In this study, bacteriophage M8AEC16, which is lytic to Escherichia coli O157:H7, isolated and characterized within the scope of our previous studies, was used to determine the stability during 6 months of storage at +4°C, -20°C and -85°C using glycerol, skimmed milk powder and carrageenan as cryoprotectants. For this purpose, bacteriophage M8AEC16, was enriched with E. coli O157:H7 ATCC 43895 and then phage suspension groups were prepared by adding three different cryoprotectants (test groups) in addition to those without cryoprotectant (control). Bacteriophage suspensions were stored at 3 different storage temperatures (+4°C, -20°C and -85°C) for six mount period. During storage, phage titers were determined on double-layer LB agar by making serial dilutions of phage suspensions on the 0th day and at the end of each month. As a result of the study, it was observed that stability was maintained at all temperatures for all groups during the first two months. However, in the third and fourth months, a decrease in the counts of bacteriophages were observed at -85°C in the glycerol added group. In addition to the control group, in the fifth month, carrageenan provided the highest preservation at all temperatures. In the sixth month, +4°C glycerol provided the best preservation, while carrageenan provided the highest preservation at other temperatures compared to the other test groups. In conclusion, the most successful result was obtained at +4°C for the preservation of Escherichia coli O157:H7 phage M8AEC16 considering the cost, usefulness and effectiveness.

A simple and humane model of inflammation, induced by the intradermal injection of 0.3 mL of sterile 2% carrageenan, was characterized in calves by measuring the volume of skin swelling plus histological analysis of skin biopsies. Carrageenan produced a biphasic increase in skin swelling, with an early edematous response followed by a more chronic cellular infiltrate. The swelling and sensitivity to pressure observed in the early response were suitable for testing the antiedematous and analgesic activity of a new nonsteroidal anti-inflammatory drug (NSAID), oxindanac. Pretreatment with intravenous oxindanac at doses from 0.5 to 8.0 mg/kg reduced the volume of swelling and this reached statistical significance (p < 0.05) at 2 mg/kg. The ED50 and ED90 values for inhibition of the peak swelling volume (4 h) were estimated to be 1 mg/kg and 2 mg/kg, respectively. These compare with an ED90 of 2.0 mg/kg for inhibition of serum TxB2 production, an index of platelet cyclo-oxygenase activity. The dose of oxindanac required for antiedematous activity correlated, therefore, with maximal inhibition of serum TxB2. The analgesic activity of oxindanac reached no clear maximum response, but statistically significant difference (p < 0.05) from placebo was reached with doses of 2 mg/kg and above. It is concluded that intradermal carrageenan produced a simple, humane and useful model for dose estimation of a new NSAID in calves.