LeVatte M A, Woods D E, Shahrabadi M S, Semple R, Sokol P A
Department of Microbiology and Infectious Diseases, University of Calgary Health Science Centre, Alberta, Canada.
J Antimicrob Chemother. 1990 Aug;26(2):215-25. doi: 10.1093/jac/26.2.215.
The effects of subinhibitory concentrations of tetracycline on surface expression of Pseudomonas aeruginosa ferripyochelin binding protein (FBP) and P. aeruginosa virulence in a pulmonary infection model in rats were examined. Rats were inoculated intratracheally with P. aeruginosa strain DG1 embedded in agar beads. One half of the inoculated animals served as untreated controls while the other half received daily injections of 15 mg/kg tetracycline. FBP was shown to be surface exposed in bacteria isolated from control animals using indirect immunofluorescence and immunoelectron microscopy. No FBP was detectable, however, on the surface of bacteria isolated from the lungs of animals treated with tetracycline. The numbers of bacteria recovered from the lungs of infected animals did not differ between control and tetracycline treated groups, although the degree of pathology observed in tetracycline treated animals was significantly lower than in untreated controls (P = 0.002, one way ANOVA). Sub-inhibitory doses of tetracycline reduced proteolytic activity in vitro, but had no effect on the activities of exotoxin A or exoenzyme S. These studies suggest that exposure to subinhibitory concentrations of tetracycline can repress FBP surface expression as well as proteolytic activity in P. aeruginosa leading to a significant decrease in lung injury during infections due to this organism.
研究了亚抑菌浓度的四环素对铜绿假单胞菌铁载体结合蛋白（FBP）的表面表达以及在大鼠肺部感染模型中铜绿假单胞菌毒力的影响。将包埋在琼脂珠中的铜绿假单胞菌菌株DG1经气管内接种到大鼠体内。接种动物的一半作为未处理的对照，另一半每天注射15mg/kg四环素。使用间接免疫荧光和免疫电子显微镜显示，从对照动物分离的细菌中FBP暴露于表面。然而，在用四环素处理的动物的肺中分离的细菌表面上未检测到FBP。尽管在四环素处理的动物中观察到的病理程度明显低于未处理的对照（单向方差分析，P = 0.002），但从感染动物的肺中回收的细菌数量在对照组和四环素处理组之间没有差异。亚抑菌剂量的四环素在体外降低了蛋白水解活性，但对外毒素A或外酶S的活性没有影响。这些研究表明，暴露于亚抑菌浓度的四环素可抑制铜绿假单胞菌中FBP的表面表达以及蛋白水解活性，从而导致该生物体感染期间肺损伤的显著减少。
