Wells C L, Maddaus M A, Jechorek R P, Simmons R L
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455.
Eur J Clin Microbiol Infect Dis. 1988 Feb;7(1):107-13. doi: 10.1007/BF01962194.
The purpose of this study was to clarify the role of the intestinal anaerobe bacteria in colonization resistance. Germfree mice were associated with Escherichia coli C25 and either (a) no other species; (b) enterococcus; (c) Escherichia coli M14 and Proteus mirabilis, or (d) Bacteroides fragilis and Bacteroides vulgatus. All species colonized the cecum in high numbers, but only enterococcus significantly limited the translocation of Escherichia coli C25 to mesenteric lymph nodes. However, the overall translocation rates were similar in all groups and ranged from 60% to 100%, due to translocation of other intestinal flora in addition to Escherichia coli C25. Conventionally reared mice were given either streptomycin, bacitracin/streptomycin or metronidazole which selectively eliminated facultative gram-negative bacteria, nearly all bacterial species or strictly anaerobic bacteria respectively. Only metronidazole significantly increased the rates of translocation of normal intestinal bacteria into mesenteric lymph nodes. Cohort groups of mice were then orally inoculated with drug resistant Escherichia coli C25, which actively colonized the cecum of all drug treated mice and translocated to the mesenteric lymph nodes of approximately half the streptomycin and metronidazole treated mice and nearly all the bacitracin/streptomycin treated mice. These results indicate that anaerobic bacteria play a pivotal role in limiting the translocation of normal intestinal bacteria, but that other bacterial groups also have a role in preventing the intestinal colonization and translocation of potential pathogens.
本研究的目的是阐明肠道厌氧菌在定植抗力中的作用。无菌小鼠与大肠杆菌C25联合，且分别（a）不与其他菌种联合；（b）与肠球菌联合；（c）与大肠杆菌M14和奇异变形杆菌联合，或（d）与脆弱拟杆菌和普通拟杆菌联合。所有菌种均大量定殖于盲肠，但只有肠球菌显著限制了大肠杆菌C25向肠系膜淋巴结的移位。然而，由于除大肠杆菌C25外其他肠道菌群的移位，所有组的总体移位率相似，范围为60%至100%。对常规饲养的小鼠分别给予链霉素、杆菌肽/链霉素或甲硝唑，它们分别选择性地清除兼性革兰氏阴性菌、几乎所有细菌种类或严格厌氧菌。只有甲硝唑显著提高了正常肠道细菌向肠系膜淋巴结的移位率。然后给小鼠队列口服接种耐药大肠杆菌C25，其在所有药物处理小鼠的盲肠中积极定殖，并移位至大约一半链霉素和甲硝唑处理小鼠以及几乎所有杆菌肽/链霉素处理小鼠的肠系膜淋巴结。这些结果表明，厌氧菌在限制正常肠道细菌的移位中起关键作用，但其他细菌群体在防止潜在病原体的肠道定殖和移位中也发挥作用。
