Clinical and paraclinical changes in experimental colisepticemia in neonatal calves

The present study aim was to assess changes in clinical signs and plasma cytokines in calves experimentally infected with Escherchia coli and use them as a tool to diagnose colisepticemia. Ten healthy Holstein-Frisian bull calves were used for this experimental study. Experimental colisepticemia was induced in calves with intravenous injection of 1.5 × 109 CFU of O111:H8 strain of E.coli. Clinical scores were recorded before induction of septicemia, every 30 minutes for 8 hours, every hour from 8 till 12 h, every 3 hours from 12 till 24 hours after bacterial challenge. Blood samples were collected to determine plasma concentration of tumor necrosis factor-α (TNF-α) and gamma interferon gamma (IFN-γ) before and after E.coli IV injection. Blood culture was performed before and after bacterial challenge to confirm colisepticemia. The present study showed that total clinical score of the calves increased with a simultaneous significant rise in plasma concentration of TNF-α and INF-γ during septicemia period (P< 0.05). Changes in the heart and respiratory rate during septicemia and using clinical scoring are not enough to assess the magnitude of infection and disease progress; therefore, it is recommended some laboratory tests be used for better evaluation of clinical status of the septic calves