Grilló M J, Marín C M, Barberán M, Blasco J M
Unidad de Sanidad Animal, Diputación General de Aragón, Zaragoza, Spain.
Vet Rec. 1999 May 15;144(20):555-8. doi: 10.1136/vr.144.20.555.
Forty yearling Brucella-free ewes were inoculated with Brucella ovis by the conjunctival route in mid or late first pregnancy. Only a few ewes excreted B ovis during pregnancy and gave birth to stillborn lambs, but most of them excreted the organism at lambing or during lactation. One of the 11 lambs which were born alive but died before they were weaned was found to be infected postmortem. In contrast, none of the 46 surviving lambs which were reared in isolation until adulthood, was found to be infected. At weaning, the 40 ewes were mated again with five Brucella-free rams. Although many of the ewes excreted B ovis, none of the rams was found to be infected when necropsied after mating. Most of the ewes that became pregnant, all having excreted B ovis during their first pregnancy, cleared the infection during the second pregnancy. However, three remained persistently infected and excreted B ovis in their milk throughout the second lactation. None of the lambs born to these three ewes was found to be infected when necropsied at weaning.
40只未感染布鲁氏菌的一岁母羊在首次妊娠中期或晚期通过结膜途径接种绵羊布鲁氏菌。只有少数母羊在怀孕期间排出绵羊布鲁氏菌并产下死胎羔羊，但大多数母羊在产羔或哺乳期间排出该病原体。11只存活但在断奶前死亡的羔羊中有1只在死后被发现感染。相比之下，46只一直隔离饲养至成年的存活羔羊均未被发现感染。断奶时，40只母羊再次与5只未感染布鲁氏菌的公羊交配。尽管许多母羊排出绵羊布鲁氏菌，但交配后剖检时未发现公羊感染。大多数怀孕的母羊在首次妊娠期间都排出过绵羊布鲁氏菌，在第二次妊娠期间清除了感染。然而，有3只母羊持续感染，并在第二次哺乳期间通过乳汁排出绵羊布鲁氏菌。这3只母羊所生的羔羊在断奶时剖检均未发现感染。
