Demonstration of a protein synthesis in starved Campylobacter jejuni cells

For many years, environmental microbiologists working on water samples, have reported differences between bacterial counts performed by culture and by microscopy. These observations have led to the demonstration of the viable but non-culturable (VNC) state in bacteria. Some hygienist specialists underlined the risk presented by pathogenic bacteria in the VNC state. The VNC state in bacteria has been studied by a number of authors, but the relation between VNC state and bacterial stress response has not been established yet, while the VNC state is generally described in responses to adverse conditions. Campylobacter jejuni enter the VNC state in response to starvation. In our study, we searched for a protein synthesis in the first hours of the cell starvation exposure. Three Campylobacter jejuni strains were suspended in filtered, sterilized, distilled water, and incubated at 4°C with gentle shaking (100 rpm). After 1, 2, 3, 4 and 5 h of starvation, C. jejuni cells were removed and subjected to a heat shock (55°C, 3 min) and to a conductimetric assay. Results obtained showed that a protein synthesis occurred in the onset of the starvation period, and that these improved the nutrient assimilation and enhanced the heat resistance in starved cells.