Cheney C P, Schad P A, Formal S B, Boedeker E C
Infect Immun. 1980 Jun;28(3):1019-27. doi: 10.1128/iai.28.3.1019-1027.1980.
We have previously described an in vitro assay for examining the mucosal adherence of a rabbit diarrheagenic Escherichia coli, RDEC-1. That assay defined the in vitro characteristics of RDEC-1 adherence to brush borders isolated from rabbit ileal epithelial cells. The present study was conducted to examine the species specificity of both in vitro RDEC-1 adherence and in vivo infectivity of RDEC-1 and to compare these specificities. Species specificity in vitro adherence was examined by using brush borders prepared from intestinal epithelial cells of rats, guinea pigs, and rabbits, as well as from a surgically resected specimen of human ileum. Strain RDEC-1 adherence to rabbit brush borders in vitro was significantly greater (P < 0.001) than its adherence to brush borders from any of the other species. Regional specificity of in vitro adherence of RDEC-1 to ileal segments of rabbit intestinal mucosa was also demonstrated. There was significantly greater adherence of RDEC-1 to rabbit ileal brush borders as compared to rabbit jejunal brush borders (P < 0.05). In vivo infectivity was assessed by inoculating RDEC-1 into rats, guinea pigs, and rabbits. RDEC-1 elicited diarrhea in all inoculated rabbits with the mean onset of illness occurring 5 days after inoculation. In contrast, none of the RDEC-1-inoculated rats or guinea pigs developed diarrhea. Furthermore, colonization studies in these animals revealed that RDEC-1 heavily colonized the ileum and cecum (10(9) RDEC-1 colony-forming units/g of tissue) of rabbits; however, only minimal colonization was observed in guinea pigs and rats. In conclusion, the correlation between in vitro adherence and in vivo infectivity that we have observed suggests that the presence of receptors, specific for bacteria, on the surface of the host intestinal mucosa determines species susceptibility to enteric colonization and infectivity by certain strains of enteropathogenic E. coli.
我们之前描述了一种用于检测兔致腹泻性大肠杆菌RDEC-1黏膜黏附性的体外检测方法。该检测方法确定了RDEC-1黏附于从兔回肠上皮细胞分离的刷状缘的体外特性。本研究旨在检测RDEC-1体外黏附的物种特异性以及RDEC-1的体内感染性，并比较这些特异性。通过使用从大鼠、豚鼠和兔的肠上皮细胞以及手术切除的人回肠标本制备的刷状缘来检测体外黏附的物种特异性。菌株RDEC-1体外对兔刷状缘的黏附显著高于其对任何其他物种刷状缘的黏附（P<0.001）。还证明了RDEC-1对兔肠黏膜回肠段体外黏附的区域特异性。与兔空肠刷状缘相比，RDEC-1对兔回肠刷状缘的黏附显著更高（P<0.05）。通过将RDEC-1接种到大鼠、豚鼠和兔体内来评估体内感染性。RDEC-1使所有接种的兔发生腹泻，平均发病时间在接种后5天。相比之下，接种RDEC-1的大鼠或豚鼠均未发生腹泻。此外，对这些动物的定植研究表明，RDEC-1在兔的回肠和盲肠中大量定植（10⁹个RDEC-1菌落形成单位/克组织）；然而，在豚鼠和大鼠中仅观察到极少的定植。总之，我们观察到的体外黏附与体内感染性之间的相关性表明，宿主肠黏膜表面存在对细菌特异的受体决定了物种对某些肠道致病性大肠杆菌菌株肠道定植和感染的易感性。
