Jones Melissa K, Warner Elizabeth, Oliver James D
Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
Appl Environ Microbiol. 2008 Jan;74(1):182-7. doi: 10.1128/AEM.02436-07. Epub 2007 Nov 9.
The opportunistic human pathogen Vibrio vulnificus survives in a wide range of ecological environments, which demonstrates its ability to adapt to highly variable conditions. Survival and gene expression under various conditions have been extensively studied in vitro; however, little work has been done to evaluate this bacterium in its natural habitat. Therefore, this study monitored the long-term survival of V. vulnificus in situ and simultaneously evaluated the expression of stress (rpoS, relA, hfq, and groEL) and putative virulence (vvpE, smcR, viuB, and trkA) genes at estuarine sites of varying salinity. Additionally, the survival and gene expression of an rpoS and an oxyR mutant were examined under the same conditions. Differences between the sampling sites in the long-term survival of any strain were not seen. However, differences were seen in the expression of viuB, trkA, and relA but our findings differed from what has been previously shown in vitro. These results also routinely demonstrated that genes required for survival under in vitro stress or host conditions are not necessarily required for survival in the water column. Overall, this study highlights the need for further in situ evaluation of this bacterium in order to gain a true understanding of its ecology and how it relates to its natural habitat.
机会性人类病原体创伤弧菌能在广泛的生态环境中生存，这表明其具备适应高度可变条件的能力。在体外已对该菌在各种条件下的存活及基因表达进行了广泛研究；然而，在其自然栖息地对这种细菌进行评估的工作却很少。因此，本研究监测了创伤弧菌在原位的长期存活情况，并同时评估了不同盐度河口位点处应激（rpoS、relA、hfq和groEL）及假定毒力（vvpE、smcR、viuB和trkA）基因的表达。此外，还在相同条件下检测了rpoS和oxyR突变体的存活及基因表达情况。未观察到任何菌株在长期存活方面存在采样位点间的差异。然而，观察到了viuB、trkA和relA表达上的差异，但我们的研究结果与先前体外研究结果不同。这些结果还常规地表明，在体外应激或宿主条件下生存所需的基因在水柱中生存不一定是必需的。总体而言，本研究强调需要对这种细菌进行进一步的原位评估，以便真正了解其生态学以及它与自然栖息地的关系。
