Isolation of pathogenic aerobic bacteria from the blood of septicaemic neonatal calves and the susceptibility of isolates to various antibiotics

An automated blood culture system (BACTEC 9240) was used for the isolation of aerobic bacteria from the blood of septicaemic neonatal calves. Blood samples were collected from 90 clinically septicaemic and 20 healthy neonatal calves and inoculated into blood culture bottles. There were 89 significant isolates from 90 positive blood cultures using the BACTEC system. Escherichia coli was the most common pathogen detected accounting for 56 (63%) out of 89 isolates. The other pathogens were beta-haemolytic streptococci (15.7%), Staphylococcus aureus (10.1%), Klebsiella sp. (5.6%) and Corynebacterium sp. (5.6%). All isolates showed a susceptibility rate of 100% to enrofloxacin, cefepim, cefoperazone/sulbactam, imipenem and meropenem while some of them were ranged from 75 to 91.7% susceptible to amoxicillin/clavulanic acid, ampicillin/sulbactam, gentamicin and cephalosporins.