Phillips James R, Tripp Timothy J, Regelmann Warren E, Schlievert Patrick M, Wangensteen O Douglas
Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Pediatr Pulmonol. 2006 Dec;41(12):1146-52. doi: 10.1002/ppul.20501.
Staphylococcus aureus is an important cause of pulmonary infections. The role of S. aureus alpha-toxin as a virulence factor is unclear. We hypothesized that airway epithelium is a target of S. aureus alpha-toxin and that exposure of airway epithelium to alpha-toxin results in damage to the airway epithelium. To examine the hypothesis that alpha-toxin is capable of independently producing airway epithelium damage as measured by permeability and morphometry, an isolated whole mouse trachea test apparatus was developed. In vitro epithelial permeability (P) was calculated and digital micrographs were analyzed morphometrically. Purified S. aureus alpha-toxin produced a significant increase in tracheal epithelial P (P < 0.05). Morphometric analysis revealed the ratio of adherent tracheal epithelium attached to the basement membrane divided by the total length of the basement membrane decreased in a dose-dependent manner with 1 microg/ml alpha-toxin and 10 microg/ml alpha-toxin (P < 0.05). We developed a novel isolated whole mouse trachea test apparatus for the measurement of tracheal epithelium damage. Increased P and separation of the tracheal epithelium from the basement membrane occurred after S. aureus alpha-toxin exposure. We conclude that mammalian airway epithelium is a target of S. aureus alpha-toxin.
金黄色葡萄球菌是肺部感染的一个重要病因。金黄色葡萄球菌α毒素作为一种毒力因子的作用尚不清楚。我们推测气道上皮是金黄色葡萄球菌α毒素的一个靶点，并且气道上皮暴露于α毒素会导致气道上皮损伤。为了检验α毒素能够独立产生如通过通透性和形态测定法所衡量的气道上皮损伤这一假说，开发了一种分离的完整小鼠气管测试装置。计算体外上皮通透性（P）并对数码显微照片进行形态测定分析。纯化的金黄色葡萄球菌α毒素使气管上皮P显著增加（P < 0.05）。形态测定分析显示，与基底膜附着的气管上皮长度与基底膜总长度之比，在1微克/毫升α毒素和10微克/毫升α毒素作用下呈剂量依赖性降低（P < 0.05）。我们开发了一种用于测量气管上皮损伤的新型分离完整小鼠气管测试装置。金黄色葡萄球菌α毒素暴露后，气管上皮的P增加且气管上皮与基底膜分离。我们得出结论，哺乳动物气道上皮是金黄色葡萄球菌α毒素的一个靶点。
