Survival of Campylobacter jejuni at different temperatures in broth, beef, chicken and cod supplemented with sodium chloride

Growth and survival of Campylobacter jejuni strains ATCC 33250 and ATCC 29428 with NaCl levels ranging from 0 to 3% were studied in brucella broth at -18, 6, 10 and 42°C. Both strains grew under microaerobic conditions at 42°C with 0 to 1% NaCl, but counts declined sharply with higher salt levels. At -18°C, there was a large initial decline in counts with little subsequent change during 5 d of storage and no appreciable effect of NaCl. At 6 or 10°C, counts decreased with increasing NaCl concentration over the 5-d period, but the organism survived in substantial numbers even with 3% NaCl. Survival of C. jejuni in ground chicken, beef and cod with 0, 1 and 2% added NaCl was determined at -18, 6 and 10°C over a 5-d period. At -18°C, survival of C. jejuni was similar in all three types of flesh, whether raw or previously cooked, and C. jejuni counts during frozen storage were not affected by the level of NaCl. Survival patterns of C. jejuni at 6 and 10°C in raw and cooked chicken and beef were very similar. Statistically significant decreases in counts occurred with increasing NaCl concentration, but the differences were slight. Substantial decreases in counts occurred in refrigerated raw cod, but less in the cooked fish. In the raw cod, counts decreased significantly with increasing NaCl concentration and the decline was more pronounced during storage at 10°C than at 6°C.