Wells C L, Jechorek R P, Erlandsen S L
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455.
J Infect Dis. 1990 Jul;162(1):82-90. doi: 10.1093/infdis/162.1.82.
The pathogenesis of Enterococcus (Streptococcus) faecalis was studied in mice with E. faecalis intestinal overgrowth (10(9) - 10(10) per gram of cecum) induced by metronidazol and streptomycin treatment coupled with oral inoculation of E. faecalis. E. faecalis was recovered from the mesenteric lymph nodes, liver, and spleen; mortality was noted in 8 (13%) of 62 mice after 14 days of E. faecalis intestinal overgrowth. Light, immunofluorescent, and electron (scanning and transmission) microscopy of ileal tissue was used in an attempt to localize E. faecalis translocating across intestinal tissue. Dense coccal bacteria were observed in the intestinal lumen, and the epithelium appeared intact. Coccal bacteria were observed adherent to the microvillus border of the entire villous epithelium, including the deeper regions of the intestinal crypts. Immunofluorescence localized E. faecalis within columnar epithelial cells, lamina propria, submucosa, and muscularis externa (including the lumen of small vessels). Transmission electron microscopy localized coccal bacteria within vacuoles in the cytoplasm of intact epithelial cells. These results indicated that E. faecalis could translocate across an intact intestinal tract and cause systemic infection and death. In this model, the intestinal epithelial cell appeared to be a portal of entry in the pathogenesis of systemic E. faecalis infection.
在通过甲硝唑和链霉素治疗并口服接种粪肠球菌诱导粪肠球菌肠道过度生长（每克盲肠含10⁹ - 10¹⁰个菌）的小鼠中，研究了粪肠球菌（粪链球菌）的发病机制。从肠系膜淋巴结、肝脏和脾脏中分离出粪肠球菌；在粪肠球菌肠道过度生长14天后，62只小鼠中有8只（13%）出现死亡。使用回肠组织的光学显微镜、免疫荧光显微镜和电子显微镜（扫描和透射）试图定位穿过肠道组织移位的粪肠球菌。在肠腔内观察到密集的球菌，上皮似乎完整。观察到球菌附着在整个绒毛上皮的微绒毛边界，包括肠隐窝的较深区域。免疫荧光将粪肠球菌定位在柱状上皮细胞、固有层、黏膜下层和外肌层（包括小血管腔）内。透射电子显微镜将球菌定位在完整上皮细胞细胞质中的液泡内。这些结果表明，粪肠球菌可穿过完整的肠道并引起全身感染和死亡。在该模型中，肠上皮细胞似乎是粪肠球菌全身感染发病机制中的一个入口。
