Hill A W, Shears A L, Hibbitt K G
Res Vet Sci. 1979 Jan;26(1):97-101.
Experimental infections of the mammary gland of newly calved cows with 500 serum resistant Escherichia coli produced a very severe form of mastitis when compared with animals in mid-lactation. Ten hours after infection the bacteria had multiplied in the milk to very high numbers (10(6)--10(7)/ml) and the animals showed signs of pyrexia, anorexia and diarrhoea. Initially the gland and milk showed little or no clinical signs of mastitis, but later the secretion became a viscous, serous fluid with little or no casein or fat. A delay in diapedesis of neutrophils into the gland appears to be the reason for the peracute state and lack of clinical signs. This form of pathogenesis may produce a paradoxical situation where the most severe cases of E coli mastitis cannot be diagnosed at a stage early enough for the animal to respond to therapy.
与处于泌乳中期的奶牛相比，用500株血清抗性大肠杆菌对刚产犊的奶牛乳腺进行实验性感染，会引发一种非常严重的乳腺炎。感染后10小时，细菌在乳汁中大量繁殖（每毫升10⁶ - 10⁷个），奶牛出现发热、厌食和腹泻症状。最初，乳腺和乳汁几乎没有或没有乳腺炎的临床症状，但后来分泌物变成了一种粘稠的浆液性液体，几乎没有酪蛋白或脂肪。中性粒细胞向乳腺的渗出延迟似乎是导致超急性状态和缺乏临床症状的原因。这种发病机制可能会产生一种矛盾的情况，即最严重的大肠杆菌乳腺炎病例在动物能够对治疗做出反应的足够早期阶段无法被诊断出来。
