Microorganisms in their natural habitats are subjected to a broad range of stressors. In order to survive and retain their vitality under those demanding conditions, they enter a state known as viable but nonculturable (VBNC). Traditional laboratory techniques cannot identify microbes in the VBNC state, but they can be brought back to life in the right circumstances. As a result, VBNC pathogens seriously jeopardize public health and food safety. More than 100 microbe species have been found to have entered the VBNC state to date, owing to a variety of chemical and physical processes. Since the VBNC syndrome was first discovered forty years ago, new methods for inducing, detecting, resuscitating, and understanding its molecular pathways have been created. To determine their effect on public health, live bacterial foodborne pathogens must be found and measured. Due to the existence of viable but nonculturable cells (VBNC), which can retain metabolic and pathogenic activity, traditional growth-based approaches have the potential to significantly underestimate the true numbers. The similar issue arises when using different culture-independent molecular techniques, such PCR, which can detect DNA from dead cells in addition to VBNC bacteria. Viability dyes and PCR have been used to selectively identify and quantify viable foodborne microorganisms, overcoming this drawback.
Key words: Viable but non culturable (VBNC), real-time PCR, Propidium Monoazide PCR
|
