Abstract:
This study was conducted in order to isolate Staphylococcus aureus in frozen animal processed products ( Mortedella ,Pastrami , and ice cream ) and exposing them to temperatures (-20°C , -30°C , -40°C) and intervene to save the injured bacteria to give the colonies that can be seen and counted for the issuance of the right decision. Sodium pyruvate in different concentrations was added, as well as vitamin B6 and B12 in different concentrations to selective Baird Parker medium (vitamin B6 + Baird Parker medium, vitamin B12 + Baird Parker medium, sodium pyruvate + Baird Parker medium, vitamin B6 + sodium pyruvate+ Baird Parker medium, vitamin B12 + sodium pyruvate + Baird Parker medium-Oxoid, England) compared with Baird Parker medium as control. Thirty samples from different centers in Khartoum State were tested. The study revealed that when adding vitamin B6 in concentration 3 ml / L at temperature of -20oC the recovery was 76.92%, whereas vitamin B12 did not show any recovery. When adding sodium pyruvate in different concentrations (0.5% , 1.0 % and 1.5% )to Baird Parker medium at -20°C the recovery was 82.35 % , 85.71 % and 75.82 % , respectively , and at temperature -30 oC the recovery was 86.96 % , 68.18 % and 0.40 %, respectively. At temperature -40oC the recovery was 24.69 %, 43.48 % and 47.62 %, respectively
Adding vitamin B6 and sodium pyruvate in concentration (3 ml +1.5 %) to Baird Parker medium at -20 °C the recovery was 77.06 %, and adding vitamin B12 and sodium pyruvate in concentration (3 ml +1.5 %) to Baird Parker medium at -20 the recovery was 94.83 %.It is concluded that, the adding of vitamin B6 at level of 3 ml / L at temperature -20oC was more effective for recovery of the injured cells.
