Elzer P H, Hagius S D, Robertson G T, Phillips R W, Walker J V, Fatemi M B, Enright F M, Roop R M
Department of Microbiology and Immunology, Louisiana State University Medical Center, Shreveport 71130, USA.
Res Vet Sci. 1996 Jan;60(1):48-50. doi: 10.1016/s0034-5288(96)90130-7.
Previous studies have shown that high-temperature-requirement A (HtrA) mutants of Brucella abortus are more sensitive to oxidative killing in vitro, are less able to survive in cultured murine macrophages and are attenuated in BALB/c mice. To measure the effect of an HtrA mutation on the virulence of B abortus in ruminants, pregnant goats in late gestation were exposed to infection by the conjunctival route with B abortus 2308 or an isogenic htrA mutant, PHE1. Infection with either 2308 or PHE1 resulted in abortion, but the serological responses to infection were consistent with 2308 but variable with PHE1. Strain 2308 was recovered post mortem both from aborted fetuses and infected dams, whereas PHE1 was recovered from neither. Nevertheless, short term studies revealed that PHE1 could be recovered from infected goats for up to two weeks after infection, suggesting that although the HtrA mutation may change the colonising ability of B abortus, the virulence of the mutant in pregnant goats is not reduced.
先前的研究表明，流产布鲁氏菌的高温需求A（HtrA）突变体在体外对氧化杀伤更敏感，在培养的小鼠巨噬细胞中存活能力较弱，并且在BALB/c小鼠中减毒。为了测定HtrA突变对流产布鲁氏菌在反刍动物中毒力的影响，将妊娠晚期的怀孕山羊通过结膜途径暴露于流产布鲁氏菌2308或同基因htrA突变体PHE1感染。用2308或PHE1感染均导致流产，但对感染的血清学反应与2308一致，而与PHE1不同。在流产胎儿和感染母羊的尸检中均发现了2308菌株，而PHE1均未检出。然而，短期研究表明，感染后长达两周可从感染山羊中分离出PHE1，这表明尽管HtrA突变可能会改变流产布鲁氏菌的定殖能力，但该突变体在怀孕山羊中的毒力并未降低。
