Khullar Madhu, Singh Raman Deep, Smriti Manu, Ganguly Nirmal Kumar
Departments of Experimental Medicine and Biotechnology1 and Medical Microbiology2, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
J Med Microbiol. 2003 Sep;52(Pt 9):741-745. doi: 10.1099/jmm.0.05186-0.
Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) can initiate entry into non-phagocytic epithelial cells by triggering certain signal transduction pathways, thereby allowing the pathogen to invade and establish a niche within host cells. Anaerobiosis has been shown to be an important inducer of the invasion process of S. Typhimurium. However, the effect of anaerobiosis on modulation of cell signalling cascades by S. Typhimurium is not known. In the present study, the phospholipase Cgamma signalling cascade was investigated in mice enterocytes, following interaction with S. Typhimurium grown under aerobic and anaerobic growth conditions. Significant increases in enterocyte intracellular calcium and inositol 1,4,5-triphosphate levels were observed on interaction with S. Typhimurium grown anaerobically compared with S. Typhimurium grown aerobically. An increased membrane/cytosolic ratio of protein kinase C was also seen with anaerobic S. Typhimurium in enterocytes compared with aerobic S. Typhimurium. These data suggest that anaerobically grown organisms are more efficient in initiating cell-signalling events than are aerobically grown bacteria. These enhanced cell signals may contribute to the increased virulence of S. Typhimurium grown anaerobically.
肠炎沙门氏菌肠炎亚种鼠伤寒血清型（鼠伤寒沙门氏菌）可通过触发某些信号转导途径启动进入非吞噬性上皮细胞的过程，从而使病原体能够侵入并在宿主细胞内建立一个生态位。已证明厌氧是鼠伤寒沙门氏菌侵袭过程的重要诱导因素。然而，厌氧对鼠伤寒沙门氏菌调节细胞信号级联反应的影响尚不清楚。在本研究中，在小鼠肠上皮细胞与在需氧和厌氧生长条件下培养的鼠伤寒沙门氏菌相互作用后，对磷脂酶Cγ信号级联反应进行了研究。与在需氧条件下培养的鼠伤寒沙门氏菌相比，观察到与在厌氧条件下培养的鼠伤寒沙门氏菌相互作用时，肠上皮细胞内的钙和肌醇1,4,5 - 三磷酸水平显著增加。与需氧的鼠伤寒沙门氏菌相比，在肠上皮细胞中厌氧的鼠伤寒沙门氏菌也观察到蛋白激酶C的膜/胞质比增加。这些数据表明，厌氧生长的生物体比需氧生长的细菌在启动细胞信号事件方面更有效。这些增强的细胞信号可能导致厌氧生长的鼠伤寒沙门氏菌毒力增加。
