PHYSIOLOGICAL-ACTIVITY OF CAMPYLOBACTER-JEJUNI FAR BELOW THE MINIMAL GROWTH TEMPERATURE

The behavior of Campylobacter jejuni at environmental temperatures was examined by determining the physiological activities of this human pa thogen, The minimal growth temperatures were found to be 32 and 31 deg rees C for strains 104 and ATCC 33560, respectively. Both strains exhi bited a sudden decrease in growth rate from the maximum to zero within a few degrees not only near the maximal growth temperature but also n ear the minimal growth temperature. This could be an indication that a temperature-dependent transition in the structure of a key enzyme(s) or regulatory compound(s) determines the minimal growth temperature. O xygen consumption, catalase activity, ATP generation, and protein synt hesis were observed at temperatures as low as 4 degrees C, indicating that vital cellular processes were still functioning. PCR analysis sho wed that cold shock protein genes, which play a role in low-temperatur e adaptation in many bacteria, are not present in C. jejuni, The fact that chemotaxis and aerotaxis could be observed at all temperatures sh ows that the pathogen is able to move to favorable places at environme ntal temperatures, which may have significant implications for the sur vival of C. jejuni in the environment.