[Effect of preservatives on survival of Campylobacter jejuni in ground pork meat].

Campylobacter jejuni strains: Pen 2, 3, 6, 10 and 20 isolated from the food-borne infections in humans were tested. Fresh ground pork samples supplemented with chemical preservatives: sodium chloride--24,000 mg/kg, sodium nitrite--125 mg/kg, potassium nitrate--500 mg/kg, sodium ascorbate--300 mg/kg and polyphosphate (Hamine S)--3000 mg/kg were contaminated by C. jejuni strains. Survival of C. jejuni in ground pork was determined immediate after the contamination and over a 2-d period at 4 degrees C on Brucella agar (Difco) containing 10% horse blood, which were incubated 48 hrs at 42 degrees C under microaerobic conditions (5% O2, 5% CO2 and 90% N2). Campylobacter jejuni was isolated from all tested samples at the initial inoculum 2.5 x 10(5) to 1.7 x 10(8) cfu/1 g of meat. It was proved that chemical preservatives, added to meat samples in concentration usually used in meat processing, were affected in differential way on the survival of different strains of C. jejuni. Campylobacter jejuni Pen 2 was resistant to all preservatives used in this studies. Campylobacter jejuni Pen 3 and Pen 10 were sensitive to sodium nitrite, and Pen 10 was sensitive also to sodium chloride, potassium nitrate and composition of all tested chemicals. Also, Campylobacter jejuni Pen 20 was sensitive to sodium chloride, but potassium nitrate, sodium ascorbate and Hamine S stimulated growth of this strain.