Effect of nisin and cinnamon on the growth and survival of entertoxigenic methicillin-resistant staph aureus in sterile milk and ice cream

الملخص EN

The effect of nosing on the survival of enterotoxin genic methicillin-resistant Staph, aurous (MRSA) was evaluated using different concentrations of nosing (0.00, 100 and 200 IU / ml) in a laboratory prepared sterile milk and inoculated with the previously isolated and identified MRS A to yield a concentration of l x lO7 cfu / ml.

The inoculated sterile milks were kept at room temperature (20 ± 2°C) and refrigerator temperature (4 ± 2°C).

MRSA counts were determined using Oxacillin Resistance Screen Agar Base (ORSAB) supplement with two antibiotics-oxacillin at (2 mg / L) and polymyxin B (50.000 IU / L).

ORSAB and pH value were determined every twelve hours.

MRSA strains couldn't be detected after 96 and 72 h in the samples of sterile milk containing nisin in concentrations of 100 and 200 IU / ml, while, in the control sample the MRSA survived till the end of the 96 h of storage at room temperature.

Moreover, MRSA failed to be detected after 48 and 24 h in the samples of sterile milk containing nosing in concentrations of 100 and 200 IU / ml and storied at refrigerator temperature, respectively.

Ice cream was prepared at the laboratory to study the effect of ground cinnamon in concentrations of 0.3 and 0.6 % on the growth and survival of enterotoxin genic MRSA a concentration of 2 x 107 cfu /ml at freezing (-4 ± 2°C) and deep freezing (-18 ± 2°C) temperatures.

The obtained results showed that the advantage of using 0.6 % is better than using of 0.3% of ground cinnamon.