The occurrence of Listeria monocytogenes in raw milk and its survival under various storage conditions

The study is aimed at the isolation of Listeria monocytogenes from raw cow's and sheep's milk, cottage cheese from unpasteurized sheep's milk, and bryndza-cheese, and at the survival of the reference strain of Listeria monocytogenes CCM 5576 under various storage conditions. As the results show, the strain was able to survive in milk at a temperature of 70 degree C for 13 minutes. The growth of Listeria monocytogenes was noticed within the range of pH from 4.0 to 11.0. However, at pH-values below 4.6 the growth was considerably reduced. The addition of sodium chloride in an amount of 1-7% did not inhibit the growth of Listeria monocytogenes