The Inducement And Research On The "Viable But Non-culturable State" For Three Types Of Pathogenic Bacteria

The viable but non-culturable state (VBNC) is a special state when the bacteria in adverse environmental conditions, the cells shrink spherical, can not be cultured and reproduced by conventional ways and still be able to recover under appropriate conditions. The VBNC bacterium are no longer able to grow and form colonies on conventional culture media, but maintain their patheogenieity, may become latent infection escaping detention to threat environment and human security.Three typical pathogenic bacteria were selected as the object in this research: e.coli, salmonella and staphylococcus aureus. In the detection of microbial indicators food and water, the gram-negative e.coli is usually as the main indicator bacteria for microbial contamination, which directly indicates whether food and water can pass the microbial detection. Salmonella is familiar pathogenic bacteria for the food and drinking water, usually causing diarrhea. S. aureus is a common food-borne gram-positive pathogenic bacteria. The VBNC state has been reported that concentrated in the gram-negative bacteria interior and abroad, while researches for gram-positive bacteria in VBNC state were very few.This study found the low temperature and heavy metals such as Cu²⁺ how to induce e.coli and salmonella, s.aureus into the VBNC state and researched the cell biology, detection methods and pathogenicity. The catalase and tween 20 were tried to use in the recovery experiments.The phenomenon of VBNC state of widely exists in the natural environment and human life, causing a potential threat to human health. More conventional cultivation methods were still used in the bacteria detection for conventional water, food hygiene inspection and quarantine of imported and exported commodities at this stage in our country, which results were clearly unreliable. Based on public health and safety considerations, the research on VBNC state of bacteria is particularly urgent to strengthen in our country and also has great practical significance.