Investigation of free staphylocoagulase from tropical animal plasma: influence of anticoagulant type, temperature and preservation's length

Abstract

biochemical identification of Staphylococcus aureus requires the search for free staphylocoagulase, performed using freeze-dried rabbit plasma. This study aims to determine the use of fresh tropical plasma and the influence of anticoagulants, temperature and shelf life of plasmas in the revelation of free staphylocoagulase. Five (5) blood samples from rats, 3 pork, 10 chickens and 10 rabbits were collected on anticoagulants. After biochemical characterization of the S. aureus ATCC 25923 reference strain, free staphylocoagulase was made from tropical animal plasmas. From the results, only plasma samples of rabbits and pigs allowed the disclosure of free staphylocoagulase. Of all the anticoagulants tested, EDTA and sodium citrate were the most effective. Part of rabbit plasma collected on EDTA was stored in the refrigerator and the other at room temperature for seven days. The search for staphylocoagulase was done every day from plasma. Results showed that temperature does not have a major influence on plasma samples, except that their conservation at room temperature slowed down the results. It is therefore preferable to obtain results in a relatively short time and to avoid the risks of contamination of the plasmas, to keep them in the refrigerator between 2 ° and 8 ° C for a maximum of 6 days.