Role of temperature, nutrition, oxygen, osmolality, and bacterial strain in inducing a viable but non-culturable state in Campylobacter jejuni

Campylobacter jejuni is a globally important foodborne pathogen that can exist environmentally in a viable but non-culturable (VBNC) state, leading to missed detection of VBNC cells in food and false results in epidemiological surveillance. To establish a method for its resuscitation from the VBNC state and enable better detection, the mechanisms by which C. jejuni are induced into the VBNC state should be understood in detail. However, experimental induction of the VBNC state can be rather time consuming. Therefore, in this study, we investigated the effects of temperature, nutrition, oxygen, and osmolality, in an attempt to achieve a shorter induction time for VBNC state in C. jejuni. Culture at 4 °C under aerobic conditions in nutrient-rich Mueller–Hinton broth was the most effective condition for inducing the VBNC state in the C. jejuni strain JCM 2013. However, in C. jejuni strains 81–176 and B17, this condition induced the VBNC state slower than in the JCM 2013 strain, suggesting that the bacterial strain characteristics also affected the induction of VBNC state. These findings provide novel insights into the effects of various conditions on inducing the VBNC state in C. jejuni.