowed by gentamycin, ciprofloxacin and amoxicillin antibiotics. However, mostrecoveredisolatesexihibited moderate to high resistance against trimethoprim, oxaciliin, enerofloxacin, tetracycline and erythromycin.For hematological parameters, a significant decrease in RBCs count, Hb concentration and PCV in the diseased broiler chicks indicated anemia. In addition, leucocytosis, lymphocytosisand monocytosis in naturally infected groups were recorded. Also, a significant increase in AST, ALT, uric acid, creatinine, gamma, alpha globulin, IL-6 and TNF-α levels were recorded in naturally infected chicks. Total protein and albumin levels were significantly decreased. The levofloxacine treated groups revealed significant increase in RBCs, Hb, and PCV as well as decreased number of total leukocytic count, lymphocyteand monocyteas compared with infected groups. Levofloxacine also improved the level of liver function,kidneyfunction,IL-6 and TNF. It could be concluded that, levofloxacin represent a promising candidate to treat bacterial infections. Staphylococcal infectionsare higher in broilers than other organisms. Therefore, the epidemiological importance and good hyagenicmeasuresshould be taken in this field to minimize the transmissible diseasesof poultry to humans.
S.aureus, isolation, PCR, spa gene, coagulase, levofloxacin, haematological, AST, antioxidant, IL6, TNF