Blood serum concentrations of total proteins and main protein fractions in weaning rabbits experimentally infected with E. coli

The objective of the present study was to evaluate the changes in the concentrations of major blood proteins associated with experimental E. coli infection in weaning rabbits. For that, in the assay group. 12 weaning White New Zealand rabbits (45 days old) were orally infected with a bacterial suspension of enteropathogenic E. coli strain type O15:H- (6.107 cfu) whereas the 6 control rabbits received only 0.9% NaCI solution. Serum total protein, albumin, globulin and lysozyme concentrations as well as plasma fibrinogen concentrations were measured before (0h) and I, 3, 7, 11, 18 and 30 days after oral treatment. In parallel, presence of coliforms was investigated in rectal samples on days 0, 1.6. 11, 16, 25 and 30. Infected rabbits began to excrete E. coli strains on day 2 after administration, whereas the first signs of diarrhoea were observed on day 5. Between days 11 and 18 severe diarrhoea was found in all rabbits and then clinical signs gradually disappeared although 3 rabbits continue to excrete the bacteria on day 30. In inoculated rabbits, hypoproteinemia and hypo-albuminemia compared to control values were evidenced since the 7th day whereas the blood concentrations of lysozyme and fibrinogen at a lesser extend were dramatically increased on days 11-18 and on days 3-18 respectively, leading to a significantly lowered albumin/globulin ratio since the 11th day. These results confirm that albumin is a negative acute phase protein (APP) while fibrinogen and lysozyme were 2 positive APP in response to an experimental bacterial infection in rabbits

Comparison of the results of serum total protein concentration measured by 3 methods: Preliminary results

The present study provides the results from a comparative study of the 3 commonly used methods for total protein (TP) measurement. The experiments were carried out with 6 dogs (4-7 year-old, weighing 12.8 ± 1.4 kg). Five blood samples were obtained by saphena venepuncture from all dogs, during the time course of the experimentally induced infection with Staphylococcus intermedius, administered subcutaneously at a dose rate of 5 ml of 1.109 CFU/ml within 14 days. TP concentration was measured by 2 macro protein techniques - biuret method (commonly used) and method of Lowry, and a modified version of biuret method (micro protein technique), suggested by Popov. Serum TP concentration determined by the method of Lowry was significantly (P < 0.001) higher than the ones obtained by standard biuret and Popov's methods. The mean differences between TP values obtained by standard biuret technique and Lowry's method and, Lowry's and Popov's method were 18.6 g/l and 23.5 g/l, respectively. There was no statistically significant difference between standard biuret method and its modified version suggested by Popov