Mihaljevic Roberta Rubesa, Sikic Maja, Klancnik Anja, Brumini Gordana, Mozina Sonja Smole, Abram Maja
Department of Microbiology, Medical Faculty, University of Rijeka, Brace Branchetta 20, HR-51000 Rijeka, Croatia.
Microb Pathog. 2007 Aug-Sep;43(2-3):120-5. doi: 10.1016/j.micpath.2007.03.004. Epub 2007 Apr 19.
Enteric pathogens are constantly exposed to stressful conditions in their natural habitat in the host and even more in the extra-host environment, including food processing. The aim of this study was to evaluate the effect of selected environmental stress factors: temperature shift, starvation and atmospheric oxygen concentration on culturability/viability of two Campylobacter jejuni isolates. Additionally, after stress exposure, in an in vitro cell culture model using Caco-2 cells, the adhesion, invasion and intracellular survival of C. jejuni were studied. Nutrient insufficiency was the most powerful stress factor which significantly affected C. jejuni culturability and viability, as well as, adhesion and invasion properties. Temperature elevation induced a transient growth arrest, and temporary loss of pathogenic potential as indicated by impaired adhesion and invasion efficiency of C. jejuni. However, bacteria recovered within 24-48h inside the Caco-2 cells. Oxidative stress neither affected C. jejuni growth nor reduced the binding and invasion into Caco-2 cells. Only 5h oxygen exposure increased the invasion capability and intraepithelial survival of the clinical isolate. Modulation of C. jejuni virulence in response to environmental stress factors may have further implications in the pathogenesis of campylobacteriosis.
肠道病原体在宿主的自然栖息地甚至在宿主外环境（包括食品加工过程）中经常面临压力条件。本研究的目的是评估选定的环境压力因素：温度变化、饥饿和大气氧浓度对两种空肠弯曲菌分离株的可培养性/活力的影响。此外，在应激暴露后，使用Caco-2细胞的体外细胞培养模型研究了空肠弯曲菌的黏附、侵袭和细胞内存活情况。营养不足是最强大的压力因素，显著影响空肠弯曲菌的可培养性和活力，以及黏附和侵袭特性。温度升高导致短暂的生长停滞，并暂时丧失致病潜力，这表现为空肠弯曲菌黏附和侵袭效率受损。然而，细菌在Caco-2细胞内24至48小时内恢复。氧化应激既不影响空肠弯曲菌的生长，也不降低其对Caco-2细胞的黏附和侵袭。仅5小时的氧气暴露增加了临床分离株的侵袭能力和上皮内存活能力。空肠弯曲菌对环境压力因素的毒力调节可能对弯曲菌病的发病机制有进一步影响。
