Duchet-Suchaux M
Ann Microbiol (Paris). 1980 Nov-Dec;131B(3):239-50.
Three enteropathogenic bovine strains of Escherichia coli (B41, B44 and 17C), carrying K99 antigen (K99+) and producing heat-stable enterotoxin (Ent+), caused infectious diarrhoea when administered orally to Swiss OF1 and CD-1 infant mice. A mortality rate of 40 t0 60% was obtained after administration of 10 E. coli B41 to mice which were less than 48 h old. A mortality rate of 80 to 100% was obtained with 10(3) E. coli B41, selected as reference inoculum. Inoculation of mice older than 48 h with the reference inoculum, resulted in variable responses and decreased mortality rate. After 10 days of age, mice were no longer sensitive to the inoculum. Inoculation of mice with each strain of E. coli in standard conditions (10(3) bacteria, mice less than 48 h old) produced similar mortality rates in OF1 mice. CD-1 mice were more resistant to strain B41 than to strains B44 and 17C. Administration of E. coli K12, to which K99 and Ent+ plasmids had been transferred, produced no pathological change in mice under the same conditions.
三株产肠毒素的牛源大肠杆菌（B41、B44和17C），携带K99抗原（K99+）并产生热稳定肠毒素（Ent+），经口接种给瑞士OF1和CD-1新生小鼠后可引起感染性腹泻。给小于48小时龄的小鼠口服10个大肠杆菌B41后，死亡率为40%至60%。选用10³个大肠杆菌B41作为参考接种物，死亡率为80%至100%。用参考接种物接种48小时龄以上的小鼠，反应各异，死亡率降低。10日龄后，小鼠对接种物不再敏感。在标准条件下（10³个细菌，小于48小时龄的小鼠）用每种大肠杆菌菌株接种OF1小鼠，产生的死亡率相似。CD-1小鼠对B41菌株的抵抗力比对B44和17C菌株更强。在相同条件下，给小鼠接种转导了K99和Ent+质粒的大肠杆菌K12，未产生病理变化。
