Pluschke G, Mercer A, Kusećek B, Pohl A, Achtman M
Infect Immun. 1983 Feb;39(2):599-608. doi: 10.1128/iai.39.2.599-608.1983.
A total of 95 Escherichia coli strains (O1:K1, O7:K1, or O18:K1), obtained from different sources of human infections and from healthy individuals, were analyzed for the ability to cause bacteremia after colonizing the gut of newborn rats. Strains of all three serotypes were able to multiply extensively in the gut after oral inoculation and to translocate (in small numbers) to the mesenteric lymph nodes. With only few exceptions, O7:K1 and O18:K1 strains were able to cause bacteremia, while O1:K1 strains could not. Mixed-infection experiments revealed that the bacteria present in the blood during a case of bacteremia are in most cases the descendants of one cell that has multiplied extraintestinally after translocation to the mesenteric lymph nodes. It appears that virulent O7:K1 and O18:K1, but not avirulent O1:K1, bacteria are able to multiply directly in the bloodstream of the newborn rats. No correlation between virulence and the source of isolation of the different strains was observed. Disease isolates thus do not seem to differ from fecal isolates of the same serotype in special virulence properties. The differences in virulence among different O serotypes of K1 E. coli observed in the rat model were comparable to their relative frequency of isolation from meningitis in newborn children.
对从人类感染的不同来源以及健康个体中获得的总共95株大肠杆菌菌株（O1:K1、O7:K1或O18:K1）进行了分析，以研究其在定殖于新生大鼠肠道后引起菌血症的能力。所有三种血清型的菌株经口服接种后都能在肠道中大量繁殖，并（少量）转移至肠系膜淋巴结。除少数例外，O7:K1和O18:K1菌株能够引起菌血症，而O1:K1菌株则不能。混合感染实验表明，菌血症病例中血液中的细菌在大多数情况下是一个细胞的后代，该细胞在转移至肠系膜淋巴结后在肠道外繁殖。看来，具有毒力的O7:K1和O18:K1细菌，而非无毒力的O1:K1细菌，能够在新生大鼠的血液中直接繁殖。未观察到毒力与不同菌株分离来源之间的相关性。因此，疾病分离株在特殊毒力特性方面似乎与相同血清型的粪便分离株没有差异。在大鼠模型中观察到的不同O血清型K1大肠杆菌之间的毒力差异与其从新生儿脑膜炎中分离的相对频率相当。
