Pasquali Paolo, Rosanna Adone, Pistoia Claudia, Petrucci Paola, Ciuchini Franco
Laboratory of Veterinary Medicine, Istituto Superiore di Sanità, Rome, Italy.
Infect Immun. 2003 May;71(5):2326-30. doi: 10.1128/IAI.71.5.2326-2330.2003.
Brucellae are gram-negative, facultative intracellular bacteria which are one of the most common causes of abortion in animals. In addition, they are the source of a severe zoonosis. In this trial, we evaluated the effect of oral inoculation of Brucella abortus RB51 in mice against a challenge infection with B. abortus 2308. First, we showed that a gastric acid neutralization prior to the oral inoculation contributed to a more homogeneous and consistent infection with both vaccine strain B. abortus RB51 and virulent strain B. abortus 2308. Successively, we assessed the clearance and the immune response following an oral infection with B. abortus RB51. Oral inoculation gave a mild infection which was cleared 42 days after infection, and it induced a delayed humoral and cell-mediated immune response. Finally, we immunized mice by oral inoculation with B. abortus RB51, and we challenged them with the virulent strain B. abortus 2308 by an oral or intraperitoneal route 42 days after vaccination. Oral inoculation of B. abortus RB51 was able to give protection to mice infected with the virulent strain B. abortus 2308 by the oral route but not to mice infected intraperitoneally. Our results indicate that oral inoculation of mice with B. abortus RB51 is able to give a protective immunity against an oral infection with virulent strains, and this protection seems to rely on an immune response at the mucosal level.
布鲁氏菌是革兰氏阴性兼性胞内菌，是动物流产最常见的病因之一。此外，它们还是严重人畜共患病的传染源。在本试验中，我们评估了给小鼠口服接种流产布鲁氏菌RB51对其抵抗流产布鲁氏菌2308攻击感染的效果。首先，我们发现口服接种前进行胃酸中和有助于用疫苗株流产布鲁氏菌RB51和强毒株流产布鲁氏菌2308实现更均匀一致的感染。接着，我们评估了口服感染流产布鲁氏菌RB51后的清除情况和免疫反应。口服接种引起轻度感染，感染后42天清除，且诱导了延迟的体液免疫和细胞介导免疫反应。最后，我们通过给小鼠口服接种流产布鲁氏菌RB51进行免疫，在接种疫苗42天后通过口服或腹腔途径用强毒株流产布鲁氏菌2308对它们进行攻击。口服接种流产布鲁氏菌RB51能够保护经口服途径感染强毒株流产布鲁氏菌2308的小鼠，但不能保护经腹腔感染的小鼠。我们的结果表明，给小鼠口服接种流产布鲁氏菌RB51能够对强毒株的口服感染产生保护性免疫，且这种保护似乎依赖于黏膜水平的免疫反应。
