Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
FEMS Microbiol Ecol. 2013 Apr;84(1):213-22. doi: 10.1111/1574-6941.12052. Epub 2013 Jan 2.
Vibrio vulnificus is responsible for 95% of all seafood-associated fatalities in the United States. When water temperatures drop below c. 13 °C, the cells enter into the viable but nonculturable (VBNC) state wherein they are unable to grow on routine media but retain viability and the ability to return to the culturable state. The aim of this study was to determine whether V. vulnificus cells in the VBNC state are protected against a variety of potentially lethal challenges (heat, oxidative, osmotic, pH, ethanol, antibiotic and heavy metal) and to examine genetic regulators that might underlie such protection. The data presented here indicate that VBNC cells of this pathogen are protected against a wide variety of stresses and retain the ability to return to the culturable state. Surprisingly, we found no significant difference in the expression of relA and spoT between VBNC and logarithmic cells, nor any significant difference in the expression of rpoS in the case of the clinical (C) genotype of this pathogen. However, expression of relA was significantly different in VBNC cells of the environmental (E) genotype compared with logarithmic cells. This might account for findings indicating an enhanced ability for E-genotype cells to withstand environmental changes better than C-genotype cells.
创伤弧菌是导致美国 95%与海鲜相关的死亡事件的元凶。当水温降至约 13°C 以下时，细胞进入存活但非可培养状态（VBNC），此时它们无法在常规培养基中生长，但仍保持活力，并能够恢复可培养状态。本研究旨在确定 VBNC 状态下的创伤弧菌细胞是否能够抵御多种潜在致命挑战（热、氧化、渗透、pH 值、乙醇、抗生素和重金属），并研究可能导致这种保护的遗传调控因子。本研究结果表明，该病原体的 VBNC 细胞能够抵御多种压力，并保持恢复可培养状态的能力。令人惊讶的是，我们发现 VBNC 细胞和对数细胞之间的 relA 和 spoT 的表达没有显著差异，也没有发现该病原体临床（C）基因型 rpoS 的表达有显著差异。然而，与对数细胞相比，环境（E）基因型的 VBNC 细胞中 relA 的表达显著不同。这可能解释了 E 基因型细胞比 C 基因型细胞更能适应环境变化的发现。
