Pongpech P, Hentges D J, Marsh W W, Eberle M E
Department of Microbiology, Texas Tech University, Lubbock 79430.
Infect Immun. 1989 Jul;57(7):2092-7. doi: 10.1128/iai.57.7.2092-2097.1989.
The effect of streptomycin on the ability of Shigella sonnei 3SR and enterotoxigenic Escherichia coli 2SR to associate with cecal tissue of mice in vivo and in vitro was examined. After orogastric challenge, both pathogens associated in significantly greater numbers (P less than or equal to 0.05) with the cecal tissue of streptomycin-treated mice than with the tissue of untreated mice. The population levels of the pathogens were also significantly greater (P less than or equal to 0.05) in the cecal contents of streptomycin-treated mice than in untreated mice. When excised cecal tissues from the two groups of mice were exposed to the pathogens in vitro, the extent of the association of the pathogens was markedly greater with tissues from streptomycin-treated mice than with tissues from untreated mice. There was also a positive correlation between the numbers of the pathogens in the suspending fluid and the extent of the tissue associations. The population size of fusiform organisms, which are the major components of the mucus layer of the ceca of mice, was reduced 100-fold by streptomycin administration. This was determined by microscopic count. Sections of cecal tissue obtained from the mice and stained with hematoxylin and eosin demonstrated that streptomycin administration greatly decreased the number of fusiform bacteria present in the mucosal microbial layer. We speculate that the partial elimination of fusiform organisms from this layer by streptomycin administration provides available association sites for pathogens so that they can successfully colonize the mouse cecum.
研究了链霉素对宋内志贺氏菌3SR和产肠毒素大肠杆菌2SR在体内和体外与小鼠盲肠组织结合能力的影响。经口胃内攻击后，与未处理小鼠的组织相比，两种病原体在链霉素处理小鼠的盲肠组织中结合的数量显著更多（P≤0.05）。在链霉素处理小鼠的盲肠内容物中，病原体的数量水平也显著高于未处理小鼠（P≤0.05）。当将两组小鼠切除的盲肠组织在体外暴露于病原体时，病原体与链霉素处理小鼠组织的结合程度明显高于未处理小鼠的组织。悬浮液中病原体的数量与组织结合程度之间也存在正相关。作为小鼠盲肠黏液层主要成分的梭形生物体的数量，通过给予链霉素减少了100倍。这是通过显微镜计数确定的。从小鼠获得并用苏木精和伊红染色的盲肠组织切片表明，给予链霉素大大减少了黏膜微生物层中存在的梭形细菌数量。我们推测，通过给予链霉素部分消除该层中的梭形生物体为病原体提供了可用的结合位点，以便它们能够成功定殖于小鼠盲肠。
