Nagy B
Infect Immun. 1980 Jan;27(1):21-4. doi: 10.1128/iai.27.1.21-24.1980.
Pregnant cows and heifers were vaccinated with a crude K99 extract prepared from an Escherichia coli K-12, K99 strain. A similar group, injected with an extract prepared from the K-12 parent strain, served as a control. Eleven calves were born to both groups and challenged orally with a mean of 1.6 x 10(11) bacteria of enterotoxic E. coli B41 (O101:K99+, ST+) at the time of first colostrum uptake (1 to 7 h after birth). As a result of challenge, no death occurred in the vaccine group, but four calves died in the control group. Six calves in the vaccine group and all calves in the control group developed diarrhea. Colostral anti-O101 titers were very similar in both groups. Anti-K99 titers of colostral samples from the vaccinated dams were, however, significantly higher as compared to those of the controls. It is suggested that colostral antibodies, raised against the crude K99 extract vaccine, exerted a protective effect on newborn calves against the challenge enterotoxigenic E. coli O101:K99+, Ent+ strain.
怀孕母牛和小母牛用从大肠杆菌K - 12、K99菌株制备的K99粗提取物进行免疫接种。另一组相似的动物注射从K - 12亲本菌株制备的提取物作为对照。两组均有11头小牛出生，并在首次摄取初乳时（出生后1至7小时）口服平均1.6×10¹¹个产肠毒素大肠杆菌B41（O101:K99 +，ST +）细菌进行攻毒。攻毒结果显示，疫苗组无死亡发生，而对照组有4头小牛死亡。疫苗组有6头小牛和对照组所有小牛出现腹泻。两组初乳中的抗O101滴度非常相似。然而，与对照组相比，接种疫苗的母牛初乳样本中的抗K99滴度显著更高。这表明，针对K99粗提取物疫苗产生的初乳抗体对新生小牛抵御产肠毒素大肠杆菌O101:K99 +、Ent +菌株的攻毒发挥了保护作用。
